Search

Your search keyword '"Covrig S"' showing total 16 results
Start Over Author "Covrig S" Database MEDLINE
16 results on '"Covrig S"'

1. Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei.

Author

Santiesteban SN, Li S, Abrams D, Alsalmi S, Androic D, Aniol K, Arrington J, Averett T, Ayerbe Gayoso C, Bane J, Barcus S, Barrow J, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Camsonne A, Castellanos J, Chen J, Chen JP, Chrisman D, Christy ME, Clarke C, Covrig S, Cruz-Torres R, Day D, Dutta D, Fuchey E, Gal C, Garibaldi F, Gautam TN, Gogami T, Gomez J, Guèye P, Hague TJ, Hansen JO, Hauenstein F, Henry W, Higinbotham DW, Holt RJ, Hyde C, Itabashi K, Kaneta M, Karki A, Katramatou AT, Keppel CE, King PM, Kurbany L, Kutz T, Lashley-Colthirst N, Li WB, Liu H, Liyanage N, Long E, Lovato A, Mammei J, Markowitz P, McClellan RE, Meddi F, Meekins D, Michaels R, Mihovilovič M, Moyer A, Nagao S, Nguyen D, Nycz M, Olson M, Ou L, Owen V, Palatchi C, Pandey B, Papadopoulou A, Park S, Petkovic T, Premathilake S, Punjabi V, Ransome RD, Reimer PE, Reinhold J, Riordan S, Rocco N, Rodriguez VM, Schmidt A, Schmookler B, Segarra EP, Shahinyan A, Širca S, Slifer K, Solvignon P, Su T, Suleiman R, Tang L, Tian Y, Tireman W, Tortorici F, Toyama Y, Uehara K, Urciuoli GM, Votaw D, Williamson J, Wojtsekhowski B, Wood S, Ye ZH, Zhang J, and Zheng X

Abstract

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6

Published
2024
Full Text
View/download PDF

2. Revealing the short-range structure of the mirror nuclei 3 H and 3 He.

Author

Li S, Cruz-Torres R, Santiesteban N, Ye ZH, Abrams D, Alsalmi S, Androic D, Aniol K, Arrington J, Averett T, Gayoso CA, Bane J, Barcus S, Barrow J, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Bulumulla D, Camsonne A, Castellanos J, Chen J, Chen JP, Chrisman D, Christy ME, Clarke C, Covrig S, Craycraft K, Day D, Dutta D, Fuchey E, Gal C, Garibaldi F, Gautam TN, Gogami T, Gomez J, Guèye P, Habarakada A, Hague TJ, Hansen JO, Hauenstein F, Henry W, Higinbotham DW, Holt RJ, Hyde C, Itabashi T, Kaneta M, Karki A, Katramatou AT, Keppel CE, Khachatryan M, Khachatryan V, King PM, Korover I, Kurbany L, Kutz T, Lashley-Colthirst N, Li WB, Liu H, Liyanage N, Long E, Mammei J, Markowitz P, McClellan RE, Meddi F, Meekins D, Beck SM, Michaels R, Mihovilovič M, Moyer A, Nagao S, Nelyubin V, Nguyen D, Nycz M, Olson M, Ou L, Owen V, Palatchi C, Pandey B, Papadopoulou A, Park S, Paul S, Petkovic T, Pomatsalyuk R, Premathilake S, Punjabi V, Ransome RD, Reimer PE, Reinhold J, Riordan S, Roche J, Rodriguez VM, Schmidt A, Schmookler B, Segarra EP, Shahinyan A, Slifer K, Solvignon P, Širca S, Su T, Suleiman R, Szumila-Vance H, Tang L, Tian Y, Tireman W, Tortorici F, Toyama Y, Uehara K, Urciuoli GM, Votaw D, Williamson J, Wojtsekhowski B, Wood S, Zhang J, and Zheng X

