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Recent developements in the calculation of the NNLO QCD corrections to the charm quark mass dependent matrix elements in B -> X_s gamma are reported. Special emphasis is put on the new results of the virtual O(alpha_s^2) fermionic…

High Energy Physics - Phenomenology · Physics 2007-12-12 Radja Boughezal

I describe the recent success in performing accurate calculations of the effects of the strong force on particles containing bottom and charm quarks. Since quarks are never seen in isolation, and so cannot be studied directly, numerical…

High Energy Physics - Lattice · Physics 2009-11-11 Christine Davies

The eigenvalue spectrum $\rho(\lambda)$ of the Dirac operator is numerically calculated in lattice QCD with 2+1 flavors of dynamical domain-wall fermions. In the high-energy regime, the discretization effects become significant. We subtract…

High Energy Physics - Lattice · Physics 2018-07-11 Katsumasa Nakayama , Hidenori Fukaya , Shoji Hashimoto

Heavy-quark effects on the equation of state for cold and dense quark matter are obtained from perturbative QCD, yielding observables parametrized only by the renormalization scale. In particular, we investigate the thermodynamics of charm…

High Energy Physics - Phenomenology · Physics 2022-02-16 José C. Jiménez , Eduardo S. Fraga

The charm quark contribution to the first moment of $g_1(x,Q^2)$ is calculated using a heavy mass expansion of the divergence of the singlet axial current. It is shown to be small.

High Energy Physics - Phenomenology · Physics 2009-12-30 M. V. Polyakov , A. Schaefer , O. V. Teryaev

Discretization artifacts proportional to the quark mass can limit the precision of strong-coupling determinations in lattice QCD, especially in the presence of heavy quarks. In this work, we perform a lattice perturbative analysis of such…

High Energy Physics - Lattice · Physics 2026-03-03 Marios Costa , Demetrianos Gavriel , Haralambos Panagopoulos , Gregoris Spanoudes

We present a strategy designed to separate several possible origins of the well-known enhancement of the Delta{I}=1/2 amplitude in non-leptonic kaon decays. In particular, we seek to disentangle the contribution of physics at the typical…

High Energy Physics - Lattice · Physics 2008-11-26 L. Giusti , P. Hernandez , M. Laine , P. Weisz , H. Wittig

We describe a new technique (published in Phys. Rev. D89 114501) to determine the contribution to the anomalous magnetic moment of the muon coming from the hadronic vacuum polarisation using lattice QCD. Our method uses Pad\'e approximants…

We computed the static potential and Wilson loops to $O(\alpha^2)$ in perturbation theory for different lattice quark and gluon actions. In general, we find short distance lattice data to be well described by ``boosted perturbation…

High Energy Physics - Lattice · Physics 2015-06-25 G. S. Bali , P. Boyle , C. T. H. Davies

Effects of heavy sea quarks on the low energy physics are described by an effective theory where the expansion parameter is the inverse quark mass, 1/$M$. At leading order in 1/$M$ (and neglecting light quark masses) the dependence of any…

The static potential between an infinitely heavy quark and antiquark is derived in the framework of perturbative QCD to three loops by performing a full calculation of the two-loop diagrams and using the renormalization group. The…

High Energy Physics - Phenomenology · Physics 2009-10-28 Markus Peter

We compute the leading-order low-energy constants of the DeltaS=1 effective weak Hamiltonian in the quenched approximation of QCD with up, down, strange, and charm quarks degenerate and light. They are extracted by comparing the predictions…

High Energy Physics - Phenomenology · Physics 2008-11-26 L. Giusti , P. Hernandez , M. Laine , C. Pena , J. Wennekers , H. Wittig

We consider the three-loop corrections to the static potential which are induced by a closed fermion loop. For the reduction of the occurring integrals a combination of the Gr\"obner and Laporta algorithm has been used and the evaluation of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexander V. Smirnov , Vladimir A. Smirnov , Matthias Steinhauser

The truncation of the perturbative series at one loop order for the mass renormalization constants remain a significant systematic uncertainty in the determination of heavy quark masses in lattice QCD. We present here a high beta Monte…

High Energy Physics - Lattice · Physics 2009-11-07 K. J. Juge

It is expected that the only effect of heavy dynamical fermions in QCD is to renormalize the gauge coupling. We derive a simple expression for the shift in the gauge coupling induced by $N_f$ flavors of heavy fermions. We compare this…

High Energy Physics - Lattice · Physics 2009-10-22 Anna Hasenfratz , Thomas A. DeGrand

We investigate the impact of including a dynamical charm quark on the properties of light hadrons. Our study uses gauge ensembles generated with the tadpole-improved Symanzik gauge action, comparing 2+1+1 flavor (HISQ fermion) ensembles at…

High Energy Physics - Lattice · Physics 2026-03-05 Tong-Wei Lin , Zun-Xian Zhang , Mengchu Cai , Hai-Yang Du , Bolun Hu , Xiangyu Jiang , Xiao-Lan Meng , Ji-Hao Wang , Peng Sun , Yi-Bo Yang , Dian-Jun Zhao

In view of the recent excitement about a tension between determinations of f_Ds from experiment and from simulations of lattice QCD with dynamical quarks, we try to clear up the picture of lattice determinations in the continuum limit of…

High Energy Physics - Lattice · Physics 2011-04-04 Jochen Heitger , Andreas Juttner

A recently proposed strategy to quantify the role of the charm quark mass in the $\Delta I=1/2$ rule is reviewed. Results for the low-energy couplings of the $\Delta S=1$ chiral effective Hamiltonian in a theory with a light charm quark…

High Energy Physics - Lattice · Physics 2008-11-26 P. Hernandez

QCD in two dimensions is investigated using the improved fermionic lattice Hamiltonian proposed by Luo, Chen, Xu, and Jiang. We show that the improved theory leads to a significant reduction of the finite lattice spacing errors. The quark…

High Energy Physics - Lattice · Physics 2016-08-15 Jun-Qin Jiang , Xiang-Qian Luo , Zhong-Hao Mei , Hamza Jirari , Helmut Kröger , Chi-Min Wu

We study field strength correlators in presence of a static quark-antiquark pair by use of lattice methods. The lattice data have been acquired recently in the context of a determination of relativistic corrections to the static interquark…

High Energy Physics - Lattice · Physics 2014-11-17 Gunnar S. Bali , Nora Brambilla , Antonio Vairo