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Related papers: Resummed B -> X_u l nu Decay Distributions to Next…

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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

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

We resum to next-to-leading order (NLO) the distribution in the light-cone momentum p+ = EX - |pX| and the spectrum in the electron energy, in the semileptonic decays B-> Xu l nu, where EX and pX are the total energy and three-momentum of…

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

We evaluate thresholds resummed spectra in B -> Xu l nu decays in next-to-leading order. We present results for the distribution in E_X and in m_X^2/E_X^2, for the distribution in E_X and E_l and for the distribution in E_X, where E_X and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Ugo Aglietti , Giulia Ricciardi , Giancarlo Ferrera

Using methods of effective field theory, factorized expressions for arbitrary B -> X_u l nu decay distributions in the shape-function region of large hadronic energy and moderate hadronic invariant mass are derived. Large logarithms are…

High Energy Physics - Phenomenology · Physics 2009-11-10 S. W. Bosch , B. O. Lange , M. Neubert , G. Paz

We calculate the decay distributions for inclusive B -> X_s gamma and B -> X_u l nu decays in the endpoint region, where radiative corrections are large. The computation is done using effective field theory methods. The matching…

High Energy Physics - Phenomenology · Physics 2011-05-05 Christian W. Bauer , Aneesh V. Manohar

It is argued that the dominant subleading shape-function contributions to the endpoint region of the charged-lepton energy spectrum in B -> X_u l nu decays can be related in a model-independent way to an integral over the B -> X_s gamma…

High Energy Physics - Phenomenology · Physics 2010-04-05 Matthias Neubert

A shape-function independent relation is derived between the partial B->X_u+l+nu decay rate with a cut on P_+=E_X-P_X<Delta and a weighted integral over the normalized B->X_s+gamma photon-energy spectrum. The leading-power contribution to…

High Energy Physics - Phenomenology · Physics 2011-02-01 Bjorn O. Lange , Matthias Neubert , Gil Paz

A leading-power factorization formula for weight functions relating the B to Xs gamma photon spectrum to arbitrary partial decay rates in B to Xu l nu is derived. These weight functions are independent of the hadronic shape function and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Bjorn O Lange

We present ``state-of-the-art'' theoretical expressions for the triple differential B->X_u l^- nu decay rate and for the B->X_s gamma photon spectrum, which incorporate all known contributions and smoothly interpolate between the…

High Energy Physics - Phenomenology · Physics 2010-11-23 Bjorn O. Lange , Matthias Neubert , Gil Paz

We show that the B \to X(s) gamma photon energy (E_gamma) spectrum can be reliably computed by resummed perturbation theory. Our calculation is based on Dressed Gluon Exponentiation (DGE) incorporating Sudakov and renormalon resummation. It…

High Energy Physics - Phenomenology · Physics 2009-11-11 Jeppe R. Andersen , Einan Gardi

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 calculate the subleading twist contributions to the endpoint of the inclusive lepton energy spectrum in B -> X_u l \nu. We show that the same two subleading twist functions that appear in the decay B -> X_s \gamma govern the subleading…

High Energy Physics - Phenomenology · Physics 2011-02-01 Christian W. Bauer , Michael Luke , Thomas Mannel

We present a QCD-based approach to the endpoint region of the lepton spectrum in $\bar B\to X_u\,\ell\,\bar\nu$ decays. We introduce a genuinely nonperturbative form factor, the shape function, which describes the fall-off of the spectrum…

High Energy Physics - Phenomenology · Physics 2010-11-01 Matthias Neubert

We derive a class of formulae relating moments of B -> Xu l nu to B -> Xs gamma in the shape function region, where m_X^2 ~ m_b Lambda_QCD. We also derive an analogous class of formulae involving the decay B -> Xs l+ l-. These results…

High Energy Physics - Phenomenology · Physics 2008-12-16 Keith S. M. Lee

We consider the decay of a heavy flavour into an inclusive hadronic state X of invariant mass m_X small with respect to its energy E_X, m_X << E_X. The electron spectrum and the hadronic mass distribution in semileptonic b -> u decays, or…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ugo Aglietti , Giulia Ricciardi

We present a next-to-leading evaluation of the resummed coefficient function for the shape function. The results confirm our previous leading order analysis, namely that the coefficient function is short-distance-dominated, and allow…

High Energy Physics - Phenomenology · Physics 2009-11-07 U. Aglietti

We present theoretical predictions for a few phenomenologically interesting distributions in the semileptonic b->u decays which are affected by Fermi motion. The perturbative effects are incorporated at the one-loop level and appear to be…

High Energy Physics - Phenomenology · Physics 2010-11-23 R. David Dikeman , N. G. Uraltsev

The triple differential spectrum in \bar{B} -> X_u l \bar{\nu} is computed by Dressed Gluon Exponentiation (DGE). In this framework the on-shell calculation, converted into hadronic variables, can be directly used as an approximation to the…

High Energy Physics - Phenomenology · Physics 2011-02-01 Jeppe R. Andersen , Einan Gardi

The inclusive decay B --> X_u l nu is of much interest because of its potential to constrain the CKM element |V_ub|. Experimental cuts required to suppress charm background restrict measurements of this decay to the shape-function region,…

High Energy Physics - Phenomenology · Physics 2009-01-08 H. M. Asatrian , C. Greub , B. D. Pecjak
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