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Related papers: Parton Sum Rules and Improved Scaling Variable

200 papers

We present a complete set of formulas for longitudinal momentum distribution functions (splitting functions) of mesons in the nucleon. It can be applied in the framework of convolution formalism to the deep-inelastic structure functions…

High Energy Physics - Phenomenology · Physics 2014-11-17 H. Holtmann , A. Szczurek , J. Speth

In the presence of a large parameter, such as mass or energy, leading behavior of individual Feynman diagrams often get cancelled in the sum. This is known to happen in large-$N_c$ QCD in the presence of a baryon, and also in the case of…

High Energy Physics - Phenomenology · Physics 2009-10-28 C. S. Lam , K. F. Liu

We reanalyze the experimental NMC data on the nonsinglet structure function $F_2^p-F_2^n$ and E866 data on the nucleon sea asymmetry $\bar{d}/\bar{u}$ using the truncated moments approach elaborated in our previous papers. With help of the…

High Energy Physics - Phenomenology · Physics 2021-01-26 A. Kotlorz , D. Kotlorz , O. V. Teryaev

We explore the possibility to construct higher-twist parton distributions in a nucleon at some low reference scale from convolution integrals of the light-cone wave functions (WFs). To this end we introduce simple models for the…

High Energy Physics - Phenomenology · Physics 2011-07-08 V. M. Braun , T. Lautenschlager , A. N. Manashov , B. Pirnay

We fit the reduced cross section for deep-inelastic electron scattering data to a three parameter ln^2 s fit, A + beta ln^2 (s/s_0), where s= [Q^2/x] (1-x) + m^2, and Q^2 is the virtuality of the exchanged photon. Over a wide range in Q^2…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. M. Block , E. L. Berger , C. -I. Tan

We discuss application of the physical QCD effective charge $\alpha_V$, defined via the heavy-quark potential, in perturbative calculations at next-to-leading order. When coupled with the Brodsky-Lepage-Mackenzie prescription for fixing the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Michael Binger , Chueng-Ryong Ji , David G. Robertson

The properties of the B-meson light-cone wave function up to next-to-leading order Fock state expansion have been studied through a comparative study of the $B\to \pi$, $K$ transition form factors within the $k_T$ factorization approach and…

High Energy Physics - Phenomenology · Physics 2009-11-13 Dai-Min Zeng , Xing-Gang Wu , Zhen-Yun Fang

Two new sum rules for the quark tensor charges of the nucleon are proposed, based on a relation connecting the quark transversity distributions to the quark helicity distributions and the quark model spin distributions, and on the sum rules…

High Energy Physics - Phenomenology · Physics 2009-10-30 Bo-Qiang Ma , Ivan Schmidt

Power corrections to the Q**2 behavior of the Nachtmann moments of the proton polarized structure function g1p are investigated at large Bjorken-x by developing a phenomenological fit of both the resonance (including the photon point) and…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Simula , M. Osipenko , G. Ricco , M. Taiuti

The modified Gottfried sum rule makes clear importance of the high energy region not only in the theoretical meaning but also in the numerical analysis. In this talk, it is shown that the soft pion theorem in the inclusive reaction at high…

High Energy Physics - Phenomenology · Physics 2011-04-15 Susumu Koretune

Gaussian sum-rules, which are related to a two-parameter Gaussian-weighted integral of a hadronic spectral function, are able to examine the possibility that more than one resonance makes a significant contribution to the spectral function.…

High Energy Physics - Phenomenology · Physics 2009-11-10 T. G. Steele , D. Harnett , G. Orlandini

We study the effects of a barely perceivable violation of Lorentz invariance on results computed using a relativistic constituent quark model wave function. The model nucleon wave function of Gross {\it et al.} is constructed such thatthere…

Nuclear Theory · Physics 2008-11-26 Alexander Kvinikhidze , Gerald A. Miller

We show that maximally twisted mass fermions can be employed to regularize on the lattice the fully unquenched QCD+QED theory with vanishing $\theta$-term. We discuss how the critical mass of the up and down quarks can be conveniently…

High Energy Physics - Lattice · Physics 2016-12-08 Roberto Frezzotti , Giancarlo Rossi , Nazario Tantalo

The momentum distributions of the constituent quarks inside the nucleon and the prominent electroproduced nucleon resonances are investigated in the two most sophisticated, available quark potential models, based respectively on the…

Nuclear Theory · Physics 2011-04-15 F. Cardarelli , E. Pace , G. Salme' , S. Simula

The generalized Gerasimov-Drell-Hearn (GDH) sum rule is known to be very sensitive to QCD radiative and power corrections. We improve the previously developed QCD-inspired model for the $Q^2$-dependence of the GDH sum rule. We take into…

High Energy Physics - Phenomenology · Physics 2010-10-27 Roman Pasechnik , Jacques Soffer , Oleg Teryaev

We analyze the Fubini-Furlan-Rosetti sum rule in the framework of covariant baryon chiral perturbation theory to leading one-loop accuracy and including next-to-leading order polynomial contributions. We discuss the relation between the…

Nuclear Theory · Physics 2009-11-11 Véronique Bernard , Bastian Kubis , Ulf-G. Meißner

Deep inelastic structure functions for the nucleon are obtained in a constituent quark model on the light cone. In the Bjorken limit the parton model is derived. Structure functions from the hadronic tensor at the scale $\mu \sim 0.25$ GeV…

Nuclear Theory · Physics 2009-09-25 H. J. Weber

Within the OPE, we the new sum rules in Heavy Quark Effective Theory in the heavy quark limit and at order 1/m_Q, using the non-forward amplitude. In particular, we obtain new sum rules involving the elastic subleading form factors chi_i(w)…

High Energy Physics - Phenomenology · Physics 2009-11-11 F. Jugeau , A. Le Yaouanc , L. Oliver , J. -C. Raynal

QCD sum rules for the nucleon are considered in complex q^2 plane with inclusion of the radiative corrections of the order alpha_s. It is shown that the radiative corrections affect mainly the residue lambda^2 of the nucleon pole. Their…

High Energy Physics - Phenomenology · Physics 2009-11-11 V. A. Sadovnikova , E. G. Drukarev , M. G. Ryskin

We investigate the widths of the recently observed charmonium like resonances X(3872), Z(4430) and Z_2(4250) using QCD sum rules. Extending previous analyses regarding these states as diquark-antiquark states or molecules of D mesons, we…

High Energy Physics - Phenomenology · Physics 2008-11-26 Su Houng Lee , Kenji Morita , Marina Nielsen