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Related papers: Shape Function Effects in B -> X_c l \nu_l

200 papers

We measured two moments of the lepton momentum spectrum in B -> X l nu, where l= e or mu, for p_l > 1.5 GeV/c. From these we derive the Heavy Quark Expansion (HQE) parameters Lambda-bar(MS-bar) = 0.39 +- 0.03(stat) +- 0.06(sys) +- 0.12(th)…

High Energy Physics - Experiment · Physics 2007-05-23 R. A. Briere

We resum to next-to-leading order (NLO) the distribution in the light-cone momentum p+ = EX - |pX| and the spectrum in the electron energy, in the semileptonic decays B-> Xu l nu, where EX and pX are the total energy and three-momentum of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Ugo Aglietti , Giulia Ricciardi , Giancarlo Ferrera

We discuss the implications of charged lepton energy cut to the hadronic invariant mass spectrum in charmless semileptonic B decays. Charged-lepton energy cut is inevitable in order to remove secondary leptonic events such as b -> c, tau ->…

High Energy Physics - Phenomenology · Physics 2011-02-01 K. K. Jeong , C. S. Kim , Yeong Gyun Kim

We reconsider the possibility that the tension in the $|V_{cb}|$ determinations from inclusive and exclusive $B$ decay modes is due to a new physics effect. We modify the Standard Model effective Hamiltonian for semileptonic $b \to c$…

High Energy Physics - Phenomenology · Physics 2017-02-01 Pietro Colangelo , Fulvia De Fazio

Nonperturbative corrections up to $m_b^{-2}$ to the heavy lepton energy distributions are investigated in the inclusive semileptonic weak decays of heavy flavors in QCD. In the case of $B$-meson decays, for $b \ra u\tau\bnu$ transitions…

High Energy Physics - Phenomenology · Physics 2009-10-22 L. Koyrakh

Compact analytic expressions have been obtained for the first order perturbative QCD corrections to the inclusive spectra of the leptons in the semileptonic decays of polarised heavy quarks. Charmed and beautiful $\Lambda$ baryons from…

High Energy Physics - Phenomenology · Physics 2007-05-23 Marek Jezabek

We present a method to compute, by numerical simulations of lattice QCD, the inclusive semileptonic differential decay rates of heavy hadrons and the structure functions which occur in deep inelastic scattering. The method is based on first…

High Energy Physics - Phenomenology · Physics 2009-10-31 U. Aglietti , M. Ciuchini , G. Corbo' , E. Franco , G. Martinelli , L. Silvestrini

We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis…

High Energy Physics - Phenomenology · Physics 2009-02-23 Guido Bell

The study of inclusive semileptonic decays of $B$ mesons is analyzed from the viewpoint of probing hadron structure and strong interactions. General formulas for the differential decay rates are given in terms of the structure functions in…

High Energy Physics - Phenomenology · Physics 2007-05-23 Changhao Jin

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 radiative corrections to $\bar{B} \to X_c \ell \bar{\nu}_\ell$ decays assuming the power counting $m_c \sim \sqrt{\Lambda_QCD m_b}$ for the charm-quark mass. Concentrating on the shape-function region, we use effective field-theory…

High Energy Physics - Phenomenology · Physics 2008-11-26 H. Boos , Th. Feldmann , T. Mannel , B. D. Pecjak

Quantum chromodynamics (QCD) effects in the semileptonic decay b -> c l nu are evaluated to the second order in the coupling constant, O(alpha_s^2), and to several orders in the expansion in quark masses, m_c/m_b. Corrections are calculated…

High Energy Physics - Phenomenology · Physics 2008-11-26 Alexey Pak , Andrzej Czarnecki

We compute the O(alpha_s) corrections to the Wilson coefficients of the dimension five operators emerging from the Operator Product Expansion of inclusive radiative B decays. We discuss the impact of the resulting O(alpha_s…

High Energy Physics - Phenomenology · Physics 2010-02-15 Thorsten Ewerth , Paolo Gambino , Soumitra Nandi

We present an updated next-to-leading order analysis of the B -> X_s gamma branching ratio and photon spectrum, including consistently the effects of Fermi motion in the heavy-quark expansion. For the Standard Model, we obtain B(B -> X_s…

High Energy Physics - Phenomenology · Physics 2011-09-13 A. L. Kagan , M. Neubert

We compute the leading order (in $\alpha_s$) perturbative QCD and power ($1/m_b^2)$ corrections to the hadronic invariant mass and hadron energy spectra in the decay $B \to X_s \ell^+ \ell^-$ in standard model. This is done both by using…

High Energy Physics - Phenomenology · Physics 2011-01-27 A. Ali , G. Hiller

Exclusive semileptonic B decays to the lightest excited charmed mesons are investigated at order $\Lambda_{QCD}/m_Q$ in the heavy quark effective theory. At zero recoil, $\Lambda_{QCD}/m_Q$ corrections to the matrix elements of the weak…

High Energy Physics - Phenomenology · Physics 2007-05-23 Zoltan Ligeti

We present the first complete $\mathcal{O}(\alpha_s^2)$ and $\mathcal{O}(\alpha_s^3)$ perturbative QCD corrections to all five heavy-to-light structure functions underlying the triple-differential semi-leptonic decay rates of heavy quarks.…

High Energy Physics - Phenomenology · Physics 2026-02-13 Long Chen , Xiang Chen , Xin Guan , Yan-Qing Ma

We compute the first two moments of the final hadronic invariant mass in inclusive semileptonic B decay, in the presence of a cut on the charged lepton energy. These moments may be measured directly by experiments at the Upsilon(4S) using…

High Energy Physics - Phenomenology · Physics 2014-11-17 Adam F. Falk , Michael Luke

I review the present state of knowledge on lepton energy spectra in the inclusive semileptonic decay of beauty hadrons, as a means to measure b polarization effects on the Z peak. Charged-lepton as well as neutrino spectra are considered.

High Energy Physics - Phenomenology · Physics 2015-06-25 Barbara Mele

The structure function of a heavy quark in a heavy hadron in electroproduction is calculated from QCD. Its deviation from the parton model prediction (a delta function) is shown to be governed by a shape function, similar to the one…

High Energy Physics - Phenomenology · Physics 2009-09-25 D. Pirjol
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