English
Related papers

Related papers: QCD Form Factors and Hadron Helicity Non-Conservat…

200 papers

Hadronization corrections to the predictions of perturbative QCD are reviewed. The existing models for the conversion of quarks and gluons into hadrons are summarized. The most successful models give a good description of the data on…

High Energy Physics - Phenomenology · Physics 2008-02-03 Bryan Webber

The nucleon form factors are calculated using a non-relativistic description in terms of constituent quarks. The emphasis is put on the reliability of present numerical methods used to solve the three-body problem in order to correctly…

Nuclear Theory · Physics 2009-10-31 B. Desplanques , B. Silvestre-Brac , F. Cano , P. Gonzalez , S. Noguera

Quark splitting in non-trivial $\theta$-vacuum with a given helicity is investigated in pQCD with a modified quark propagator. We found that the quark splitting functions were modified by the presence of a topologically non-trivial QCD…

High Energy Physics - Phenomenology · Physics 2015-05-20 Hongxi Xing , Xin-Nian Wang , Feng Yuan

The ratio $R_p$ between the electric and magnetic proton form factors has been recently measured at JLab up to $Q^2=8.5 ~GeV^2$. We have extended the calculation of the nucleon form factors with the hypercentral Constituent Quark Model and…

Nuclear Theory · Physics 2015-06-30 E. Santopinto , A. Vassallo , M. M. Giannini , M. De Sanctis

A formalism for the relativistic description of hadron decays within the constituent quark model is presented. First, hadron amplitudes of the light--cone constituent quark model, in particular the weak transition form factors at spacelike…

High Energy Physics - Phenomenology · Physics 2009-10-28 D. Melikhov

Gravitational form factors (GFFs) of hadrons encode essential information about the internal distributions of mass, spin, pressure, and shear among their quark and gluon constituents. We compute the quark and gluon GFFs of the proton using…

High Energy Physics - Phenomenology · Physics 2025-06-10 Sreeraj Nair , Chandan Mondal , Siqi Xu , Xingbo Zhao , James P. Vary

We present the first direct calculation on the gravitational form factors (GFFs) of the $N \rightarrow \Delta$ transition using an analytic method, the QCD light-cone sum rules. The matrix element of the quark part of the energy momentum…

High Energy Physics - Phenomenology · Physics 2023-03-22 U. Özdem , K. Azizi

In the framework of pertubative QCD it is argued that in the elastic $ed$-scattering at $Q^{2}\sim$ few $(GeV/c)^{2}$ the light-cone-frame helicity-flip amplitudes could not be omitted. The obtained $\frac{B}{A}$ ratio of Rosenbluth…

High Energy Physics - Phenomenology · Physics 2009-10-22 A. Kobushkin , A. Syamtomov

In this article, we calculate the vector form factors $f^+_{K\pi}(Q^2)$ and $f^-_{K\pi}(Q^2)$ within the framework of the light-cone QCD sum rules approach. The numerical values of the $f^+_{K\pi}(Q^2)$ are compatible with the existing…

High Energy Physics - Phenomenology · Physics 2008-11-26 Z. G. Wang , S. L. Wan

The effects of large scale mechanical forcing on the dynamics of rotating turbulent flows are studied by means of numerical simulations, varying systematically the nature of the mechanical force in time. We demonstrate that the…

Fluid Dynamics · Physics 2016-06-29 Vassilios Dallas , Steve Tobias

The properties of the non-forward quark-quark correlation function are examined. We derive constraints on the correlation function from the transformation properties of the fundamental fields of QCD occurring in its definition. We further…

High Energy Physics - Phenomenology · Physics 2008-11-26 Sabrina Casanova

In the heavy quark effective theory, hadronic matrix elements of currents between two hadrons containing a heavy quark are expanded in inverse powers of the heavy quark masses, with coefficients that are functions of the kinematic variable…

High Energy Physics - Phenomenology · Physics 2009-10-22 Adam F. Falk , Matthias Neubert

The recent LHCb angular analysis of the exclusive decay B->K^*mu+mu- has indicated significant deviations from the Standard Model expectations. Accurate predictions can be achieved at large K*-meson recoil for an optimised set of…

High Energy Physics - Phenomenology · Physics 2015-06-22 Sébastien Descotes-Genon , Lars Hofer , Joaquim Matias , Javier Virto

We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^*p\to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio…

High Energy Physics - Phenomenology · Physics 2014-11-17 V. M. Belyaev , A. V. Radyushkin

It is shown that the form factors in the semileptonic decay of ground state heavy mesons to light pseudoscalar mesons are dominated by the vector meson pole at all momentum transfers. First, the general approaches to modeling form factors…

High Energy Physics - Phenomenology · Physics 2009-10-28 Benjamin Grinstein , Paul F. Mende

We use local quark-hadron duality to estimate the purely nonperturbative soft contribution to the $\gamma^* p \to \Delta$ form factors. Our results are in agreement with existing experimental data. We predict that the ratio…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. M. Belyaev , A. V. Radyushkin

We argue that at moderately large momentum transfer -t <10 GeV^2, hadronic form factors and wide-angle Compton scattering amplitudes are dominated by mechanism corresponding to overlap of soft wave functions. We show that the soft…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. V. Radyushkin

We obtain the gravitational form factors (GFFs) and investigate their applications for the description of the mechanical properties, i.e., the distributions of pressures, shear forces inside proton, and the mechanical radius, in a…

High Energy Physics - Phenomenology · Physics 2020-12-29 Dipankar Chakrabarti , Chandan Mondal , Asmita Mukherjee , Sreeraj Nair , Xingbo Zhao

We perform a perturbative QCD analysis of the gluonic gravitational form factors (GFFs) of the proton and pion at large momentum transfer. We derive the explicit factorization formula of the GFFs in terms of the distribution amplitudes of…

High Energy Physics - Phenomenology · Physics 2021-11-03 Xuan-Bo Tong , Jian-Ping Ma , Feng Yuan

In the fragmentation of a heavy quark into a heavy meson whose light degrees of freedom have angular momentum $3/2$, all the helicity probabilities are completely determined in the heavy quark limit up to a single probability $w_{3/2}$. We…

High Energy Physics - Phenomenology · Physics 2009-10-28 Tzu Chiang Yuan