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Related papers: Shape function effects in B -> X_s gamma and B -> …

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The inclusive spectra of radiative and semi-leptonic B-meson decays near the endpoint is computed taking into account renormalons in the Sudakov exponent (Dressed Gluon Exponentiation). In this framework we demonstrate the factorization of…

High Energy Physics - Phenomenology · Physics 2009-11-10 Einan Gardi

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

The goal of the SIMBA collaboration is to provide a global fit to the available data in inclusive B -> X_s gamma and B -> X_u l nu decays. By performing a global fit one is able to simultaneously determine the relevant normalizations, i.e.…

High Energy Physics - Phenomenology · Physics 2011-01-19 Florian U. Bernlochner , Heiko Lacker , Zoltan Ligeti , Iain W. Stewart , Frank J. Tackmann , Kerstin Tackmann

We derive precise standard model predictions for the dilepton invariant mass and the tau energy distributions in inclusive B -> Xc tau nu decay. We include Lambda_QCD^2/m_b^2 and alpha_s corrections using the 1S short-distance mass scheme,…

High Energy Physics - Phenomenology · Physics 2014-09-05 Zoltan Ligeti , Frank J. Tackmann

We derive factorization theorems for Lambda_QCD/mb power corrections to inclusive B-decays in the endpoint region, where mX^2 ~mb Lambda_QCD. In B-> Xu e nu our results are for the full triply differential rate. A complete enumeration of…

High Energy Physics - Phenomenology · Physics 2011-01-27 Keith S. M. Lee , Iain W. Stewart

We study the O(Lambda/mb) corrections to the singly and doubly differential hadronic invariant mass spectra d\Gamma/dsH and d\Gamma/dsH dq^2 in b -> u decays, and discuss the implications for the extraction of the CKM matrix element |Vub|.…

High Energy Physics - Phenomenology · Physics 2010-11-23 Craig N. Burrell , Michael E. Luke , Alexander R. Williamson

The most precise comparison between theory and experiment for the B -> Xs l+ l- rate is in the low q^2 region, but the hadronic uncertainties associated with an experimentally required cut on m_X potentially spoil the search for new physics…

High Energy Physics - Phenomenology · Physics 2014-11-18 Keith S. M. Lee , Zoltan Ligeti , Iain W. Stewart , Frank J. Tackmann

The calculation of partial decay rates in B --> X_u l nu decays at next-to-next-to-leading order (NNLO) in alpha_s and to leading order in 1/m_b is described. New results for the hard function are combined with known results for the jet…

High Energy Physics - Phenomenology · Physics 2008-10-17 Ben D. Pecjak

We study the Lambda_QCD/M_B corrections from subleading shape functions in inclusive B-meson decays. We propose a natural and smooth interpolation from the endpoint region to the full phase space, and derive expressions for the triple…

High Energy Physics - Phenomenology · Physics 2014-11-18 Frank J. Tackmann

We show that most spectra in the semileptonic decay B -> X_u + l + nu, such as for example the distribution in the light-cone momentum p_+ = E_X - p_X recently considered, do not have the same long-distance structure of the photon spectrum…

High Energy Physics - Phenomenology · Physics 2009-11-11 U. Aglietti

Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matthias Neubert

We demonstrate, by an explicit one-loop calculation, that at leading twist the nonperturbative effects in B -> gamma l nu, B -> gamma gamma and B -> gamma l+ l- radiative decays are contained in a common multiplicative factor…

High Energy Physics - Phenomenology · Physics 2009-10-09 S. Descotes-Genon , C. T. Sachrajda

We study inclusive semi-leptonic (B -> X_c \ell \nu) decay using the power counting m_c ~ \sqrt{Lambda_{QCD} m_b}. Assuming this scaling for the charm-quark mass, the decay kinematics can be chosen to access the shape-function region even…

High Energy Physics - Phenomenology · Physics 2009-11-11 H. Boos , Th. Feldmann , T. Mannel , B. D. Pecjak

A theoretical analysis of the partial inclusive B-->X_s gamma decay rate with a cut E_gamma>E_0 on photon energy must deal with short-distance contributions associated with three different mass scales: the hard scale m_b, an intermediate…

High Energy Physics - Phenomenology · Physics 2009-11-11 Thomas Becher , Matthias Neubert

Using results on soft-collinear factorization for inclusive B-meson decay distributions, a systematic study of the partial $B\to X_s\gamma$ decay rate with a cut $E_\gamma > E_0$ on photon energy is performed. For values of $E_0$ below…

High Energy Physics - Phenomenology · Physics 2009-11-10 Matthias Neubert

We calculate the set of O(alpha_s^2) corrections to the branching ratio and to the photon energy spectrum of the decay process B -> X_s gamma originating from the interference of diagrams involving the electromagnetic dipole operator O_7…

High Energy Physics - Phenomenology · Physics 2014-11-21 H. M. Asatrian , T. Ewerth , A. Ferroglia , C. Greub , G. Ossola

A new class of enhanced non-perturbative corrections to the inclusive B->X_s+gamma decay rate is identified, which contribute first at order Lambda/m_b in the heavy-quark expansion and cannot be described using a local operator product…

High Energy Physics - Phenomenology · Physics 2008-11-26 Seung J. Lee , Matthias Neubert , Gil Paz

We present a concise review of the recent theoretical progress concerning the standard model calculation of the inclusive radiative anti-B --> X(s) gamma decay. Particular attention is thereby devoted to the calculations of the…

High Energy Physics - Phenomenology · Physics 2008-07-13 Ulrich Haisch

We apply the operator product expansion to resum the leading nonperturbative corrections to the endpoint region of the lepton spectrum in inclusive semileptonic $B\to X_q\,\ell\,\bar\nu$ decays, taking into account a finite quark mass $m_q$…

High Energy Physics - Phenomenology · Physics 2011-07-19 Thomas Mannel , Matthias Neubert

We resum to next-to-leading order the distribution in the ratio of the invariant hadron mass mX to the total hadron energy EX and the distribution in mX in the semileptonic decays B -> Xu l nu. By expanding our formulas, we obtain the…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ugo Aglietti , Giulia Ricciardi , Giancarlo Ferrera