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1. The ${Q^{p}_{\rm Weak}}$ experiment

Author

P. Solvignon, Wouter Deconinck, Riad Suleiman, D. G. Meekins, V. M. Gray, M. Poelker, J. A. Magee, S. Yang, S. Wells, Amrendra Narayan, R. T. Jones, T. Averett, B. Waidyawansa, D. Gaskell, Jean-Francois Rajotte, K. E. Myers, S. Kowalski, W. S. Duvall, William A. Tobias, M. K. Jones, W. T. H. van Oers, J. W. Martin, F. Guo, Joseph Grames, W. R. Falk, Kent Paschke, K. Grimm, J. Balewski, D. S. Armstrong, G. R. Smith, S. Covrig, J. A. Dunne, K. Johnston, V. Tadevosyan, P. Wang, Fatiha Benmokhtar, J. Mei, Vladimir Nelyubin, T. A. Forest, M. Kargiantoulakis, J. Leacock, J.C. Cornejo, M. M. Dalton, A.K. Opper, A. Mkrtchyan, Darko Androić, R. Silwal, V. Tvaskis, M. J. McHugh, W. D. Ramsay, L. Lee, Neven Simicevic, P. M. King, R. Mahurin, R. S. Beminiwattha, Michael Gericke, D. Zou, S. Zhamkochyan, J. Diefenbach, N. Nuruzzaman, Dipangkar Dutta, Roger Carlini, S. K. Phillips, D. T. Spayde, A. M. Micherdzinska, S. A. Page, M. H. Shabestari, J. R. Hoskins, D. C. Jones, Michael Pitt, Ross D. Young, Jongmin Lee, J. Birchall, Jay Benesch, K. A. Dow, L. Z. Ndukum, J. F. Dowd, A. R. Lee, Juliette Mammei, R. Michaels, J. M. Finn, J. Pan, J. Leckey, A. Asaturyan, A. Subedi, S. A. Wood, M. Elaasar, H. Mkrtchyan, C. A. Davis, D. J. Mack, S. MacEwan, T. Seva, E. Korkmaz, B. Sawatzky, J. Beaufait, R. Subedi, and J. Roche

Subjects
Quark, Physics, Nuclear and High Energy Physics, Particle physics, Proton, media_common.quotation_subject, Physics beyond the Standard Model, Momentum transfer, Weinberg angle, Parity (physics), Electron, Condensed Matter Physics, Asymmetry, Atomic and Molecular Physics, and Optics, Nuclear physics, Physical and Theoretical Chemistry, media_common
Abstract

In May 2012, the $Q^{p}_{\rm Weak}$ collaboration completed a two year measurement program to determine the weak charge of the proton ${Q^{p}_W} = ( 1 - 4\sin^2{\theta_{W}})$ at the Thomas Jefferson National Accelerator Facility (TJNAF). The experiment was designed to produce a 4.0 % measurement of the weak charge, via a 2.5 % measurement of the parity violating asymmetry in the number of elastically scattered 1.165 GeV electrons from protons, at forward angles. At the proposed precision, the experiment would produce a 0.3 % measurement of the weak mixing angle at a momentum transfer of Q 2 = 0.026 GeV2, making it the most precise stand alone measurement of the weak mixing angle at low momentum transfer. In combination with other parity measurements, $Q^{p}_{\rm Weak}$ will also provide a high precision determination of the weak charges of the up and down quarks. At the proposed precision, a significant deviation from the Standard Model prediction could be a signal of new physics at mass scales up to ≃ 6 TeV, whereas agreement would place new and significant constraints on possible Standard Model extensions at mass scales up to ≃ 2 TeV. This paper provides an overview of the physics and the experiment, as well as a brief look at some preliminary diagnostic and analysis data.

Published
2013
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2. The tracking analysis in the Q-weak experiment

