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Related papers: Reevaluating Uncertainties in $\bar B\to X_s\gamma…

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We study the effect of supersymmetric contributions to the effective quark transition $b\to s\gamma\gamma$, including leading order QCD effects. We apply the discussion to the decay $B_s\to\gamma\gamma$. Even though one-particle irreducible…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Bertolini , J. Matias

We show that in the Standard Model the parametrically leading (by a factor 1/alpha_s) contribution to the inclusive CP asymmetry in B->X_{s,d}+gamma decays arises from a long-distance effect in the interference of the electromagnetic dipole…

High Energy Physics - Phenomenology · Physics 2011-04-29 Michael Benzke , Seung J. Lee , Matthias Neubert , Gil Paz

In $B \to X_s \gamma $ there are perturbative $QCD$ corrections at order $\alpha_s$ not only to the single quark line process $ b \to s \gamma$ but also coming from a set of diagrams where the weak interaction vertex involves a gluon which…

High Energy Physics - Phenomenology · Physics 2009-10-28 John F. Donoghue , Alexey A. Petrov

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

The direct CP-asymmetry in the inclusive $B \to X_d \gamma$ and $B \to X_d e^+ e^ - $ decays is investigated in the two-Higgs doublet extension of the Standard Model (2HDM). The investigation is performed in the lowest non-vanishing order…

High Energy Physics - Phenomenology · Physics 2009-10-31 H. H. Asatryan , H. M. Asatrian , G. K. Yeghiyan , G. K. Savvidy

We study the inclusive $H_b \to X_s \gamma$ decay with $H_b$ a beauty baryon, in particular $\Lambda_b$, employing an expansion in the heavy quark mass at $\mathit{O}(m_b^{-3})$ at leading order in $\alpha_s$, keeping the dependence on the…

High Energy Physics - Phenomenology · Physics 2023-11-08 P. Colangelo , F. De Fazio , F. Loparco

Supersymmetric loop contributions can lead to different decay rates of H+\to t\bar b and H-\to b\bar t. We calculate the decay rate asymmetry \delta^CP = \frac{\Gamma(H+\to t\bar b)-\Gamma(H-\to b\bar t)}{{\Gamma(H+\to t\bar b)+\Gamma(H-\to…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. Christova , H. Eberl , S. Kraml , W. Majerotto

I review the NLO QCD calculations of the branching ratio for B--> X_s gamma in the SM. Including the leading electromagnetic corrections, one obtaines BR(B-> X_s gamma)=(3.32 +- 0.30)*10^{-4}. Confronting theory with the newest data, an…

High Energy Physics - Phenomenology · Physics 2007-05-23 C. Greub

Efforts to predict the rare exclusive decay $B\to K^{\ast}\gamma$ from the well known inclusive decay $b\to s\gamma$ are frustrated by the effect of the large recoil momentum. We show how to reduce the large uncertainty in calculating this…

High Energy Physics - Phenomenology · Physics 2009-10-22 Patrick J. O'Donnell , Humphrey K. K. Tung

Using the most general, model independent effective Hamiltonian, the rare B_s ->\gamma \nu \bar{\nu} decay with polarized photon is studied. The sensitivity of the branching ratio and photon polarization to the new Wilson coefficients are…

High Energy Physics - Phenomenology · Physics 2009-11-07 Berin Sirvanli , Gursevil Turan

The standard model prediction for the $B\to X_{s,d}\gamma$ decay amplitude with a right-handed photon is believed to be tiny, suppressed by $m_{s,d}/m_b$, compared to the amplitude with a left-handed photon. We show that this suppression is…

High Energy Physics - Phenomenology · Physics 2014-11-18 Benjamin Grinstein , Yuval Grossman , Zoltan Ligeti , Dan Pirjol

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 B --> X_s {\gamma} decay, where X_s is any strange hadronic state, is studied using a data sample of (382.8\pm 4.2) \times 10^6 e^+ e^- --> \Upsilon(4S) --> BBbar events collected by the BABAR experiment at the PEP-II…

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

We present an update on total and partial branching fractions and on CP asymmetries in the semi-inclusive decay B -> Xs l+l-. Further, we summarize our results on branching fractions and CP asymmetries for semi-inclusive and fully-inclusive…

High Energy Physics - Experiment · Physics 2015-03-10 G. Eigen , representing the BABAR collaboration

I point out that $B \to X_q \l^+ \l^-$ decays $(q = s, d)$ are sensitive probes of possible violation of CKM unitarity. I compute the decay rates and asymmetries in a minimal extension of the Standard Model containing an additional…

High Energy Physics - Phenomenology · Physics 2022-03-02 L. T. Handoko

Inclusive $H_b \to X_s \, \gamma$ decays, with $H_b$ a beauty baryon, are treated exploiting an expansion up to the third order in the inverse of the $b$ quark mass $m_b$ and to LO in $\alpha_s$, keeping the dependence on the hadron spin.…

High Energy Physics - Phenomenology · Physics 2024-10-10 Francesco Loparco

We calculate the most interesting rare and CP-violating K and B decays in the Littlest Higgs model with T-parity. We give a collection of Feynman rules including v^2/f^2 contributions that are presented here for the first time and could…

High Energy Physics - Phenomenology · Physics 2010-04-06 Monika Blanke , Andrzej J. Buras , Anton Poschenrieder , Stefan Recksiegel , Cecilia Tarantino , Selma Uhlig , Andreas Weiler

We combine the resummations for radiative corrections and for the heavy quark expansion to study the inclusive radiative decay $B \to X_s\gamma$. The infrared renormalon ambiguity is also taken into account. Including both theoretical and…

High Energy Physics - Phenomenology · Physics 2009-10-28 Hsiang-nan Li , Hoi-Lai Yu

Interference between the photonic dipole operator Q_7 and the current-current operators Q_{1,2} gives one of the most important QCD corrections to the B -> X_s gamma decay rate. So far, the O(alpha_s^2) part of this correction has been…

High Energy Physics - Phenomenology · Physics 2015-03-09 Michal Czakon , Paul Fiedler , Tobias Huber , Mikolaj Misiak , Thomas Schutzmeier , Matthias Steinhauser

Using the most general model independent form of the effective Hamiltonian, the rare B_s --> \gamma \ell^+ \ell^- decays are studied by taking into account the polarization of the photon. The total and the differential branching ratios for…

High Energy Physics - Phenomenology · Physics 2011-09-13 U. O. Yilmaz , B. B. Sirvanli , G. Turan