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Valence quark distributions in transversally and longitudinally polarizied rho mesons in the region of intermediate x are obtained by generalizied QCD sum rules. Power corrections up to d=6 are taken into account. Comparison of the results…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. G. Oganesian

A symmetry-preserving continuum approach to the two valence-body bound-state problem is used to calculate the valence, glue and sea distributions within the pion; unifying them with, inter alia, electromagnetic pion elastic and transition…

High Energy Physics - Phenomenology · Physics 2020-04-22 Minghui Ding , Khépani Raya , Daniele Binosi , Lei Chang , Craig D. Roberts , Sebastian M. Schmidt

In light of recent experimental progress in determining the pressure and shear distributions in the proton, these quantities are calculated in a model with confined quarks supplemented by the pion field required by chiral symmetry. The…

High Energy Physics - Phenomenology · Physics 2023-12-11 Shiryo Owa , A. W. Thomas , X. G. Wang

We analyze new QCD sum rules for the pion wave function $\phi_{\pi}(x)$, obtained recently by A.V. Radyushkin in the framework of the non-local vacuum condensates method for non-diagonal correlators, and suggest a new approach for…

High Energy Physics - Phenomenology · Physics 2016-09-01 A. P. Bakulev , S. V. Mikhailov

In this paper, I investigate the gluon distributions for the kaon and pion, as well as the improvement of the valence-quark distributions, in the framework of the gauge-invariant nonlocal chiral quark model (NL$\chi$QM), where the momentum…

High Energy Physics - Phenomenology · Physics 2025-06-23 Parada T. P. Hutauruk

Pion valence distributions in nuclear medium and vacuum are studied in a light-front constituent quark model. The in-medium input for studying the pion properties is calculated by the quark-meson coupling model. We find that the in-medium…

High Energy Physics - Phenomenology · Physics 2017-01-20 J. P. B. C de Melo , K. Tsushima , I. Ahmed

We argue that parton distributions in coordinate space provide a more natural object for nonperturbative methods compared to the usual momentum distributions in which the physics of different longitudinal distances is being mixed. To…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Braun , P. Górnicki , L. Mankiewicz

We study the pion form factor in a broad range of spacelike momentum transfers within the local-duality version of QCD sum rules. We make use of the recently calculated two-loop double spectral density of the $<AVA>$ correlator including…

High Energy Physics - Phenomenology · Physics 2008-11-26 Victor Braguta , Wolfgang Lucha , Dmitri Melikhov

We consider the pion structure in the region of low and moderately high momentum transfers: at low $Q^2$, the pion is treated as a composite system of constituent quarks; at moderately high momentum transfers, $Q^2=10\div25\;GeV^2$, the…

High Energy Physics - Phenomenology · Physics 2009-10-28 V. Anisovich , D. Melikhov , V. Nikonov

The distributions of the quark number and chiral condensate over the gauge fields are computed for QCD in Euclidean space at nonzero quark chemical potential. As both operators are non-hermitian the distributions are in the complex plane.…

High Energy Physics - Lattice · Physics 2014-11-20 M. P. Lombardo , K. Splittorff , J. J. M. Verbaarschot

In my talk I discuss the theoretical and experimental status of the pion distribution amplitude (DA). I show that the QCD sum rule method with nonlocal condensates (NLC) for the pion DA gives us admissible sets (bunches) of DAs for each…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alexander P. Bakulev

We calculate the QCD moments of the pion structure function using Drell-Yan data on the quark distributions in the pion and a phenomenological model for the resonance region. The extracted higher twist corrections are found to be larger…

High Energy Physics - Phenomenology · Physics 2014-11-17 W. Melnitchouk

We study the quark Wigner distributions of the pion meson which are the phase-space distributions containing the most general one-parton information.Using the pion wavefunctions deduced from a light-cone quark model, we calculate the Wigner…

High Energy Physics - Phenomenology · Physics 2018-10-03 Zhi-Lei Ma , Zhun Lu

The impulse-approximation expression used hitherto to define the pion's valence-quark distribution function is flawed because it omits contributions from the gluons which bind quarks into the pion. A corrected leading-order expression…

Based on both the constituent quark picture and the instanton model for QCD vacuum, we calculate the unpolarized and polarized gluon distributions in the constituent quark and in the nucleon. Our approach consists of the two main steps. At…

High Energy Physics - Phenomenology · Physics 2016-05-04 Nikolai Kochelev , Hee-Jung Lee , Baiyang Zhang , Pengming Zhang

We use phenomenological nonlocal Lagrangians, which lead to non trivial forms for the quark propagator, to describe the pion. We define a procedure, based on the Dyson-Schwinger equations, for the calculation of the pion parton…

High Energy Physics - Phenomenology · Physics 2009-11-11 S. Noguera , V. Vento

We present the first systematic study of higher-twist light-cone distribution amplitudes of the nucleon in QCD. We find that the valence three-quark state is described at small transverse separations by eight independent distribution…

High Energy Physics - Phenomenology · Physics 2016-09-06 V. Braun , R. J. Fries , N. Mahnke , E. Stein

The transverse-momentum dependent quark distributions are studied in the limit of the large number of colors Nc. The leading orders of Nc are determined for all twist-2 distributions including the T-odd functions. The isospin structure of…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. V. Pobylitsa

We present a systematic study of twist three light-cone distribution amplitudes of vector mesons in QCD, which is based on conformal expansion and takes into account meson and quark mass corrections. A complete set of distribution…

High Energy Physics - Phenomenology · Physics 2010-01-07 Patricia Ball , V. M. Braun , Y. Koike , K. Tanaka

We present a factorization formula for valence quark distributions in a hadron in x-->1 limit. For the example of pion, we arrive at the form of factorization by analyzing momentum flow in the leading and high-order Feynman diagrams. The…

High Energy Physics - Phenomenology · Physics 2010-04-05 Xiangdong Ji , Jian-Ping Ma , Feng Yuan