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The correlation between vorticity and spin alignment in heavy-ion collisions can be probed through polarization measurements of hadrons, whose total spin originates from both constituent-quark spins and orbital angular momentum in the…

We calculate the valence quark distribution functions of the $\pi$ meson using the non-relativistic chiral constituent quark model. The $\pi$ wave function is obtained by solving the two-body Schr\"odinger equation within the framework of…

High Energy Physics - Phenomenology · Physics 2023-08-21 Qian Wu , Chengdong Han , Di Qing , Wei Kou , JuJun Xie , Fan Wang , Xurong Chen

We present the full O(alpha_s) longitudinal spin-spin correlations for heavy-quark pair production at e+ e- high-energy colliders in closed analytical form. In such reactions, quark and antiquark have strongly correlated spins, and the…

High Energy Physics - Phenomenology · Physics 2009-10-30 M. M. Tung , J. Bernabeu , J. Penarrocha

A QCD factorization formalism was recently proposed for evaluating heavy quarkonium production at large $p_T$ at collider energies. With systematically calculated short-distance partonic hard parts and evolution kernels of fragmentation…

High Energy Physics - Phenomenology · Physics 2014-06-11 Yan-Qing Ma , Jian-Wei Qiu , Hong Zhang

We present an analytical calculation of the $\alpha_s$ corrections for the coefficient of $\rho_D/m_Q^3$ term in the heavy quark expansion for the inclusive semileptonic decays of heavy hadrons, such as $B \to X_c \ell \bar{\nu}$. The full…

High Energy Physics - Phenomenology · Physics 2019-11-20 Thomas Mannel , Alexei A. Pivovarov

Based on the light-cone (LC) framework and the $k_T$ factorization formalism, the transverse momentum effects and the different helicity components' contributions to the pion form factor $F_{\pi}(Q^2)$ are recalculated. In particular, the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Xing-Gang Wu , Tao Huang

New results at four-loop order in perturbative QCD for the first two Taylor coefficients of the heavy quark vacuum polarization function are presented. They can be used to perform a precise determination of the charm- and bottom-quark mass.…

High Energy Physics - Phenomenology · Physics 2009-01-07 K. G. Chetyrkin , J. H. Kühn , C. Sturm

We study the effect of the resummation of logarithms for t\bar{t} production near threshold and inclusive electromagnetic decays of heavy quarkonium. This analysis is complete at next-to-next-to-leading order and includes the full…

High Energy Physics - Phenomenology · Physics 2009-11-11 Antonio Pineda , Adrian Signer

In a consistently formulated pQCD framework incorporating non-zero mass heavy quark partons, there is still the freedom to define parton distributions obeying either mass-independent or mass-dependent evolution equations, contrary to…

High Energy Physics - Phenomenology · Physics 2009-10-30 Fredrick I. Olness , Randall J. Scalise

We present all relevant details of our calculation of the complete next-to-leading order (O(alpha_s^2 alpha)) QCD corrections to heavy flavor photoproduction with longitudinally polarized point-like photons and hadrons. In particular we…

High Energy Physics - Phenomenology · Physics 2011-01-25 I. Bojak , M. Stratmann

With Wilson quarks, on-shell O($a$) improvement of the lattice QCD action is achieved by including the Sheikholeslami-Wohlert term and two further operators of mass dimension 5, which amount to a mass-dependent rescaling of the bare…

High Energy Physics - Lattice · Physics 2024-02-02 Mattia Dalla Brida , Roman Höllwieser , Francesco Knechtli , Tomasz Korzec , Stefan Sint , Rainer Sommer

The three-loop QCD corrections to the $\rho$ parameter from top and bottom quark loops are calculated. The result differs from the one recently calculated by Avdeev et al. As function of the pole mass the numerical value is given by…

High Energy Physics - Phenomenology · Physics 2016-09-01 K. G. Chetyrkin , J. H. Kuehn , M. Steinhauser

We provide analytical results for the $O(\alpha_s)$ corrections to the polar angle dependence of the longitudinal spin-spin correlation asymmetry in $e^+e^-\to q\bar q$. For top quark pair production the $O(\alpha_s)$ corrections to the…

High Energy Physics - Phenomenology · Physics 2014-03-13 S. Groote , J. G. Körner , J. A. Leyva

The contribution of quarks with masses m >> Lambda_QCD is the only part of the structure functions in deep-inelastic scattering (DIS) which is not yet known at the next-to-next-to-leading order (NNLO) of perturbative QCD. We present…

High Energy Physics - Phenomenology · Physics 2016-08-09 H. Kawamura , N. A. Lo Presti , S. Moch , A. Vogt

In this work corrections to low energy punctual effective quark couplings up to the eighth order are calculated by considering vacuum polarization effects with the scalar quark-antiquark condensate. The departing point is a QCD-based NJL…

High Energy Physics - Phenomenology · Physics 2014-08-11 Ademar Paulo , Fabio L. Braghin

The complete next to leading logarithmic (${\cal O}(\alpha_{s})$) corrections to the spin dependent weak deep inelastic structure functions $g_{1},g_{3}$ and $g_{4}$, are calculated using dimensional regularization within the HVBM method.…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. de Florian , R. Sassot

We use a recently completed O(alpha_s^2) fixed-order calculation of the heavy-flavour production cross section in e+e- collisions to compute the heavy-quark fragmentation function. We fit the result of our calculation, convoluted with a…

High Energy Physics - Phenomenology · Physics 2009-10-31 Paolo Nason , Carlo Oleari

We calculate the longitudinal contribution to the alignment polarization $\Pl$ of quarks produced in $e^+e^-$ annihilation. In the Standard Model, the longitudinal alignment polarization vanishes at the Born term level and thus receives its…

High Energy Physics - Phenomenology · Physics 2007-05-23 S. Groote , J. G. K"orner , M. M. Tung

We present in detail the calculation of the O(alpha_s^3) inclusive total cross section for the process pp -> t-tbar-h, in the Standard Model, at the CERN Large Hadron Collider with center-of-mass energy sqrt(s_H)=14 TeV. The calculation is…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Dawson , C. Jackson , L. H. Orr , L. Reina , D. Wackeroth

We introduce a model independent method for the determination of the hadronic contribution to the QED running coupling, $\Delta\alpha_{\text{HAD}}(M_{Z}^{2})$, requiring no $e^+e^-$ annihilation data as input. This is achieved by…

High Energy Physics - Phenomenology · Physics 2015-06-11 S. Bodenstein , C. A. Dominguez , K. Schilcher , H. Spiesberger
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