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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

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

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

The goal of the SIMBA collaboration is to provide a global fit to the available measurements of 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…

High Energy Physics - Phenomenology · Physics 2013-03-06 Florian U. Bernlochner , Heiko Lacker , Zoltan Ligeti , Iain W. Stewart , Frank J. Tackmann , Kerstin Tackmann

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

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 derive the strange quark transverse momentum distribution for the $% b\to s\gamma $ decay. A resummed formula is presented showing the singularity structure in the impact parameter $b$. We observe the appearance of a new next-to-leading…

High Energy Physics - Phenomenology · Physics 2007-05-23 Roberto Sghedoni

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

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

The determination of |Vub| from inclusive semileptonic B decays is limited by uncertainties in modelling the decay distributions in b->ulnu transitions. The largest uncertainties arise from the limited knowledge of the appropriate b quark…

High Energy Physics - Experiment · Physics 2010-04-05 Robert V. Kowalewski , Sven Menke

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 ratio between the photon spectrum in B -> X_s gamma and the differential semileptonic rate wrt the hadronic variable M_X/E_X is a short-distance quantity calculable in perturbation theory and independent of the Fermi motion of the b…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ugo Aglietti , Marco Ciuchini , Paolo Gambino

We present parton distribution functions which include a quantitative estimate of its uncertainties. The parton distribution functions are optimized with respect to deep inelastic proton data, expressing the uncertainties as a density…

High Energy Physics - Phenomenology · Physics 2007-05-23 Walter T. Giele , Stephane A. Keller , David A. Kosower

In the heavy-quark limit, the decay spectrum for radiative and semileptonic inclusive B-meson decays is determined by a universal structure function, i.e. the shape function. We study the constraints on the bilocal heavy-quark operator for…

High Energy Physics - Phenomenology · Physics 2009-11-10 Hiroyuki Kawamura , Jiro Kodaira , Kazuhiro Tanaka

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

We derive a new parton-like formula, which establishes a simple connection between the electroweak decay rate $\Gamma (\bar B \to X_s\gamma$) and the rate of a free b-quark decay. The main features of our approach are the treatment of the…

High Energy Physics - Phenomenology · Physics 2009-10-31 Y. -Y. Keum , P. Yu. Kulikov , I. M. Narodetskii , H. S. Song

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 determine the b-quark shape function parameters in the shape function scheme, m_b(SF) and \mu_\pi^2(SF), using the Belle B->X_s gamma photon energy spectrum. We assume three models for the form of the shape function; exponential,…

High Energy Physics - Experiment · Physics 2007-05-23 I. Bizjak , A. Limosani , T. Nozaki

Using a combination of the operator product and heavy quark expansions, we resum the leading nonperturbative contributions to the inclusive photon spectrum in $B\to X_s\,\gamma$ decays. The shape of the spectrum is determined by a universal…

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

The shape function of $B$-meson defined in heavy quark effective theory (HQET) plays a crucial role in the analysis of inclusive $B$ decays, and constitutes one of the dominant uncertainties in the determination of CKM matrix element…

High Energy Physics - Phenomenology · Physics 2025-04-30 Wei Wang , Ji Xu , Qi-An Zhang , Shuai Zhao
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