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Related papers: Collins-Soper Kernel in the QCD Instanton Vacuum

200 papers

We present results from a study of light meson spectra and structure obtained within the framework of light-front QCD formulated on a transverse lattice. We discuss how imposing Lorentz covariance conditions on meson dispersion relations…

High Energy Physics - Phenomenology · Physics 2009-11-07 M. Burkardt , S. K. Seal

Semi-Inclusive Deep-Inelastic Scattering provides unique access to the three-dimensional momentum and spin structure of the proton, enabling precise studies of parton dynamics and hadronization in QCD. We present a transverse-momentum…

High Energy Physics - Phenomenology · Physics 2026-02-09 Jun Gao , Hai Tao Li , Hua Xing Zhu , Yu Jiao Zhu

We propose a method to non-perturbatively calculate the forward-scattering matrix elements relevant to inclusive semi-leptonic B meson decays. Corresponding hadronic structure functions at unphysical kinematics are accessible through…

High Energy Physics - Lattice · Physics 2019-12-06 Shoji Hashimoto

We present the first lattice determination of the two lowest Gegenbauer moments of the leading-twist pion and kaon light-cone distribution amplitudes with full control of all errors. The calculation is carried out on 35 different CLS…

This work presents the first calculation in lattice QCD of three moments of spin-averaged and spin-polarized generalized parton distributions in the proton. It is shown that the slope of the associated generalized form factors decreases…

High Energy Physics - Lattice · Physics 2012-08-27 LHPC , SESAM Collaborations , : , Ph. Hagler , J. W. Negele , D. B. Renner , W. Schroers , Th. Lippert , K. Schilling

We present the first lattice-QCD calculation of the isovector polarized parton distribution functions (both helicity and transversity) using the large-momentum effective field theory (LaMET) approach for direct Bjorken-$x$ dependence. We…

High Energy Physics - Phenomenology · Physics 2016-09-21 Jiunn-Wei Chen , Saul D. Cohen , Xiangdong Ji , Huey-Wen Lin , Jian-Hui Zhang

Within the theory of Quantum Chromodynamics (QCD), the rich structure of hadrons can be quantitatively characterized, among others, using a basis of universal non-perturbative functions: parton distribution functions (PDFs), generalized…

High Energy Physics - Lattice · Physics 2019-06-14 Krzysztof Cichy , Martha Constantinou

We present a global analysis of Sivers functions, transversity distribution functions, and Collins fragmentation functions within the transverse momentum dependent factorization. This analysis encompasses the latest data from semi-inclusive…

High Energy Physics - Phenomenology · Physics 2024-12-25 Chunhua Zeng , Hongxin Dong , Tianbo Liue , Peng Sun , Yuxiang Zhao

In this paper we implement Schwinger-Keldysh closed-time path integral formalism in non-equilibrium QCD to the definition of Collins-Soper fragmentation function. We consider a high p_T parton in QCD medium at initial time t_0 with…

High Energy Physics - Phenomenology · Physics 2014-11-18 Gouranga C Nayak

We discuss the evolution of the eight leading twist transverse momentum dependent parton distribution functions, which turns out to be universal and spin independent. By using the highest order perturbatively calculable ingredients at our…

High Energy Physics - Phenomenology · Physics 2015-06-11 Miguel G. Echevarria , Ahmad Idilbi , Andreas Schäfer , Ignazio Scimemi

We present a fit of the transverse momentum spectrum for Drell-Yan and semi-inclusive deep inelastic scattering data, based on transverse momentum dependent (TMD) factorization at N$^4$LL accuracy. Our analysis shows good agreement with the…

High Energy Physics - Phenomenology · Physics 2025-10-06 Valentin Moos , Ignazio Scimemi , Alexey Vladimirov , Pia Zurita

Using soft collinear effective field theory, we derive the factorization theorem for the quasi-transverse-momentum-dependent (quasi-TMD) operator. We check the factorization theorem at one-loop level and compute the corresponding…

High Energy Physics - Phenomenology · Physics 2020-05-06 Alexey A. Vladimirov , Andreas Schäfer

We show that the geometry of the Wilson lines, entering the operator definition of the transverse-momentum dependent parton distributions and that of the soft factor, follows from the kinematics of the underlying physical process in…

High Energy Physics - Phenomenology · Physics 2014-04-08 A. A. Vladimirov , N. G. Stefanis

We show the results of low-energy chiral quark models for soft matrix elements involving pions and photons. Such soft elements, upon convolution with the hard matrix elements, are relevant in various high-energy processes. We focus on…

High Energy Physics - Phenomenology · Physics 2009-10-02 Wojciech Broniowski , Enrique Ruiz Arriola

A global analysis of the experimental data on azimuthal asymmetries in semi-inclusive deep inelastic scattering (SIDIS), from the HERMES and COMPASS Collaborations, and in e+e- --> h1 h2 X processes, from the BELLE Collaboration, is…

High Energy Physics - Phenomenology · Physics 2010-04-06 M. Anselmino , M. Boglione , U. D'Alesio , A. Kotzinian , F. Murgia , A. Prokudin , C. Turk

In this paper we briefly review the transverse momentum dependent generalized parton model and its application to the study of azimuthal asymmetries in the distribution of leading hadrons (mainly pions) inside large transverse momentum jets…

High Energy Physics - Phenomenology · Physics 2015-06-16 Umberto D'Alesio , Francesco Murgia , Cristian Pisano

The instanton contribution to the quark distribution functions in the nucleon is estimated. It is shown, that taking into account the instanton induced interaction between quarks allows to explain the anomalous violation of the Ellis-Jaffe…

High Energy Physics - Phenomenology · Physics 2007-05-23 N. I. Kochelev

We study the gluon parton densities [parton distribution functions (PDFs), transverse momentum distributions (TMDs), generalized parton distributions (GPDs)] and form factors in soft-wall AdS/QCD. We show that the power behavior of gluon…

High Energy Physics - Phenomenology · Physics 2021-05-18 Valery E. Lyubovitskij , Ivan Schmidt

We study QCD evolution equations of the first transverse-momentum-moment of the naive-time-reversal-odd fragmentation functions - the Collins function and the polarizing fragmentation function. We find for the Collins function case that the…

High Energy Physics - Phenomenology · Physics 2011-02-23 Zhong-Bo Kang

The in-medium dispersion of hard partons, encoded in their so-called asymptotic mass, receives large non-perturbative contributions from classical gluons, i.e. soft gluons with large occupation numbers. Here, we discuss how the analytical…

High Energy Physics - Phenomenology · Physics 2023-07-19 Jacopo Ghiglieri , Guy D. Moore , Philipp Schicho , Niels Schlusser , Eamonn Weitz