Author

T. Averett, M. M. Dalton, A.K. Opper, W. D. Ramsay, D. T. Spayde, K. Johnston, Kent Paschke, J. Mei, J.C. Cornejo, William A. Tobias, F. Guo, P. M. King, W. R. Falk, Vladimir Nelyubin, S. A. Wood, R. Mahurin, J. Leacock, Fatiha Benmokhtar, D. J. Mack, Jean-Francois Rajotte, S. A. Page, D. G. Meekins, J. Pan, Michael Gericke, S. Wells, S. Kowalski, J. Balewski, W. S. Duvall, J. Leckey, R. T. Jones, A. Mkrtchyan, M. H. Shabestari, J. W. Martin, Nuruzzaman, M. Elaasar, C. A. Davis, L. Z. Ndukum, B. Sawatzky, M. Kargiantoulakis, J. Grames, J. A. Magee, Roger Carlini, S. K. Phillips, P. Solvignon, G. D. Cates, S. Yang, Jongmin Lee, D. C. Jones, J. Diefenbach, N. Morgan, Wouter Deconinck, W. T. H. van Oers, Darko Androić, R. Michaels, V. M. Gray, A. R. Lee, B. Waidyawansa, S. MacEwan, T. Seva, E. Korkmaz, Jay Benesch, V. Tvaskis, J. Beaufait, R. Subedi, A. Asaturyan, R. Suleiman, S. Zhamkochyan, K. E. Myers, H. Mkrtchyan, D. S. Armstrong, G. R. Smith, J. A. Dunne, P. Wang, L. Lee, Dipangkar Dutta, K. Grimm, A. Subedi, S. Covrig, M. J. McHugh, Michael Pitt, Neven Simicevic, J. M. Finn, J. R. Hoskins, J. Roche, J. Birchall, T. A. Forest, Juliette Mammei, A. Micherdzinska, V. Tadevosyan, M. K. Jones, R. Silwal, Amrendra Narayan, M. Poelker, D. Gaskell, R. S. Beminiwattha, Ross D. Young, and J. F. Dowd

Subjects
Physics, Nuclear and High Energy Physics, Particle physics, Spectrometer, business.industry, Scattering, media_common.quotation_subject, Momentum transfer, Tracking system, Parity (physics), Kinematics, Electron, Condensed Matter Physics, 01 natural sciences, Asymmetry, Atomic and Molecular Physics, and Optics, 010305 fluids & plasmas, Nuclear physics, q-weak experiment, 0103 physical sciences, Physical and Theoretical Chemistry, 010306 general physics, business, Nuclear Experiment, media_common
Abstract

The Q-weak experiment at Jefferson Laboratory measured the parity violating asymmetry (A P V ) in elastic electron-proton scattering at small momentum transfer squared (Q 2=0.025 (G e V/c)2), with the aim of extracting the proton’s weak charge ( ${Q^p_W}$ ) to an accuracy of 5 %. As one of the major uncertainty contribution sources to ${Q^p_W}$ , Q 2 needs to be determined to ∼1 % so as to reach the proposed experimental precision. For this purpose, two sets of high resolution tracking chambers were employed in the experiment, to measure tracks before and after the magnetic spectrometer. Data collected by the tracking system were then reconstructed with dedicated software into individual electron trajectories for experimental kinematics determination. The Q-weak kinematics and the analysis scheme for tracking data are briefly described here. The sources that contribute to the uncertainty of Q 2 are discussed, and the current analysis status is reported.

Published
2016

3. The Qweak experimental apparatus

Author

J. R. Hoskins, R. S. Beminiwattha, J. Birchall, J. Diefenbach, Juliette Mammei, J. Balewski, Erik Urban, J. F. Dowd, K. Johnston, G. Clark, P.W. Rose, B. Sawatzky, P. Solvignon, M. Kargiantoulakis, M. Elaasar, J. Mei, S. Sobczynski, A. Micherdzinska, A. Kubera, M. K. Jones, R.B. Zielinski, Mitchell D. Anderson, T. Averett, R. Suleiman, V. M. Gray, E. Henderson, R.D. Carlini, S. A. Wood, Neven Simicevic, J. D. Bowman, A. Mkrtchyan, Amber McCreary, Darko Androić, V. Tvaskis, E. Bonnell, N. Morgan, R. Mahurin, Kent Paschke, R. Averill, J. Beaufait, J. Roche, S. Zhamkochyan, D. J. Mack, C. A. Davis, Fatiha Benmokhtar, S. A. Page, D.C. Dean, J. M. Finn, P. Medeiros, Jean-Francois Rajotte, R. Subedi, G. D. Cates, S. Wells, F. Guo, S. MacEwan, P. Wang, J. A. Dunne, Jongmin Lee, T. Seva, E. Korkmaz, S. K. Phillips, D. C. Jones, P. Brindza, Amrendra Narayan, M. Poelker, J. Pan, J. Leacock, A. R. Lee, V. Tadevosyan, D. Gaskell, Y. Liang, R. Michaels, M. M. Dalton, D.J. Harrison, A.K. Opper, J. Grames, M. McDonald, S. Kowalski, J.C. Cornejo, W. S. Duvall, W. D. Ramsay, A. Asaturyan, J. Leckey, K. Grimm, J. W. Martin, B. Stokes, P. M. King, Michael Gericke, K. E. Mesick, H. Mkrtchyan, E. Ihloff, J. A. Magee, Nadeem A. Khan, L. Lee, J. Kelsey, Trent Allison, Jay Benesch, S. Yang, D. T. Spayde, B. Waidyawansa, D.B. Brown, S. Covrig Dusa, Dipangkar Dutta, W. R. Falk, R. Silwal, A. Subedi, Vladimir Nelyubin, J. Bessuille, D. G. Meekins, R. T. Jones, J. Hansknecht, Nuruzzaman, W. T. H. van Oers, K.D. Finelli, Michael Pitt, J.R. Echols, D. S. Armstrong, G. R. Smith, Douglas Storey, M. J. McHugh, M. H. Shabestari, J. Musson, K. A. Dow, L. Z. Ndukum, Wouter Deconinck, W.R. Roberts, William A. Tobias, and B. S. Cavness

