偏極ビーム・標的によるDrell-Yan過程でのスピン観測量と核子構造
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Transcript 偏極ビーム・標的によるDrell-Yan過程でのスピン観測量と核子構造
偏極ビーム・標的による
Drell-Yan過程での
スピン観測量と核子構造
田中和廣 (順天堂大)
X
D IS :
p X
S ID IS :
p X
The first global fit at LO
Anselmino et al., PRD75 (’07) 054032
arXiv: 0807.0173
T q x 0
n o d ata fo r x 0 .4
Drell-Yan: p p
AT T
d
d
d
d
X
Q
2
2
2
2
2
2
e q T q ( x1 , Q ) T q ( x 2 , Q ) T q ( x1 , Q ) T q ( x 2 , Q )
q
2
2
2
2
2
e q q ( x1 , Q ) q ( x 2 , Q ) q ( x1 , Q ) q ( x 2 , Q )
q
p p
AT T
J-PARC:
S 10 Ge V , x 1,2 0. 1
X
2
2
2
2
2
e q T q ( x1 , Q ) T q ( x 2 , Q ) T q ( x1 , Q ) T q ( x 2 , Q )
q
q
2
2
2
2
2
e q q ( x1 , Q ) q ( x 2 , Q ) q ( x1 , Q ) q ( x 2 , Q )
GSI:
S
6 G e V , x 1,2 0. 2
Kawamura, Kodaira, Tanaka,
NPB777 (’07) 203
resummation
PTP 118 (’07) 581
PLB662 (’08) 139
2
QT
Q ,y
@ J-PARC
@ J-PARC
Q 2 G eV , y= 0
@ GSI
S 14.5 G eV , Q 4 G eV , y=0
@ RHIC
S 500 G eV , y= 2
AL T
q
d
d
d
d
2
2
q
2
q
2
2
e q q ( x 1 , Q ) x 2 g T ( x 2 , Q ) x 1 h L ( x 1 , Q ) T q ( x 2 , Q ) x 1 x 2
q
2
2
2
e q q ( x 1 , Q ) q ( x 2 , Q ) x 1 x 2
h L , gT : twist-3 parton distri butions
1
2
hL (x , Q ) 2 x dy
q
2
T q(y, Q )
y
x
q
gT ( x , Q )
2
1
x
2
q(y, Q )
" genuine tw ist-3 "
2
dy
y
" genuine tw ist-3 "
Wandzura-Wilczek part
@J-PARC
S 10 GeV
(from presentation by S. Yoshida)
x F x1 x 2
@GSI
S 6.7 GeV
(Koike, Tanaka, Yoshida, arXiv:0805.2289)
Summary
Drell-Yan processes using
polarized beam and target
at J-PARC
A LL
q (x )
ATT
T q ( x ), T q ( x )
A LT
q q g three-body correlat ion
including large x region
Clean! unique!!