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In this work, we investigate the radiative leptonic decays D_(s)^- \to \gamma \ell \bar\nu (\ell = e, \mu) at tree level within the non-relativistic consistuent quark model and the effective Lagrangian for the heavy flavor decays. We find…

High Energy Physics - Phenomenology · Physics 2009-11-07 Cai-Dian Lu , Ge-Liang Song

We calculate the main observables in $B_{u,d}\to (\rho,\omega,K^*)\gamma$ and $B_s\to (\bar K^*,\phi)\gamma$ decays, i.e. branching ratios and CP and isospin asymmetries. We include QCD factorisation results and also the dominant…

High Energy Physics - Phenomenology · Physics 2008-11-26 Patricia Ball , Gareth W. Jones , Roman Zwicky

We derive a factorization theorem that describes an energetic hadron h fragmenting from a jet produced by a parton i, where the jet invariant mass is measured. The analysis yields a "fragmenting jet function" G_i^h(s,z) that depends on the…

High Energy Physics - Phenomenology · Physics 2011-02-23 Massimiliano Procura , Iain W. Stewart

The element |V_{ub}| of the quark mixing matrix can be extracted with small theoretical uncertainties by combining weighted integrals over the endpoint regions of the lepton spectrum in B -> X_u l nu decays and the photon spectrum in B ->…

High Energy Physics - Phenomenology · Physics 2014-11-17 Matthias Neubert

We test the parton model approach to inclusive $B \ra \gamma X_s$ and $B \ra e \bar{\nu} X_u$ processes by calculating a few moments of the distribution function. The $1/m_Q$ expansion of $b$-quark distribution function is discussed. We…

High Energy Physics - Phenomenology · Physics 2015-06-25 Kang Young Lee , Jae Kwan Kim

The order alpha_s^2 contribution to the inclusive semileptonic decay width of a b quark \Gamma(b -> X_u e \bar{\nu}_e) is calculated analytically for zero mass u quarks.

High Energy Physics - Phenomenology · Physics 2009-10-31 T. van Ritbergen

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

The photon spectrum in B -> X_s gamma decay, where X_s is any strange hadronic state, is studied using a data sample of 88.5 million e+e- -> Upsilon(4S) -> BBbar decays collected by the BaBar experiment at SLAC. The partial branching…

High Energy Physics - Experiment · Physics 2010-03-19 The BaBar Collaboration , B. Aubert

We have systematically investigated the semi-inclusive B decays $B\to MX$, which are manifestations of the quark decay $b \to Mq$, within a framework inspired by QCD-improved factorization. These decays are theoretically clean and have…

High Energy Physics - Phenomenology · Physics 2017-08-23 Hai-Yang Cheng

In this talk, we consider the computation of D and B fragmentation functions in e+e- annihilation. We present an improved differential cross section that merges together the O(alpha_s^2) fixed-order calculation and the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Carlo Oleari

We show that the leading-power $B$ meson wave function can be extracted reliably from the photon energy spectrum of the $B\to\gamma l\nu$ decay up to $O(1/m_b^2)$ and $O(\alpha_s^2)$ uncertainty, $m_b$ being the $b$ quark mass and…

High Energy Physics - Phenomenology · Physics 2009-11-11 Yeo-Yie Charng , Hsiang-Nan Li

Based on a new, exact QCD factorization formula for the partial B->X_s+gamma decay rate with a restriction on large photon energy, improved predictions are presented for the partial moments <E_gamma> and <E_gamma^2>-<E_gamma>^2 of the…

High Energy Physics - Phenomenology · Physics 2009-11-11 Matthias Neubert

The elementary fragmentation function that describes the process $q\to \pi$ is predicted applying crossing and charge symmetry to the cut diagram of the pion valence quark distribution function. This elementary probability distribution…

High Energy Physics - Phenomenology · Physics 2025-06-23 Roberto Correa da Silveira , Fernando E. Serna , Bruno El-Bennich

We examine the physics content of fragmentation functions for inclusive hadron production in a quark jet and argue that it can be calculated in low energy effective theories. As an example, we present a calculation of $u$-quark…

High Energy Physics - Phenomenology · Physics 2009-09-25 Xiangdong Ji , Zheng-Kun Zhu

With the expected large increase in data sets, previously not measured decays will be studied at Belle II. We derive standard model predictions for the $B\to X_u \tau\bar\nu$ decay rate and distributions. The region in the lepton energy…

High Energy Physics - Phenomenology · Physics 2022-05-09 Zoltan Ligeti , Michael Luke , Frank J. Tackmann

Motivated by the rapid development of heavy flavor physics experiment, we study the tree-dominated nonleptonic $\bar{B}_{u,d,s}^* \to D_{u,d,s}^*V$~($V=D^{*-},D_s^{*-},K^{*-},{\rho}^-$) decays within the factorization approach. The relevant…

High Energy Physics - Phenomenology · Physics 2019-09-18 Qin Chang , Yunyun Zhang , Xiaonan Li

We present preliminary results from a lepton-tagged fully-inclusive measurement of $B \to X_{s}\gamma$ decays, where $X_{s}$ is any strange hadronic state. Results are based on a BaBar data set of 88.5 million $B\bar{B}$ pairs at the…

High Energy Physics - Experiment · Physics 2012-08-27 BaBar Collaboration

Next-to-leading order parton fragmentation functions into light mesons are presented. They have been extracted from real and simulated $e^+e^-$ data and used to predict inclusive single particle distributions at different machines.

High Energy Physics - Phenomenology · Physics 2007-05-23 Simona Rolli

Using the recently proposed ALPHA algorithm (and the resulting code) I compute the rate (at tree level) for the process $\gamma\gamma\rightarrow\bar\nu_e e^- u \bar d$. The bulk of the contribution is due to W pair production and decay.…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Moretti

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