Jefferson Lab E Collaboration Institutions CMU, Cal-State LA, Duke, Florida International, Hampton, UIUC, JLab, Kharkov, Kentucky, Kent State, Kyungpook National South Korea, LANL, Lanzhou Univ. China, Longwood Univ. Umass, Mississippi State, MIT, UNH, ODU, Rutgers, Syracuse, Temple, UVa, William & Mary, Univ. Sciences & Tech China, Inst. of Atomic Energy China, Seoul National South Korea, Glasgow, INFN Roma and Univ. Bari Italy, Univ. Blaise Pascal France, Univ. of Ljubljana Slovenia, Yerevan Physics Institute Armenia. Collaboration members K. Allada, K. Aniol, J.R.M. Annand, T. Averett, F. Benmokhtar, W. Bertozzi, P.C. Bradshaw, P. Bosted, A. Camsonne, M. Canan, G.D. Cates, C. Chen,, J.-P. Chen (Co-SP), W. Chen, K. Chirapatpimol, E. Chudakov,, E. Cisbani(Co-SP), J. C. Cornejo, F. Cusanno, M. M. Dalton, W. Deconinck, P.A.M. Dolph, C. de Jager, R. De Leo, X. Deng, A. Deur, H. Ding, C. Dutta, C. Dutta, D. Dutta, L. El Fassi, S. Frullani, H. Gao(Co-SP), F. Garibaldi, D. Gaskell, S. Gilad, R. Gilman, O. Glamazdin, S. Golge, L. Guo, D. Hamilton, O. Hansen, D.W. Higinbotham, T. Holmstrom, J. Huang, M. Huang, H. Ibrahim, M. Iodice, X. Jiang (Co-SP), G. Jin, M. Jones, J. Katich, A. Kelleher, A. Kolarkar, W. Korsch, J.J. LeRose, X. Li, Y. Li, R. Lindgren, N. Liyanage, E. Long, H.-J. Lu, D.J. Margaziotis, P. Markowitz, S. Marrone, D. McNulty, Z.-E. Meziani, R. Michaels, B. Moffit, C. Munoz Camacho, S. Nanda, A. Narayan, V. Nelyubin, B. Norum, Y. Oh, M. Osipenko, D. Parno,, J. C. Peng(Co-SP), S. K. Phillips, M. Posik, A. Puckett, X. Qian, Y. Qiang, A. Rakhman, R. Ransome, S. Riordan, A. Saha, B. Sawatzky,E. Schulte, A. Shahinyan, M. Shabestari, S. Sirca, S. Stepanyan, R. Subedi, V. Sulkosky, L.-G. Tang, A. Tobias, G.M. Urciuoli, I. Vilardi, K. Wang, Y. Wang, B. Wojtsekhowski, X. Yan, H. Yao, Y. Ye, Z. Ye, L. Yuan, X. Zhan, Y. Zhang, Y.-W. Zhang, B. Zhao, X. Zheng, L. Zhu, X. Zhu, X. Zong.

Neutron Transversity: Current Status and the Future Xin Qian Kellogg Radiation Lab Caltech

Transverse Momentum Dependent PDFs TMD Nucleon Spin QCD Dynam ics Quark OAM/ Spin QCD Factoriz ation 3-D Tomogr aphy Lattice QCD Models TMD f 1 u (x,k T )‏

Leading-Twist TMD PDFs f 1 = f 1T  = Sivers Helicity g 1 = h1 =h1 = Transversity h1 =h1 =Boer-Mulders h 1T  = Pretzelosity g 1T = Worm Gear h 1L  = Worm Gear (Kotzinian-Mulders) : Survive trans. momentum integration Nucleon Spin Quark Spin

Separation of Collins, Sivers and pretzelocity effects through angular dependence

N qq N Helicity state Rich Physics in TMDs (Transversity) Some characteristics of transversity  h 1T = g 1L for non-relativistic quarks  No gluon transversity in nucleon  Soffer’s bound |h 1T | <= (f 1 +g 1L )/2 Violation of Soffer bound due to QCD confiment? J. P. Ralston arxiv:  Chiral-odd → difficult to access in inclusive DIS Tensor Charge: Integration of transversity over x.  Calculable in LQCD