Subjects
Physics, Nuclear and High Energy Physics, business.industry, Compton scattering, Collimator, Electron, Helicity, law.invention, Nuclear physics, Optics, Beamline, law, Scintillation counter, Cathode ray, Physics::Accelerator Physics, Parity violation, Electron scattering, Liquid hydrogen target, business, Instrumentation, Cherenkov radiation
Abstract

The Jefferson Lab Q weak experiment determined the weak charge of the proton by measuring the parity-violating elastic scattering asymmetry of longitudinally polarized electrons from an unpolarized liquid hydrogen target at small momentum transfer. A custom apparatus was designed for this experiment to meet the technical challenges presented by the smallest and most precise e → p asymmetry ever measured. Technical milestones were achieved at Jefferson Lab in target power, beam current, beam helicity reversal rate, polarimetry, detected rates, and control of helicity-correlated beam properties. The experiment employed 180 μA of 89% longitudinally polarized electrons whose helicity was reversed 960 times per second. The electrons were accelerated to 1.16 GeV and directed to a beamline with extensive instrumentation to measure helicity-correlated beam properties that can induce false asymmetries. Moller and Compton polarimetry were used to measure the electron beam polarization to better than 1%. The electron beam was incident on a 34.4 cm liquid hydrogen target. After passing through a triple collimator system, scattered electrons between 5.8° and 11.6° were bent in the toroidal magnetic field of a resistive copper-coil magnet. The electrons inside this acceptance were focused onto eight fused silica Cherenkov detectors arrayed symmetrically around the beam axis. A total scattered electron rate of about 7 GHz was incident on the detector array. The detectors were read out in integrating mode by custom-built low-noise pre-amplifiers and 18-bit sampling ADC modules. The momentum transfer Q 2 =0.025 GeV 2 was determined using dedicated low-current ( ~ 100 pA ) measurements with a set of drift chambers before (and a set of drift chambers and trigger scintillation counters after) the toroidal magnet.

Published
2015

4. Qweak: First Direct Measurement of the Proton’s Weak Charge

Author

J. R. Hoskins, V. Tadevosyan, J. Diefenbach, K. Johnston, J. Birchall, S.A. Page, D. S. Armstrong, M. J. McHugh, J. Mei, H. Nuhait, C. A. Davis, M. Elaasar, Juliette Mammei, T. Averett, Wouter Deconinck, J. A. Magee, P. Wang, S. Yang, G.R. Smith, W. R. Falk, P. Zang, H. Mkrtchyan, W. T. H. van Oers, D. G. Meekins, J. Pan, F. Guo, J. Roche, Vladimir Nelyubin, W.D. Ramsay, J. Beaufait, B. Sawatzky, Fatiha Benmokhtar, M.L. Pitt, D. C. Jones, N. Morgan, R. Suleiman, N. Simicevic, V. Tvaskis, R. Michaels, Michael Gericke, B. Waidyawansa, Roger Carlini, J. Leckey, T. A. Forest, R. T. Jones, Jay Benesch, J. M. Finn, J. Balewski, M. M. Dalton, J. Grames, L. Lee, Jean-Francois Rajotte, Dipangkar Dutta, S. Kowalski, L. Z. Ndukum, W. S. Duvall, D. J. Mack, J. W. Martin, A.K. Opper, M. Kargiantoulakis, S.A. Wood, T. Seva, P. Solvignon, G. D. Cates, V. M. Gray, Jongmin Lee, K. Grimm, S. Covrig, A. R. Lee, J. Leacock, R. Mahurin, D.T. Spayde, R. Silwal, A. Mkrtchyan, S.K. Phillips, A. Asaturyan, S. Zhamkochyan, S. MacEwan, E. Korkmaz, J.C. Cornejo, K. E. Myers, P. M. King, K. Bartlett, Darko Androić, A. Subedi, J. A. Dunne, Amrendra Narayan, R. Subedi, D. Gaskell, K.D. Paschke, A. Micherdzinska, M.H. Shabestari, M. K. Jones, W.A. Tobias, C. Gal, R. S. Beminiwattha, M. Poelker, Ross D. Young, J. F. Dowd, and S.P. Wells

