Contalbrigo Marco INFN Ferrara QCD Evolution 13 7

Contalbrigo Marco INFN Ferrara QCD Evolution 13 7 th May 2013, JLab – Newport News

The Spin Degree of Freedom Spin degrees of freedom can explain otherwise surprising phenomena and bring new insights into nuclear matter structure Fundamental: do not neglect it !! ep→ep PRC 68, 034325 (2003) x. F Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 2

The Spin Degree of Freedom In our exploration of the QCD micro-world Fundamental: do not neglect spin !! Two questions in Hadronic Physics await explanation since too long Single Spin Asymmetries Proton Spin Budget AN ? √s = 20 Ge. V p. T< 2 Ge. V/c x. F Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 3

Quantum Phase-space Distributions of Quarks Wpq(x, k. T, r) “Mother” Wigner distributions 2 d d 3 r Probability to find a quark q in a nucleon P with a certain polarization in a position r & momentum k k. T T) (F TMD PDFs: fpu(x, k. T), … Semi-inclusive measurements Momentum transfer to quark Direct info about momentum distribution May explain SSA & Lam-Tung AN √s = 20 Ge. V p. T< 2 Ge. V/c GPDs: Hpu(x, x, t), … d 2 k T 0 t, = 0 x= PDFs fpu(x), … Exclusive Measurements Momentum transfer to target Direct info about spatial distribution May solve proton spin puzzle x. F Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 4

A World-wide Challenge EIC Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 5

The SIDIS Landscape Limit defined by luminosity EIC Different Q 2 for same x range 1034 1032 1031 1035 Complementary experiments Sea Contalbrigo M. Valence QCD Evolution Workshop, 7 th May 2013, JLab 6

add Hall D (and beam line) 12 Ge. VCEBAF 6 Ge. V Upgrade magnets and power supplies Beam current 90 m. A Beam polarization 85 % CHL-2 2008 -2014: Construction (funded at 99%) May 2012 6 Ge. V Accelerator Shutdown starts May 2013 Accelerator Commissioning starts October 2013 Enhance equipment in existing halls Hall Commissioning starts 2013 -2015 Pre-Ops (beam commissioning) Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 8

JLab 12 Experimental Halls Hall-C Hall-A Spectrometer Pair, polarized 3 He target up to to 1038 cm-2 s-1 hadron ID Super High Momentum Spectrometer (SHMS) unpolarized SIDIS, hadron ID Hall-B Hall-A CLAS 12 H, D polarized targets up to 1035 cm-2 s-1 “complete” acceptance, hadron ID Contalbrigo M. SOLID 3 He, NH 3 polarized targets up to 1036 cm-2 s-1 large acceptance, pion ID QCD Evolution Workshop, 7 th May 2013, JLab 11

The Hall-C High-momentum Spectrometers SIDIS cross-section factorization tests HMS 7 Ge. V/c spectrometer 10 o-90 o angular range e/h, p/K ID by Cherenkov Super-HMS 11 Ge. V/c spectrometer 5 o-25 o angular range e/h, p/K ID by Cherenkov Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 13

The CLAS 12 Large-Acceptance Spectrometer FTOF Luminosity up to 1035 cm-2 s-1 Highly polarized electron beam EC DC R 3 R 2 R 1 RICH H and D polarized targets Broad kinematic range coverage (current to target fragmentation) HTCC TOF + RICH for hadron ID PCAL Solenoid Torus TMDs and GPDs comprehensive study, with special care on applicability Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 14

CLAS 12 Kinematic Coverage Electron Large electron scattering angles (> 20 o) mandatory to reach high Q 2 values acceptance p+ Intermediate anguar range (15 -25 o) mandatory to reach high PT values Electron The CLAS 12 forward detector is perfectly suitable for high-Q 2 and high-p. T measurements since designed to cover up to 40 degrees angles Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 15