Abstract

When protons and neutrons (nucleons) are bound into atomic nuclei, they are close enough to feel significant attraction, or repulsion, from the strong, short-distance part of the nucleon-nucleon interaction. These strong interactions lead to hard collisions between nucleons, generating pairs of highly energetic nucleons referred to as short-range correlations (SRCs). SRCs are an important but relatively poorly understood part of nuclear structure 1-3 , and mapping out the strength and the isospin structure (neutron-proton (np) versus proton-proton (pp) pairs) of these virtual excitations is thus critical input for modelling a range of nuclear, particle and astrophysics measurements 3-5 . Two-nucleon knockout or 'triple coincidence' reactions have been used to measure the relative contribution of np-SRCs and pp-SRCs by knocking out a proton from the SRC and detecting its partner nucleon (proton or neutron). These measurements 6-8 have shown that SRCs are almost exclusively np pairs, but they had limited statistics and required large model-dependent final-state interaction corrections. Here we report on measurements using inclusive scattering from the mirror nuclei hydrogen-3 and helium-3 to extract the np/pp ratio of SRCs in systems with a mass number of three. We obtain a measure of the np/pp SRC ratio that is an order of magnitude more precise than previous experiments, and find a marked deviation from the near-total np dominance observed in heavy nuclei. This result implies an unexpected structure in the high-momentum wavefunction for hydrogen-3 and helium-3. Understanding these results will improve our understanding of the short-range part of the nucleon-nucleon interaction., (© 2022. The Author(s), under exclusive licence to Springer Nature Limited.)

Published
2022
Full Text
View/download PDF

3. Measurement of the Nucleon F_{2}^{n}/F_{2}^{p} Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment.

Author

Abrams D, Albataineh H, Aljawrneh BS, Alsalmi S, Androic D, Aniol K, Armstrong W, Arrington J, Atac H, Averett T, Gayoso CA, Bai X, Bane J, Barcus S, Beck A, Bellini V, Bhatt H, Bhetuwal D, Biswas D, Blyth D, Boeglin W, Bulumulla D, Butler J, Camsonne A, Carmignotto M, Castellanos J, Chen JP, Cohen EO, Covrig S, Craycraft K, Cruz-Torres R, Dongwi B, Duran B, Dutta D, Fuchey E, Gal C, Gautam TN, Gilad S, Gnanvo K, Gogami T, Gomez J, Gu C, Habarakada A, Hague T, Hansen JO, Hattawy M, Hauenstein F, Higinbotham DW, Holt RJ, Hughes EW, Hyde C, Ibrahim H, Jian S, Joosten S, Karki A, Karki B, Katramatou AT, Keith C, Keppel C, Khachatryan M, Khachatryan V, Khanal A, Kievsky A, King D, King PM, Korover I, Kulagin SA, Kumar KS, Kutz T, Lashley-Colthirst N, Li S, Li W, Liu H, Liuti S, Liyanage N, Markowitz P, McClellan RE, Meekins D, Beck SM, Meziani ZE, Michaels R, Mihovilovic M, Nelyubin V, Nguyen D, Nuruzzaman, Nycz M, Obrecht R, Olson M, Owen VF, Pace E, Pandey B, Pandey V, Paolone M, Papadopoulou A, Park S, Paul S, Petratos GG, Petti R, Piasetzky E, Pomatsalyuk R, Premathilake S, Puckett AJR, Punjabi V, Ransome RD, Rashad MNH, Reimer PE, Riordan S, Roche J, Salmè G, Santiesteban N, Sawatzky B, Scopetta S, Schmidt A, Schmookler B, Segal J, Segarra EP, Shahinyan A, Širca S, Sparveris N, Su T, Suleiman R, Szumila-Vance H, Tadepalli AS, Tang L, Tireman W, Tortorici F, Urciuoli GM, Wojtsekhowski B, Wood S, Ye ZH, Ye ZY, and Zhang J