Subjects
Physics, Particle physics, Proton, 010308 nuclear & particles physics, QC1-999, media_common.quotation_subject, Hadron, Charge (physics), Elementary particle, 7. Clean energy, 01 natural sciences, Asymmetry, Standard Model, Nuclear physics, 0103 physical sciences, Physics::Accelerator Physics, Grand Unified Theory, Nuclear Experiment, 010306 general physics, Nucleon, media_common
Abstract

The Q weak experiment, which took data at Jefferson Lab in the period 2010 - 2012, will precisely determine the weak charge of the proton by measuring the parity-violating asymmetry in elastic e-p scattering at 1.1 GeV using a longitudinally polarized electron beam and a liquid hydrogen target at a low momentum transfer of Q 2 = 0.025 (GeV/c)2 . The weak charge of the proton is predicted by the Standard Model and any significant deviation would indicate physics beyond the Standard Model. The technical challenges and experimental apparatus for measuring the weak charge of the proton will be discussed, as well as the method of extracting the weak charge of the proton. The results from a small subset of the data, that has been published, will also be presented. Furthermore an update will be given of the current status of the data analysis.

Published
2017
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5. Measurement of the neutron electric form factor via recoil polarimetry

Author

Chen Yan, E. Crouse, W. M. Zhang, W. Tireman, S. A. Wood, M. Elaasar, E. Christy, W. F. Vulcan, A. Yu. Semenov, S. Kowalski, L. Cole, D. J. Mack, Brian Raue, Paul Gueye, H. Fenker, S. Wells, A. R. Baldwin, D. M. Manley, A. Aghalarian, W. Kim, Hartmuth Arenhövel, James J. Kelly, Neven Simicevic, S. Tajima, L. G. Tang, S. Churchwell, C. E. Keppel, H. Mkrtchian, John C. Mitchell, L. Gan, J. Roche, B. D. Anderson, M. Farkhondeh, Hongbo Zhu, K. Garrow, John M. Finn, A.K. Opper, H. Breuer, Stephen Taylor, C. F. Perdrisat, Y. Sato, Sung-Chul Yang, V. A. Punjabi, S. Stepanian, P. E. Ulmer, Richard Madey, C. Yan, V. Tadevosian, A. Ahmidouch, W. Seo, M. K. Jones, A. Lung, Xiaofeng Zhu, Brad Plaster, G. R. Smith, L. Yuan, B. Hu, Rolf Ent, Donal Day, T. Reichelt, J. Reinhold, C. R. Howell, F. R. Wesselmann, Oliver Keith Baker, G. MacLachlan, R. Asaturian, J. W. Watson, Pete Markowitz, M. Khandaker, R. D. Carlini, and S. Danagulian

Subjects
Nuclear physics, Physics, Nuclear and High Energy Physics, Recoil, Electric form factor, Polarimetry, Neutron, Parametrization
Published
2003
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7. Letter of intent to build an off-axis detector to study nu(mu) ---> nu(e) oscillations with the NuMI neutrino beam

