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Related papers: Taming the B --> X(s) gamma spectrum by Dressed Gl…

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We compute the differential B -> X_s gamma decay width in the Standard Model as a function of the photon energy using Dressed Gluon Exponentiation (DGE). The resummed spectrum is matched with the fixed-order expansion, making use of the…

High Energy Physics - Phenomenology · Physics 2010-10-27 Jeppe R. Andersen , Einan Gardi

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

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

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

Power corrections to differential cross sections near a kinematic threshold are analysed by Dressed Gluon Exponentiation. Exploiting the factorization property of soft and collinear radiation, the dominant radiative corrections in the…

High Energy Physics - Phenomenology · Physics 2017-08-23 Einan Gardi

The photon energy spectrum in inclusive weak radiative B -> X_s gamma decay is computed to order alpha_s^2 beta_0. This result is used to extract a value for the HQET parameter $\bar\Lambda$ from the average <1-2E_\gamma/m_B>, and a value…

High Energy Physics - Phenomenology · Physics 2011-05-05 Zoltan Ligeti , Michael Luke , Aneesh V. Manohar , Mark B. Wise

The thrust distribution in e+e- annihilation is calculated exploiting its exponentiation property in the two-jet region t = 1-T << 1. We present a general method (DGE) to calculate a large class of logarithmically enhanced terms, using the…

High Energy Physics - Phenomenology · Physics 2009-11-07 Einan Gardi , Johan Rathsman

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

By combining a recent estimate of the total B-->X_s gamma branching fraction at O(alpha_s^2) with a detailed analysis of the effects of a cut E_gamma>1.6GeV on photon energy, a prediction for the partial B-->X_s gamma branching fraction at…

High Energy Physics - Phenomenology · Physics 2008-11-26 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

Perturbative and non-perturbative aspects of differential cross-sections close to a kinematic threshold are studied applying ``dressed gluon exponentiation'' (DGE). The factorization property of soft and collinear gluon radiation is…

High Energy Physics - Phenomenology · Physics 2009-11-07 Einan Gardi

We present a general all-order formulation of Sudakov resummation in QCD in terms of dispersion integrals. We show that the Sudakov exponent can be written as a dispersion integral over spectral density functions, weighted by characteristic…

High Energy Physics - Phenomenology · Physics 2008-11-26 Einan Gardi , Georges Grunberg

The main challenge in computing inclusive cross sections and decay spectra in QCD is posed by kinematic thresholds. The threshold region is characterized by stringent phase-space constraints that are reflected in large perturbative…

High Energy Physics - Phenomenology · Physics 2008-11-26 Einan Gardi

We investigate the behaviour of the perturbative relation between the photon energy spectrum in B -> Xs gamma and the hadronic P+ spectrum in semileptonic B -> Xu l nu decay at high orders in perturbation theory in the "large-beta_0" limit,…

High Energy Physics - Phenomenology · Physics 2009-09-02 Francisco Campanario , Michael Luke , Saba Zuberi

The main obstacle in describing inclusive decay spectra in QCD - which, in particular, limits the precision in extrapolating the measured \bar{B} \to X(s) gamma rate to the full phase space as well as in extracting |V_{ub}| from inclusive…

High Energy Physics - Phenomenology · Physics 2007-05-23 Einan Gardi , Jeppe R. Andersen

Event-shape distributions in $e^+e^-$ annihilation offer a unique lab oratory for understanding perturbative and non-perturbative aspects of QCD. Dressed Gluon Exponentiation is a resummation method designed to evaluate differ ential cross…

High Energy Physics - Phenomenology · Physics 2017-08-23 Einan Gardi , Johan Rathsman

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

We study power corrections to a recently introduced family of event shapes, the class of angularities, within the formalism of dressed gluon exponentiation (DGE). We find that the universal scaling rule for the leading power corrections…

High Energy Physics - Phenomenology · Physics 2009-11-10 Carola F. Berger , Lorenzo Magnea

The "Tapered Gridded Estimator" (TGE) is a novel way to directly estimate the angular power spectrum from radio-interferometric visibility data that reduces the computation by efficiently gridding the data, consistently removes the noise…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-27 Samir Choudhuri , Nirupam Roy , Somnath Bharadwaj , Sk. Saiyad Ali , Abhik Ghosh , Prasun Dutta

We derive the dominant part of the O(\alpha_s^2) correction to the photon energy spectrum in the inclusive decay B-> X_s+gamma. The detailed knowledge of the spectrum is important for relating the theoretical calculations of the B-> X_s +…

High Energy Physics - Phenomenology · Physics 2011-01-27 Kirill Melnikov , Alexander Mitov
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