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We present the current status of our lattice QCD determination of the charm quark mass using $N_\mathrm{f}=2+1$ dynamical, non-perturbatively $\mathrm{O}(a)$ improved Wilson fermions. A subset of CLS ensembles with five different lattice…

High Energy Physics - Lattice · Physics 2019-09-13 Jochen Heitger , Fabian Joswig , Simon Kuberski

We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay rate of a $b$-quark into inclusive semileptonic charmless final states. Our calculation provides genuine two-loop QCD corrections, beyond the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Mathias Brucherseifer , Fabrizio Caola , Kirill Melnikov

We consider non-perturbative QCD effects on the energy spectrum of either one of the photons in B -> X_s gamma gamma. These are due to the subprocesses in which a charm quark loop interacts with a self-consistently produced background…

High Energy Physics - Phenomenology · Physics 2008-11-26 S. Rai Choudhury , York-Peng Yao

We calculate the three-loop master integrals of Ref. [1] [arXiv:1709.02160] in analytic form. This allows us to present the fermionic contributions to the $\Delta B=2$ Wilson coefficients of the $B$-$\bar B$ decay matrix in…

High Energy Physics - Phenomenology · Physics 2022-07-06 Artyom Hovhannisyan , Ulrich Nierste

QCD corrections to the gluino induced contribution to b --> s gamma are shown to be important in order to extract reliable bounds on the off-diagonal elements of the squark mass matrices.

High Energy Physics - Phenomenology · Physics 2007-05-23 C. Greub , T. Hurth , D. Wyler

In this paper we take the first step towards a complete next-to-next-to-leading logarithmic (NNLL) calculation of the inclusive decay rate for $B \to X_s\gamma$. We consider the virtual corrections of order $\alphas^2 n_f$ to the matrix…

High Energy Physics - Phenomenology · Physics 2008-11-26 Kay Bieri , Christoph Greub , Matthias Steinhauser

We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis…

High Energy Physics - Phenomenology · Physics 2009-02-23 Guido Bell

We compute the fermionic contribution to the strong coupling $\alpha_{qq}$ extracted from the static force in Lattice QCD up to order $g^4$ in perturbation theory. This allows us to subtract the leading fermionic lattice artifacts from…

High Energy Physics - Lattice · Physics 2018-04-18 Salvatore Cali , Francesco Knechtli , Tomasz Korzec , Haralambos Panagopoulos

We study radiative corrections to $\bar{B} \to X_c \ell \bar{\nu}_\ell$ decays assuming the power counting $m_c \sim \sqrt{\Lambda_QCD m_b}$ for the charm-quark mass. Concentrating on the shape-function region, we use effective field-theory…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Boos , Th. Feldmann , T. Mannel , B. D. Pecjak

Next-to-leading order QCD corrections to the $\gamma^{*} \longrightarrow Q\bar{Q}-Reggeon$ vertex are calculated, where $Q\bar{Q}$ denotes a heavy quark pair $c\bar c$ or $b\bar b$. The heavy quark mass effects on the photon impact factor…

High Energy Physics - Phenomenology · Physics 2022-09-14 Li Ping Sun , Long Bin Chen , Cong Feng Qiao , Kuang Ta Chao

We present a complete calculation of the Leading Order QCD corrections to the quark level decay amplitude for b -> s gamma gamma and study their relevance for both the inclusive branching ratio BR(B -> X_s gamma gamma) and for the exclusive…

High Energy Physics - Phenomenology · Physics 2014-11-17 Laura Reina , Giulia Ricciardi , Amarjit Soni

The inclusive decay rate b to ccs is enhanced considerably due to perturbative QCD corrections. We recalculate the dominant part of the NLO-QCD corrections, because they cannot be reconstructed from the literature and we give the full…

High Energy Physics - Phenomenology · Physics 2015-06-16 Fabian Krinner , Alexander Lenz , Thomas Rauh

Interference between the photonic dipole operator Q_7 and the current-current operators Q_{1,2} gives one of the most important QCD corrections to the B -> X_s gamma decay rate. So far, the O(alpha_s^2) part of this correction has been…

High Energy Physics - Phenomenology · Physics 2015-03-09 Michal Czakon , Paul Fiedler , Tobias Huber , Mikolaj Misiak , Thomas Schutzmeier , Matthias Steinhauser

The observables epsilon_K and Delta M_K play a prominent role in particle physics due to their sensitivity to new physics at short distances. To take advantage of this potential, a firm theoretical prediction of the standard-model…

High Energy Physics - Phenomenology · Physics 2012-03-21 Joachim Brod , Martin Gorbahn

We present preliminary results for the charm quark mass in the $N_f=4$ RGI scheme. These were obtained using $N_f=2+1$ CLS ensembles with $\mathcal{O}(a)$ non-perturbatively improved Wilson fermions. We employed five different lattice…

High Energy Physics - Lattice · Physics 2022-06-10 Gunnar Bali , Sjoerd Bouma , Sara Collins , Wolfgang Söldner

We discuss the impact of the charm quark mass in the CTEQ NNLO global analysis of parton distribution functions of the proton. The $\bar{\rm MS}$ mass $m_c(m_c)$ of the charm quark is extracted in the S-ACOT-$\chi$ heavy-quark factorization…

High Energy Physics - Phenomenology · Physics 2013-07-01 Jun Gao , Marco Guzzi , Pavel M. Nadolsky

The decay of B mesons can be predicted within the Heavy Quark Expansion as the decay of a free bottom quark plus corrections which are suppressed by powers of $1/m_b$. This contribution to Loops&Legs 2024 describes the calculation of the…

High Energy Physics - Phenomenology · Physics 2024-07-02 Manuel Egner

We evaluate two-loop b -> s gamma matrix elements of all the four-quark operators containing no derivatives. Contrary to previous calculations, no expansion in the mass ratio mc/mb is performed, and all the possible Dirac and flavor…

High Energy Physics - Phenomenology · Physics 2009-11-07 Andrzej J. Buras , Andrzej Czarnecki , Mikolaj Misiak , Joerg Urban

The $B_c(^1S_0)$ meson to S-wave Charmonia transition form factors are calculated in next-to-leading order(NLO) accuracy of Quantum Chromodynamics(QCD). Our results indicate that the higher order corrections to these form factors are…

High Energy Physics - Phenomenology · Physics 2015-05-27 Cong-Feng Qiao , Peng Sun , Feng Yuan

The results of analytical evaluation of $O(\alpha_s^2)$ QCD contributions due to the nonvanishing quark masses to $\Gamma_{H\rightarrow q_f\overline{q}_f}$ are presented. The ``triangle anomaly'' type contributions are included. As a…

High Energy Physics - Phenomenology · Physics 2011-01-25 Levan R. Surguladze