Parton Distributions (CTEQ6) (Torino) Unpolarized Helicity Transversity

Rich Physics in TMDs (Sivers Function) Correlation between nucleon spin with quark orbital angular momentum Burkhardt : chromodynamic lensing Final-State-Interaction Important test for Factorization

Experiments on polarized ``neutron’’ urgently needed!! u quark dominated Sensitive to d quark Sensitive to u quark

E Setup Electron beam: E = 5.9 GeV 40 cm transversely polarized 3 He BigBite at 30 o as electron arm: P e = 0.6 ~ 2.5 GeV/c HRSL at 16 o as hadron arm: P h = 2.35 GeV/c Average beam current 12 uA (15 uA in proposal) Average 3 He polarization is ~55%. (42% in proposal) e Polarized 3 He Target  HRS L 16 o  e’e’ BigBite 30 o Two large installation Devices: 3 He target + BigBite Spectrometer.

Why Polarized 3 He Target ? Effective Polarized Neutron Target! ~90% ~1.5% ~8% SS’D High luminosity: L(n) = cm -2 s mins spin exchange with K/Rb hybrid cells Pioneer studies performed at KRL A NEW RECORD! Reached a steady 60% polarization with 15  A beam and 20 minute spin flip! A NEW RECORD! Thanks to the hard work of the entire target group!

High Resolution Spectrometer Left HRS to detect hadrons of p h = 2.35 GeV/c Gas Cherenkov + VDC + Scintillator + Lead-glass detectors Aerogel Cherenkov counter – n = RICH detector – n = 1.30 Kaon detection: – A1: Pion rejection > 90 % – RICH: K/  separation ~ 4  – TOF: K/  separation ~ 4  e  Coincidence Time  < 400 ps  K p  K 4 σ Separation Cherenkov Ring From RICH

Electron Arm: BigBite Wire Chamber Tracking Shower system and Gas Cerenkov for electron PID. Wire chamber Gas Cerenkov Shower system Scintillator Magnetic field shielding Optics Slot-slit 64 msr large out-of-plane acceptance, essential for separating Collins/Sivers effect

BigBite Optics Multi-Carbon Target for vertex reconstruction Sieve Slot for angular reconstruction Hydrogen elastic scattering at 1.2 GeV and 2.4 GeV for momentum reconstruction Also positive optics BigBite Sieve Slit

Contamination (Photon-Induced Electron) π o induced electrons: – Direct Decay to γe + e - – γ interacted with material, pair production – Same kinematics for e + and e - Single: – Method I: (e + Data Directly) – Method II: MC Coincidence channel: – Ratio method, – Direct from e + Data Consistent with Hall B/C Data Single Coincidence X-bin1234 π+π+21%8%2.4%1.0% π-π-24%14%5%2.0% Uncer. Rel.20%25%35%50%

3 He Results After correction of N 2 dilution (dedicated reference cell data) Model (fitting) uncertainties are shown in blue band. Other systematic uncertainties shown in red band. Non-zero Collins moments at highest x bin for π + (2.3 σ stat. + sys. + mod.) Favor a negative values for Sivers π + results.

Comparison with World Data

Proton Dilution Effective Polarization Approach Plane Wave Approximation f n measured with dedicated data. Corrected by Proton Asymmetries. Nuclear effect ISI under control: S. Scopetta PRD (2007) Unpolarized FSI: <3.5% from multiplicity measurement Spin-dependent FSI were estimated to be well below 1% within a simple Glauber rescattering model

Results on Neutron Sizable Collins π + asymmetries at x=0.34? – Sign of violation of Soffer’s inequality? – Data are limited by stat. Needs more precise data! Negative Sivers π + Asymmetry – Consistent with HERMES/COMPASS – Independent demonstration of negative d quark Sivers function. Model (fitting) uncertainties shown in blue band. Radiative correction: bin migration + uncer. of asy. Spin-dependent FSI estimated <1% (Glauber rescattering + no correction) Diffractive rho: 3-10%

Best Measurements on Neutron at High x

Paper Appeared on arXiv arXiv: , will submit in a few days.

