Search

Your search keyword '"P.L. Cole"' showing total 29 results
Start Over Author "P.L. Cole"
29 results on '"P.L. Cole"'

1. Beam spin asymmetry measurements of deeply virtual π0 production with CLAS12

Author

A. Kim, S. Diehl, K. Joo, V. Kubarovsky, P. Achenbach, Z. Akbar, J.S. Alvarado, Whitney R. Armstrong, H. Atac, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, I. Bedlinskiy, B. Benkel, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, K.T. Brinkmann, W.J. Briscoe, W.K. Brooks, S. Bueltmann, V.D. Burkert, R. Capobianco, D.S. Carman, J.C. Carvajal, A. Celentano, G. Charles, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, B. Clary, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Dilks, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, S. Fegan, A. Filippi, C. Fogler, G. Gavalian, G.P. Gilfoyle, G. Gosta, F.X. Girod, D.I. Glazier, A.A. Golubenko, R.W. Gothe, L. Guo, K. Hafidi, H. Hakobyan, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Yu-Chun Hung, Y. Ilieva, D.G. Ireland, E. Isupov, H.S. Jo, R. Johnston, S. Joosten, M. Khachatryan, A. Khanal, W. Kim, V. Klimenko, A. Kripko, S.E. Kuhn, L. Lanza, M. Leali, M.L. Kabir, S. Lee, P. Lenisa, X. Li, I. .J.D. MacGregor, D. Marchand, V. Mascagna, B. McKinnon, D. Matamoros, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, P. Moran, C. Munoz Camacho, P. Naidoo, K. Neupane, D. Nguyen, S. Niccolai, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, A. Radic, N. Ramasubramanian, Trevor Reed, J. Richards, M. Ripani, J. Ritman, P. Rossi, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, Y.G. Sharabian, E.V. Shirokov, U. Shrestha, D. Sokhan, N. Sparveris, M. Spreafico, S. Stepanyan, I.I. Strakovsky, S. Strauch, J. Tan, N. Trotta, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Wishart, M.H. Wood, M. Yurov, N. Zachariou, J. Zhang, V. Ziegler, and M. Zurek

Subjects
Physics, QC1-999
Abstract

The new experimental measurements of beam spin asymmetry were performed for the deeply virtual exclusive π0 production in a wide kinematic region with the photon virtualities Q2 up to 6.6 GeV2 and the Bjorken scaling variable xB in the valence regime. The data were collected by the CEBAF Large Acceptance Spectrometer (CLAS12) at Jefferson Lab with longitudinally polarized 10.6 GeV electrons scattered on an unpolarized liquid-hydrogen target. Sizable asymmetry values indicate a substantial contribution from transverse virtual photon amplitudes to the polarized structure functions. The interpretation of these measurements in terms of the Generalized Parton Distributions (GPDs) demonstrates their sensitivity to the chiral-odd GPD E¯T, which contains information on quark transverse spin densities in unpolarized and polarized nucleons and provides access to the nucleon's transverse anomalous magnetic moment. Additionally, the data were compared to a theoretical model based on a Regge formalism that was extended to the high photon virtualities.

Published
2024
Full Text
View/download PDF

2. A multidimensional study of the structure function ratio σLT′/σ0 from hard exclusive π+ electro-production off protons in the GPD regime

Author

S. Diehl, A. Kim, K. Joo, P. Achenbach, Z. Akbar, M.J. Amaryan, H. Atac, H. Avagyan, C. Ayerbe Gayoso, L. Baashen, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, W.A. Booth, F. Bossù, S. Boiarinov, K.-Th. Brinkmann, W.J. Briscoe, S. Bueltmann, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, G. Clash, P.L. Cole, M. Contalbrigo, G. Costantini, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, S. Fegan, A. Filippi, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, D.I. Glazier, A.A. Golubenko, G. Gosta, R.W. Gothe, Y. Gotra, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, H.S. Jo, M. Khachatryan, A. Khanal, W. Kim, A. Kripko, V. Kubarovsky, V. Lagerquist, J.-M. Laget, L. Lanza, M. Leali, S. Lee, P. Lenisa, X. Li, K. Livingston, I. .J .D. MacGregor, D. Marchand, V. Mascagna, B. McKinnon, Z.E. Meziani, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, E. Molina, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, M. Ouillon, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, S.J. Paul, W. Phelps, N. Pilleux, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, T. Reed, J. Richards, M. Ripani, J. Ritman, P. Rossi, F. Sabatié, C. Salgado, S. Schadmand, A. Schmidt, Y. Sharabian, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, M. Spreafico, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Trotta, M. Turisini, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Williams, R. Wishart, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and M. Zurek

Subjects
Exclusive single pion, Eletroproduction, GPD, CLAS12, Physics, QC1-999
Abstract

A multidimensional extraction of the structure function ratio σLT′/σ0 from the hard exclusive e→p→e′nπ+ reaction above the resonance region has been performed. The study was done based on beam-spin asymmetry measurements using a 10.6 GeV incident electron beam on a liquid-hydrogen target and the CLAS12 spectrometer at Jefferson Lab. The measurements focus on the very forward regime (t/Q2 ≪ 1) with a wide kinematic range of xB in the valence regime (0.17 < xB < 0.55), and virtualities Q2 ranging from 1.5 GeV2 up to 6 GeV2. The results and their comparison to theoretical models based on Generalized Parton Distributions demonstrate the sensitivity to chiral-odd GPDs and the directly related tensor charge of the nucleon. In addition, the data is compared to an extension of a Regge formalism at high photon virtualities. It was found that the Regge model provides a better description at low Q2, while the GPD model is more appropriate at high Q2.

Published
2023
Full Text
View/download PDF

3. Photoproduction of K+Λ(1405)→K+π0Σ0 extending to forward angles and low momentum transfer

Author

G. Scheluchin, T.C. Jude, S. Alef, P. Bauer, D. Bayadilov, R. Beck, A. Braghieri, P.L. Cole, D. Elsner, R. Di Salvo, A. Fantini, O. Freyermuth, F. Frommberger, F. Ghio, A. Gridnev, D. Hammann, J. Hannappel, K. Kohl, N. Kozlenko, A. Lapik, P. Levi Sandri, V. Lisin, G. Mandaglio, R. Messi, D. Moricciani, A. Mushkarenkov, V. Nedorezov, D. Novinskiy, P. Pedroni, A. Polonskiy, B.-E. Reitz, M. Romaniuk, H. Schmieden, V. Sumachev, and V. Tarakanov

Subjects
Strangeness photoproduction, Λ(1405), BGOOD, Physics, QC1-999
Abstract

K+Λ(1405) photoproduction has been studied at the BGOOD experiment via the all neutral decay, Λ(1405)→Σ0π0. The unique BGOOD experimental setup allows both the cross section and Λ(1405) invariant mass distribution (line shape) to be measured over a broad K+ polar angle range, extending to extreme forward K+ angles unattainable at previous experiments.Evidence is provided for the role of a triangle singularity driven by the N⁎(2030) resonance, which appears to contribute significantly to K+Λ(1405) photoproduction. This is observed in the integrated cross section which was determined with unprecedented energy resolution and supported by the angular distributions. The measured line shape is also in agreement with the previous results of CLAS and ANKE, and is consistent with two poles derived in χPT based models.

Published
2022
Full Text
View/download PDF

4. Evidence of a dibaryon spectrum in coherent π0π0d photoproduction at forward deuteron angles

Author

T.C. Jude, S. Alef, R. Beck, A. Braghieri, P.L. Cole, D. Elsner, R. Di Salvo, A. Fantini, O. Freyermuth, F. Frommberger, F. Ghio, A. Gridnev, K. Kohl, N. Kozlenko, A. Lapik, P. Levi Sandri, V. Lisin, G. Mandaglio, D. Moricciani, V. Nedorezov, D. Novinskiy, P. Pedroni, A. Polonskiy, B.-E. Reitz, M. Romaniuk, G. Scheluchin, H. Schmieden, A. Stuglev, V. Sumachev, and V. Tarakanov

Subjects
BGOOD, Dibaryon, Coherent photoproduction, Physics, QC1-999
Abstract

The coherent reaction, γd→π0π0d was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 2850MeV. A full kinematic reconstruction was made, with final state deuterons identified in the forward spectrometer and π0 decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by models of coherent photoproduction and instead supports the three isoscalar dibaryon candidates reported by the ELPH collaboration at 2.38, 2.47 and 2.63GeV/c2. A low mass enhancement in the π0π0 invariant mass is also observed at the d⁎(2380) centre-of-mass energy which is consistent with the ABC effect. At higher centre-of-mass energies, a narrow peak in the π0d invariant mass at 2114MeV/c2 with a width of 20MeV/c2 supports a sequential two-dibaryon decay mechanism.

