English
Related papers

Related papers: Shape function effects in B -> X_s gamma and B -> …

200 papers

The inclusive B -> Xs l+ l- decay rate in the large q^2 region (q^2 > m_{\psi'}^2) receives significant nonperturbative corrections. The resulting uncertainties can be drastically reduced by normalizing the rate to the B -> Xu l nu rate…

High Energy Physics - Phenomenology · Physics 2008-11-26 Zoltan Ligeti , Frank J. Tackmann

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

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 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

We give a brief overview about perturbative corrections to the inclusive decay mode B to X_s gamma in supersymmetric models.

High Energy Physics - Phenomenology · Physics 2011-11-17 Christoph Greub , Tobias Hurth , Volker Pilipp , Christof Schuepbach

We construct an effective field theory valid for processes in which highly energetic light-like particles interact with collinear and soft degrees of freedom, using the decay B -> X_s + gamma near the endpoint of the photon spectrum, x = 2…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. W. Bauer , S. Fleming , M. Luke

We calculate the shape of the photon spectrum for $B\rightarrow X_{s}+\gamma$ decay in the presence of a background chromomagnetic field for the case of SU(2) gauge group. The effect of the external field resembles the Zeeman effect - the…

High Energy Physics - Phenomenology · Physics 2009-10-28 Alexander Kyatkin

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

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

We perform infrared factorization of differential rates of radiative and semileptonic inclusive decays of the B meson in the end-point region of photon and charged lepton spectrum, respectively, in the leading heavy quark mass limit. We…

High Energy Physics - Phenomenology · Physics 2014-11-17 G. P. Korchemsky , G. Sterman

We consider the decay of a heavy flavour into an inclusive hadronic state X of invariant mass m_X small with respect to its energy E_X, m_X << E_X. The electron spectrum and the hadronic mass distribution in semileptonic b -> u decays, or…

High Energy Physics - Phenomenology · Physics 2009-10-31 Ugo Aglietti , Giulia Ricciardi

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 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 examine the anomalous dimension matrix appropriate for the phase space restricted B --> X(u) ell anti-nu and B --> X(s) gamma decay spectra to subleading nonperturbative order. The effects of the time ordered products of the HQET…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael Trott , Alexander R. Williamson

The flavor-changing electromagnetic dipole operator O_7 gives the dominant contribution to the B -> Xs gamma decay rate. We calculate two-loop QCD corrections to its matrix element together with the corresponding bremsstrahlung…

High Energy Physics - Phenomenology · Physics 2013-07-02 I. Blokland , A. Czarnecki , M. Misiak , M. Slusarczyk , F. Tkachov

Recently, it was shown that in inclusive B -> Xs l+ l- decay, an angular decomposition provides three independent (q^2 dependent) observables. A strategy was formulated to extract all measurable Wilson coefficients in B -> Xs l+ l- from a…

High Energy Physics - Phenomenology · Physics 2009-08-03 Keith S. M. Lee , Frank J. Tackmann

The moments of the photon spectrum in the inclusive $B\to X_s\,\gamma$ decay can be calculated to order $\alpha_s$ accuracy at present, without knowing the $\alpha_s$ corrections to the effective Hamiltonian. We discuss the standard model…

High Energy Physics - Phenomenology · Physics 2009-10-28 Anton Kapustin , Zoltan Ligeti

The photon spectrum in the inclusive electromagnetic radiative decays of the $B$ meson, $B \to X_{s} \gamma$ plus $B \to X_{d} \gamma$, is studied using a data sample of $(382.8 \pm 4.2) \times 10^6$ $\Upsilon(4S) \to B\overli\ ne{B}$…

High Energy Physics - Experiment · Physics 2013-05-30 The BaBar Collaboration

We present a complete calculation of the Leading Order QCD corrections to the quark level decay amplitude for b -> s gamma gamma and study their relevance for both the inclusive branching ratio BR(B -> X_s gamma gamma) and for the exclusive…

High Energy Physics - Phenomenology · Physics 2014-11-17 Laura Reina , Giulia Ricciardi , Amarjit Soni

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