Calculation of Transverse-Momentum-Dependent Evolution for Sivers Transverse Single Spin Asymmetry Measurements

We study the single-spin asymmetry ATsin(2ϕ−ϕS) in the pion-induced Drell-Yan process within the transverse momentum dependent factorization (TMD factorization). The asymmetry can be expressed as the convolution of the Boer-Mulders function and the transversity function. We numerically estimate the asymmetry ATsin(2ϕ−ϕS) at the COMPASS kinematics with the model results for the pion meson distributions from the light-cone wave function approach and the available parametrization for the proton distributions. We also include the TMD evolution formalism both proton and pion parton distribution functions by using two different parametrizations on nonperturbative Sudakov form factor. We find that the asymmetry ATsin(2ϕ−ϕS) as functions of xp, xπ, xF and q⊥ is qualitatively consistent with the recent COMPASS measurement.

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Sivers effect in single spin asymmetry based on the covariant parton model

International Journal of Modern Physics A ◽

10.1142/s0217751x17501767 ◽

2017 ◽

Vol 32 (28n29) ◽

pp. 1750176

Author(s):

H. Mahdizadeh Saffar ◽

A. Mirjalili ◽

S. Atashbar Tehrani ◽

M. M. Yazdanpanah

Keyword(s):

Experimental Data ◽

Transverse Momentum ◽

Spin Asymmetry ◽

Parton Model ◽

Single Spin Asymmetry ◽

Unknown Parameters ◽

Kaon Production ◽

Single Spin ◽

Sivers Function ◽

Global Fit

Sivers effect is describing the correlation between the transverse polarization of nucleon and the transverse momentum, [Formula: see text], of its unpolarized constituent partons. This effect is an outstanding subject and in this regard, a great deal in recent years has been considered from experimental and phenomenological points of view. It also plays an essential role to extend our understanding from nucleon structure. Semi-inclusive DIS (SIDIS) process provides us an opportunity to access to Sivers function which is dependent on transverse momentum of partons. In this paper, for the first time the covariant parton model is used to deliver us the [Formula: see text] and [Formula: see text] dependence part of Sivers function. Based on this model, this combinatory dependence is arising out from the HERAPDF parametrization group. In this paper the other required parametrized functions in Sivers function is also changed with respect to Ref. 1. The unknown parameters which exist in Sivers function can be extracted, doing a global fit over the recent available experimental data, including HERMES, COMPASS and JLAB collaborations for the single spin asymmetry (SSA) in [Formula: see text] and [Formula: see text] meson production as well as kaon production to constrain the evolved strange quark. This is done, considering advanced mathematical manipulations to overcome the difficulties which exist to compute the required multiple integrals and finally employing the CERN MINIUTE program to do a global fit. Our results for SSA are in good agreement with the available experimental data. For more confirmation a comparison between our results and the ones from Ref. 2 is also done.

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Energy and transverse momentum dependence of single-spin asymmetry of very forward neutron in polarized pp collision

Journal of Physics Conference Series ◽

10.1088/1742-6596/295/1/012097 ◽

2011 ◽

Vol 295 ◽

pp. 012097 ◽

Cited By ~ 6

Author(s):

Kiyoshi Tanida ◽

Keyword(s):

Transverse Momentum ◽

Spin Asymmetry ◽

Single Spin Asymmetry ◽

Momentum Dependence ◽

Transverse Momentum Dependence ◽

Single Spin

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AN of Single Heavy Flavor Decay Muon in the PHENIX Experiment at RHIC

International Journal of Modern Physics Conference Series ◽

10.1142/s2010194516600430 ◽

2016 ◽

Vol 40 ◽

pp. 1660043 ◽

Cited By ~ 1

Author(s):

Xiaorong Wang ◽

Feng Wei

Keyword(s):

Transverse Momentum ◽

Spin Asymmetry ◽

Single Spin Asymmetry ◽

Transverse Spin ◽

Heavy Flavor ◽

Spin Asymmetries ◽

Single Spin ◽

Phenix Experiment ◽

Single Spin Asymmetries ◽

Heavy Flavor Production

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.

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