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Related papers: Subleading Shape-Function Effects and the Extracti…

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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

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

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 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

It has recently been pointed out that a new class of subleading shape functions involving B-meson matrix elements of non-local four-quark operators contributes at order Lambda_{QCD}/m_b to B->X_u+l+nu decay distributions in the endpoint…

High Energy Physics - Phenomenology · Physics 2009-01-07 Matthias Neubert

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

Owing to the fact that m_c^2 ~ m_b \Lambda_QCD, the endpoint region of the charged lepton energy spectrum in the inclusive decay B -> X_c l \nu_l is affected by the Fermi motion of the initial-state b quark bound in the B meson. This effect…

High Energy Physics - Phenomenology · Physics 2009-11-10 Thomas Mannel , Frank J. Tackmann

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

Recently, it was shown that in inclusive B -> Xs l+ l- decay, an angular decomposition provides three independent (q^2 dependent) observables. A strategy was formulated to extract all measurable Wilson coefficients in B -> Xs l+ l- from a…

High Energy Physics - Phenomenology · Physics 2009-08-03 Keith S. M. Lee , Frank J. Tackmann

We derive the triply differential spectrum for the inclusive rare decay B -> Xs l+ l- in the shape function region, in which Xs is jet-like with $mX^2 \lesssim mb \Lambda_QCD$. Experimental cuts make this a relevant region. The perturbative…

High Energy Physics - Phenomenology · Physics 2008-11-26 Keith S. M. Lee , Iain W. Stewart

The contributions of subleading shape functions to inclusive decay distributions of B mesons are derived from a systematic two-step matching of QCD current correlators onto soft-collinear and heavy-quark effective theory. At tree-level, the…

High Energy Physics - Phenomenology · Physics 2010-02-03 Stefan W. Bosch , Matthias Neubert , Gil Paz

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

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

In this paper we investigate the subleading twist corrections to the photon energy spectrum in the decay Lambda_b -> X_s \gamma and to the lepton energy spectrum in Lambda_b -> X_u l \bar{\nu}. As a first step we rederive the matching…

High Energy Physics - Phenomenology · Physics 2011-01-27 Michael Kraetz , Thomas Mannel

We perform factorization of the most general distribution in semileptonic B -> X_u decays and we resum the threshold logarithms to next-to-leading order. From this (triple-differential) distribution, any other distribution is obtained by…

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

In order to extract the Cabibbo-Kobayashi-Maskawa matrix element |V_{ub}| from B -> X_u l anti-nu_l decays, the overwhelming background from B -> X_c l anti-nu_l decays must be reduced by appropriate acceptance cuts. We study the…

High Energy Physics - Phenomenology · Physics 2008-11-26 B. A. Kniehl , G. Kramer , J. -F. Yang

The total B->Xs gamma decay rate and the CKM-matrix element Vub play an important role in finding indirect evidence for new physics affecting the flavor sector of the Standard Model, complementary to direct searches at the LHC and Tevatron.…

High Energy Physics - Phenomenology · Physics 2011-05-18 Florian U. Bernlochner , Heiko Lacker , Zoltan Ligeti , Iain W. Stewart , Frank J. Tackmann , Kerstin Tackmann

The leptonic radiative decay $B \to \gamma l\nu$ is of great importance in the determination of $B$ meson wave functions, and evaluating the form factors $ F_{V,A}$ are the essential problem on the study of this channel. We computed…

High Energy Physics - Phenomenology · Physics 2019-01-16 Yue-Long Shen , Zhi-Tian Zou , Yan-Bing Wei

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

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
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