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We present a method to evaluate the pion structure functions from a box diagram calculation. Pion and constituent quark fields are coupled through the simplest pseudoscalar coupling. The gamma^* pi -> q \bar q cross-section is evaluated and…

High Energy Physics - Phenomenology · Physics 2009-11-07 J. P. Lansberg , F. Bissey , J. R. Cudell , J. Cugnon , M. Jaminon , P. Stassart

We report the results of a new measurement of spin structure functions of the deuteron in the region of moderate momentum transfer ($Q^2$ = 0.27 -- 1.3 (GeV/c)$^2$) and final hadronic state mass in the nucleon resonance region ($W$ = 1.08…

High Energy Physics - Experiment · Physics 2019-08-15 J. Yun , S. E. Kuhn , G. E. Dodge , T. A. Forest , M. Taiuti

Using the light-front pion wave function based on a Bethe-Salpeter amplitude model, we study the properties of the pion in symmetric nuclear matter. The pion model we adopt is well constrained by previous studies to explain the pion…

High Energy Physics - Phenomenology · Physics 2014-09-10 J. P. B. C. de Melo , K. Tsushima , Bruno El-Bennich , E. Rojas , T. Frederico

Partonic structure of constituent quark (or{\it{valon}}) in the Next-to-Leading Order is used to calculate pion structure function. This is a further demonstration of the finding that the constituent quark structure is universal, and once…

High Energy Physics - Phenomenology · Physics 2009-11-10 Firooz Arash

We investigate shadowing corrections to the polarized deuteron structure functions g_1^d and b_1. In the kinematic domain of current fixed target experiments we observe that shadowing effects in g_1^d are approximately twice as large as for…

Nuclear Theory · Physics 2009-10-30 J. Edelmann , G. Piller , W. Weise

The deuteron disintegration process with the emission of fast proton in the vicinity of the kinematical boundary of the reaction, when Feynman variable $x\to 2$, is studied. The consideration is fulfilled in the framework of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. A. Braun , V. V. Vechernin

A coherent state of pions is introduced to the nonrelativistic quark model. The coherent pair approximation is employed for the pion field in order to maintain the spin-isospin symmetry. In this approximation the pion is localized in the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Masanori Morishita , Masaki Arima

The electromagnetic form factors of $\pi$ and $K$ mesons and deuteron are calculated in modified impulse approximation using instant form of relativistic Hamiltonian dynamics. The different model wave functions are used. Meson wave function…

High Energy Physics - Phenomenology · Physics 2007-05-23 A. F. Krutov , V. E. Troitsky

Nuclear effects in the spin-dependent structure function $g_1$ of the deuteron are studied in the kinematics of future experiments at CEBAF, ($\nu \leq 3~GeV, ~Q^2 \leq 2~GeV^2$). The magnitude of nuclear effects is found to be…

Nuclear Theory · Physics 2015-06-26 C. Ciofi degli Atti , S. Scopetta , A. Yu. Umnikov , L. P. Kaptari

Measurements are reported of the proton and deuteron spin structure functions g1 at beam energies of 29.1, 16.2, and 9.7 GeV and g2 at a beam energy of 29.1 GeV. The integrals of g1 over x have been evaluated at fixed Q**2 = 3 (GeV/c)**2…

High Energy Physics - Phenomenology · Physics 2012-08-27 E143 collaboration

The structure and electroweak properties of the pion in symmetric nuclear matter are presented in the framework of the Nambu--Jona-Lasinio model. The pion is described as a bound state of a dressed quark-antiquark pair governed by the…

Nuclear Theory · Physics 2020-01-08 Parada. T. P. Hutauruk , Yongseok Oh , K. Tsushima

We examine the present status of the Bjorken sum rule in the light of recent data on the spin structure functions of the proton, neutron and deuteron obtained by the CERN and SLAC experimental groups. We also discuss the role of possible…

High Energy Physics - Phenomenology · Physics 2008-02-03 Philip G. Ratcliffe

The spin dependent deuteron structure functions are investigated in the relativistic model of deuteron. It is shown that the deuteron structure function $g_{2}(X)$ can be considered properly only in the infinite momentum frame where the…

High Energy Physics - Phenomenology · Physics 2009-10-28 N. L. Ter-Isaakyan

The strong interaction shift $\epsilon$ and broadening {\Gamma} in pionic deuterium have been determined in a high statistics study of the {\pi}D(3p - 1s) X-ray transition using a high-resolution crystal spectrometer. The pionic deuterium…

The chiral-odd structure function h_{1}^D(x) and the tensor charge of the deuteron are studied within the Bethe-Salpeter formalism for the deuteron amplitude. Utilizing a simple model for the nucleon structure function, h_1^N, h_1^D(x) is…

High Energy Physics - Phenomenology · Physics 2009-10-28 A. Yu. Umnikov , Han-xin He , F. C. Khanna

Precise measurements of the spin structure functions of the proton $g_1^p(x,Q^2)$ and deuteron $g_1^d(x,Q^2)$ are presented over the kinematic range $0.0041 \leq x \leq 0.9$ and $0.18 $ GeV$^2$ $\leq Q^2 \leq 20$ GeV$^2$. The data were…

High Energy Physics - Experiment · Physics 2012-08-03 The HERMES Collaboration , A. Airapetian

Pion loop fluctuations of the constituent u and d quarks are shown to give only a minute contribution to the intrinsic charge radius of the neutron, under the assumption that the pion-quark coupling constant has its conventional value, with…

High Energy Physics - Phenomenology · Physics 2011-02-01 L. Ya. Glozman , D. O. Riska

Shadowing corrections to structure functions of heavy nuclei are calculated at very low values of Bjorken-$x$ and at values of the momentum transfer relevant to recent experiments. Good agreement is obtained with data from the E665…

Nuclear Theory · Physics 2008-11-26 W. Melnitchouk , A. W. Thomas

A color-flavor-spin singlet state of six quarks $uuddss$ ($S$, or sexaquark) has been argued to be a potentially undiscovered deeply bound, long-lived hadron. Theoretical calculations of the $S$ mass have been made in the literature, widely…

High Energy Physics - Phenomenology · Physics 2023-09-28 Glennys R. Farrar , Zihui Wang

Pion structure functions are considered in the framework of QCD sum rules at the next to leading order. The 2-loop diargam, representing the gluon exchange between the struck quark and spectator, is calculated for space-like pion momentum…

High Energy Physics - Phenomenology · Physics 2007-05-23 K. N. Zyablyuk