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JLAB12 and the S tructure of H adrons. Contalbrigo Marco INFN Ferrara. QCD Evolution 13 7 th May 2013, JLab – Newport News. The Spin D egree of Freedom. e p → e p. - PowerPoint PPT Presentation
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Contalbrigo Marco INFN Ferrara
QCD Evolution 137th May 2013, JLab – Newport News
JLAB12 AND THESTRUCTURE OF HADRONS
Spin degrees of freedom can explain otherwise surprising phenomena and bring new insights into nuclear matter structure
e p → e p
e p → e p
PRC 68, 034325 (2003)
xF
Fundamental: do not neglect it !!
2Contalbrigo M.
The Spin Degree of Freedom
QCD Evolution Workshop, 7th May 2013, JLab
In our exploration of the QCD micro-world
Fundamental: do not neglect spin !!
3Contalbrigo M.
The Spin Degree of Freedom
Two questions in Hadronic Physics await explanation since too long
gqff
f LGLqq )(21
21
pT< 2 GeV/c√s = 20 GeV
xF
AN
Proton Spin Budget Single Spin Asymmetries
? QCD Evolution Workshop, 7th May 2013, JLab
PDFs fpu(x),…
TMD PDFs: fpu(x,kT),…
d 2kT x=
0,t=0
Wpq(x,kT,r) “Mother” Wigner distributions
d3r d 2k
T
Exclusive MeasurementsMomentum transfer to targetDirect info about spatial distribution
Semi-inclusive measurementsMomentum transfer to quarkDirect info about momentum distribution
(FT)
GPDs: Hpu(x,x,t), …
Quantum Phase-space Distributions of Quarks
pT< 2 GeV/c√s = 20 GeV
xF
AN
May solveproton spin puzzle
May explain SSA & Lam-Tung
Probability to find a quark q in a nucleon P with a certain polarization in a position r & momentum k
4Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
A World-wide Challenge
5Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
EIC
YOUR TEXT HERE
Limit defined by luminosity
1032
1031
1035
Different Q2 for same x range
EIC
1034
Valence
Complementary experiments
Sea
The SIDIS Landscape
6Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
THE JLAB12 FACILITY
6 GeV CEBAF
CHL-2
Upgrade magnets and power supplies
12 GeV CEBAF
Enhance equipment in existing halls
add Hall D (and beam line)
2008-2014: Construction (funded at 99%)
May 20126 GeV Accelerator Shutdown starts
May 2013 Accelerator Commissioning starts
October 2013 Hall Commissioning starts
2013-2015 Pre-Ops (beam commissioning)
Beam current 90 mABeam polarization 85 %
8Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
11Contalbrigo M.
Super High Momentum Spectrometer (SHMS)unpolarized SIDIS, hadron ID
Hall-C
Spectrometer Pair, polarized 3He target up to to 1038 cm-2 s-1 hadron ID
Hall-A
Hall-B
CLAS12 H,D polarized targets up to 1035 cm-2 s-1 “complete” acceptance, hadron ID
SOLID 3He, NH3 polarized targets up to 1036 cm-2 s-1 large acceptance, pion ID
Hall-A
JLab12 Experimental Halls
QCD Evolution Workshop, 7th May 2013, JLab
The Hall-C High-momentum Spectrometers
13Contalbrigo M.
Super-HMS11 GeV/c spectrometer
5o-25o angular rangee/h, p/K ID by Cherenkov
HMS7 GeV/c spectrometer10o-90o angular range
e/h, p/K ID by Cherenkov
QCD Evolution Workshop, 7th May 2013, JLab
SIDIS cross-section factorization tests
DC R3R2R1EC
Torus
FTOF
PCAL
HTCC
Solenoid
The CLAS12 Large-Acceptance Spectrometer
14Contalbrigo M.
Luminosity up to 1035 cm-2 s-1
Broad kinematic range coverage (current to target fragmentation)
TOF + RICH for hadron ID
H and D polarized targets
Highly polarized electron beam
RICH
QCD Evolution Workshop, 7th May 2013, JLab
TMDs and GPDs comprehensive study, with special care on applicability
CLAS12 Kinematic Coverage
15Contalbrigo M.
Intermediate anguar range (15-25o) mandatory to reach high PT values
Large electron scattering angles (> 20o) mandatory to reach high Q2 values
Electron
The CLAS12 forward detector is perfectly suitable for high-Q2 and high-pT measurements since designed to cover up to 40 degrees angles
Electron p+acceptance
QCD Evolution Workshop, 7th May 2013, JLab
Advantages: Minimize nuclear background smaller dilution, no attenuation at large pT Weak holding field (BdL ~ 0.1 Tm) wide acceptance, negligible beam deflection
Disadvantages: Very long polarizing times (months) Sensitivity to local heating by charged beams
HD-Ice target vs standard nuclear targets (less luminosity for higher purity)
16Contalbrigo M.
