Detector requirement form TMD working groupJ. 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 Q2 range) • Mauro Anselmino: Model, <kT>, <pT> EMC data • Naomi Makins: HERMES, K+ asymmetry >+ @ low z !• Ming-Xiong Liu: RHIC-spin, K- asymmetry ~ K+ !, > 0

• Yi Qiang: n/3He@Hall A, 6 GeV/12 GeV, valence, 4-d mapping• Marco Contalbrigo: f1/g1 PT dep. diff., CLAS12: unpol, long. • Alexei Prokudin: sea Sivers also important, sqrt(s)=20, 65, PT 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, Chiral06 4

6 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,PT,Q2) (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 (>1034) Detector requirements, PID very important

SIDIS @ Electron Ion Collider

qP

PPz

PP

qPy

qP

Qx

p

hp

iep

p

p

2

2

q

qpP hh

S

h

Ion-at-rest frame

(Trento convention)

Lab Frame sPP

yx

Q iep

2

2

syxQ 2

Applied Cuts for DISElectron: 2.5°< ϴ < 150°P > 1.0 GeV/cFull azimuthal-angular coverageDIS cut: Q2 > 1 Large W cuts

0.8 > y > 0.05

Capability to detect high momentum electronNo need to cover very forward angle for electron

Applied Cuts for SIDIS

Hadron: 40°< ϴ < 175° 0.7 GeV/c < P < 10 GeV/cFull azimuthal-angular coverageLow momentum, large polar angluar coverage

SIDIS cut: Large MX cuts 0.8 > z > 0.2Low PT kinematics PT < 1.0 GeV/c

High PT kinematics PT > 1.0 GeV/c

10

Mapping of TSSA

Lower y cut, more overlap with 12 GeV

0.05 < y < 0.8

12 GeV: from approved SoLID SIDIS experiment

11

Study both Proton and Neutronion momentum

z

PN Z/A

Flavor separation, Combine the datathe lowest achievable x limited by the effective neutron beam

Cross Section in MCLow PT cross section:

A. Bacchetta hep-ph/0611265 JHEP 0702:093 (2007)

High PT cross section:M. Anselmino et al. Eur. Phys. K. A31 373 (2007)

2 hH dPdddzdydx

d

hhhfe

fe

fe dddpdddp

d

cos cos

• PDF: CTEQ6M• FF: Binneweis et al PRD 52 4947• <pt

2> = 0.2 GeV2 <kt2> = 0.25 GeV2

• NLO calculation at large PT

– <pt2> = 0.25 GeV2

– <kt2> = 0.28 GeV2

– K factor assumed to be larger than 1.

6x6 Jacobian calculation

Calculation InformationCalculation code is from Ma et al. (Peking

University)PDF: MRST 2004FF: Kretzer’s fit EPJC 22 269 2001Collins/Pretzelosity: PRD 054008 (2009)

PT dependence: Anselmino et al arXiv: 0807.0173Sivers TMD: Anselmino et al arXiv: 0807.0166Collins Fragmentation function: Anselmino et al 0807.0173

Q2 =10 GeV2

S: 11 GeV + 60 GeV

14

Projection with Proton• 11 + 60 GeV 36 days L = 3x1034 /cm2/s 2x10-3 Q2<10 GeV2

4x10-3 Q2>10 GeV2

• 3 + 20 GeV 36 days L = 1x1034/cm2/s 3x10-3 Q2<10 GeV2

7x10-3 Q2>10 GeV2

Polarization 80%Overall efficiency 70%

z: 12 bins 0.2 - 0.8PT: 5 bins 0-1 GeV

φh angular coverage consideredShow the average of Collins/Sivers/Pretzlosity projections Also π-

15

Projection with 3He (neutron)• 11 + 60 GeV 72 days• 3 + 20 GeV 72 days • 12 GeV SoLid

3He: 86.5% effective polarization Dilution factor: 3

D: 88% effective polarization Effective dilution

Equal stat. for proton and neutron (combine 3He and D)

8

11 + 60 GeV 3 + 20 GeV

P 36 d (3x1034/cm2/s) 36 d (1x1034/cm2/s)

D 72 d 72 d3He 72 d 72 d

16

Proton π+ (z = 0.3-0.7)

Proton K+ (z = 0.3-0.7)

High PT kinematics

High PT : hadron momentum dramatically increase require high momentum PID, large polar angular coverage

PT dependence (High PT) on p of π+ 10 bins 1 -- 10 GeV in log(PT

)

Simulation (results still preliminary)Use HERMES Tunes Pythia (From H. Avagyan)First try 11+60 configuration.Physics includes:

VMDDirectGVMDDIS (intrinsic charm)

This is what we want!!

Event GeneratorQ2: 0.8-1500y: 0.2-0.8LUND Fragmentation.Major decay channel of D meson are

)()()(

)()()(0

0

suKduucD

usKduucD

Branching ratio: 3.8+-0.07%

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>0.4Q2>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 0.5-1 GeV to 5-6 GeV/c, higher for high PT,

Good PID: kaons/pionsLarge polar angular coverageGood resolution

High Luminosity (in a wide range of s) essential to achieve precise mapping of SSAs in 4-D projection.