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Related papers: Electromagnetic Logarithms in B -> X_s l+ l-

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The inclusive B -> Xs l+ l- decay rate in the large q^2 region (q^2 > m_{\psi'}^2) receives significant nonperturbative corrections. The resulting uncertainties can be drastically reduced by normalizing the rate to the B -> Xu l nu rate…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zoltan Ligeti , Frank J. Tackmann

We compute the next-to-next-to-leading order (NNLO) QCD corrections to b \to c l \bar \nu_l decay rate at a fully differential level. Arbitrary cuts on kinematic variables of the decay products can be imposed. Our computation can be used to…

High Energy Physics - Phenomenology · Physics 2014-11-18 Kirill Melnikov

We compute the two-loop corrections to the coefficient of the b --> s gamma magnetic penguin present in the limits of heavy top and/or heavy higgs. This kind of corrections affects in a significant way the observables measured at LEP. On…

High Energy Physics - Phenomenology · Physics 2009-10-09 A. Strumia

We study model-independently the implications of non-standard scalar and pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^- (l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from scalar and…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Hiller , F. Krüger

We calculate the full two-loop electroweak matching corrections to the operator governing the decay B_q --> l^+ l^- in the Standard Model. Their inclusion removes an electroweak scheme and scale uncertainty of about 7% of the branching…

High Energy Physics - Phenomenology · Physics 2014-02-26 Christoph Bobeth , Martin Gorbahn , Emmanuel Stamou

We give a brief review of the next-to-leading logarithmic results in $B \to X_s \gamma$. Combining the results of different groups, a practically complete next-to-leading-logarithmic prediction of the inclusive decay rate was recently…

High Energy Physics - Phenomenology · Physics 2007-05-23 Christoph Greub , Tobias Hurth

The decay Bs to mu+ mu- is one of the milestones of the flavor program at the LHC. We reappraise its Standard Model prediction. First, by analyzing the theoretical rate in the light of its main parametric dependence, we highlight the…

High Energy Physics - Phenomenology · Physics 2015-06-11 Andrzej J. Buras , Jennifer Girrbach , Diego Guadagnoli , Gino Isidori

We present a concise review of the recent theoretical progress concerning the standard model calculation of the inclusive radiative Bbar -> X_s gamma decay. Particular attention is thereby devoted to the calculations of the…

High Energy Physics - Phenomenology · Physics 2007-06-23 Ulrich Haisch

We calculate the radiative corrections to the nonleptonic inclusive B decay mode $b\to c ud$ taking into account the charm quark mass. The corrections increase the decay rate by (4--8)\%, depending on the renormalization point. Using these…

High Energy Physics - Phenomenology · Physics 2009-10-28 P. Ball

Using a known result by Falk et al. for the 1/m_b^2 correction to the dilepton invariant mass spectrum in the decay B \rightarrow X_s \mu^+ \mu^-, we calculate the 1/m_b^2 correction to the left-right muon polarization asymmetry in this…

High Energy Physics - Phenomenology · Physics 2011-01-27 Oliver Baer , Nicolas Pott

O(alpha^2 ln^2(m_mu/m_e)) QED corrections to the electron spectrum and angular distribution in muon decay are evaluated. Impact on the determination of Michel parameters is estimated. Current theoretical uncertainty in the muon decay…

High Energy Physics - Phenomenology · Physics 2011-03-31 Andrej Arbuzov , Andrzej Czarnecki , Andrei Gaponenko

We review the theoretical understanding of the branching ratio and photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD, including consistently the effects of Fermi motion. For the Standard Model, we obtain B(B ->…

High Energy Physics - Phenomenology · Physics 2007-05-23 Matthias Neubert

We compute the decay rate for the CKM-suppressed electromagnetic penguin decay $B \to X_d + \gamma$ (and its charge conjugate) in NLO QCD, including leading power corrections in $1/m_b^2$ and $1/m_c^2$ in the standard model. The average…

High Energy Physics - Phenomenology · Physics 2014-11-17 A. Ali , H. Asatrian , C. Greub

We obtain predictions for $B_{(s)}\to e^+e^-\gamma$ and $B_{(s)}\to \mu^+\mu^-\gamma$ decays. All the contributions containing long-distance QCD effects are calculated in the framework of relativistic quark model. The contributions of the…

High Energy Physics - Phenomenology · Physics 2016-10-31 Anastasiia Kozachuk , Dmitri Melikhov , Nikolai Nikitin

We compute the order 1/m_b^3 nonperturbative contributions to the inclusive differential B\to X_c\ell\bar\nu decay rate. They are parametrized by the expectation values of two local and four nonlocal dimension-six operators. We use our…

High Energy Physics - Phenomenology · Physics 2011-01-27 Martin Gremm , Anton Kapustin

In this paper we investigate the effect of the resummation of threshold logs on the rate for B -> X_s gamma. We calculate the differential rate dGamma/dE_gamma including the infinite set of terms of the form alpha_s^n log^{n+1}(1-x) and…

High Energy Physics - Phenomenology · Physics 2009-10-31 Adam K. Leibovich , I. Z. Rothstein

Part of the order $\alpha_s$ correction to the inclusive $B\to X_s\,\gamma$ photon spectrum is enhanced by $\log(m_b^2/m_s^2)$. We discuss its origin and sum the corrections proportional to $[\alpha_s\log(m_b^2/\mu^2)]^n$ to all orders.…

High Energy Physics - Phenomenology · Physics 2011-01-27 Anton Kapustin , Zoltan Ligeti , H. David Politzer

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andre H. Hoang , Zoltan Ligeti , Aneesh V. Manohar

I discuss an application of numerical techniques for massive two-loop Feynman diagram evaluation to a phenomenologically very important rare decay process, B -> X_s l+l-. This process, currently being measured at B factories, has been…

High Energy Physics - Phenomenology · Physics 2007-05-23 Adrian Ghinculov

The radiative leptonic $B\to \gamma\ell\nu_{\ell}$ decay serves as an ideal platform to determine the $B$-meson inverse moment which is a fundamental nonperturbative parameter for the $B$ meson. In this paper, we explore precise QCD…

High Energy Physics - Phenomenology · Physics 2025-09-25 Bo-Yan Cui , Yue-Long Shen , Chao Wang , Yan-Bing Wei