SCALE DEPENDENCE OF TWIST-3 CORRELATION FUNCTIONS

2011 ◽  
Vol 04 ◽  
pp. 146-156
Author(s):  
Zhong-Bo Kang ◽  
Jian-Wei Qiu
Keyword(s):  
Correlation Functions ◽  
Evolution Equations ◽  
Scale Dependence ◽  
Leading Order ◽  
Coupling Constant ◽  
Parton Distributions ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Similarities And Differences

In this talk, we introduce two sets of twist-3 quark-gluon correlation functions that are relevant to transverse single spin asymmetries, and present corresponding evolution equations at the leading order in strong coupling constant, αs. The similarities and differences between the evolution of the leading power parton distributions and that of the twist-3 multiparton correlation functions are also discussed.

scholarly journals Introduction to the Transverse-Momentum-Weighted Technique in the Twist-3 Collinear Factorization Approach

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Hongxi Xing ◽  
Shinsuke Yoshida
Keyword(s):  
Transverse Momentum ◽  
Leading Order ◽  
Precise Description ◽  
Collinear Factorization ◽  
Factorization Approach ◽  
Hard Part ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Single Spin Asymmetries ◽  
Successful Approach

The twist-3 collinear factorization framework has drawn much attention in recent decades as a successful approach in describing the data for single spin asymmetries (SSAs). Many SSAs data have been experimentally accumulated in a variety of energies since the first measurement was done in the late 1970s and it is expected that the future experiments like Electron-Ion-Collider will provide us with more data. In order to perform a consistent and precise description of the data taken in different kinematic regimes, the scale evolution of the collinear twist-3 functions and the perturbative higher-order hard part coefficients are mandatory. In this paper, we introduce the techniques for next-to-leading order (NLO) calculation of transverse-momentum-weighted SSAs, which can be served as a useful tool to derive the QCD evolution equation for twist-3 functions and to verify the QCD collinear factorization for twist-3 observables at NLO, as well as obtain the finite NLO hard part coefficients.

scholarly journals HADRON TOMOGRAPHY

2006 ◽  
Vol 21 (04) ◽  
pp. 926-929 ◽  
Author(s):  
MATTHIAS BURKARDT
Keyword(s):  
Impact Parameter ◽  
Parton Distributions ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Generalized Parton Distributions ◽  
Single Spin Asymmetries ◽  
The Impact

Generalized parton distributions can be used to obtain information about the dependence of parton distributions on the impact parameter. Potential consequences for T -odd single-spin asymmetries are discussed.

scholarly journals EVOLUTION EQUATIONS OF TWIST-THREE PARTON DISTRIBUTIONS

2011 ◽  
Vol 04 ◽  
pp. 157-167
Author(s):  
BJÖRN PIRNAY
Keyword(s):  
Recent Work ◽  
Correlation Functions ◽  
Evolution Equations ◽  
Spin Asymmetry ◽  
Scale Dependence ◽  
Transverse Spin ◽  
Collinear Factorization ◽  
Parton Distributions ◽  
Gluon Momentum

We report on a recent work concerning the scale dependence of twist-three correlation functions relevant for the single transverse spin asymmetry in the framework of collinear factorization. Evolution equations are presented for both the flavor–nonsinglet and flavor–singlet distributions. Our results do not agree with previous calculations of the evolution in the limit of vanishing gluon momentum. Possible sources for this discrepancy are identified.

scholarly journals ESTIMATING THE SIGN AND SIZE OF THE TRANSVERSE SINGLE TARGET-SPIN ASYMMETRY IN INCLUSIVE DIS

2014 ◽  
Vol 25 ◽  
pp. 1460012 ◽  
Author(s):  
MARC SCHLEGEL
Keyword(s):  
Correlation Functions ◽  
Spin Asymmetry ◽  
Photon Correlation ◽  
Photon Exchange ◽  
Spin Asymmetries ◽  
Single Spin ◽  
Two Photon ◽  
Single Spin Asymmetries ◽  
Single Target ◽  
Perturbative Part

The single-spin asymmetry of unpolarized leptons scattering deep-inelastically off transversely polarized nucleons is discussed. This observable is generated by a two-photon exchange between lepton and nucleon. In a partonic description of the asymmetry the non-perturbative part is given in terms of multiparton correlations: quark-gluon correlation functions and quark-photon correlation functions. Using input from models and data fits for these twist-3 correlation functions, estimates for the single-spin asymmetries for a proton and a neutron are presented.

scholarly journals QCD EVOLUTION OF NAIVE-TIME-REVERSAL-ODD QUARK-GLUON CORRELATION FUNCTIONS

2012 ◽  
Vol 20 ◽  
pp. 118-128 ◽  
Author(s):  
ZHONG-BO KANG ◽  
JIAN-WEI QIU
Keyword(s):  
Transverse Momentum ◽  
Strong Coupling ◽  
Time Reversal ◽  
Correlation Functions ◽  
Scale Dependence ◽  
Strong Coupling Constant ◽  
Leading Order ◽  
Coupling Constant ◽  
Mulders Function

In this talk, we examine the existing calculations of QCD evolution kernels for the scale dependence of two sets of twist-3 quark-gluon correlation functions, Tq,F(x, x) and [Formula: see text], which are the first transverse-momentum-moment of the naive-time-reversal-odd Sivers and Boer-Mulders function, respectively. The evolution kernels at the leading order in strong coupling constant αs were derived by several groups with apparent differences. We identify the sources of discrepancies and are able to reconcile the results from various groups.

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