scholarly journals Single-spin asymmetries in $$p^\uparrow p \rightarrow J/\psi +X$$ within a TMD approach: role of the color octet mechanism

2019 ◽  
Vol 79 (12) ◽  
Author(s):  
Umberto D’Alesio ◽  
Francesco Murgia ◽  
Cristian Pisano ◽  
Sangem Rajesh
Keyword(s):  
Cross Sections ◽  
Spin Asymmetry ◽  
Parton Model ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Color Octet ◽  
Target Mode ◽  
Color Octet Mechanism

AbstractWe calculate the transverse single-spin asymmetry (SSA) for $$J/\psi $$J/ψ production in proton-proton collisions, within non-relativistic QCD, employing the transverse momentum dependent, generalized parton model, which includes both spin and intrinsic motion effects. In particular, we study the role of the color octet mechanism in accessing the gluon Sivers function. In doing that, we also show, within this approach, how the singularities coming from color octet terms in the low-$$P_T$$PT region can be handled, leading to finite cross sections. Predictions for both unpolarized cross sections and SSAs are given and compared against PHENIX data. Estimates for LHCb in the fixed target mode are also presented.

scholarly journals Single-Spin Asymmetries AULsinϕh in Semi-Inclusive Pions Production

2016 ◽  
Vol 40 ◽  
pp. 1660045 ◽  
Author(s):  
Zhun Lu ◽  
Wenjuan Mao
Keyword(s):  
Pion Production ◽  
Neutral Pion ◽  
Spin Asymmetry ◽  
Distribution Functions ◽  
Proton Target ◽  
Deuteron Target ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries

The single-spin asymmetry [Formula: see text] of charged and neutral pion production in semi-inclusive deep-inelastic scattering on longitudinally polarized nucleon targets is studied. We particularly consider the effects of the twist-3 transverse-momentum dependent distribution functions [Formula: see text] and [Formula: see text], which are calculated in two different spectator-diquark models. We estimate the asymmetry for [Formula: see text], [Formula: see text] and [Formula: see text] produced off the proton target at HERMES and compare the results with the HERMES measurements. We also predict the same asymmetric moment for different pions at the kinematics of CLAS 5.5 GeV on a proton target, as well as at COMPASS on a deuteron target for comparison.

scholarly journals Transverse Single-Spin Asymmetries in Proton-Proton Collisions at the AFTER@LHC Experiment in a TMD Factorisation Scheme

2015 ◽  
Vol 2015 ◽  
pp. 1-12 ◽  
Author(s):  
M. Anselmino ◽  
U. D’Alesio ◽  
S. Melis
Keyword(s):  
Spin Asymmetry ◽  
Parton Model ◽  
Fixed Target ◽  
Proton Proton ◽  
Spin Asymmetries ◽  
Proton Collisions ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Target Experiment ◽  
Proton Proton Collisions

The inclusive large-pTproduction of a single pion, jet or direct photon, and Drell-Yan processes, are considered for proton-proton collisions in the kinematical range expected for the fixed-target experiment AFTER, proposed at LHC. For all these processes, predictions are given for the transverse single-spin asymmetry,AN, computed according to a Generalised Parton Model previously discussed in the literature and based on TMD factorisation. Comparisons with the results of a collinear twist-3 approach, recently presented, are made and discussed.

scholarly journals Single-spin asymmetry ATsin(2ϕ−ϕS) in π−p Drell-Yan process within TMD factorization

2022 ◽  
Vol 258 ◽  
pp. 03002
Author(s):  
Hui Li ◽  
Xiaoyu Wang ◽  
Zhun Lu
Keyword(s):  
Spin Asymmetry ◽  
Distribution Functions ◽  
Single Spin Asymmetry ◽  
Parton Distribution Functions ◽  
Sudakov Form Factor ◽  
Transverse Momentum Dependent ◽  
Single Spin ◽  
Mulders Function ◽  
Light Cone Wave Function ◽  
The Asymmetry

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.

scholarly journals THE SPIN STRUCTURE OF THE NUCLEON IN LIGHT-CONE QUARK MODELS

2009 ◽  
Vol 24 (35n37) ◽  
pp. 2903-2912 ◽  
Author(s):  
B. PASQUINI ◽  
S. BOFFI ◽  
P. SCHWEITZER
Keyword(s):  
Transverse Momentum ◽  
Light Cone ◽  
Parton Distributions ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Generalized Parton Distributions ◽  
Quark Spin ◽  
Quark Models ◽  
Impact Parameter Space

The quark spin densities related to generalized parton distributions in impact-parameter space and to transverse-momentum dependent parton distributions are reviewed within a light-cone quark model, with focus on the role of the different spin-spin and spin-orbit correlations of quarks. Results for azimuthal spin asymmetries in semi-inclusive deep inelastic scattering due to T -even transverse-momentum dependent parton distributions are also discussed.

scholarly journals Cross sections and transverse single-spin asymmetries in forward jet production from proton collisions ats=500 GeV

2015 ◽  
Vol 750 ◽  
pp. 660-665 ◽  
Author(s):  
L.C. Bland ◽  
E.J. Brash ◽  
H.J. Crawford ◽  
A.A. Derevschikov ◽  
K.A. Drees ◽  
...  
Keyword(s):  
Cross Sections ◽  
Spin Asymmetries ◽  
Proton Collisions ◽  
Jet Production ◽  
Single Spin ◽  
Single Spin Asymmetries

scholarly journals Single spin asymmetries in ℓp↑→hX processes and transverse momentum dependent factorization

2014 ◽  
Vol 89 (11) ◽  
Author(s):  
M. Anselmino ◽  
M. Boglione ◽  
U. D’Alesio ◽  
S. Melis ◽  
F. Murgia ◽  
...  
Keyword(s):  
Transverse Momentum ◽  
Transverse Momentum Dependent ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries
Sign in / Sign up

Export Citation Format

Share Document