Soffer positivity bound and a suggestion for measuring valence quark transverse spin distributions at BNL RHIC

1995 ◽  
Vol 51 (9) ◽  
pp. 4880-4883 ◽  
Author(s):  
Dennis Sivers
Keyword(s):  
Valence Quark ◽  
Transverse Spin ◽  
Spin Distributions

scholarly journals THE KINETIC INTERPRETATION OF THE DGLAP EQUATION, ITS KRAMERS–MOYAL EXPANSION AND POSITIVITY OF HELICITY DISTRIBUTIONS

2005 ◽  
Vol 20 (20n21) ◽  
pp. 4863-4897 ◽  
Author(s):  
ALESSANDRO CAFARELLA ◽  
CLAUDIO CORIANÓ
Keyword(s):  
Numerical Solution ◽  
Numerical Study ◽  
Valence Quark ◽  
Quark Distribution ◽  
Transverse Spin ◽  
Leading Order ◽  
Dglap Equation ◽  
Spin Distribution ◽  
Formal Properties ◽  
Fokker Planck

According to a rederivation — due to Collins and Qiu — the DGLAP equation can be reinterpreted (in leading order) in a probabilistic way. This form of the equation has been used indirectly to prove the bound |Δ f(x, Q)| < f(x, Q) between polarized and unpolarized distributions, or positivity of the helicity distributions, for any Q. We reanalyze this issue by performing a detailed numerical study of the positivity bounds of the helicity distributions. To obtain the numerical solution we implement an x-space based algorithm for polarized and unpolarized distributions to next-to-leading order in αs, which we illustrate. We also elaborate on some of the formal properties of the Collins–Qiu form and comment on the underlying regularization, introduce a Kramers–Moyal expansion of the equation and briefly analyze its Fokker–Planck approximation. These follow quite naturally once the master version is given. We illustrate this expansion both for the valence quark distribution qV and for the transverse spin distribution h1.

TRANSVERSE SPIN FLUCTUATIONS IN γ - Mn (37 % Fe) ALLOY

1988 ◽  
Vol 49 (C8) ◽  
pp. C8-183-C8-184 ◽  
Author(s):  
J. J. Milczarek ◽  
K. Mikke ◽  
E. Jaworska
Keyword(s):  
Spin Fluctuations ◽  
Transverse Spin

scholarly journals Valence-quark distribution of the kaon and pion from lattice QCD

2021 ◽  
Vol 103 (1) ◽  
Author(s):  
Huey-Wen Lin ◽  
Jiunn-Wei Chen ◽  
Zhouyou Fan ◽  
Jian-Hui Zhang ◽  
Rui Zhang
Keyword(s):  
Lattice Qcd ◽  
Valence Quark ◽  
Quark Distribution

scholarly journals Spin-orbit coupling affecting the evolution of transverse spin

2019 ◽  
Vol 1 (3) ◽  
Author(s):  
Jörg S. Eismann ◽  
Peter Banzer ◽  
Martin Neugebauer
Keyword(s):  
Orbit Coupling ◽  
Transverse Spin ◽  
Spin Orbit Coupling ◽  
Spin Orbit

scholarly journals Global analysis of the Sivers functions at NLO+NNLL in QCD

2021 ◽  
Vol 2021 (1) ◽  
Author(s):  
Miguel G. Echevarria ◽  
Zhong-Bo Kang ◽  
John Terry
Keyword(s):  
Pair Production ◽  
Global Analysis ◽  
Vector Boson ◽  
Lepton Pair ◽  
Transverse Spin ◽  
Dglap Evolution ◽  
Spin Asymmetries ◽  
Lepton Pair Production ◽  
Asymmetry Data ◽  
The Impact

Abstract We perform global fit to the quark Sivers function within the transverse momentum dependent (TMD) factorization formalism in QCD. We simultaneously fit Sivers asymmetry data from Semi-Inclusive Deep Inelastic Scattering (SIDIS) at COMPASS, HERMES, and JLab, from Drell-Yan lepton pair production at COMPASS, and from W/Z boson at RHIC. This extraction is performed at next-to-leading order (NLO) and next-to-next-to leading logarithmic (NNLL) accuracy. We find excellent agreement between our extracted asymmetry and the experimental data for SIDIS and Drell-Yan lepton pair production, while tension arises when trying to describe the spin asymmetries of W/Z bosons at RHIC. We carefully assess the situation, and we study in details the impact of the RHIC data and their implications through different ways of performing the fit. In addition, we find that the quality of the description of W/Z vector boson asymmetry data could be strongly sensitive to the DGLAP evolution of Qiu-Sterman function, besides the usual TMD evolution. We present discussion on this and the implications for measurements of the transverse-spin asymmetries at the future Electron Ion Collider.

Sign in / Sign up

Export Citation Format

Share Document