SoLID Physics Program in Hall A at Jefferson Lab

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1 SoLID Physics Program in Hall A at Jefferson Lab Seamus Riordan University of Massachusetts, Amherst sriordan@physics.umass.edu October 5, 01 Seamus Riordan DNP 01 SoLID 1/9

2 SoLID Collaboration Program PIs: Paul Souder, Haiyan Gao, J.P. Chen, Xiaodong Jiang, J.C. Peng, Jin Huang, Yi Qiang, W. B. Yan, Kalyan Allada, Zein-Eddine Meziani, Kawtar Hafidi, Xin Qian, Nikos Spaveris, Zhiwen Zhao Over 00 collaborators at over 60 of institutions around the world: Jefferson Lab; Syracuse; University of Massachusetts, Amherst; Univeristy of Virginia; Argonne National Laboratory; College of William and Mary; Smith College; Rutgers; Duke University; California State University, Los Angeles; INFN, Sezione di Roma; Temple University; Ohio University; University of Maryland, College Park; Massachusetts Institute of Technology; Carnegie Mellon University; Tel Aviv University; Longwood University; Florida International University; Los Alamos National Laboratory; University of Kentucky; Universidad Autónoma de México; University of Wisconsin; Hampton University; University of Science and Technology of China; Virginia Tech; Univerisity of Illinois, Urbana-Champaign; Institute of Applied Physics, Huangshan University; Seoul National University; Mississippi State University; Louisiana Tech University; NSC Kharkov Institute for Physics and Technology; Tsinghua University; School of Physics, Beijing University; China Institute of Atomic Energy; Lanzhou University; LPC Clermont, Universit Blaise Pascal; SUNY Stony Brook; Kent State University; University of Winnipeg; Boston University; California Institute of Technology; Huazhong University of Science and Technology; Cagliari University; University of Bari; University of Ferrara; INFN Laboratori Nazionali di Frascati; INFN, Sezione di Pavia; Univerisity degi Sudi di Perguria; Rome-Tor Vergata University; Torino University; Jozef Stefan Institute; Lawrence Berkeley National Laboratory; New Mexico State University; Old Dominion University; School of Physics, Peking University; Pennsylvania State University; Shangdong University; St Mary s University; University of Connecticut; University of Glasgow; University of Michigan; University of New Hampshire; University of North Carolina; The Hall A Collaboration; George Washington University; INFN Catania; Xavier University of Louisiana Seamus Riordan DNP 01 SoLID /9

3 Parity-violating DIS σ DIS provides information on longitudinal nucleon structure Has proven to be crucial in realizing quarks and asymptotic freedom pqcd has been very successful for these processes Parity-violating studies provide additional handle on en scattering γ Z * xf(x,q 1. ) g/10 MSTW 008 NLO PDFs Q = 10 GeV xf(x,q 1. ) u 0.6 F γz = x q e q g q V (q + q) c,c s,s d u d F γz 3 = x q e q g q A (q q) x x 0 1 Seamus Riordan DNP 01 SoLID 3/9

4 Parity-violating Asymmetry For Q M Z, ignoring Q dependence: A PV = G F Q 4 πα [Y 1a 1 (x) + Y 3 a 3 (x)] For Q M : Y 1 1, Y 3 a 1 (x) = g e A a 3 (x) = g e V 1 (1 y) 1 + (1 y), y = ν E F γz 1 C1i e q (q + q) = F 1 e q (q + q) F γz 3 F 1 = Ci e q (q q) e q (q + q) Powerful method to get at couplings Isoscalar target in x tests PDF cancellation assumptions Isoscalar target in Q picks out specific higher twist components Seamus Riordan DNP 01 SoLID 4/9

5 PVDIS Measurements - SoLID Proposed Setup Solenoidal Large Intensity Device - 1 GeV Hall A at JLab SoLID provides huge acceptance < p < 8 GeV < Q < 10 GeV 0. < x bj < 1 Acceptance 40% Lumin Hz/cm Utilize existing magnet (CLEO-II likely candidate) Unique experiment - true counting mode PV measurement Divided into 30 independent sectors Necessary rate > 00 khz presents challenges for analysis Seamus Riordan DNP 01 SoLID 5/9

6 PVDIS Physics - Precision Deuterium powerful, since q(x) cancel for large x Measuring A PV across this region puts enormous constraints on C 1q and C q compared to present world data Alternatively, gives us sin θ W, Λ few TeV C q not as well constrained, could contain unique new physics (leptophobic Z ) C 1u + C 1d vs. C 1u C 1d SoLID C u +C d vs. C u C d SoLID Hall A PVDIS Q weak APV SLAC Bates Bates SLAC PDG Fit Seamus Riordan DNP 01 SoLID 6/9

7 PVDIS Physics - Precision Deuterium powerful, since q(x) cancel for large x Measuring A PV across this region puts enormous constraints on C 1q and C q compared to present world data Alternatively, gives us sin θ W, Λ few TeV Seamus Riordan DNP 01 SoLID 6/9

8 Clean Measurement of d/u with PVDIS d/u as x 1 gives information on valence quark dynamics - models give varying predictions on behavior [ ] a p 1 (x) = 1C1u u(x) 6C 1d d(x) = 4u(x) + d(x) [ ] u(x) 0.91d(x) u(x) + 0.5d(x) SU(6) DSE pqcd Broken SU(6) DSE - Wilson et al., Phys Rev C89, 0505 (01) Seamus Riordan DNP 01 SoLID 7/9 Broad uncertainties from neutron Three experiments at JLab measure this: BONuS, SBS Tritium, SoLID PVDIS on proton is direct measurement

9 Approved Measurement Approved for 169 days (requested 338) LD, 10 days: 10 days on LD (60 at 11 GeV, 60 at 6.6 GeV) Also, 90 days on LH 11 GeV Seamus Riordan DNP 01 SoLID 8/9

10 Other Physics Part of a growing program! SIDIS J/ψ at threshold P N, on p, 3 He, transversity P N, on 3 He, worm-gear 45 days approved Test of J/ψ production mechanisms 60 days approved Potentially PVDIS on Pb (IV EMC), g 5 polarized PDFs,... Seamus Riordan DNP 01 SoLID 9/9