scholarly journals Single transverse-spin asymmetry in high transverse momentum pion production inppcollisions

2006 ◽  
Vol 74 (11) ◽  
Author(s):  
Chris Kouvaris ◽  
Jian-Wei Qiu ◽  
Werner Vogelsang ◽  
Feng Yuan
2012 ◽  
Vol 20 ◽  
pp. 168-176
Author(s):  
LEONARD GAMBERG

We consider the cross section for semi-inclusive deep inelastic scattering in Fourier space, conjugate to the outgoing hadron's transverse momentum, where convolutions of transverse momentum dependent parton distribution functions and fragmentation functions become simple products. Individual asymmetric terms in the cross section can be projected out by means of a generalized set of weights involving Bessel functions. Advantages of employing these Bessel weights are that they suppress (divergent) contributions from high transverse momentum and that soft factors cancel in (Bessel-) weighted asymmetries. Also, the resulting compact expressions immediately connect to previous work on evolution equations for transverse momentum dependent parton distribution and fragmentation functions and to quantities accessible in lattice QCD. Bessel-weighted asymmetries are thus model independent observables that augment the description and our understanding of correlations of spin and momentum in nucleon structure.


2006 ◽  
Vol 73 (9) ◽  
Author(s):  
Xiangdong Ji ◽  
Jian-Wei Qiu ◽  
Werner Vogelsang ◽  
Feng Yuan

2016 ◽  
Vol 40 ◽  
pp. 1660043 ◽  
Author(s):  
Xiaorong Wang ◽  
Feng Wei

Transverse single-spin asymmetries provide valuable information about the spin structure of the nucleon. At RHIC energies, heavy-flavor production is dominated by gluon-gluon fusion, and the subsequent decay into high [Formula: see text] electrons or muons can be observed statistically in a collider detector like PHENIX. The transverse single-spin asymmetry in heavy-flavor production originates from the initial state correlation between the internal transverse momentum of the parton and the transverse spin of the nucleon (similar with the known Sivers effect). The measurement of transverse single-spin asymmetry of single muons from heavy flavor decay at RHIC serves as a clean probe and would provide important information on the gluon Sivers function. In 2012, the PHENIX experiment collected 9.2 [Formula: see text] integrated luminosity in transversely polarized [Formula: see text] collisions at [Formula: see text] = 200 GeV with a polarization of [Formula: see text]. The signal-to-background ratio was improved by a factor of two compared to the previous RHIC 2006 and 2008 results in high transverse momentum region ([Formula: see text]GeV). The recent PHENIX preliminary results of transverse single-spin asymmetries of single heavy flavor decay muon at forward-rapidity will be shown and the possible improvement on this measurement in 2015 with the help of the FVTX detector will be discussed.


1978 ◽  
Vol 18 (7) ◽  
pp. 2235-2238 ◽  
Author(s):  
E. W. Beier ◽  
R. Patton ◽  
K. Raychaudhuri ◽  
H. Takeda ◽  
R. Thern ◽  
...  

2012 ◽  
Vol 20 ◽  
pp. 129-136
Author(s):  
ZHONG-BO KANG

We review the relation between the QCD perturbative resummation and evolution. Particularly we emphasize briefly the idea on how to use the evolution equation to resum the important double logarithms appeared in the perturbative QCD expansion when the process involves two distinctive scales Q1 ≫ Q2. We present the resummation formalism for the single transverse spin asymmetry for both semi-inclusive deep inelastic scattering and Drell-Yan production processes.


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