Abstract

The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19

Published
2022
Full Text
View/download PDF

4. Ruling out Color Transparency in Quasielastic ^{12}C(e,e^{'}p) up to Q^{2} of 14.2  (GeV/c)^{2}.

Author

Bhetuwal D, Matter J, Szumila-Vance H, Kabir ML, Dutta D, Ent R, Abrams D, Ahmed Z, Aljawrneh B, Alsalmi S, Ambrose R, Androic D, Armstrong W, Asaturyan A, Assumin-Gyimah K, Ayerbe Gayoso C, Bandari A, Basnet S, Berdnikov V, Bhatt H, Biswas D, Boeglin WU, Bosted P, Brash E, Bukhari MHS, Chen H, Chen JP, Chen M, Christy EM, Covrig S, Craycraft K, Danagoulian S, Day D, Diefenthaler M, Dlamini M, Dunne J, Duran B, Evans R, Fenker H, Fomin N, Fuchey E, Gaskell D, Gautam TN, Gonzalez FA, Hansen JO, Hauenstein F, Hernandez AV, Horn T, Huber GM, Jones MK, Joosten S, Karki A, Keppel C, Khanal A, King PM, Kinney E, Ko HS, Kohl M, Lashley-Colthirst N, Li S, Li WB, Liyanage AH, Mack D, Malace S, Markowitz P, Meekins D, Michaels R, Mkrtchyan A, Mkrtchyan H, Nazeer SJ, Nanda S, Niculescu G, Niculescu I, Nguyen D, Nuruzzaman, Pandey B, Park S, Pooser E, Puckett A, Rehfuss M, Reinhold J, Santiesteban N, Sawatzky B, Smith GR, Sun A, Tadevosyan V, Trotta R, Wood SA, Yero C, and Zhang J

Abstract

Quasielastic ^{12}C(e,e^{'}p) scattering was measured at spacelike 4-momentum transfer squared Q^{2}=8, 9.4, 11.4, and 14.2  (GeV/c)^{2}, the highest ever achieved to date. Nuclear transparency for this reaction was extracted by comparing the measured yield to that expected from a plane-wave impulse approximation calculation without any final state interactions. The measured transparency was consistent with no Q^{2} dependence, up to proton momenta of 8.5  GeV/c, ruling out the quantum chromodynamics effect of color transparency at the measured Q^{2} scales in exclusive (e,e^{'}p) reactions. These results impose strict constraints on models of color transparency for protons.

Published
2021
Full Text
View/download PDF

5. Probing the Deuteron at Very Large Internal Momenta.

Author

Yero C, Abrams D, Ahmed Z, Ahmidouch A, Aljawrneh B, Alsalmi S, Ambrose R, Armstrong W, Asaturyan A, Assumin-Gyimah K, Ayerbe Gayoso C, Bandari A, Bane J, Basnet S, Berdnikov VV, Bericic J, Bhatt H, Bhetuwal D, Biswas D, Boeglin WU, Bosted P, Brash E, Bukhari MHS, Chen H, Chen JP, Chen M, Christy ME, Covrig S, Craycraft K, Danagoulian S, Day D, Diefenthaler M, Dlamini M, Dunne J, Duran B, Dutta D, Ent R, Evans R, Fenker H, Fomin N, Fuchey E, Gaskell D, Gautam TN, Gonzalez FA, Hansen JO, Hauenstein F, Hernandez AV, Horn T, Huber GM, Jones MK, Joosten S, Kabir ML, Karki A, Keppel CE, Khanal A, King P, Kinney E, Lashley-Colthirst N, Li S, Li WB, Liyanage AH, Mack DJ, Malace SP, Matter J, Meekins D, Michaels R, Mkrtchyan A, Mkrtchyan H, Nazeer SJ, Nanda S, Niculescu G, Niculescu M, Nguyen D, Nuruzzaman N, Pandey B, Park S, Perdrisat CF, Pooser E, Rehfuss M, Reinhold J, Sawatzky B, Smith GR, Sun A, Szumila-Vance H, Tadevosyan V, Wood SA, and Zhang J

Abstract

We measure ^{2}H(e,e^{'}p)n cross sections at 4-momentum transfers of Q^{2}=4.5±0.5  (GeV/c)^{2} over a range of neutron recoil momenta p_{r}, reaching up to ∼1.0  GeV/c. We obtain data at fixed neutron recoil angles θ_{nq}=35°, 45°, and 75° with respect to the 3-momentum transfer q[over →]. The new data agree well with previous data, which reached p_{r}∼500  MeV/c. At θ_{nq}=35° and 45°, final state interactions, meson exchange currents, and isobar currents are suppressed and the plane wave impulse approximation provides the dominant cross section contribution. We compare the new data to recent theoretical calculations, where we observe a significant discrepancy for recoil momenta p_{r}>700  MeV/c.

