Detector requirement form TMD working group J. P. Chen for the TMD working group June 5, 2010, EIC Detector Workshop, JLab TMD Program - A lot of enthusiasm, very rich physics - Beyond 1-d leading-twist distributions - Direct link with orbital motion (orbital angular momentum) - Transverse motion: spin-orbit correlations, multi-parton correlations, dynamics of confinement and QCD - Transverse structure -> multi-dimension - Valence, Sea and Gluon - Consensus: “flagship/golden” program for MEIC Thanks to Haiyan Gao, Min Huang, Xin Qian, … for slides/simulations.

Briefing on Talks from Duke Workshop Jianwei Qiu: L sensitive to short-d fluctuations, T sensitive to structure low PT and high PT, factorization, evolution (Kang), Tri-gluon correlations, D-meson production->L g (Gluon OAM) Daniel Boer: jet SIDIS, Sivers (no fragmentation) Sudakov suppression (need large Q 2 range) Mauro Anselmino: Model,, EMC data Naomi Makins: HERMES, K + asymmetry >  low z ! Ming-Xiong Liu: RHIC-spin, K - asymmetry ~ K + !,  >  0 Yi Qiang: n/ 3 A, 6 GeV/12 GeV, valence, 4-d mapping Marco Contalbrigo: f 1 /g 1 P T dep. diff., CLAS12: unpol, long. Alexei Prokudin: sea Sivers also important, sqrt(s)=20, 65, P T to 5. Leonard Gamberg: soft factor, Sivers-GPD(E) diff mother Bernhard Musch: Gauge link on Lattice, no T-odd, cut-off, s-factor Yuhong Zhang: MELIC design, options (3 curves), people like the option with high luminosity for wide range of s Simulations: Harut Avagyan, Min Huang

“Leading-Twist” TMD Quark Distributions Quark Nucleon Unpol. Long. Trans. Unpol. Long. Trans.

J.P. Chen, GDH, Chiral GeV Preliminary Results

12 GeV: 3-D Projections for Collins and Sivers Asymmetry (  + )

Simulations for EIC SIDIS Simulations of phase space and projections in 4-d (x,z,P T,Q 2 ) (done by Min Huang/Xin Qian) Choose transverse nucleon single spin asymmetries as example -  /K: simulations checked - D mesons: a new simulation, preliminary results  Needs MEIC with broad range of s and high L (>10 34 )  Detector requirements, PID very important

Electron Ion Collider Ion-at-rest frame (Trento convention) Lab Frame

Applied Cuts for DIS  Electron: 2.5° 1.0 GeV/c  Full azimuthal- angular coverage DIS cut: Q 2 > 1 Large W cuts 0.8 > y > 0.05 Capability to detect high momentum electron No need to cover very forward angle for electron

Applied Cuts for SIDIS  Hadron: 40°< < 175° 0.7 GeV/c < P < 10 GeV/c  Full azimuthal-angular coverage  Low momentum, large polar angluar coverage SIDIS cut: Large M X cuts 0.8 > z > 0.2 Low P T kinematics P T < 1.0 GeV/c High P T kinematics P T > 1.0 GeV/c

10 Mapping of TSSA Lower y cut, more overlap with 12 GeV 0.05 < y < GeV: from approved SoLID SIDIS experiment

11 Study both Proton and Neutron ion momentum z P N Z/A Flavor separation, Combine the data the lowest achievable x limited by the effective neutron beam

Cross Section in MC Low P T cross section: A. Bacchetta hep-ph/ JHEP 0702:093 (2007) High P T cross section: M. Anselmino et al. Eur. Phys. K. A (2007) PDF: CTEQ6M FF: Binneweis et al PRD = 0.2 GeV 2 = 0.25 GeV 2 NLO calculation at large PT – = 0.25 GeV 2 – = 0.28 GeV 2 – K factor assumed to be larger than 1. 6x6 Jacobian calculation

Calculation Information Calculation code is from Ma et al. (Peking University) PDF: MRST 2004 FF: Kretzer’s fit EPJC Collins/Pretzelosity: PRD (2009) P T dependence: Anselmino et al arXiv: Sivers TMD: Anselmino et al arXiv: Collins Fragmentation function: Anselmino et al Q 2 =10 GeV 2 S: 11 GeV + 60 GeV

14 Projection with Proton GeV 36 days L = 3x10 34 /cm 2 /s 2x10 -3 Q 2 <10 GeV 2 4x10 -3 Q 2 >10 GeV GeV 36 days L = 1x10 34 /cm 2 /s 3x10 -3 Q 2 <10 GeV 2 7x10 -3 Q 2 >10 GeV 2 Polarization 80% Overall efficiency 70% z: 12 bins P T : 5 bins 0-1 GeV φ h angular coverage considered Show the average of Collins/Sivers/Pretzlosity projections Also π -

15 Projection with 3 He (neutron) GeV 72 days GeV 72 days 12 GeV SoLid 3 He : 86.5% effective polarization Dilution factor: 3 D : 88% effective polarization Effective dilution Equal stat. for proton and neutron (combine 3 He and D) GeV GeV P36 d (3x10 34 /cm 2 /s)36 d (1x10 34 /cm 2 /s) D72 d 3 He72 d

16 Proton π + (z = )

Proton K + (z = )

High P T kinematics High P T : hadron momentum dramatically increase require high momentum PID, large polar angular coverage

P T dependence (High P T ) on p of π + 10 bins GeV in log(P T )

Simulation (results still preliminary) Use HERMES Tunes Pythia (From H. Avagyan) First try configuration. Physics includes: VMD Direct GVMD DIS (intrinsic charm) This is what we want!!

Event Generator Q 2 : y: LUND Fragmentation. Major decay channel of D meson are Branching ratio: %

PT >1.0 cut will remove most of events from VMD and DIS. GVMD is a significant background. At high Q2, the GVMD will be smaller.

D meson

Z>0.4 Q 2 >2.0 Need low momentum and forward angle coverage.

Summary on detector requirements from TMD simulation Large angular coverage, but no need the extreme “forward” / “backward” angular coverage for electrons/hadrons Scattered electron Resolution and PID at high momentum Leading hadron momentum large momentum range GeV to 5-6 GeV/c, higher for high P T, Good PID: kaons/pions Large polar angular coverage Good resolution High Luminosity (in a wide range of s) essential to achieve precise mapping of SSAs in 4-D projection.