Author

P. Lucas, Panagiotis Spentzouris, Patrick Huber, J. Schneps, A. De Santo, D. G. Michael, David Petyt, P. Slattery, S. Avvakumov, H. Minakata, H. J. Kang, R. Hatcher, Hiroshi Nunokawa, C. W. Walter, D. S. Ayres, K. S. McFarland, Adam Para, T. Joffe-Minor, T. Kafka, V. J. Guarino, R. Shrock, P. deBarbaro, S. Manly, B. Kayser, Gary Drake, W. Metcalf, R. A. Richards, N.V. Mokhov, V. Makeev, R. L. Talaga, Sacha E Kopp, S. Menary, N. Morgan, P. Shanahan, R. Ray, H. R. Gallagher, N. Tagg, P. Kasper, C. Cueva, G.D. Barr, I. Trostin, D. A. Harris, S.M. Grimes, A. Marchionni, J. Cooper, A. C. Weber, Walter Winter, D. Naples, B. C. Choudhary, W. Sakumoto, Stephen J. Parke, Kirk T. McDonald, H. S. Budd, Stanley G. Wojcicki, P. J. Litchfield, G. Tzanakos, Juergen Thomas, Manfred Lindner, K-B. Luk, D. E. Reyna, K. Ruddick, A. Mann, S. M. Seun, Raymond Lee, V. Scarpino, J. Hylen, E. Blucher, S. Childress, E. Kearns, Marvin L Marshak, K.H. Hicks, David B. Cline, D. Carey, A.K. Opper, Carl H. Albright, F. DeJongh, R. Svoboda, M. C. Goodman, Ken Heller, J. K. Nelson, D.S. Carman, V. Ryabov, Karol Lang, E. A. Peterson, G. F. Pearce, J.H. Cobb, M. Zielinski, K. Lee, S. Geer, J. L. Thron, G. M. Irwin, Philip Harris, C. Bromberg, Kate Scholberg, G. J. Feldman, T. Patzak, C.R. Brune, N. Giokaris, S. Pordes, P. M. Border, A. Bodek, K. M. Heeger, S. M. S. Kasahara, Alexandre Lebedev, Caren Hagner, D. M. DeMuth, Kai Zuber, Thomas R. Chase, N. Pearson, R. Imlay, J. Urheim, Alec Habig, V. Paolone, L. Mualem, and G. Ginther

Subjects
Nuclear physics, Physics, Particle physics, Physics::Instrumentation and Detectors, MINOS, Measurements of neutrino speed, High Energy Physics::Experiment, Solar neutrino problem, Neutrino, Neutrino oscillation, NuMI, Particle detector, Lepton
Abstract

The NuMI neutrino beam line and the MINOS experiment represent a major investment of US High Energy Physics in the area of neutrino physics. The forthcoming results could decisively establish neutrino oscillations as the underlying physics mechanism for the atmospheric $\numu$ deficit and provide a precise measurement of the corresponding oscillation parameters, $\dmsq23$ and $\sinsq2t23$.neutrino sector may well be within our reach. The full potential of the NuMI neutrino beam can be exploited by complementing the MINOS detector, under construction, with a new detector(s) placed at some off-axis position and collecting data in parallel with MINOS. The first phase of the proposed program includes a new detector, optimized for $\nue$ detection, with a fiducial mass of the order of 20 kton and exposed to neutrino and antineutrino beams. In a five year run its sensitivity to the $\numutonue$ oscillations will be at least a factor of ten beyond the current limit. The future direction of the program will depend on the results of this first phase, but it is very likely that it will be a combination of a significant increase of the neutrino beam intensity via an upgraded proton source and an increase of the detector mass by a factor of five or so. Depending on the circumstances, the goals of Phase II may be a further increase of the sensitivity of a search for $\numutonue$ oscillations, or, perhaps, a measurement of the CP violating phase $\delta$ in the lepton sector.

Published
2002
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8. Implications of far-side dominance for the disagreement between distorted wave theory and well-matched intermediate energy (d, p) reactions

Author

S. W. Wissink, C. C. Foster, D.W. Miller, J.W. Seubert, E. J. Stephenson, D.A. Low, P. Schwandt, J.D. Brown, H. Nann, J.A. Gering, C. Olmer, R.C. Johnson, V.R. Cupps, W.P. Jones, J. A. Tostevin, and A.K. Opper

Subjects
Physics, Nuclear and High Energy Physics, Amplitude, Dominance (ethology), Classical mechanics, Intermediate energy, Quantum mechanics, Observable, Spin-½
Abstract

Distorted wave calculations of large l n -transfer (d, p) reactions near 90 MeV indicate that far-side dominance reduces the number of effective amplitudes at large angles to two or three, making many spin observables redundant. Comparisons of A y with A yy data for 116 Sn(d, p) 117 Sn, and A yy with p y data for 66 Zn(d, p) 67 Zn, do not confirm this expectation.

Published
1986
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