scholarly journals QCD Factorization and PDFs from Lattice QCD Calculation

2015 ◽  
Vol 37 ◽  
pp. 1560041 ◽  
Author(s):  
Yan-Qing Ma ◽  
Jian-Wei Qiu
Keyword(s):  
Euclidean Space ◽  
Minkowski Space ◽  
Lattice Qcd ◽  
Correlation Functions ◽  
Parton Distribution ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Qcd Factorization ◽  
The Matrix

In this talk, we review a QCD factorization based approach to extract parton distribution and correlation functions from lattice QCD calculation of single hadron matrix elements of quark-gluon operators. We argue that although the lattice QCD calculations are done in the Euclidean space, the nonperturbative collinear behavior of the matrix elements are the same as that in the Minkowski space, and could be systematically factorized into parton distribution functions with infrared safe matching coefficients. The matching coefficients can be calculated perturbatively by applying the factorization formalism on to asymptotic partonic states.

RECENT PROGRESS ON NUCLEON STRUCTURE WITH LATTICE QCD

2014 ◽  
Vol 25 ◽  
pp. 1460039 ◽  
Author(s):  
HUEY-WEN LIN
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Recent Progress ◽  
Distribution Functions ◽  
Nucleon Structure ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Bjorken X ◽  
Systematic Control ◽  
Made In

I review recent progress made in the calculation of nucleon structure in lattice QCD. Due to space limitations, I will focus on a few specific topics: systematic control of lattice-QCD matrix elements, probing TeV-physics with the aid of nucleon tensor and scalar charges, and Bjorken-x dependence of nucleon parton distribution functions.

scholarly journals QCD factorization for chiral-odd parton quasi- and pseudo-distributions

2021 ◽  
Vol 2021 (10) ◽  
Author(s):  
Vladimir M. Braun ◽  
Yao Ji ◽  
Alexey Vladimirov
Keyword(s):  
Correlation Functions ◽  
Momentum Space ◽  
Parton Distribution ◽  
Distribution Functions ◽  
Factorization Theorem ◽  
Position Space ◽  
Parton Distribution Functions ◽  
Transversity Distribution ◽  
Qcd Factorization ◽  
Lattice Calculations

Abstract We study chiral-odd quark-antiquark correlation functions suitable for lattice calculations of twist-three nucleon parton distribution functions hL(x) and e(x), and also the twist-two transversity distribution δq(x). The corresponding factorized expressions are derived in terms of the twist-two and twist-three collinear distributions to one-loop accuracy. The results are presented both in position space, as the factorization theorem for Ioffe-time distributions, and in momentum space, for quasi- and pseudo-distributions. We demonstrate that the twist-two part of the hL quasi(pseudo)-distribution can be separated from the twist-three part by virtue of an exact Jaffe-Ji-like relation.

scholarly journals The continuum and leading twist limits of parton distribution functions in lattice QCD

2021 ◽  
Vol 2021 (11) ◽  
Author(s):  
Joseph Karpie ◽  
Kostas Orginos ◽  
Anatoly Radyushkin ◽  
Savvas Zafeiropoulos ◽  
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Continuum Limit ◽  
Jacobi Polynomials ◽  
Parton Distribution Function ◽  
Systematic Errors ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
The Continuum

Abstract In this study, we present continuum limit results for the unpolarized parton distribution function of the nucleon computed in lattice QCD. This study is the first continuum limit using the pseudo-PDF approach with Short Distance Factorization for factorizing lattice QCD calculable matrix elements. Our findings are also compared with the pertinent phenomenological determinations. Inter alia, we are employing the summation Generalized Eigenvalue Problem (sGEVP) technique in order to optimize our control over the excited state contamination which can be one of the most serious systematic errors in this type of calculations. A crucial novel ingredient of our analysis is the parameterization of systematic errors using Jacobi polynomials to characterize and remove both lattice spacing and higher twist contaminations, as well as the leading twist distribution. This method can be expanded in further studies to remove all other systematic errors.

scholarly journals Light-Cone Parton Distribution Functions from Lattice QCD

2018 ◽  
Vol 121 (11) ◽  
Author(s):  
Constantia Alexandrou ◽  
Krzysztof Cichy ◽  
Martha Constantinou ◽  
Karl Jansen ◽  
Aurora Scapellato ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Light Cone ◽  
Distribution Functions ◽  
Parton Distribution Functions

scholarly journals Computation of parton distributions from the quasi-PDF approach at the physical point