Published
2022
Full Text
View/download PDF

5. Beam-spin asymmetry Σ for Σ− hyperon photoproduction off the neutron

Author

N. Zachariou, E. Munevar, B.L. Berman, P. Bydžovský, A. Cieplý, G. Feldman, Y. Ilieva, P. Nadel-Turonski, D. Skoupil, A.V. Sarantsev, D.P. Watts, M.J. Amaryan, G. Angelini, W.R. Armstrong, H. Atac, H. Avakian, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, L. Biondo, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, D.S. Carman, J.C. Carvajal, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, M. Contalbrigo, G. Costantini, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, R. Dupre, M. Dugger, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, A. Fradi, G. Gavalian, G.P. Gilfoyle, F.X. Girod, C. Gleason, A.A. Golubenko, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, T.B. Hayward, D. Heddle, K. Hicks, A. Hobart, M. Holtrop, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, D. Keller, A. Khanal, M. Khandaker, A. Kim, F.J. Klein, A. Kripko, V. Kubarovsky, L. Lanza, M. Leali, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, B. McKinnon, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, K. Neupane, S. Niccolai, G. Niculescu, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, P. Pandey, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, B.A. Raue, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatie, C. Salgado, A. Schmidt, R.A. Schumacher, Y.G. Sharabian, E.V. Shirokov, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, P. Stoler, I.I. Strakovsky, S. Strauch, R. Tyson, M. Ungaro, L. Venturelli, H. Voskanyan, A. Vossen, E. Voutier, K. Wei, X. Wei, R. Wishart, M.H. Wood, B. Yale, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report a new measurement of the beam-spin asymmetry, Σ, for the γ→n→K+Σ− reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions from an isobar model indicate strong sensitivity to N(1720)3/2+, Δ(1900)1/2−, and N(1895)1/2−, which corroborates results from a recent combined analysis of all KΣ channels. When our data are incorporated in the fits of partial-wave analyses, one observes significant changes in γ-n couplings of resonances which have small branching ratios to the πN channel.

Published
2022
Full Text
View/download PDF

6. 12C(e,e'pN) measurements of short range correlations in the tensor-to-scalar interaction transition region

Author

I. Korover, J.R. Pybus, A. Schmidt, F. Hauenstein, M. Duer, O. Hen, E. Piasetzky, L.B. Weinstein, D.W. Higinbotham, S. Adhikari, K. Adhikari, M.J. Amaryan, Giovanni Angelini, H. Atac, L. Barion, M. Battaglieri, A. Beck, I. Bedlinskiy, Fatiha Benmokhtar, A. Bianconi, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, L. Clark, B. Clary, P.L. Cole, M. Contalbrigo, V. Crede, R. Cruz-Torres, A. D'Angelo, R. De Vita, M. Defurne, A. Denniston, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, R. Fersch, A. Filippi, T. Forest, G. Gavalian, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, T.B. Hayward, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, M. Khachatryan, A. Khanal, M. Khandaker, A. Kim, C.W. Kim, F.J. Klein, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, V. Lucherini, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, B. McKinnon, S. Mey-Tal Beck, T. Mineeva, M. Mirazita, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, K. Neupane, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, R.A. Schumacher, E.P. Segarra, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, T. Wang, D. Watts, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, Z.W. Zhao, and X. Zheng

Subjects
Physics, QC1-999
Abstract

High-momentum configurations of nucleon pairs at short-distance are probed using measurements of the 12C(e,e′p) and 12C(e,e′pN) reactions (where N is either n or p), at high-Q2 and xB>1.1. The data span a missing-momentum range of 300–1000 MeV/c and are predominantly sensitive to the transition region of the strong nuclear interaction from a Tensor to Scalar interaction. The data are well reproduced by theoretical calculations using the Generalized Contact Formalism with both chiral and phenomenological nucleon-nucleon (NN) interaction models. This agreement suggests that the measured high missing-momentum protons up to 1000 MeV/c predominantly belong to short-ranged correlated (SRC) pairs. The measured 12C(e,e′pN) / 12C(e,e′p) and 12C(e,e′pp) / 12C(e,e′pn) cross-section ratios are consistent with a decrease in the fraction of proton-neutron SRC pairs and increase in the fraction of proton-proton SRC pairs with increasing missing momentum. This confirms the transition from an isospin-dependent tensor NN interaction at ∼400 MeV/c to an isospin-independent scalar interaction at high-momentum around ∼800 MeV/c as predicted by theoretical calculation.

Published
2021
Full Text
View/download PDF

7. Observation of a cusp-like structure in the γp → K+Σ0 cross section at forward angles and low momentum transfer

Author

T.C. Jude, S. Alef, P. Bauer, D. Bayadilov, R. Beck, A. Bella, J. Bieling, A. Braghieri, P.L. Cole, D. Elsner, R. Di Salvo, A. Fantini, O. Freyermuth, F. Frommberger, F. Ghio, S. Goertz, A. Gridnev, D. Hammann, J. Hannappel, K. Kohl, N. Kozlenko, A. Lapik, P. Levi Sandri, V. Lisin, G. Mandaglio, F. Messi, R. Messi, D. Moricciani, V. Nedorezov, V.A. Nikonov, D. Novinskiy, P. Pedroni, A. Polonskiy, B.-E. Reitz, M. Romaniuk, A.V. Sarantsev, G. Scheluchin, H. Schmieden, A. Stuglev, V. Sumachev, V. Vegna, V. Tarakanov, and T. Zimmermann

Subjects
Strangeness photoproduction, BGOOD, Physics, QC1-999
Abstract

The γp→K+Σ0 differential cross section at extremely forward angles was measured at the BGOOD experiment. A three-quarter drop in strength over a narrow range in energy and a strong dependence on the polar angle of the K+ in the centre-of-mass of the reaction is observed at a centre-of-mass energy of 1900 MeV. Residing close to multiple open and hidden strangeness thresholds, the structure appears consistent with meson-baryon threshold effects which may contribute to the reaction mechanism.

Published
2021
Full Text
View/download PDF

8. Measurement of the beam spin asymmetry of e→p→e′p′η in the deep-inelastic regime with CLAS

Author

B. Zhao, A. Kim, K. Joo, I. Bedlinskiy, W. Kim, V. Kubarovsky, M. Ungaro, S. Adhikari, Z. Akbar, G. Angelini, H. Avakian, J. Ball, N.A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, V. Batourine, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, V.D. Burkert, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, A. Filippi, T.A. Forest, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H.S. Jo, S. Johnston, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Klein, F.J. Klein, S.E. Kuhn, S.V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, B. McKinnon, C.A. Meyer, Z.E. Meziani, M. Mirazita, V. Mokeev, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, H. Voskanyan, E. Voutier, R. Wang, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

The beam spin asymmetry of the exclusive pseudoscalar channel e→p→e′p′η was measured for the first time in the deep-inelastic regime (W>2 GeV/c2 and Q2>1 GeV2/c2) using a longitudinally polarized 5.78 GeV electron beam at Jefferson Lab with the CEBAF Large Acceptance Spectrometer. The data were accumulated in 144 four-dimensional bins of Q2, xB, −t and ϕ over a wide kinematic range, where ϕ is the azimuthal angle between the lepton and hadron scattering planes, The measured azimuthal dependence with large amplitudes of the sin⁡ϕ moments is a clear indication of a substantial contribution to the polarized cross-section from transversely polarized virtual photons. In the framework of generalized parton distributions (GPDs) this contribution is expressed via longitudinal-transverse interference between chiral-even and chiral-odd GPDs. The experimental results are compared to the existing theoretical models demonstrating the sensitivity to the product of chiral-odd and chiral-even GPDs and provide new constraints to the existing GPD parameterizations. Keywords: Nucleon structure, CLAS collaboration, Deeply Virtual Meson Production, Chiral-odd generalized parton distributions