Published
2020
Full Text
View/download PDF

6. Probing Few-Body Nuclear Dynamics via ^{3}H and ^{3}He (e,e^{'}p)pn Cross-Section Measurements.

Author

Cruz-Torres R, Nguyen D, Hauenstein F, Schmidt A, Li S, Abrams D, Albataineh H, Alsalmi S, Androic D, Aniol K, Armstrong W, Arrington J, Atac H, Averett T, Ayerbe Gayoso C, Bai X, Bane J, Barcus S, Beck A, Bellini V, Benmokhtar F, Bhatt H, Bhetuwal D, Biswas D, Blyth D, Boeglin W, Bulumulla D, Camsonne A, Castellanos J, Chen JP, Cohen EO, Covrig S, Craycraft K, Dongwi B, Duer M, Duran B, Dutta D, Fuchey E, Gal C, Gautam TN, Gilad S, Gnanvo K, Gogami T, Golak J, Gomez J, Gu C, Habarakada A, Hague T, Hansen O, Hattawy M, Hen O, Higinbotham DW, Hughes E, Hyde C, Ibrahim H, Jian S, Joosten S, Kamada H, Karki A, Karki B, Katramatou AT, Keppel C, Khachatryan M, Khachatryan V, Khanal A, King D, King P, Korover I, Kutz T, Lashley-Colthirst N, Laskaris G, Li W, Liu H, Liyanage N, Markowitz P, McClellan RE, Meekins D, Mey-Tal Beck S, Meziani ZE, Michaels R, Mihovilovič M, Nelyubin V, Nuruzzaman N, Nycz M, Obrecht R, Olson M, Ou L, Owen V, Pandey B, Pandey V, Papadopoulou A, Park S, Patsyuk M, Paul S, Petratos GG, Piasetzky E, Pomatsalyuk R, Premathilake S, Puckett AJR, Punjabi V, Ransome R, Rashad MNH, Reimer PE, Riordan S, Roche J, Sargsian M, Santiesteban N, Sawatzky B, Segarra EP, Schmookler B, Shahinyan A, Širca S, Skibiński R, Sparveris N, Su T, Suleiman R, Szumila-Vance H, Tadepalli AS, Tang L, Tireman W, Topolnicki K, Tortorici F, Urciuoli G, Weinstein LB, Witała H, Wojtsekhowski B, Wood S, Ye ZH, Ye ZY, and Zhang J

Abstract

We report the first measurement of the (e,e^{'}p) three-body breakup reaction cross sections in helium-3 (^{3}He) and tritium (^{3}H) at large momentum transfer [⟨Q^{2}⟩≈1.9  (GeV/c)^{2}] and x_{B}>1 kinematics, where the cross section should be sensitive to quasielastic (QE) scattering from single nucleons. The data cover missing momenta 40≤p_{miss}≤500  MeV/c that, in the QE limit with no rescattering, equals the initial momentum of the probed nucleon. The measured cross sections are compared with state-of-the-art ab initio calculations. Overall good agreement, within ±20%, is observed between data and calculations for the full p_{miss} range for ^{3}H and for 100≤p_{miss}≤350  MeV/c for ^{3}He. Including the effects of rescattering of the outgoing nucleon improves agreement with the data at p_{miss}>250  MeV/c and suggests contributions from charge-exchange (SCX) rescattering. The isoscalar sum of ^{3}He plus ^{3}H, which is largely insensitive to SCX, is described by calculations to within the accuracy of the data over the entire p_{miss} range. This validates current models of the ground state of the three-nucleon system up to very high initial nucleon momenta of 500  MeV/c.

Published
2020
Full Text
View/download PDF

7. Revealing Color Forces with Transverse Polarized Electron Scattering.

Author

Armstrong W, Kang H, Liyanage A, Maxwell J, Mulholland J, Ndukum L, Ahmidouch A, Albayrak I, Asaturyan A, Ates O, Baghdasaryan H, Boeglin W, Bosted P, Brash E, Butuceanu C, Bychkov M, Carter P, Chen C, Chen JP, Choi S, Christy ME, Covrig S, Crabb D, Danagoulian S, Daniel A, Davidenko AM, Davis B, Day D, Deconinck W, Deur A, Dunne J, Dutta D, El Fassi L, Ellis C, Ent R, Flay D, Frlez E, Gaskell D, Geagla O, German J, Gilman R, Gogami T, Gomez J, Goncharenko YM, Hashimoto O, Higinbotham D, Horn T, Huber GM, Jones M, Jones MK, Kalantarians N, Kang HK, Kawama D, Keith C, Keppel C, Khandaker M, Kim Y, King PM, Kohl M, Kovacs K, Kubarovsky V, Li Y, Liyanage N, Luo W, Mack D, Mamyan V, Markowitz P, Maruta T, Meekins D, Melnik YM, Meziani ZE, Mkrtchyan A, Mkrtchyan H, Mochalov VV, Monaghan P, Narayan A, Nakamura SN, Nuruzzaman A, Pentchev L, Pocanic D, Posik M, Puckett A, Qiu X, Reinhold J, Riordan S, Roche J, Rondón OA, Sawatzky B, Shabestari M, Slifer K, Smith G, Soloviev LF, Solvignon P, Tadevosyan V, Tang L, Vasiliev AN, Veilleux M, Walton T, Wesselmann F, Wood S, Yao H, Ye Z, Zhang J, and Zhu L