Transversely Polarized HD-Ice Target
HD-ice ran from Nov/11 to May/12 at Jlab R&D work required to run with electron beams
E06-101up to 108 g/sT1 ~ years
Deuterium dilution is under control
Suitable for di-hadron and recoil proton
Ph2 T
R
QCD Evolution Workshop, 7th May 2013, JLab
17Contalbrigo M.
The Hall-A High-Luminosity Spectrometers
Present: spectrometer pair Future: large acceptance detector
QCD Evolution Workshop, 7th May 2013, JLab
High-luminosity3He target
GEM trackersPID challenging
Ultimate statistical precision in the valence region
Polarize 3He Target
18Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
PDFS AND TMDS
U L T
U
L
T
Quark polarisation
Nuc
leon
pol
aris
atio
n
T1h
T1fSivers
Pretzelosity
Worm-gear Collinear physicstensor charge
Leading Twist TMDs
20Contalbrigo M.
D-wave componentnot-spherical shape
of the nucleon
Orbital quark motionnon-trivial gauge linkprocess dependence
Proton wave components with
different OAM
L1h
Worm-gear
Proton wave components with
different OAM
Spin effects in unpolarized reactions
1fNumber Density
1gHelicity
1hTransversity
1h
Boer Mulders
pT dependence of quark helicity
pT dependence of number density
QCD Evolution Workshop, 7th May 2013, JLab
N/q U L T
U
L
T
The SIDIS Casequark polarisation
nucl
eon
pola
risat
ion
1fNumber
1gHelicity
T1fSivers
1h
Boer-Mulders
L1h
Density
Worm-gear
Worm-gear
DF
FF
21Contalbrigo M.
T1hTransversity
1h
DF FF
Pretzelosity
SIDIS cross section(transversely pol. target):
Involved phenomenology due to theconvolution over transverse momentum
TMD factorization for PT<<Q
QCD Evolution Workshop, 7th May 2013, JLab
Longitudinal Cross-section
22Contalbrigo M.
RDIS0 at Q2∞ due to scattering off spin-½ quarks
RDIS sensitive to gluon and higher-twist effects
RSIDIS(z,pT) = un-integrated RDIS
To be accounted in any TMDasymmetry interpretation
QCD Evolution Workshop, 7th May 2013, JLab
Cornell data of 70’s
E12-06-104 Hall-C
At pT > 0.2 GeV/c use dependencies measured in CLAS12 experiment
Small-Ph Dependence
23Contalbrigo M.
Map pf pT dependence for pion off proton and deuteron targets
T QCD Evolution Workshop, 7th May 2013, JLab
E12-09-017 Hall-C
Hall C - JLab
Perturbative regionCollinear factorization
Non-perturbative TMD factorization
Unpolarized Target
24Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
Boer-Mulders spin-orbit effect
E12-06-112 Hall-B
Band: Phys Rev D78 034035Boer-Mulders from DY data
Collins from chiral limit
Line: Phys Rev D78 045022Boer-Mulders from Sivers
Collins from e+e- data
kaon
Unpolarized Target
25Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-09-008 Hall-B
In the perturbative limit 1/PT behavior expected ALU~ 1/Q (Twist-3)
Measurements of kinematic (x,Q2,z,PT) will probe HT distribution functions
E12-06-112 Hall-B
ep e’ KX
kaon
Unpolarized Target
26Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-09-008 Hall-B
In the perturbative limit 1/PT behavior expected ALU~ 1/Q (Twist-3)
Measurements of kinematic (x,Q2,z,PT) will probe HT distribution functions
E12-06-112 Hall-B
ep e’ KX
Quark Helicity
27Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-07-104 Hall-B
E12-06-109 Hall-B
E12-06-122 Hall-A
E12-06-110 Hall-C
Transverse momentum dependenceof quark helicity vs number densityQuark helicity at high-x is sensitive
to orbital angular momentum.
Quark Helicity at High-x
28Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-07-104 Hall-B
Transversity Signals
29Contalbrigo M.
1st collinear extraction !
hXlld '
hXllp '
1st extraction of Transversity!
Anselmino et al. Phys. Rev. D 75 (2007)
Soffer bound
xh1(
x)d
xh1(
x)u
xh1(
x, k
)T
uxh
1(x,
k )T
d
Bacchetta et al., PRL 107 (2011)
NO DATA
Gauss Ansatz
High-x and tensor charge
Gaussian ansatz & role of Q2 evolution ?