Published
2019
Full Text
View/download PDF

9. First results on nucleon resonance photocouplings from the γp → π+π−p reaction

Author

E. Golovatch, V.D. Burkert, D.S. Carman, R.W. Gothe, K. Hicks, B.S. Ishkhanov, V.I. Mokeev, E. Pasyuk, S. Adhikari, Z. Akbar, M.J. Amaryan, H. Avakian, J. Ball, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, F. Cao, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, L. Clark, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, N. Harrison, M. Hattawy, D. Heddle, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, S. Johnston, K. Joo, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, B. McKinnon, C.A. Meyer, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, D. Riser, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, N. Tyler, M. Ungaro, H. Voskanyan, E. Voutier, R. Wang, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report the first experimental measurements of the nine 1-fold differential cross sections for the γp→π+π−p reaction, obtained with the CLAS detector at Jefferson Laboratory. The measurements cover the invariant mass range of the final state hadrons from 1.6 GeV

Published
2019
Full Text
View/download PDF

10. Double polarisation observable G for single pion photoproduction from the proton

Author

N. Zachariou, D.P. Watts, J. McAndrew, L. Zana, M. Bashkanov, I.I. Strakovsky, R. Workman, A.V. Sarantsev, V. Nikonov, K.P. Adhikari, S. Adhikari, M.J. Amaryan, G. Angelini, W.R. Armstrong, H. Atac, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A.S. Biselli, M. Bondi, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, D.S. Carman, J.C. Carvajal, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, B.A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, M. Defurne, A. Deur, S. Diehl, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, G. Gavalian, G.P. Gilfoyle, F.X. Girod, D.I. Glazier, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, M. Hattawy, D. Heddle, K. Hicks, A. Hobart, M. Holtrop, Q. Huang, Y. Ilieva, D.G. Ireland, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S. Joosten, D. Keller, A. Khanal, M. Khandaker, A. Kim, F.J. Klein, A. Kripko, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, Z.E. Meziani, T. Mineeva, V. Mokeev, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, K. Neupane, A. Ni, S. Niccolai, G. Niculescu, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, O. Pogorelko, Y. Prok, D. Protopopescu, M. Ripani, B.G. Ritchie, J. Ritman, A. Rizzo, G. Rosner, J. Rowley, F. Sabatié, C. Salgado, A. Schmidt, R.A. Schumacher, Y.G. Sharabian, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, S. Strauch, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, X. Wei, B. Yale, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report measurements of π+ and π0 meson photoproduction from longitudinally spin-polarised protons by an energy tagged (0.73-2.3 GeV) and linearly polarised photon beam. A close to complete solid angle coverage for the reaction products was provided by the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The double-polarisation observable G is extracted from Maximum Likelihood fits to the data, enabling the first accurate determination for the reaction γ→p→→π+n, while also significantly extending the kinematic coverage for γ→p→→π0p. This large data set provides an important constraint on the properties and spectrum of excited nucleon states decaying to Nπ in the mass range from 1.4 to 2.2 GeV, as well as for background (non-resonant) photoproduction processes. The considerable improvement achieved in the description of the observable G within the SAID and Bonn-Gatchina approaches after implementation of our data, illustrates that the partial-wave analyses now significantly extend the knowledge on Nπ photoproduction amplitudes at W>1.8 GeV. A partial-wave analysis using the new high-precision data set has a large impact on the extracted properties of high-spin nucleon excited states.

Published
2021
Full Text
View/download PDF

11. Beam–target helicity asymmetry E in K+Σ− photoproduction on the neutron

Author

N. Zachariou, D.P. Watts, J. Fleming, A.V. Sarantsev, V.A. Nikonov, A. D'Angelo, M. Bashkanov, C. Hanretty, T. Kageya, F.J. Klein, M. Lowry, H. Lu, A. Sandorfi, X. Wei, I. Zonta, K.P. Adhikari, S. Adhikari, M.J. Amaryan, G. Angelini, G. Asryan, H. Atac, L. Barion, C. Bass, M. Battaglieri, I. Bedlinskiy, F. Benmokhtar, A. Bianconi, A.S. Biselli, F. Bossù, S. Boiarinov, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V. Burkert, D.S. Carman, J.C. Carvajal, A. Celentano, G. Charles, P. Chatagnon, T. Chetry, G. Ciullo, P.L. Cole, M. Contalbrigo, N. Dashyan, R. De Vita, A. Deur, S. Diehl, C. Djalali, R. Dupre, H. Egiyan, M. Ehrhart, A. El Alaoui, P. Eugenio, S. Fegan, R. Fersch, A. Filippi, G. Gavalian, N. Gevorgyan, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, M. Hattawy, D. Heddle, K. Hicks, D. Ho, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H.S. Jo, K. Joo, S.J. Joosten, D. Keller, M. Khachatryan, A. Khanal, M. Khandaker, C.W. Kim, W. Kim, V. Kubarovsky, L. Lanza, M. Leali, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, N. Markov, L. Marsicano, V. Mascagna, M. Mayer, B. McKinnon, Z.E. Meziani, T. Mineeva, V. Mokeev, E. Munevar, C. Munoz Camacho, P. Nadel Turonski, T.R. O'Connell, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, K. Park, E. Pasyuk, P. Peng, W. Phelps, O. Pogorelko, J. Poudel, J.W. Price, Y. Prok, A.J.R. Puckett, B.A. Raue, M. Ripani, A. Rizzo, G. Rosner, C. Salgado, A. Schmidt, R.A. Schumacher, U. Shrestha, D. Sokhan, O. Soto, N. Sparveris, I.I. Strakovsky, S. Strauch, J.A. Tan, N. Tyler, M. Ungaro, L. Venturelli, H. Voskanyan, E. Voutier, N.K. Walford, C.S. Whisnant, M.H. Wood, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We report a measurement of a beam–target double-polarisation observable (E) for the γ→n→(p)→K+Σ−(p) reaction. The data were obtained impinging the circularly-polarised energy-tagged photon beam of Hall B at Jefferson Lab on a longitudinally-polarised frozen-spin hydrogen deuteride (HD) nuclear target. The E observable for an effective neutron target was determined for centre-of-mass energies 1.70≤W≤2.30 GeV, with reaction products detected over a wide angular acceptance by the CLAS spectrometer. These new double-polarisation data give unique constraints on the strange decays of excited neutron states. Inclusion of the new data within the Bonn-Gatchina theoretical model results in significant changes for the extracted photocouplings of a number of established nucleon resonances. Possible improvements in the PWA description of the experimental data with additional “missing” resonance states, including the N(2120)3/2− resonance, are also quantified.

Published
2020
Full Text
View/download PDF

12. Semi-inclusive π0 target and beam-target asymmetries from 6 GeV electron scattering with CLAS

Author

S. Jawalkar, S. Koirala, H. Avakian, P. Bosted, K.A. Griffioen, C. Keith, S.E. Kuhn, K.P. Adhikari, S. Adhikari, D. Adikaram, Z. Akbar, M.J. Amaryan, S. Anefalos Pereira, J. Ball, N.A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, J. Brock, W.K. Brooks, S. Bültmann, V.D. Burkert, Frank Thanh Cao, C. Carlin, D.S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P.L. Cole, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, C. Djalali, G. Ddoge, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, R. Fersch, A. Filippi, J.A. Fleming, T.A. Forest, A. Fradi, M. Garçon, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, C. Gleason, W. Gohn, E. Golovatch, R.W. Gothe, M. Guidal, N. Guler, L. Guo, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, G. Hollis, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, N. Markov, M. Mayer, M.E. McCracken, B. McKinnon, C.A. Meyer, T. Mineeva, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A.I. Ostrovidov, R. Paremuzyan, K. Park, E. Pasyuk, E. Phelps, W. Phelps, J. Pierce, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, D. Riser, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, E. Seder, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I. Stankovic, S. Strauch, M. Taiuti, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, X. Wei, L.B. Weinstein, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

We present precision measurements of the target and beam-target spin asymmetries from neutral pion electroproduction in deep-inelastic scattering (DIS) using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. We scattered 6-GeV, longitudinally polarized electrons off longitudinally polarized protons in a cryogenic 14NH3 target, and extracted double and single target spin asymmetries for ep→e′π0X in multidimensional bins in four-momentum transfer (1.0