Experimental Overview SoLID (proposed for PVDIS) 3 He(e,e’π +/- )‏ – Large acceptance: ~100 msr for polarized (without baffles) – High luminosity High pressure polarized 3 He target – SIDIS: improve by a factor of GeV beam,15 µA (unpolarized/polarized)‏ Unpolarized H/D/ 3 He factorization test & dilution corrections Two approved experiments: E & E – SSA in SIDIS Pion Production on a Transversely/ Longitudinally Polarized 3 He Target at 8.8 and 11 GeV. White paper: H. Gao et al. Eur. Phys. J. Plus 126:2 (2011) Also SBS Transversity Program focus on high Q 2.

SoLID Setup for SIDIS on 3 He Shared device with PVDIS: – GEM Tracker – Light Gas Cerenkov – Calorimeter Shared R&D in – GEM – Light collection in magnetic field. – Fast DAQ – New Calorimeter System Additional devices of MRPC, scintillator plane, heavy gas Cerenkov which provide us the capability in hadron detection.

Projections (1 of 48 bins 0.3<z<0.7)

Selected Physics Motivation 10% measurement of d quark transversity – Test of Soffers bound at high x Search for sign change in Sivers function – Measure Sivers function at high P T – Data at high x low Q2 for evolution studies – Precision data to test First non-zero measurement of Pretzlosity DSA: Worm-gear functions – Test model calculations ‐> h 1L =? ‐g 1T – Connections with Collinear PDFs through WW approx. and LIR.

Bright Future for TMDs Golden channel of Electron- Ion Collider Dream!

TMDs at EIC Sea quark TMDs, what will happen at very low x? Gluon Sivers through back-to-back D-meson production Twist-3 tri-gluon correlation through D-meson production TSSA at medium/large P T Twist-3 approach vs. TMDs Test Collins-Soper Evolution for high vs. low Q 2 at large x. See more discussion in Duke EIC-TMD workshop summary: – M. Anselmino et al. arxiv: EPJ A47,

Summary Measuring Transversity and TMDs through SIDIS open a new window to understand nucleon (spin) structure. First Direct Neutron E Best neutron results in the valence quark region. “Interesting behavior” of d transversity at large x. Independently confirmation of negative d quark Sivers function. Transversity and TMDs: from exploration to precision JLab 12 GeV energy upgrade: an ideal tool for this study A large acceptance SoLID with high luminosity 3 He target TMD: sea quark, gluon, evolution studies TMD vs. twist-3 collinear pdf at large P EIC

BigBite Wire Chamber Three Chambers, 6 planes each, 200 wires each plane: more than 3000 wires in total. – Connecting/Debuging/Understanding Special thanks to Brandon Craver and Seamus Riordan Monitor the hit efficiency Offline calibration: residual σ ~ 180 um – Time Offset Calibration – Drift Time to Drift Distance conversion – Wire Position – Iteration procedure with help of tracking

Understanding BigBite Tracking Tracking: Pattern match tree search (Ole) Online: Low luminosity + Event Display – use elastic electron events (high energy deposition in calorimeter): >85% – Tracking efficiency vs. luminosity Offline: – BigBite GEANT3 Simulation (Comgeant) >95% – 1 st pass hydrogen elastic cross section measurement ~95%

Check of BigBite Optics Different combination of sieve/target Sieve runs at 5 th pass, carbon foils run at 5 th pass 5 th pass hydrogen elastic to check the behavior at high momentum

Data Quality Check A good data sample is a key for the success of data analysis – Low level checks on detector responses on different detectors E.g. PMT responses of Gas Cerenkov – Low level checks on trigger rates/DAQ live times Identified problems as Q1 quenching Occasions with DAQ problems – Careful catalog of all the runs Web-based Run list (PHP-MYSQL) – More than one month dedicated time in this work.

Fun with Data Taking Special thanks to our spokespersons for giving us a lot of freedom in playing with our system. – Understand the timing and trigger circuit -> Creation of BigBite retiming circuit + firmly establish all the delays – Understanding the distribution/background -> BigBite Positive polarity run – During Janurary run: four problems (Gas Cerenkov spectrum, live time, Helicity signals, Left arm EDTP signal) gradually happened -> a loose L1A cable in the left HRS

Rich Physics Topics Pion Collins/Sivers SSA Moments DSA Moments with polarized beam Results on Kaons/Protons – Observation of anti-proton DIS Ay (inclusive, also g 2 ) Large asymmetries on inclusive hadron. …