QCD Evolution Workshop, 7th May 2013, JLab
The Sivers effect
30Contalbrigo M.
Non zero signals for p+ and K+
Significant Q2 evolution ?
K+ signals larger than p+?
K+-p
T3 correlator from pp Sivers moment from SIDIS
Sign change is a crucial test of TMDs factorization
Coverage at large x and relation with Drell-Yan
Sign mismatch between SIDIS and pp SSA ?
Coverage at large pT and x and relation with twist-3 collinear approach
HERMES p
?
?
x
arXiv:1112.4423
arXiv:1107.4446
Related to quark orbital angular
momentum
QCD Evolution Workshop, 7th May 2013, JLab
CLAS12 Projections
31Contalbrigo M.
Collins asymmetry
Large x important to constrain the tensor charge
Sivers asymmetry
High resolution and broad range in pT to test perturb. non-perturb. transient and for Bessel function analysis
QCD Evolution Workshop, 7th May 2013, JLab
C12-11-111 Hall-B
Statistical Precision @ CLAS12
32Contalbrigo M.
Statistical errors 4D analysis on p+
QCD Evolution Workshop, 7th May 2013, JLab
Statistical Precision @ CLAS12
33Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
Q2 dependence of Sivers asymmetry Test of TMDs evolution
Di-hadron channel for h1
Test of TMDs extraction
E12-12-109 Hall-B
Sensitivity to so-far not-observed distributions
C12-11-111 Hall-B
34Contalbrigo M.
Precise 3D measurementon 3He with hadron ID ✓ neutron TMD ✓ flavor separation
)X 40 days
3He AUT with Super-BigBite
QCD Evolution Workshop, 7th May 2013, JLab
E12-11-007 Hall-A
35Contalbrigo M.
3He Target with SOLID
AUT
AUL
QCD Evolution Workshop, 7th May 2013, JLab
Luminosity: up to 1036 cm-2 s-1
Acceptance:
Electron 8-26 degreesPion 8-16 degrees
Forward detector
Large angle detector
E12-10-006 Hall-A
E12-11-007 Hall-A
AUT
AUL
36Contalbrigo M.
NH3 Target with SOLID
C12-11-108 Hall-A
J.-P. Chen
QCD Evolution Workshop, 7th May 2013, JLab
FFS AND GPDS
Generalized parton distributionsEncompass parton distributions and form factors
Longitudinal momentum and transverse spatial positioncorrelated information
Access OAM Lq= Jq-½S via Ji sum rule
38Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
GPDs from FFs
39Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
Inconsistency in DATA ?
Diehl et al. arXiv: 1302.4604
Bacchetta et al. arXiv: 1107.5755
40Contalbrigo M.
Nucleon Form Factors at High Q2
QCD Evolution Workshop, 7th May 2013, JLab
Ratio of quasi-elastice-p to e-n scatterings off a deuteron target
Related to GPDs at high |t| structure of the nucleon at small transverse distances
E12-09-019 Hall-A
E12-07-104 Hall-B
Nucleon Form Factors at High Q2
41Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
Ratio of recoil polarizations
E12-11-009 Hall-C
Asymmetry in quasi-elastic scattering
E12-09-016 Hall-AE12-07-109 Hall-A
42Contalbrigo M.
DVCS
QCD Evolution Workshop, 7th May 2013, JLab
E12-06-114 Hall-A
p-DVCS AUL and ALU @ CLAS12
43Contalbrigo M.
120 daysbeam time
AUL
Q2
Q2
x
x
ALU
-t
85 daysbeam time
QCD Evolution Workshop, 7th May 2013, JLab
C12-06-119 Hall-B
p-DVCS AUT @ CLAS12
44Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
C12-12-010 Hall-B
ALTAUTALTAUT
d-DVCS ALU @ CLAS12
45Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-11-003 Hall-B
DVMP
46Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
Exclusive p and k Electro-production
47Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
E12-07-105 Hall-C
E12-09-011 Hall-C
Exclusive f and the Gluonic Radius
48Contalbrigo M. QCD Evolution Workshop, 7th May 2013, JLab
From t slope average impact parameter
E12-12-107 Hall-B
The JLab12 Charge
49Contalbrigo M.
Complete mapping (3D) of the nucleon in the valence regionHigh potential of the complementary programs of 3 experimental halls
QCD Evolution Workshop, 7th May 2013, JLab
Start of Accelerator commissioning expected in Novemberand running beam to Hall-A in February 2014