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We show how radiative QCD corrections calculated in terms of quarks can be incorporated at the hadron level in inclusive semileptonic B-meson decays. The bound state effects are described by a momentum distribution function of the $b$…

High Energy Physics - Phenomenology · Physics 2011-09-13 Changhao Jin , Emmanuel A. Paschos

We derive the lepton spectrum in semileptonic beauty decays from a nonperturbative treatment of QCD; it is based on an expansion in $1/m_Q$ with $m_Q$ being the heavy flavour quark mass. The leading corrections arising on the $1/m_Q$ level…

High Energy Physics - Phenomenology · Physics 2011-05-05 I. I. Bigi , M. Shifman , N. G. Uraltsev , A. Vainshtein

We examine the large-order behaviour of a recently proposed renormalization-group-improved expansion of the Adler function in perturbative QCD, which sums in an analytically closed form the leading logarithms accessible from…

High Energy Physics - Phenomenology · Physics 2013-01-08 Gauhar Abbas , B. Ananthanarayan , Irinel Caprini , Jan Fischer

We consider the one-loop renormalization of QED in curved space-time with additional Lorentz and/or CPT breaking terms. The renormalization group equations in the vacuum sector are derived. In the special case of Minkowski metric and with…

High Energy Physics - Theory · Physics 2009-11-11 G. de Berredo-Peixoto , I. L. Shapiro

A method of evaluation of spacelike QCD observables ${\cal D}(Q^2)$ is presented, motivated by the renormalon structure of these quantities.

High Energy Physics - Phenomenology · Physics 2019-10-16 Gorazd Cvetic

We employ optimal renormalization group analysis to semi-leptonic $\tau$-decay polarization functions and extract the strange quark mass from their moments measured by the ALEPH and OPAL collaborations. The optimal renormalization group…

High Energy Physics - Phenomenology · Physics 2017-03-03 B. Ananthanarayan , Diganta Das

Returning to the old problems in ordinary QED, by an appropriate extension of the dimensional regularization method in noncommutative space we try to provide a quite coherent look into NCQED.The renormalisation of theories, the $\beta$…

High Energy Physics - Theory · Physics 2007-05-23 Nguyen Tien Binh

I review some of the recent developments in the theoretical description of weak inclusive decays of heavy mesons. The topics cover the value of $|V_{cb}|$ as extracted from semileptonic inclusive decays and a short discussion of the…

High Energy Physics - Phenomenology · Physics 2007-05-23 P. Ball

We compute the SUSY effective hamiltonian that describes the |\Delta S|=1 semileptonic decays of tau leptons. We provide analytical expressions for supersymmetric contribution to tau --> u bar{s} nu_{tau} transition in mass insertion…

High Energy Physics - Phenomenology · Physics 2008-11-26 D. Delepine , G. Faisl , S. Khalil , G. Lopez Castro

We revisit Sakurai's remark on the regularities of lepton-pair widths for mesons, extending the panorama to radiative $X \to \gamma \gamma$ and total decays. The regularities persist, and somehow surprisingly some of them seem to relate…

High Energy Physics - Phenomenology · Physics 2007-05-23 Alejandro Rivero

In this article, we assume the two nonets of scalar mesons below and above 1 GeV are all $\bar{q}q$ states, and study the semi-leptonic decays $B\to S\ell^-\bar{\nu}_{\ell}$, $B\to S\ell^+\ell^-$ and $B\to S\bar{\nu}\nu$ both in the…

High Energy Physics - Phenomenology · Physics 2015-08-03 Zhi-Gang Wang

Inspired by the relation between the hadronic decay of the tau lepton and the electron-positron annihilation into hadrons, we derive new tests of perturbative QCD. We design a set of commensurate scale relations to test the self-consistency…

High Energy Physics - Phenomenology · Physics 2007-05-23 J. R. Pelaez , S. J. Brodsky , N. Toumbas

We compute O(alpha_s^2) QCD corrections to the lepton invariant mass spectrum in the decay b --> u l nu_l, relevant for the determination of the CKM matrix element |V_{ub}|. Our method can also be used to evaluate moments of the lepton…

High Energy Physics - Phenomenology · Physics 2010-11-23 Andrzej Czarnecki , Kirill Melnikov

This is a review of new results on the Tau lepton. The lifetime has been measured with improved precision, allowing the test of lepton universality to 0.2% level. There are several new measurements of the branching ratios for the hadronic…

High Energy Physics - Experiment · Physics 2011-09-13 K. K. Gan

We present complete O(alpha_s^2) corrections to the decay b-->c+l+nu at the point where the invariant mass of the leptons sqrt{q^2} equals the c quark mass. We use this result, together with previously obtained corrections at the ends of…

High Energy Physics - Phenomenology · Physics 2011-01-25 Andrzej Czarnecki , Kirill Melnikov

We study the inclusive semileptonic B decays in the parton model. The model gives a decay spectrum which is in excellent agreement with experiment and makes several predictions to be tested in the forseeable future.

High Energy Physics - Phenomenology · Physics 2009-09-25 C. H. Jin , W. F. Palmer , E. A. Paschos

We perform a global analysis of exclusive hadronic tau decays into one and two mesons using the low-energy limit of the Standard Model Effective Field Theory up to dimension six, assuming left-handed neutrinos. A controlled theoretical…

High Energy Physics - Phenomenology · Physics 2020-03-24 Sergi Gonzàlez-Solís , Alejandro Miranda , Javier Rendón , Pablo Roig

We obtain analytical five-loop results for the renormalization group $\beta$-function of Quantum Electrodynamics with the single lepton in different renormalization schemes. The theoretical consequences of the results obtained are…

High Energy Physics - Phenomenology · Physics 2015-06-05 A. L. Kataev , S. A. Larin

Decay rate, forward-backward asymmetry and polarization asymmetries of final state leptons in B-> K_{1}tau ^{+}tau ^{-}, where K_{1} is the axial vector meson, are calculated in Standard Model and in the universal extra dimension (UED)…

High Energy Physics - Phenomenology · Physics 2008-11-26 Asif Saddique , M. Jamil Aslam , Cai-Dian Lu

Tau-lepton decays with up to two $\pi^0$'s in the final state, $\tau^+ \to \pi^+ \bar{\nu}_\tau$, $\rho^+ (\pi^+\pi^0) \bar{\nu}_\tau$, $a^+_1 (\pi^+\pi^0\pi^0) \bar{\nu}_\tau$, are used to study the performance of the barrel part of the…

Instrumentation and Detectors · Physics 2016-03-28 Trong Hieu Tran , Vladislav Balagura , Vincent Boudry , Jean-Claude Brient , Henri Videau