Published
2018
Full Text
View/download PDF

13. Differential cross section for γd → ωd using CLAS at Jefferson Lab

Author

T. Chetry, K. Hicks, N. Compton, M. Sargsian, S. Adhikari, J. Ball, I. Balossino, L. Barion, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, V.D. Burkert, D.S. Carman, A. Celentano, G. Charles, G. Ciullo, L. Clark, Brandon A. Clary, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, G. Gavalian, Y. Ghandilyan, K.L. Giovanetti, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, N. Harrison, M. Hattawy, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, S. Johnston, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, V. Mokeev, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, O. Pogorelko, J.W. Price, Y. Prok, M. Ripani, D. Riser, B.G. Ritchie, A. Rizzo, G. Rosner, C. Salgado, R.A. Schumacher, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, M. Ungaro, H. Voskanyan, E. Voutier, L.B. Weinstein, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

The cross section for coherent ω-meson photoproduction off the deuteron has been measured for the first time as a function of the momentum transfer t=(Pγ−Pω)2 and photon energy Eγ using the CLAS detector at the Thomas Jefferson National Accelerator Facility. The cross sections are measured in the energy range 1.4

Published
2018
Full Text
View/download PDF

14. Hard exclusive pion electroproduction at backward angles with CLAS

Author

K. Park, M. Guidal, R.W. Gothe, B. Pire, K. Semenov-Tian-Shansky, J.-M. Laget, K.P. Adhikari, S. Adhikari, Z. Akbar, H. Avakian, J. Ball, I. Balossino, N.A. Baltzell, L. Barion, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, W.J. Briscoe, W.K. Brooks, V.D. Burkert, F.T. Cao, D.S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, M. Garçon, Y. Ghandilyan, G.P. Gilfoyle, F.X. Girod, E. Golovatch, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, C.E. Hyde, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, S. Johnston, K. Joo, M.L. Kabir, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, W. Kim, F.J. Klein, V. Kubarovsky, S.E. Kuhn, L. Lanza, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, M. Mirazita, V. Mokeev, R.A. Montgomery, C. Munoz Camacho, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, M. Paolone, R. Paremuzyan, E. Pasyuk, W. Phelps, O. Pogorelko, J. Poudel, J.W. Price, Y. Prok, D. Protopopescu, M. Ripani, A. Rizzo, P. Rossi, F. Sabatié, C. Salgado, R.A. Schumacher, Y. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, J.A. Tan, M. Ungaro, H. Voskanyan, E. Voutier, X. Wei, N. Zachariou, and J. Zhang

Subjects
Physics, QC1-999
Abstract

We report on the first measurement of cross sections for exclusive deeply virtual pion electroproduction off the proton, ep→e′nπ+, above the resonance region at backward pion center-of-mass angles. The φπ⁎-dependent cross sections were measured, from which we extracted three combinations of structure functions of the proton. Our results are compatible with calculations based on nucleon-to-pion transition distribution amplitudes (TDAs). These non-perturbative objects are defined as matrix elements of three-quark-light-cone-operators and characterize partonic correlations with a particular emphasis on baryon charge distribution inside a nucleon. Keywords: TDA, Exclusive single pion, Eletroproduction, CLAS

Published
2018
Full Text
View/download PDF

15. Photon beam asymmetry Σ in the reaction γ→p→pω for Eγ=1.152 to 1.876 GeV

Author

P. Collins, B.G. Ritchie, M. Dugger, F.J. Klein, A.V. Anisovich, E. Klempt, V.A. Nikonov, A. Sarantsev, K.P. Adhikari, S. Adhikari, D. Adikaram, Z. Akbar, S. Anefalos Pereira, H. Avakian, J. Ball, N.A. Baltzell, M. Bashkanov, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, V.D. Burkert, Frank Thanh Cao, T. Cao, D.S. Carman, A. Celentano, G. Charles, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, M. Contalbrigo, O. Cortes, V. Crede, N. Dashyan, R. De Vita, E. De Sanctis, M. Defurne, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, A. Filippi, J.A. Fleming, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, C. Gleason, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, D. Heddle, K. Hicks, G. Hollis, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, H.S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, V. Kubarovsky, S.V. Kuleshov, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, C.A. Meyer, Z.E. Meziani, T. Mineeva, V. Mokeev, R.A. Montgomery, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J.W. Price, S. Procureur, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, A. Rizzo, G. Rosner, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, I. Stankovic, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, X. Wei, M.H. Wood, N. Zachariou, J. Zhang, and Z.W. Zhao

Subjects
Physics, QC1-999
Abstract

Photon beam asymmetry Σ measurements for ω photoproduction in the reaction γ→p→ωp are reported for photon energies from 1.152 to 1.876 GeV. Data were taken using a linearly-polarized tagged photon beam, a cryogenic hydrogen target, and the CLAS spectrometer in Hall B at Jefferson Lab. The measurements obtained markedly increase the size of the database for this observable, extend coverage to higher energies, and resolve discrepancies in previously published data. Comparisons of these new results with predictions from a chiral-quark-based model and from a dynamical coupled-channels model indicate the importance of interferences between t-channel meson exchange and s- and u-channel contributions, underscoring sensitivity to the nucleon resonances included in those descriptions. Comparisons with the Bonn–Gatchina partial-wave analysis indicate the Σ data reported here help to fix the magnitudes of the interference terms between the leading amplitudes in that calculation (Pomeron exchange and the resonant portion of the JP=3/2+ partial wave), as well as the resonant portions of the smaller partial waves with JP=1/2−, 3/2−, and 5/2+. Keywords: Omega photoproduction, Polarization observable, Beam asymmetry

Published
2017
Full Text
View/download PDF

16. Photon beam asymmetry Σ for η and η′ photoproduction from the proton

Author

P. Collins, B.G. Ritchie, M. Dugger, A.V. Anisovich, M. Döring, E. Klempt, V.A. Nikonov, D. Rönchen, D. Sadasivan, A. Sarantsev, K.P. Adhikari, Z. Akbar, M.J. Amaryan, S. Anefalos Pereira, H. Avakian, J. Ball, I. Balossino, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, A.S. Biselli, W.J. Briscoe, W.K. Brooks, V.D. Burkert, Frank Thanh Cao, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, G. Ciullo, L. Clark, L. Colaneri, P.L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, E. Fanchini, G. Fedotov, A. Filippi, J.A. Fleming, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, C. Gleason, E. Golovatch, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, D. Heddle, K. Hicks, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H.S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, C.A. Meyer, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, G. Murdoch, P. Nadel-Turonski, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, I.I. Strakovsky, S. Strauch, M. Taiuti, Ye Tian, B. Torayev, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, X. Wei, N. Zachariou, and J. Zhang

Subjects
Physics, QC1-999
Abstract

Measurements of the linearly-polarized photon beam asymmetry Σ for photoproduction from the proton of η and η′ mesons are reported. A linearly-polarized tagged photon beam produced by coherent bremsstrahlung was incident on a cryogenic hydrogen target within the CEBAF Large Acceptance Spectrometer. Results are presented for the γp→ηp reaction for incident photon energies from 1.070 to 1.876 GeV, and from 1.516 to 1.836 GeV for the γp→η′p reaction. For γp→ηp, the data reported here considerably extend the range of measurements to higher energies, and are consistent with the few previously published measurements for this observable near threshold. For γp→η′p, the results obtained are consistent with the few previously published measurements for this observable near threshold, but also greatly expand the incident photon energy coverage for that reaction. Initial analysis of the data reported here with the Bonn–Gatchina model strengthens the evidence for four nucleon resonances – the N(1895)1/2−, N(1900)3/2+, N(2100)1/2+ and N(2120)3/2− resonances – which presently lack the “four-star” status in the current Particle Data Group compilation, providing examples of how these new measurements help refine models of the photoproduction process. Keywords: Meson photoproduction, Eta photoproduction, Eta-prime photoproduction, Polarization observable, Photon beam asymmetry

Published
2017
Full Text
View/download PDF

17. Differential cross sections and polarization observables from CLAS K⁎ photoproduction and the search for new N⁎ states