Abstract

The Spin Asymmetries of the Nucleon Experiment measured two double spin asymmetries using a polarized proton target and polarized electron beam at two beam energies, 4.7 and 5.9 GeV. A large-acceptance open-configuration detector package identified scattered electrons at 40° and covered a wide range in Bjorken x (0.3

Published
2019
Full Text
View/download PDF

8. First determination of the weak charge of the proton.

Author

Androic D, Armstrong DS, Asaturyan A, Averett T, Balewski J, Beaufait J, Beminiwattha RS, Benesch J, Benmokhtar F, Birchall J, Carlini RD, Cates GD, Cornejo JC, Covrig S, Dalton MM, Davis CA, Deconinck W, Diefenbach J, Dowd JF, Dunne JA, Dutta D, Duvall WS, Elaasar M, Falk WR, Finn JM, Forest T, Gaskell D, Gericke MT, Grames J, Gray VM, Grimm K, Guo F, Hoskins JR, Johnston K, Jones D, Jones M, Jones R, Kargiantoulakis M, King PM, Korkmaz E, Kowalski S, Leacock J, Leckey J, Lee AR, Lee JH, Lee L, MacEwan S, Mack D, Magee JA, Mahurin R, Mammei J, Martin JW, McHugh MJ, Meekins D, Mei J, Michaels R, Micherdzinska A, Mkrtchyan A, Mkrtchyan H, Morgan N, Myers KE, Narayan A, Ndukum LZ, Nelyubin V, Nuruzzaman, van Oers WT, Opper AK, Page SA, Pan J, Paschke KD, Phillips SK, Pitt ML, Poelker M, Rajotte JF, Ramsay WD, Roche J, Sawatzky B, Seva T, Shabestari MH, Silwal R, Simicevic N, Smith GR, Solvignon P, Spayde DT, Subedi A, Subedi R, Suleiman R, Tadevosyan V, Tobias WA, Tvaskis V, Waidyawansa B, Wang P, Wells SP, Wood SA, Yang S, Young RD, and Zhamkochyan S

Abstract

The Q(weak) experiment has measured the parity-violating asymmetry in ep elastic scattering at Q(2)=0.025(GeV/c)(2), employing 145 μA of 89% longitudinally polarized electrons on a 34.4 cm long liquid hydrogen target at Jefferson Lab. The results of the experiment's commissioning run, constituting approximately 4% of the data collected in the experiment, are reported here. From these initial results, the measured asymmetry is A(ep)=-279±35 (stat) ± 31 (syst) ppb, which is the smallest and most precise asymmetry ever measured in ep scattering. The small Q(2) of this experiment has made possible the first determination of the weak charge of the proton Q(W)(p) by incorporating earlier parity-violating electron scattering (PVES) data at higher Q(2) to constrain hadronic corrections. The value of Q(W)(p) obtained in this way is Q(W)(p)(PVES)=0.064±0.012, which is in good agreement with the standard model prediction of Q(W)(p)(SM)=0.0710±0.0007. When this result is further combined with the Cs atomic parity violation (APV) measurement, significant constraints on the weak charges of the up and down quarks can also be extracted. That PVES+APV analysis reveals the neutron's weak charge to be Q(W)(n)(PVES+APV)=-0.975±0.010.

