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Related papers: Two-loop virtual QCD correction to the B -> X_s l+…

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The experimental information on b --> s l^+ l^- decays has grown enormously during the last couple of years due to BaBar, Belle, CDF and LHCb. Especially, exclusive modes B --> K^(*) l^+ l^-, which have the largest rate and are easily…

High Energy Physics - Phenomenology · Physics 2012-08-16 Christoph Bobeth

We obtain the two-loop QCD corrections to the Higgs plus three-parton amplitudes with dimension-seven operators in Higgs effective field theory. This provides the two-loop S-matrix elements for Higgs plus one-jet production at the LHC with…

High Energy Physics - Phenomenology · Physics 2020-03-18 Qingjun Jin , Gang Yang

We investigate electromagnetic corrections to the rare $B$-meson leptonic decay $B_{s,d} \to \mu^+\mu^-$ from scales below the bottom-quark mass $m_b$. Contrary to QCD effects, which are entirely contained in the $B$-meson decay constant,…

High Energy Physics - Phenomenology · Physics 2018-01-10 Martin Beneke , Christoph Bobeth , Robert Szafron

We consider QCD radiative corrections to $W^+W^-b {\bar b}$ production with leptonic decays and massive bottom quarks at the LHC. We perform an exact next-to-leading order (NLO) calculation within the $q_T$-subtraction formalism and…

High Energy Physics - Phenomenology · Physics 2025-07-17 Luca Buonocore , Massimiliano Grazzini , Stefan Kallweit , Jonas M. Lindert , Chiara Savoini

We compute the QCD corrections at next-to-leading order for the process $gg \rightarrow ZH$, including both the virtual two-loop terms and real-emission contributions. The two-loop box diagrams in the virtual corrections are approximated…

High Energy Physics - Phenomenology · Physics 2022-08-24 Giuseppe Degrassi , Ramona Gröber , Marco Vitti , Xiaoran Zhao

We present the two-loop virtual QCD corrections to the scattering of massless distinct quarks in conventional dimensional regularisation. The structure of the infrared divergences agrees with that predicted by Catani while expressions for…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Anastasiou , E. W. N. Glover , C. Oleari , M. E. Tejeda-Yeomans

The program package XLOOPS calculates massive one- and two-loop Feynman diagrams. It consists of five parts: i) a graphical user interface ii) routines for generating diagrams from particle input iii) procedures for calculating one-loop…

High Energy Physics - Phenomenology · Physics 2011-02-11 L. Brücher , J. Franzkowski , A. Frink , D. Kreimer

We present a complete $O(\alpha_s^2)$ correction to the differential width of the inclusive semileptonic decay $b\to cl\nu_l$ at the kinematical point of vanishing invariant mass of the leptons, $q^2=0$. Together with the recently computed…

High Energy Physics - Phenomenology · Physics 2014-11-17 Andrzej Czarnecki , Kirill Melnikov

We discuss two-loop leading and angular-dependent next-to-leading logarithmic electroweak virtual corrections to arbitrary processes at energies above the electroweak scale. The relevant Feynman diagrams involving soft-collinear gauge…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ansgar Denner , Michael Melles , Stefano Pozzorini

Applying effective Lagrangian method and on-shell scheme, we analyze the electroweak corrections to the rare decay $b\rightarrow s+\gamma$ from some special two loop diagrams in which a closed heavy fermion loop is attached to the virtual…

High Energy Physics - Phenomenology · Physics 2014-11-21 Xiu-Yi Yang , Tai-Fu Feng

We briefly report on NLO QCD corrections to the $pp \to t\bar{t} B +X$ process, where $B$ stands for $H,\,W^\pm$ or $Z$. In the calculation all double-, single and non-resonant Feynman diagrams, interferences and finite-width effects are…

High Energy Physics - Phenomenology · Physics 2022-07-28 Malgorzata Worek

We have recently presented the complete O(alpha_s^2) corrections to the semileptonic decay width of the b quark at maximal recoil. Here we discuss various technical aspects of that calculation and further applications of similar methods. In…

High Energy Physics - Phenomenology · Physics 2016-08-25 Andrzej Czarnecki , Kirill Melnikov

We consider two-loop leading and next-to-leading logarithmic virtual corrections to arbitrary processes with external massless fermions in the electroweak Standard Model at energies well above the electroweak scale. Using the…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. Denner , B. Jantzen , S. Pozzorini

In the framework of SU(2) singlet down type vectorlike quark model, we present a comprehensive analysis for decays B-> X_s \gamma, B->X_sl^+l^- and B-> K\pi. As for B-> X_s\gamma, we include the QCD running from the mass of the down-type…

High Energy Physics - Phenomenology · Physics 2007-05-23 T. Morozumi , Z. Xiong , T. Yoshikawa

The exclusive production of $J/\psi$ through Higgs boson radiative decay may serve a clean channel to extracting the charm quark Yukawa coupling. We calculate the two-loop QCD corrections to $H\rightarrow J/\psi(\Upsilon)+\gamma$ using an…

High Energy Physics - Phenomenology · Physics 2024-09-02 Yu Jia , Zhewen Mo , Jia-Yue Zhang

We use a sample of 384 million BBbar events collected with the Babar detector at the PEP-II e+e- collider to study angular distributions in the rare decays B -> K* l+l-, where l+l- is either e+e- or mu+mu-. For low dilepton invariant…

High Energy Physics - Experiment · Physics 2010-04-12 The BABAR Collaboration , B. Aubert

We compute $\mathcal O(\alpha^2 Z)$ radiative corrections to superallowed $\beta$ decays with a heavy-particle effective field theory that systematically describes the interactions of low-energy ultrasoft photons with nuclei. We calculate…

High Energy Physics - Phenomenology · Physics 2025-11-27 Òscar L. Crosas , Emanuele Mereghetti

This paper describes a method of numerical evaluating high-order QED contributions to the electron anomalous magnetic moment. The method is based on subtraction of infrared and ultraviolet divergences in Feynman-parametric space before…

High Energy Physics - Phenomenology · Physics 2018-11-07 Sergey Volkov

The single renormalon-chain contribution to the correlator of scalar currents in QCD is calculated in the $\bar{MS}$-scheme in the limit of a large $N_f$. We find that in the factorial growth of the coefficients due to renormalons takes…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. J. Broadhurst , A. L. Kataev , C. J. Maxwell

We present the two-loop QED and QCD corrections to the $f\bar fH$ Yukawa coupling that are induced by the exchange of a virtual photon or gluon, respectively, with a heavy-fermion loop inserted. As an application, we study the corresponding…

High Energy Physics - Phenomenology · Physics 2009-10-28 Bernd A. Kniehl