Author

A.V. Anisovich, K. Hicks, E. Klempt, V.A. Nikonov, A. Sarantsev, W. Tang, D. Adikaram, Z. Akbar, M.J. Amaryan, S. Anefalos Pereira, R.A. Badui, J. Ball, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, W.J. Briscoe, V.D. Burkert, D.S. Carman, A. Celentano, S. Chandavar, T. Chetry, G. Ciullo, L. Clark, P.L. Cole, N. Compton, M. Contalbrigo, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, E. Fanchini, G. Fedotov, A. Filippi, J.A. Fleming, N. Gevorgyan, Y. Ghandilyan, K.L. Giovanetti, F.X. Girod, C. Gleason, R.W. Gothe, K.A. Griffioen, L. Guo, C. Hanretty, N. Harrison, M. Hattawy, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, H.S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khandaker, W. Kim, F.J. Klein, V. Kubarovsky, L. Lanza, P. Lenisa, K. Livingston, I.J.D. MacGregor, N. Markov, B. McKinnon, C.A. Meyer, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, E. Munevar, C. Munoz Camacho, G. Murdoch, P. Nadel-Turonski, L.A. Net, A. Ni, S. Niccolai, I. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, R. Paremuzyan, K. Park, E. Pasyuk, P. Peng, W. Phelps, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, A.J.R. Puckett, B.A. Raue, M. Ripani, B.G. Ritchie, G. Rosner, P. Roy, F. Sabatié, R.A. Schumacher, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, I. Stankovic, S. Stepanyan, S. Strauch, V. Sytnik, Ye. Tian, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, M.H. Wood, N. Zachariou, J. Zhang, and I. Zonta

Subjects
Physics, QC1-999
Abstract

The reaction γp→K⁎+Λ was measured using the CLAS detector for photon energies between the threshold and 3.9 GeV at the Thomas Jefferson National Accelerator Facility. For the first time, spin-density matrix elements have been extracted for this reaction. Differential cross sections, spin density matrix elements, and the Λ recoil polarization are compared with theoretical predictions using the BnGa partial wave analysis. The main result is the evidence for significant contributions from N(1895)1/2− and N(2100)1/2+ to the reaction. Branching ratios for decays into K⁎Λ for these resonances and further resonances are reported. Keywords: Baryon spectroscopy, Meson photoproduction, Polarization observables

Published
2017
Full Text
View/download PDF

18. Target and double spin asymmetries of deeply virtual π0 production with a longitudinally polarized proton target and CLAS

Author

A. Kim, H. Avakian, V. Burkert, K. Joo, W. Kim, K.P. Adhikari, Z. Akbar, S. Anefalos Pereira, R.A. Badui, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, P. Bosted, W.J. Briscoe, W.K. Brooks, S. Bültmann, T. Cao, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, T. Chetry, L. Colaneri, P.L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, C. Djalali, H. Egiyan, A. El Alaoui, L. El Fassi, P. Eugenio, G. Fedotov, R. Fersch, A. Filippi, J.A. Fleming, A. Fradi, M. Garc con, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, L. Guo, K. Hafidi, C. Hanretty, M. Hattawy, D. Heddle, K. Hicks, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, D. Jenkins, H. Jiang, H.S. Jo, S. Joosten, D. Keller, G. Khachatryan, M. Khandaker, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, S.V. Kuleshov, L. Lanza, P. Lenisa, H.Y. Lu, I.J.D. MacGregor, N. Markov, P. Mattione, M.E. McCracken, B. McKinnon, V. Mokeev, A. Movsisyan, E. Munevar, P. Nadel-Turonski, L.A. Net, S. Niccolai, M. Osipenko, A.I. Ostrovidov, M. Paolone, K. Park, E. Pasyuk, W. Phelps, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, M. Ripani, A. Rizzo, G. Rosner, P. Rossi, P. Roy, C. Salgado, R.A. Schumacher, E. Seder, Y.G. Sharabian, Iu. Skorodumina, G.D. Smith, D. Sokhan, N. Sparveris, S. Stepanyan, P. Stoler, I.I. Strakovsky, S. Strauch, V. Sytnik, M. Taiuti, B. Torayev, M. Ungaro, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, L.B. Weinstein, N. Zachariou, L. Zana, and J. Zhang

Subjects
Nucleon structure, CLAS collaboration, Deeply Virtual Meson Production, Chiral-odd generalized parton distributions, Longitudinally polarized target, Physics, QC1-999
Abstract

The target and double spin asymmetries of the exclusive pseudoscalar channel e→p→→epπ0 were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of Q2, xB, −t and ϕ. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs H˜T and ET, and complement previous measurements of unpolarized structure functions sensitive to the GPDs HT and E¯T. These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.

Published
2017
Full Text
View/download PDF

19. High precision measurement of Compton scattering in the 5 GeV region

Author

P. Ambrozewicz, L. Ye, Y. Prok, I. Larin, A. Ahmidouch, K. Baker, V. Baturin, L. Benton, A. Bernstein, V. Burkert, E. Clinton, P.L. Cole, P. Collins, D. Dale, S. Danagoulian, G. Davidenko, R. Demirchyan, A. Deur, A. Dolgolenko, D. Dutta, G. Dzyubenko, A. Evdokimov, G. Fedotov, J. Feng, M. Gabrielyan, L. Gan, H. Gao, A. Gasparian, N. Gevorkyan, S. Gevorkyan, A. Glamazdin, V. Goryachev, L. Guo, V. Gyurjyan, K. Hardy, J. He, E. Isupov, M.M. Ito, L. Jiang, H. Kang, D. Kashy, M. Khandaker, P. Kingsberry, F. Klein, A. Kolarkar, M. Konchatnyi, O. Korchin, W. Korsch, O. Kosinov, S. Kowalski, M. Kubantsev, A. Kubarovsky, V. Kubarovsky, D. Lawrence, X. Li, M. Levillain, H. Lu, L. Ma, P. Martel, V. Matveev, D. McNulty, B. Mecking, A. Micherdzinska, B. Milbrath, R. Minehart, R. Miskimen, V. Mochalov, B. Morrison, S. Mtingwa, I. Nakagawa, S. Overby, E. Pasyuk, M. Payen, K. Park, R. Pedroni, W. Phelps, D. Protopopescu, D. Rimal, B.G. Ritchie, D. Romanov, C. Salgado, A. Shahinyan, A. Sitnikov, D. Sober, S. Stepanyan, W. Stephens, V. Tarasov, S. Taylor, A. Teymurazyan, J. Underwood, A. Vasiliev, V. Vishnyakov, D.P. Weygand, M. Wood, Y. Zhang, S. Zhou, and B. Zihlmann

Subjects
Physics, QC1-999
Abstract

The cross section of atomic electron Compton scattering γ+e→γ′+e′ was measured in the 4.400–5.475 GeV photon beam energy region by the PrimEx collaboration at Jefferson Lab with an accuracy of 2.6% and less. The results are consistent with theoretical predictions that include next-to-leading order radiative corrections. The measurements provide the first high precision test of this elementary QED process at beam energies greater than 0.1 GeV.

Published
2019
Full Text
View/download PDF

20. Measurement of nuclear transparency ratios for protons and neutrons

Author

M. Duer, O. Hen, E. Piasetzky, L.B. Weinstein, A. Schmidt, I. Korover, E.O. Cohen, H. Hakobyan, S. Adhikari, G. Angelini, H. Avakian, C. Ayerbe Gayoso, L. Barion, M. Battaglieri, A. Beck, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W. Brooks, V.D. Burkert, F. Cao, D.S. Carman, A. Celentano, P. Chatagnon, T. Chetry, G. Ciullo, P.L. Cole, M. Contalbrigo, O. Cortes, V. Crede, R. Cruz Torres, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, S. Diehl, C. Djalali, R. Dupre, Burcu Duran, H. Egiyan, M. Ehrhart, A. El Alaoui, L. El Fassi, P. Eugenio, A. Filippi, T.A. Forest, G.P. Gilfoyle, F.X. Girod, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, C. Hanretty, N. Harrison, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, M. Holtrop, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, H.S. Jo, S. Johnston, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khachatryan, A. Khanal, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, S.V. Kuleshov, L. Lanza, G. Laskaris, P. Lenisa, K. Livingston, I.J.D. MacGregor, D. Marchand, B. McKinnon, S. Mey-Tal Beck, T. Mineeva, M. Mirazita, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, B. Mustapha, P. Nadel-Turonski, S. Niccolai, G. Niculescu, M. Osipenko, A.I. Ostrovidov, M. Paolone, L.L. Pappalardo, R. Paremuzyan, E. Pasyuk, M. Patsyuk, D. Payette, J. Price, D. Pocanic, O. Pogorelko, Y. Prok, D. Protopopescu, B.A. Raue, M. Ripani, D. Riser, A. Rizzo, G. Rosner, P. Rossi, F. Sabatié, C. Salgado, B.A. Schmookler, R.A. Schumacher, E.P. Segarra, Y.G. Sharabian, Iu. Skorodumina, D. Sokhan, O. Soto, N. Sparveris, S. Stepanyan, S. Strauch, M. Taiuti, J.A. Tan, M. Ungaro, H. Voskanyan, E. Voutier, R. Wang, X. Wei, N. Zachariou, J. Zhang, Z.W. Zhao, and X. Zheng

Subjects
Physics, QC1-999
Abstract

This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e,e′n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted in two kinematical regions, corresponding to knockout of mean-field nucleons and to the breakup of Short-Range Correlated nucleon pairs. The extracted neutron transparency ratios are consistent with each other for the two measured kinematical regions and agree with the proton transparencies extracted from new and previous (e,e′p) measurements, including those from neutron-rich nuclei such as lead. The data also agree with and confirm the Glauber approximation that is commonly used to interpret experimental data. The nuclear-mass-dependence of the extracted transparencies scales as Aα with α=−0.289±0.007, which is consistent with nuclear-surface dominance of the reactions.