Published
2013
Full Text
View/download PDF

9. Polarization components in π0 photoproduction at photon energies up to 5.6 GeV.

Author

Luo W, Brash EJ, Gilman R, Jones MK, Meziane M, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy ME, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Strakovsky II, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

We present new data for the polarization observables of the final state proton in the (1)H(γ,p)π(0) reaction. These data can be used to test predictions based on hadron helicity conservation and perturbative QCD. These data have both small statistical and systematic uncertainties and were obtained with beam energies between 1.8 and 5.6 GeV and for π(0) scattering angles larger than 75° in the center-of-mass frame. The data extend the polarization measurements database for neutral pion photoproduction up to E(γ)=5.6 GeV. The results show a nonzero induced polarization above the resonance region. The polarization transfer components vary rapidly with the photon energy and π(0) scattering angle in the center-of-mass frame. This indicates that hadron helicity conservation does not hold and that the perturbative QCD limit is still not reached in the energy regime of this experiment.

Published
2012
Full Text
View/download PDF

10. Search for effects beyond the born approximation in polarization transfer observables in e(over→)p elastic scattering.

Author

Meziane M, Brash EJ, Gilman R, Jones MK, Luo W, Pentchev L, Perdrisat CF, Puckett AJ, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Ates O, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Kang H, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Markowitz P, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nuruzzaman, Nedev S, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer PE, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Širca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Suleiman R, Tomasi-Gustafsson E, Vasiliev A, Vanderhaeghen M, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

Intensive theoretical and experimental efforts over the past decade have aimed at explaining the discrepancy between data for the proton electric to magnetic form factor ratio, G(E)/G(M), obtained separately from cross section and polarization transfer measurements. One possible explanation for this difference is a two-photon-exchange contribution. In an effort to search for effects beyond the one-photon-exchange or Born approximation, we report measurements of polarization transfer observables in the elastic H(e[over →],e(')p[over →]) reaction for three different beam energies at a Q(2)=2.5  GeV(2), spanning a wide range of the kinematic parameter ε. The ratio R, which equals μ(p)G(E)/G(M) in the Born approximation, is found to be independent of ε at the 1.5% level. The ε dependence of the longitudinal polarization transfer component P(ℓ) shows an enhancement of (2.3±0.6)% relative to the Born approximation at large ε., (© 2011 American Physical Society)

Published
2011
Full Text
View/download PDF

11. Recoil polarization measurements of the proton electromagnetic form factor ratio to Q2 = 8.5  GeV2.

Author

Puckett AJ, Brash EJ, Jones MK, Luo W, Meziane M, Pentchev L, Perdrisat CF, Punjabi V, Wesselmann FR, Ahmidouch A, Albayrak I, Aniol KA, Arrington J, Asaturyan A, Baghdasaryan H, Benmokhtar F, Bertozzi W, Bimbot L, Bosted P, Boeglin W, Butuceanu C, Carter P, Chernenko S, Christy E, Commisso M, Cornejo JC, Covrig S, Danagoulian S, Daniel A, Davidenko A, Day D, Dhamija S, Dutta D, Ent R, Frullani S, Fenker H, Frlez E, Garibaldi F, Gaskell D, Gilad S, Gilman R, Goncharenko Y, Hafidi K, Hamilton D, Higinbotham DW, Hinton W, Horn T, Hu B, Huang J, Huber GM, Jensen E, Keppel C, Khandaker M, King P, Kirillov D, Kohl M, Kravtsov V, Kumbartzki G, Li Y, Mamyan V, Margaziotis DJ, Marsh A, Matulenko Y, Maxwell J, Mbianda G, Meekins D, Melnik Y, Miller J, Mkrtchyan A, Mkrtchyan H, Moffit B, Moreno O, Mulholland J, Narayan A, Nedev S, Nuruzzaman, Piasetzky E, Pierce W, Piskunov NM, Prok Y, Ransome RD, Razin DS, Reimer P, Reinhold J, Rondon O, Shabestari M, Shahinyan A, Shestermanov K, Sirca S, Sitnik I, Smykov L, Smith G, Solovyev L, Solvignon P, Subedi R, Tomasi-Gustafsson E, Vasiliev A, Veilleux M, Wojtsekhowski BB, Wood S, Ye Z, Zanevsky Y, Zhang X, Zhang Y, Zheng X, and Zhu L

Abstract

Among the most fundamental observables of nucleon structure, electromagnetic form factors are a crucial benchmark for modern calculations describing the strong interaction dynamics of the nucleon's quark constituents; indeed, recent proton data have attracted intense theoretical interest. In this Letter, we report new measurements of the proton electromagnetic form factor ratio using the recoil polarization method, at momentum transfers Q2=5.2, 6.7, and 8.5  GeV2. By extending the range of Q2 for which G(E)(p) is accurately determined by more than 50%, these measurements will provide significant constraints on models of nucleon structure in the nonperturbative regime.