Transversely Polarized HD-Ice Target HD-Ice target vs standard nuclear targets (less luminosity for higher purity) Advantages: Deuterium dilution is under control Ø Minimize nuclear background smaller dilution, no attenuation at large p. T Ø Weak holding field (Bd. L ~ 0. 1 Tm) wide acceptance, negligible beam deflection Suitable for di-hadron and recoil proton Ø Very long polarizing times (months) Ø Sensitivity to local heating by charged beams Ph 2 T Disadvantages: R HD-ice ran from Nov/11 to May/12 at Jlab R&D work required to run with electron beams E 06 -101 up to 108 g/s T 1 ~ years Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 16

The Hall-A High-Luminosity Spectrometers High-luminosity 3 He target GEM trackers PID challenging Present: spectrometer pair Future: large acceptance detector Ultimate statistical precision in the valence region Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 17

Polarize 3 He Target Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 18

Leading Twist TMDs Quark polarisation Nucleon polarisation U U L Number Density p. T dependence of quark helicity L T Spin effects in unpolarized reactions p. T dependence of number density Boer Mulders Helicity Proton wave components with different OAM Worm-gear Transversity T Sivers Collinear physics tensor charge Worm-gear Pretzelosity Orbital quark motion non-trivial gauge link process dependence Contalbrigo M. Proton wave components with different OAM QCD Evolution Workshop, 7 th May 2013, JLab D-wave component not-spherical shape of the nucleon 20

The SIDIS Case quark polarisation nucleon polarisation N/q U U Number Density T SIDIS cross section (transversely pol. target): Boer-Mulders TMD factorization for PT<<Q L T L Helicity Worm-gear Transversity Sivers Worm-gear Pretzelosity DF Contalbrigo M. Involved phenomenology due to the convolution over transverse momentum FF QCD Evolution Workshop, 7 th May 2013, JLab 21

Longitudinal Cross-section Cornell data of 70’s To be accounted in any TMD asymmetry interpretation E 12 -06 -104 Hall-C RDIS 0 at Q 2 ∞ due to scattering off spin-½ quarks RDIS sensitive to gluon and higher-twist effects RSIDIS(z, p. T) = un-integrated RDIS Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 22

Small-Ph Dependence T Map pf p. T dependence for pion off proton and deuteron targets E 12 -09 -017 Hall-C At p. T > 0. 2 Ge. V/c use dependencies measured in CLAS 12 experiment Hall C - JLab Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 23

Unpolarized Target Perturbative region Collinear factorization Non-perturbative TMD factorization Boer-Mulders spin-orbit effect E 12 -06 -112 Hall-B Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 24

Unpolarized Target ep e’ KX E 12 -09 -008 Hall-B kaon Line: Phys Rev D 78 045022 Boer-Mulders from Sivers Collins from e+e- data Band: Phys Rev D 78 034035 Boer-Mulders from DY data Collins from chiral limit Measurements of kinematic (x, Q 2, z, PT) will probe HT distribution functions E 12 -06 -112 Hall-B In the perturbative limit 1/PT behavior expected Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab ALU~ 1/Q (Twist-3) 25

Unpolarized Target ep e’ KX E 12 -09 -008 Hall-B kaon Measurements of kinematic (x, Q 2, z, PT) will probe HT distribution functions E 12 -06 -112 Hall-B In the perturbative limit 1/PT behavior expected Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab ALU~ 1/Q (Twist-3) 26

Quark Helicity Transverse momentum dependence of quark helicity vs number density Quark helicity at high-x is sensitive to orbital angular momentum. E 12 -07 -104 Hall-B E 12 -06 -109 Hall-B E 12 -06 -110 Hall-C E 12 -06 -122 Hall-A Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 27

Quark Helicity at High-x E 12 -07 -104 Hall-B Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 28

Transversity Signals High-x and tensor charge Gaussian ansatz & role of Q 2 evolution NO DATA xhu 1(x, k ) xhd 1(x, k ) Soffer bound T xhd 1(x) 1 st collinear extraction ! T xhu 1(x) 1 st extraction of Transversity! ? Gauss Ansatz Anselmino et al. Phys. Rev. D 75 (2007) Contalbrigo M. Bacchetta et al. , PRL 107 (2011) QCD Evolution Workshop, 7 th May 2013, JLab 29