Published
2019
Full Text
View/download PDF

21. First measurement of the helicity asymmetry E in η photoproduction on the proton

Author

I. Senderovich, B.T. Morrison, M. Dugger, B.G. Ritchie, E. Pasyuk, R. Tucker, J. Brock, C. Carlin, C.D. Keith, D.G. Meekins, M.L. Seely, D. Rönchen, M. Döring, P. Collins, K.P. Adhikari, D. Adikaram, Z. Akbar, M.D. Anderson, S. Anefalos Pereira, R.A. Badui, J. Ball, N.A. Baltzell, M. Battaglieri, V. Batourine, I. Bedlinskiy, A.S. Biselli, S. Boiarinov, W.J. Briscoe, W.K. Brooks, V.D. Burkert, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P.L. Cole, M. Contalbrigo, O. Cortes, V. Credé, A. D'Angelo, N. Dashyan, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J.A. Fleming, A. Fradi, B. Garillon, Y. Ghandilyan, G.P. Gilfoyle, K.L. Giovanetti, F.X. Girod, D.I. Glazier, J.T. Goetz, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, D. Jenkins, H. Jiang, H.S. Jo, K. Joo, S. Joosten, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, F.J. Klein, V. Kubarovsky, M.C. Kunkel, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, P. Mattione, B. McKinnon, C.A. Meyer, T. Mineeva, V. Mokeev, R.A. Montgomery, A. Movsisyan, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, M. Osipenko, K. Park, S. Park, P. Peng, W. Phelps, S. Pisano, O. Pogorelko, J.W. Price, Y. Prok, A.J.R. Puckett, M. Ripani, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, D. Schott, R.A. Schumacher, E. Seder, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, N. Sparveris, S. Stepanyan, P. Stoler, I.I. Strakovsky, S. Strauch, V. Sytnik, Ye Tian, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, X. Wei, M.H. Wood, N. Zachariou, L. Zana, J. Zhang, Z.W. Zhao, and I. Zonta

Subjects
Physics, QC1-999
Abstract

Results are presented for the first measurement of the double-polarization helicity asymmetry E for the η photoproduction reaction γp→ηp. Data were obtained using the FROzen Spin Target (FROST) with the CLAS spectrometer in Hall B at Jefferson Lab, covering a range of center-of-mass energy W from threshold to 2.15 GeV and a large range in center-of-mass polar angle. As an initial application of these data, the results have been incorporated into the Jülich–Bonn model to examine the case for the existence of a narrow N⁎ resonance between 1.66 and 1.70 GeV. The addition of these data to the world database results in marked changes in the predictions for the E observable from that model. Further comparison with several theoretical approaches indicates these data will significantly enhance our understanding of nucleon resonances. Keywords: Eta photoproduction, Polarization observable, Helicity asymmetry

Published
2016
Full Text
View/download PDF

22. First measurement of the polarization observable E in the p→(γ→,π+)n reaction up to 2.25 GeV

Author

S. Strauch, W.J. Briscoe, M. Döring, E. Klempt, V.A. Nikonov, E. Pasyuk, D. Rönchen, A.V. Sarantsev, I. Strakovsky, R. Workman, K.P. Adhikari, D. Adikaram, M.D. Anderson, S. Anefalos Pereira, A.V. Anisovich, R.A. Badui, J. Ball, V. Batourine, M. Battaglieri, I. Bedlinskiy, N. Benmouna, A.S. Biselli, J. Brock, W.K. Brooks, V.D. Burkert, T. Cao, C. Carlin, D.S. Carman, A. Celentano, S. Chandavar, G. Charles, L. Colaneri, P.L. Cole, N. Compton, M. Contalbrigo, O. Cortes, V. Crede, N. Dashyan, A. D'Angelo, R. De Vita, E. De Sanctis, A. Deur, C. Djalali, M. Dugger, R. Dupre, H. Egiyan, A. El Alaoui, L. El Fassi, L. Elouadrhiri, P. Eugenio, G. Fedotov, S. Fegan, A. Filippi, J.A. Fleming, T.A. Forest, A. Fradi, N. Gevorgyan, Y. Ghandilyan, K.L. Giovanetti, F.X. Girod, D.I. Glazier, W. Gohn, E. Golovatch, R.W. Gothe, K.A. Griffioen, M. Guidal, L. Guo, K. Hafidi, H. Hakobyan, C. Hanretty, N. Harrison, M. Hattawy, K. Hicks, D. Ho, M. Holtrop, S.M. Hughes, Y. Ilieva, D.G. Ireland, B.S. Ishkhanov, E.L. Isupov, D. Jenkins, H. Jiang, H.S. Jo, K. Joo, S. Joosten, C.D. Keith, D. Keller, G. Khachatryan, M. Khandaker, A. Kim, W. Kim, A. Klein, F.J. Klein, V. Kubarovsky, S.E. Kuhn, P. Lenisa, K. Livingston, H.Y. Lu, I.J.D. MacGregor, N. Markov, B. McKinnon, D.G. Meekins, C.A. Meyer, V. Mokeev, R.A. Montgomery, C.I. Moody, H. Moutarde, A. Movsisyan, E. Munevar, C. Munoz Camacho, P. Nadel-Turonski, L.A. Net, S. Niccolai, G. Niculescu, I. Niculescu, G. O'Rielly, M. Osipenko, A.I. Ostrovidov, K. Park, P. Peng, W. Phelps, J.J. Phillips, S. Pisano, O. Pogorelko, S. Pozdniakov, J.W. Price, S. Procureur, Y. Prok, D. Protopopescu, A.J.R. Puckett, B.A. Raue, M. Ripani, B.G. Ritchie, A. Rizzo, G. Rosner, P. Roy, F. Sabatié, C. Salgado, D. Schott, R.A. Schumacher, E. Seder, M.L. Seely, I. Senderovich, Y.G. Sharabian, A. Simonyan, Iu. Skorodumina, G.D. Smith, D.I. Sober, D. Sokhan, N. Sparveris, P. Stoler, S. Stepanyan, V. Sytnik, M. Taiuti, Ye Tian, A. Trivedi, R. Tucker, M. Ungaro, H. Voskanyan, E. Voutier, N.K. Walford, D.P. Watts, X. Wei, M.H. Wood, N. Zachariou, L. Zana, J. Zhang, Z.W. Zhao, and I. Zonta

Subjects
Baryon spectroscopy, Pion photoproduction, Polarization observables, FROST experiment, Physics, QC1-999
Abstract

First results from the longitudinally polarized frozen-spin target (FROST) program are reported. The double-polarization observable E, for the reaction γ→p→→π+n, has been measured using a circularly polarized tagged-photon beam, with energies from 0.35 to 2.37 GeV. The final-state pions were detected with the CEBAF Large Acceptance Spectrometer in Hall B at the Thomas Jefferson National Accelerator Facility. These polarization data agree fairly well with previous partial-wave analyses at low photon energies. Over much of the covered energy range, however, significant deviations are observed, particularly in the high-energy region where high-L multipoles contribute. The data have been included in new multipole analyses resulting in updated nucleon resonance parameters. We report updated fits from the Bonn–Gatchina, Jülich–Bonn, and SAID groups.