Published
2010
Full Text
View/download PDF

12. Transverse beam spin asymmetries in forward-angle elastic electron-proton scattering.

Author

Armstrong DS, Arvieux J, Asaturyan R, Averett T, Bailey SL, Batigne G, Beck DH, Beise EJ, Benesch J, Bimbot L, Birchall J, Biselli A, Bosted P, Boukobza E, Breuer H, Carlini R, Carr R, Chant N, Chao YC, Chattopadhyay S, Clark R, Covrig S, Cowley A, Dale D, Davis C, Falk W, Finn JM, Forest T, Franklin G, Furget C, Gaskell D, Grames J, Griffioen KA, Grimm K, Guillon B, Guler H, Hannelius L, Hasty R, Allen AH, Horn T, Johnston K, Jones M, Kammel P, Kazimi R, King PM, Kolarkar A, Korkmaz E, Korsch W, Kox S, Kuhn J, Lachniet J, Lee L, Lenoble J, Liatard E, Liu J, Loupias B, Lung A, Marchand D, Martin JW, McFarlane KW, McKee DW, McKeown RD, Merchez F, Mkrtchyan H, Moffit B, Morlet M, Nakagawa I, Nakahara K, Neveling R, Ong S, Page S, Papavassiliou V, Pate SF, Phillips SK, Pitt ML, Poelker M, Porcelli TA, Quéméner G, Quinn B, Ramsay WD, Rauf AW, Real JS, Roche J, Roos P, Rutledge GA, Secrest J, Simicevic N, Smith GR, Spayde DT, Stepanyan S, Stutzman M, Sulkosky V, Tadevosyan V, Tieulent R, Van de Wiele J, van Oers WT, Voutier E, Vulcan W, Warren G, Wells SP, Williamson SE, Wood SA, Yan C, Yun J, and Zeps V

Abstract

We have measured the beam-normal single-spin asymmetry in elastic scattering of transversely polarized 3 GeV electrons from unpolarized protons at Q2=0.15, 0.25 (GeV/c)2. The results are inconsistent with calculations solely using the elastic nucleon intermediate state and generally agree with calculations with significant inelastic hadronic intermediate state contributions. A(n) provides a direct probe of the imaginary component of the 2gamma exchange amplitude, the complete description of which is important in the interpretation of data from precision electron-scattering experiments.

Published
2007
Full Text
View/download PDF

13. Strange-quark contributions to parity-violating asymmetries in the forward g0 electron-proton scattering experiment.

Author

Armstrong DS, Arvieux J, Asaturyan R, Averett T, Bailey SL, Batigne G, Beck DH, Beise EJ, Benesch J, Bimbot L, Birchall J, Biselli A, Bosted P, Boukobza E, Breuer H, Carlini R, Carr R, Chant N, Chao YC, Chattopadhyay S, Clark R, Covrig S, Cowley A, Dale D, Davis C, Falk W, Finn JM, Forest T, Franklin G, Furget C, Gaskell D, Grames J, Griffioen KA, Grimm K, Guillon B, Guler H, Hannelius L, Hasty R, Hawthorne Allen A, Horn T, Johnston K, Jones M, Kammel P, Kazimi R, King PM, Kolarkar A, Korkmaz E, Korsch W, Kox S, Kuhn J, Lachniet J, Lee L, Lenoble J, Liatard E, Liu J, Loupias B, Lung A, MacLachlan GA, Marchand D, Martin JW, McFarlane KW, McKee DW, McKeown RD, Merchez F, Mkrtchyan H, Moffit B, Morlet M, Nakagawa I, Nakahara K, Nakos M, Neveling R, Niccolai S, Ong S, Page S, Papavassiliou V, Pate SF, Phillips SK, Pitt ML, Poelker M, Porcelli TA, Quéméner G, Quinn B, Ramsay WD, Rauf AW, Real JS, Roche J, Roos P, Rutledge GA, Secrest J, Simicevic N, Smith GR, Spayde DT, Stepanyan S, Stutzman M, Sulkosky V, Tadevosyan V, Tieulent R, van de Wiele J, van Oers W, Voutier E, Vulcan W, Warren G, Wells SP, Williamson SE, Wood SA, Yan C, Yun J, and Zeps V