2018 ◽  
Vol 175 ◽  
pp. 14008 ◽  
Author(s):  
Constantia Alexandrou ◽  
Simone Bacchio ◽  
Krzysztof Cichy ◽  
Martha Constantinou ◽  
Kyriakos Hadjiyiannakou ◽  
...  
Keyword(s):  
Pion Mass ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Physical Point ◽  
Parton Distributions ◽  
The Matrix ◽  
First Results ◽  
Perturbative Renormalization ◽  
Vector Combination

We show the first results for parton distribution functions within the proton at the physical pion mass, employing the method of quasi-distributions. In particular, we present the matrix elements for the iso-vector combination of the unpolarized, helicity and transversity quasi-distributions, obtained with Nf = 2 twisted mass cloverimproved fermions and a proton boosted with momentum [see formula in PDF] = 0.83 GeV. The momentum smearing technique has been applied to improve the overlap with the proton boosted state. Moreover, we present the renormalized helicity matrix elements in the RI’ scheme, following the non-perturbative renormalization prescription recently developed by our group.

scholarly journals Parton Distribution Functions and Lattice QCD

2019 ◽  
Vol 206 ◽  
pp. 01003
Author(s):  
Huey-Wen Lin
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Pion Mass ◽  
Effective Field ◽  
Distribution Functions ◽  
Large Momentum ◽  
Parton Distribution Functions ◽  
Proton Structure ◽  
Nonperturbative Renormalization ◽  
First Time

Recently, there have been rapid developments in lattice-QCD calculations of proton structure, especially in the parton distribution functions (PDFs). We overcame a longstanding obstacle and for the first time in lattice-QCD are able to directly calculate the Bjorken-x dependence of the quark, helicity and transversity distributions. The PDFs are obtained using the large-momentum effective field theory (LaMET) framework where the full Bjorken-x dependence of finite-momentum PDFs, called “quasi-PDFs”, can be calculated on the lattice. The quasi-PDF nucleon matrix elements are renormalized non-perturbatively in RI/MOM-scheme. Following a nonperturbative renormalization of the parton quasi-distribution in a regularization-independent momentum-subtraction scheme, we establish its matching to the $ \overline {{\rm{MS}}} $ PDF and calculate the non-singlet matching coefficient at next-to-leading order in perturbation theory. In this proceeding, I will show the progress that has been made in recent years, highlighting the latest state-of-the art PDF calculations at the physical pion mass. Future impacts on the large-x global PDF fits are also discussed.

scholarly journals Progress in computing parton distribution functions from the quasi-PDF approach

2018 ◽  
Vol 175 ◽  
pp. 06021 ◽  
Author(s):  
Constantia Alexandrou ◽  
Krzysztof Cichy ◽  
Martha Constantinou ◽  
Kyriakos Hadjiyiannakou ◽  
Karl Jansen ◽  
...  
Keyword(s):  
Parton Distribution ◽  
Distribution Functions ◽  
Matrix Elements ◽  
Parton Distribution Functions ◽  
Mass Collaboration ◽  
Twisted Mass ◽  
The Future ◽  
Systematic Effects ◽  
Perturbative Renormalization

We discuss the current developments by the European Twisted Mass Collaboration in extracting parton distribution functions from the quasi-PDF approach. We concentrate on the non-perturbative renormalization prescription recently developed by us, using the RI′ scheme. We show results for the renormalization functions of matrix elements needed for the computation of quasi-PDFs, including the conversion to the MS scheme, and for renormalized matrix elements. We discuss the systematic effects present in the Z-factors and the possible ways of addressing them in the future.

scholarly journals Pion parton distribution functions from lattice QCD

2004 ◽  
Vol 129-130 ◽  
pp. 281-283 ◽  
Author(s):  
I. Wetzorke ◽  
M. Guagnelli ◽  
K. Jansen ◽  
F. Palombi ◽  
R. Petronzio ◽  
...  
Keyword(s):  
Lattice Qcd ◽  
Parton Distribution ◽  
Distribution Functions ◽  
Parton Distribution Functions
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