Published
2015
Full Text
View/download PDF

23. Alignment of the CLAS12 central hybrid tracker with a Kalman Filter

Author

S.J. Paul, A. Peck, M. Arratia, Y. Gotra, V. Ziegler, R. De Vita, F. Bossù, M. Defurne, H. Atac, C. Ayerbe Gayoso, L. Baashen, N.A. Baltzell, L. Barion, M. Bashkanov, M. Battaglieri, I. Bedlinskiy, B. Benkel, F. Benmokhtar, A. Bianconi, L. Biondo, A.S. Biselli, M. Bondi, S. Boiarinov, K.-Th. Brinkmann, W.J. Briscoe, W.K. Brooks, D. Bulumulla, V.D. Burkert, R. Capobianco, D.S. Carman, J.C. Carvajal, P. Chatagnon, V. Chesnokov, T. Chetry, G. Ciullo, P.L. Cole, G. Costantini, A. D’Angelo, N. Dashyan, A. Deur, S. Diehl, C. Djalali, R. Dupre, A. El Alaoui, L. El Fassi, L. Elouadrhiri, A. Filippi, K. Gates, G. Gavalian, Y. Ghandilyan, G.P. Gilfoyle, A.A. Golubenko, G. Gosta, R.W. Gothe, K. Griffioen, M. Guidal, H. Hakobyan, M. Hattawy, F. Hauenstein, T.B. Hayward, D. Heddle, A. Hobart, M. Holtrop, Y. Ilieva, D.G. Ireland, E.L. Isupov, H.S. Jo, R. Johnston, K. Joo, D. Keller, M. Khachatryan, A. Khanal, A. Kim, W. Kim, V. Klimenko, A. Kripko, L. Lanza, M. Leali, P. Lenisa, X. Li, I.J.D. MacGregor, D. Marchand, L. Marsicano, V. Mascagna, B. McKinnon, C. McLauchlin, S. Migliorati, T. Mineeva, M. Mirazita, V. Mokeev, C. Munoz Camacho, P. Nadel-Turonski, P. Naidoo, K. Neupane, D. Nguyen, S. Niccolai, M. Nicol, G. Niculescu, M. Osipenko, P. Pandey, M. Paolone, R. Paremuzyan, N. Pilleux, O. Pogorelko, M. Pokhrel, J. Poudel, J.W. Price, Y. Prok, T. Reed, M. Ripani, J. Ritman, F. Sabatié, S. Schadmand, A. Schmidt, E.V. Shirokov, U. Shrestha, P. Simmerling, D. Sokhan, N. Sparveris, M. Spreafico, I.I. Strakovsky, S. Strauch, J.A. Tan, R. Tyson, M. Ungaro, S. Vallarino, L. Venturelli, H. Voskanyan, E. Voutier, D.P. Watts, X. Wei, R. Wishart, M.H. Wood, N. Zachariou, Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)

Subjects
Nuclear and High Energy Physics, data analysis method, Physics - Instrumentation and Detectors, FOS: Physical sciences, [PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex], High Energy Physics - Experiment, High Energy Physics - Experiment (hep-ex), CLAS, [PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex], ddc:530, tracking detector, [PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det], Nuclear Experiment (nucl-ex), numerical calculations, Nuclear Experiment, Instrumentation, Alignment, track data analysis, Settore FIS/04, Detector, Instrumentation and Detectors (physics.ins-det), detector: alignment, Kalman filter, cosmic radiation, semiconductor detector: microstrip, performance
Abstract

International audience; Several factors can contribute to the difficulty of aligning the sensors of tracking detectors, including a large number of modules, multiple types of detector technologies, and non-linear strip patterns on the sensors. The latter two of these three factors apply to the CLAS12 CVT, which is a hybrid detector consisting of planar silicon sensors with non-parallel strips, and cylindrical micromegas sensors with longitudinal and arc-shaped strips located within a 5 T superconducting solenoid. To align this detector, we used the Kalman Alignment Algorithm, which accounts for correlations between the alignment parameters without requiring the time-consuming inversion of large matrices. This is the first time that this algorithm has been adapted for use with hybrid technologies, non-parallel strips, and curved sensors. We present the results for the first alignment of the CLAS12 CVT using straight tracks from cosmic rays and from a target with the magnetic field turned off. After running this procedure, we achieved alignment at the level of l. 967 10μm, and the widths of the residual spectra were greatly reduced. These results attest to the flexibility of this algorithm and its applicability to future use in the CLAS12 CVT and other hybrid or curved trackers, such as those proposed for the future Electron-Ion Collider.

Published
2023
Full Text
View/download PDF

24. Photoproduction of K+ Δ(1405) → K+ π0 Σ0 extending to forward angles and low momentum transfer

Author

G. Scheluchin, T.C. Jude, S. Alef, P. Bauer, D. Bayadilov, R. Beck, A. Braghieri, P.L. Cole, D. Elsner, R. Di Salvo, A. Fantini, O. Freyermuth, F. Frommberger, F. Ghio, A. Gridnev, D. Hammann, J. Hannappel, K. Kohl, N. Kozlenko, A. Lapik, P. Levi Sandri, V. Lisin, G. Mandaglio, R. Messi, D. Moricciani, A. Mushkarenkov, V. Nedorezov, D. Novinskiy, P. Pedroni, A. Polonskiy, B.-E. Reitz, M. Romaniuk, H. Schmieden, V. Sumachev, and V. Tarakanov

Subjects
Nuclear and High Energy Physics, Strangeness photoproduction, BGOOD, Lambda(1405), Settore FIS/04
Published
2022

25. Performance of BDX-MINI veto systems

Author

M. Spreafico, M. Battaglieri, M. Bondí, A. Celentano, P.L. Cole, M. De Napoli, R. De Vita, L. Marsicano, N. Randazzo, E.S. Smith, D. Snowden-Ifft, and M. Wood

Subjects
Nuclear and High Energy Physics, Instrumentation
Published
2023
Full Text
View/download PDF

26. Production of nuclei in neutron unbound states via primary fragmentation of 48Ca

Author

D. Denby, Graham F. Peaslee, R. Howes, S. Mosby, L.O. Wagner, Michael Thoennessen, C. R. Hoffman, B. A. Luther, Warren F. Rogers, M.J. Strongman, E. Breitbach, Andreas Schiller, Derek Padilla, A. Fritsch, G. Christian, A.M. Hayes, Thomas Baumann, E. Mosby, C.C. Hall, D. Absalon, P. V. Pancella, Joseph E. Finck, Paul DeYoung, J. A. Brown, D. Albertson, Nathan Frank, D. Bazin, P.L. Cole, W. A. Peters, and Jerry Hinnefeld

Subjects
Nuclear reaction, Physics, Nuclear and High Energy Physics, Astrophysics::High Energy Astrophysical Phenomena, Nuclear Theory, Coincidence, Neutron spectroscopy, Nuclear physics, Fragmentation (mass spectrometry), Neutron, Atomic physics, Nuclear Experiment, Nucleon, Spectroscopy
Abstract

The method of sequential neutron decay spectroscopy beginning with a primary beam of 60 MeV/nucleon 48Ca was investigated as a potential tool to measure unbound resonances in neutron-rich nuclei. Neutrons were measured in coincidence with fragments, and unbound resonances were observed for 10Li, 12,13Be, and 23O. The method is currently limited to resonances with small decay energies ( E decay ≲ 100 keV ) in lighter ( Z ⩽ 10 ) nuclei, and the possibility of extending it to heavier, more neutron-rich nuclei will be discussed.

Published
2008
Full Text
View/download PDF

27. Measuring the 20.2-ms half life of the 472-keV line from the isomer Na-24m with pulsed photons at the Idaho Accelerator Center

Author

Douglas P. Wells, E.T.E. Reedy, R. Spaulding, J.F. Harmon, P.L. Cole, and J.L. Farley

Subjects
Nuclear and High Energy Physics, Photon, Chemistry, Half-life, law.invention, Nuclear physics, Angular distribution, law, Shielded cable, Ionization chamber, Atomic physics, Hpge detector, Instrumentation, Beam (structure), Line (formation)
Abstract

At the Idaho Accelerator Center, we employed a pulsed bremsstrahlung photon beam generated from the 44-MeV, 1300 MHz L-band electron Linac which was then directed onto a 99.9% natural magnesium target (isotopically 10% 25Mg). We investigated a method of measuring the 20.2 ms half life of the photoproduced 24mNa isomer created in the process: γ + 25Mg → p + 24mNa. The telltale 472-keV gamma line was measured between the photon pulses with an HPGe detector shielded within a lead cave. We used an ion chamber for monitoring the photon beam and used a novel arrangement of Zr/Ni foils for ascertaining the angular distribution of the beam profile. We discuss our preliminary results and future plans for extracting photonuclear cross sections.