Abstract

We have measured parity-violating asymmetries in elastic electron-proton scattering over the range of momentum transfers 0.12 < or =Q2 < or =1.0 GeV2. These asymmetries, arising from interference of the electromagnetic and neutral weak interactions, are sensitive to strange-quark contributions to the currents of the proton. The measurements were made at Jefferson Laboratory using a toroidal spectrometer to detect the recoiling protons from a liquid hydrogen target. The results indicate nonzero, Q2 dependent, strange-quark contributions and provide new information beyond that obtained in previous experiments.

Published
2005
Full Text
View/download PDF

14. Parity-violating electron deuteron scattering and the proton's neutral weak axial vector form factor.

Author

Ito TM, Averett T, Barkhuff D, Batigne G, Beck DH, Beise EJ, Blake A, Breuer H, Carr R, Clasie B, Covrig S, Danagoulian A, Dodson G, Dow K, Dutta D, Farkhondeh M, Filippone BW, Franklin W, Furget C, Gao H, Gao J, Gustafsson K, Hannelius L, Hasty R, Hawthorne-Allen AM, Herda MC, Jones CE, King P, Korsch W, Kowalski S, Kox S, Kramer K, Lee P, Liu J, Martin JW, McKeown RD, Mueller B, Pitt ML, Plaster B, Quéméner G, Réal JS, Ritter J, Roche J, Savu V, Schiavilla R, Seely J, Spayde D, Suleiman R, Taylor S, Tieulent R, Tipton B, Tsentalovich E, Wells SP, Yang B, Yuan J, Yun J, and Zwart T

Abstract

We report on a new measurement of the parity-violating asymmetry in quasielastic electron scattering from the deuteron at backward angles at Q2=0.038 (GeV/c)2. This quantity provides a determination of the neutral weak axial vector form factor of the nucleon, which can potentially receive large electroweak corrections. The measured asymmetry A=-3.51+/-0.57 (stat)+/-0.58 (syst) ppm is consistent with theoretical predictions. We also report on updated results of the previous experiment at Q2=0.091 (GeV/c)2, which are also consistent with theoretical predictions.

Published
2004
Full Text
View/download PDF

15. Strange magnetism and the anapole structure of the proton.

Author

Hasty R, Hawthorne-Allen AM, Averett T, Barkhuff D, Beck DH, Beise EJ, Blake A, Breuer H, Carr R, Covrig S, Danagoulian A, Dodson G, Dow K, Farkhondeh M, Filippone BW, Gao J, Herda MC, Ito TM, Jones CE, Korsch W, Kramer K, Kowalski S, Lee P, McKeown RD, Mueller B, and Pitt M

Abstract

The violation of mirror symmetry in the weak force provides a powerful tool to study the internal structure of the proton. Experimental results have been obtained that address the role of strange quarks in generating nuclear magnetism. The measurement reported here provides an unambiguous constraint on strange quark contributions to the proton's magnetic moment through the electron-proton weak interaction. We also report evidence for the existence of a parity-violating electromagnetic effect known as the anapole moment of the proton. The proton's anapole moment is not yet well understood theoretically, but it could have important implications for precision weak interaction studies in atomic systems such as cesium.

Published
2000
Full Text
View/download PDF

16. Parity violation in elastic electron-proton scattering and the Proton's strange magnetic form factor

Author

Spayde DT, Averett T, Barkhuff D, Beck DH, Beise EJ, Benson C, Breuer H, Carr R, Covrig S, DelCorso J, Dodson G, Dow K, Eppstein C, Farkhondeh M, Filippone BW, Frazier P, Hasty R, Ito TM, Jones CE, Korsch W, Kowalski S, Lee P, Maneva E, McCarty K, McKeown RD, and Mikell J

Abstract

We report a new measurement of the parity-violating asymmetry in elastic electron scattering from the proton at backward scattering angles. This asymmetry is sensitive to the strange magnetic form factor of the proton as well as electroweak axial radiative corrections. The new measurement of A = -4.92+/-0.61+/-0.73 ppm provides a significant constraint on these quantities. The implications for the strange magnetic form factor are discussed in the context of theoretical estimates for the axial corrections.

Published
2000
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results