Related to quark orbital angular momentum The Sivers effect ar. Xiv: 1112. 4423 Coverage at large x and relation with Drell-Yan Sign change is a crucial test of TMDs factorization ? ar. Xiv: 1107. 4446 Non zero signals for p+ and K+ Significant Q 2 evolution ? K+ signals larger than p+ ? x Coverage at large p. T and x and relation with twist-3 collinear approach K+-p+ HERMES p Sign mismatch between SIDIS and pp SSA ? T 3 correlator from pp Contalbrigo M. ? QCD Evolution Workshop, 7 th May 2013, JLab Sivers moment from SIDIS 30

CLAS 12 Projections High resolution and broad range in p. T to test perturb. non-perturb. transient and for Bessel function analysis Large x important to constrain the tensor charge Collins asymmetry Contalbrigo M. C 12 -11 -111 Hall-B QCD Evolution Workshop, 7 th May 2013, JLab Sivers asymmetry 31

Statistical Precision @ CLAS 12 Statistical errors 4 D analysis on p+ Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 32

Statistical Precision @ CLAS 12 Sensitivity to so-far not-observed distributions C 12 -11 -111 Hall-B Q 2 dependence of Sivers asymmetry Test of TMDs evolution Di-hadron channel for h 1 Test of TMDs extraction E 12 -12 -109 Hall-B Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 33

3 He AUT with Super-Big. Bite )X 40 days E 12 -11 -007 Hall-A Precise 3 D measurement on 3 He with hadron ID ✓ neutron TMD ✓ flavor separation Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 34

3 He Target with SOLID E 12 -10 -006 Hall-A Luminosity: up to 1036 cm-2 s-1 AAUT UT E 12 -11 -007 Hall-A Large angle detector AAULUL Forward detector Acceptance: Electron 8 -26 degrees Pion 8 -16 degrees Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 35

NH 3 Target with SOLID C 12 -11 -108 Hall-A J. -P. Chen Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 36

Generalized parton distributions Encompass parton distributions and form factors Longitudinal momentum and transverse spatial position correlated information Access OAM Lq= Jq-½DS via Ji sum rule Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 38

GPDs from FFs Inconsistency in DATA ? Diehl et al. ar. Xiv: 1302. 4604 Bacchetta et al. ar. Xiv: 1107. 5755 Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 39

Nucleon Form Factors at High Q 2 Related to GPDs at high |t| structure of the nucleon at small transverse distances E 12 -09 -019 Hall-A E 12 -07 -104 Hall-B Ratio of quasi-elastic e-p to e-n scatterings off a deuteron target Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 40

Nucleon Form Factors at High Q 2 E 12 -07 -109 Hall-A Ratio of recoil polarizations Contalbrigo M. E 12 -09 -016 Hall-A E 12 -11 -009 Hall-C Asymmetry in quasi-elastic scattering QCD Evolution Workshop, 7 th May 2013, JLab 41

DVCS E 12 -06 -114 Hall-A Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 42

p-DVCS AUL and ALU @ CLAS 12 C 12 -06 -119 Hall-B Q 2 ALU 85 days beam time Q 2 AUL -t x 120 days beam time x Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 43

p-DVCS AUT @ CLAS 12 ALT AA UTUT C 12 -12 -010 Hall-B Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 44

d-DVCS ALU @ CLAS 12 E 12 -11 -003 Hall-B Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 45

DVMP Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 46

Exclusive p and k Electro-production E 12 -07 -105 Hall-C E 12 -09 -011 Hall-C Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 47

Exclusive f and the Gluonic Radius E 12 -12 -107 Hall-B From t slope average impact parameter Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 48

The JLab 12 Charge Start of Accelerator commissioning expected in November and running beam to Hall-A in February 2014 Complete mapping (3 D) of the nucleon in the valence region High potential of the complementary programs of 3 experimental halls Contalbrigo M. QCD Evolution Workshop, 7 th May 2013, JLab 49