Published
2007
Full Text
View/download PDF

28. Exclusive ρ0 meson electroproduction from hydrogen at CLAS

Author

C. Hadjidakis, M. Guidal, M. Garçon, J.-M. Laget, E.S. Smith, M. Vanderhaeghen, G. Adams, P. Ambrozewicz, E. Anciant, M. Anghinolfi, B. Asavapibhop, G. Asryan, G. Audit, T. Auger, H. Avakian, H. Bagdasaryan, J.P. Ball, S. Barrow, M. Battaglieri, K. Beard, M. Bektasoglu, M. Bellis, N. Benmouna, N. Bianchi, A.S. Biselli, S. Boiarinov, B.E. Bonner, S. Bouchigny, R. Bradford, D. Branford, W.J. Briscoe, W.K. Brooks, V.D. Burkert, C. Butuceanu, J.R. Calarco, D.S. Carman, B. Carnahan, C. Cetina, S. Chen, P.L. Cole, A. Coleman, D. Cords, P. Corvisiero, D. Crabb, H. Crannell, J.P. Cummings, E. De Sanctis, R. DeVita, P.V. Degtyarenko, L. Dennis, K.V. Dharmawardane, K.S. Dhuga, J.-P. Didelez, C. Djalali, G.E. Dodge, D. Doughty, P. Dragovitsch, M. Dugger, S. Dytman, O.P. Dzyubak, H. Egiyan, K.S. Egiyan, L. Elouadrhiri, A. Empl, P. Eugenio, L. Farhi, R. Fatemi, R.J. Feuerbach, T.A. Forest, V. Frolov, H. Funsten, S.J. Gaff, G. Gavalian, G.P. Gilfoyle, K.L. Giovanetti, P. Girard, C.I.O. Gordon, R.W. Gothe, K.A. Griffioen, M. Guillo, M. Guler, L. Guo, V. Gyurjyan, R.S. Hakobyan, J. Hardie, D. Heddle, F.W. Hersman, K. Hicks, H. Hleiqawi, M. Holtrop, E. Hourany, J. Hu, C.E. Hyde-Wright, Y. Ilieva, D. Ireland, M.M. Ito, D. Jenkins, H.-S. Jo, K. Joo, H.G. Juengst, J.H. Kelley, J. Kellie, M. Khandaker, K.Y. Kim, K. Kim, W. Kim, A. Klein, F.J. Klein, A.V. Klimenko, M. Klusman, M. Kossov, L.H. Kramer, S.E. Kuhn, J. Kuhn, J. Lachniet, J. Langheinrich, D. Lawrence, T. Lee, Ji Li, K. Livingstone, K. Lukashin, J.J. Manak, C. Marchand, S. McAleer, J.W.C. McNabb, B.A. Mecking, J.J. Melone, M.D. Mestayer, C.A. Meyer, K. Mikhailov, R. Minehart, M. Mirazita, R. Miskimen, L. Morand, S.A. Morrow, V. Muccifora, J. Mueller, G.S. Mutchler, J. Napolitano, R. Nasseripour, S.O. Nelson, S. Niccolai, G. Niculescu, I. Niculescu, B.B. Niczyporuk, R.A. Niyazov, M. Nozar, G.V. O'Rielly, M. Osipenko, K. Park, E. Pasyuk, G. Peterson, S.A. Philips, N. Pivnyuk, D. Pocanic, O. Pogorelko, E. Polli, S. Pozdniakov, B.M. Preedom, J.W. Price, Y. Prok, D. Protopopescu, L.M. Qin, B.A. Raue, G. Riccardi, G. Ricco, M. Ripani, B.G. Ritchie, F. Ronchetti, P. Rossi, G. Rosner, D. Rowntree, P.D. Rubin, F. Sabatié, K. Sabourov, C. Salgado, J.P. Santoro, V. Sapunenko, R.A. Schumacher, V.S. Serov, Y.G. Sharabian, J. Shaw, S. Simionatto, A.V. Skabelin, L.C. Smith, D.I. Sober, M. Spraker, A. Stavinsky, S. Stepanyan, B.E. Stokes, P. Stoler, S. Strauch, M. Taiuti, S. Taylor, D.J. Tedeschi, U. Thoma, R. Thompson, A. Tkabladze, L. Todor, C. Tur, M. Ungaro, M.F. Vineyard, A.V. Vlassov, K. Wang, L.B. Weinstein, H. Weller, D.P. Weygand, C.S. Whisnant, M. Williams, E. Wolin, M.H. Wood, A. Yegneswaran, J. Yun, and L. Zana

Subjects
Nuclear and High Energy Physics, Particle physics, Meson, Hadron, Elementary particle, Parton, PHOTONS, 01 natural sciences, Particle identification, High Energy Physics - Experiment, Nuclear physics, ELASTIC ELECTROPRODUCTION, Cross section (physics), LARGE Q(2), 0103 physical sciences, Nuclear Experiment, NUCLEON, 010306 general physics, VIRTUAL COMPTON-SCATTERING, HIGH-ENERGIES, Boson, Physics, 010308 nuclear & particles physics, VIRTUAL COMPTON-SCATTERING, VECTOR-MESONS, ELASTIC ELECTROPRODUCTION, DIFFRACTIVE PRODUCTION, PARTON DISTRIBUTIONS, HIGH-ENERGIES, LARGE Q(2), NUCLEON, PHOTOPRODUCTION, PHOTONS, PARTON DISTRIBUTIONS, DIFFRACTIVE PRODUCTION, PHOTOPRODUCTION, High Energy Physics::Experiment, Nucleon, VECTOR-MESONS
Abstract

The longitudinal and transverse components of the cross section for the $e p\to e^\prime p \rho^0$ reaction were measured in Hall B at Jefferson Laboratory using the CLAS detector. The data were taken with a 4.247 GeV electron beam and were analyzed in a range of $x_B$ from 0.2 to 0.6 and of $Q^2$ from 1.5 to 3.0 GeV$^2$. The data are compared to a Regge model based on effective hadronic degrees of freedom and to a calculation based on Generalized Parton Distributions. It is found that the transverse part of the cross section is well described by the former approach while the longitudinal part can be reproduced by the latter., Comment: 6 pages, 4 figures

Full Text
View/download PDF

29. The commissioning of the Hall-B beamline of Jefferson Lab for coherently producing a beam of linearly-polarized photons

Author

J.A. Mueller, P.L. Cole, Friedrich Klein, J. C. Sanabria, K. Livingston, D. J. Tedeschi, and J. Kellie

Subjects
Physics, Particle physics, Photon, Meson, Spectrometer, Bremsstrahlung, Collimator, Collimated light, law.invention, Nuclear physics, Beamline, law, Physics::Accelerator Physics, Nuclear Experiment, Nucleon
Abstract

The set of experiments forming the g8 run took place this past summer (06/04/01- 8/13/01) in Hall B of Jefferson Lab. These experiments made use of a beam of linearly-polarized photons produced through coherent bremsstrahlung and represent the first time such a probe has been employed at Jefferson Lab. Among the several new and upgraded Hall-B beamline devices commissioned prior to the production running of g8a were the photon tagger, the coherent bremsstrahlung facility (goniometer + an instrumented collimator), a photon profiler, and the PrimEx dipole + pair spectrometer telescopes. We essentially commissioned a new beam-line for photon running in Hall B. The scientific purpose of g8 is to improve the understanding of the underlying symmetry of the quark degrees of freedom in the nucleon, the nature of the parity exchange between the incident photon and the target nucleon, and the mechanism of associated strangeness production in electromagnetic reactions. With the high-quality beam of the tagged and collimated linearly-polarized photons arid the nearly complete angular coverage of the Hall-B spectrometer, we seek to extract the differential cross sections and polarization observables for the photoproduction of vector mesons and kaons at photon energies ranging between 1.1 and 2.25 GeV. For themore » first phase of g8, i.e. g8a, we collected approximately 1.8 billion triggers for 1.75 lte E_{vec-gamma} lte 2.25 GeV. In this paper, we report on the results of the commissioning of the beamline devices for the g8a run.« less

Catalog

Books, media, physical & digital resources
See catalog results