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We compute the two-loop BSM contributions to the $h\longrightarrow \gamma\gamma$ decay width in the aligned THDM. We adopt the simplifying assumptions of vanishing EW gauge couplings and vanishing mass of the SM-like Higgs boson, which…

High Energy Physics - Phenomenology · Physics 2023-10-13 Giuseppe Degrassi , Pietro Slavich

We study supersymmetric (SUSY) effects on $C_7(\mu_b)$ and $C'_7(\mu_b)$ which are the Wilson coefficients (WCs) for $b \to s \gamma$ at b-quark mass scale $\mu_b$ and are closely related to radiative $B$-meson decays. The SUSY-loop…

High Energy Physics - Phenomenology · Physics 2021-11-05 H. Eberl , K. Hidaka , E. Ginina , A. Ishikawa

We show the three-loop calculation of the matching coefficients $\mathcal{C}_J$ for the four heavy flavor-changing currents in nonrelativistic Quantum Chromodynamics effective theory and confirm the surprising observation of the…

High Energy Physics - Phenomenology · Physics 2023-10-19 Wei Tao , Zhen-Jun Xiao , Ruilin Zhu

We study the spectra of the bottomonium and B_c states within perturbative QCD up to order alpha_s^4. The O(Lambda_QCD) renormalon cancellation between the static potential and the pole mass is performed in the epsilon-expansion scheme. We…

High Energy Physics - Phenomenology · Physics 2009-06-12 N. Brambilla , Y. Sumino , A. Vairo

The weak phase \gamma can be determined using untagged B^0\to DK_S or B_s\to D\phi, D\eta^{(')} decays. In the past, the small lifetime difference y\equiv \Delta\Gamma/(2\Gamma) has been neglected in B^0, while the CP violating parameter…

High Energy Physics - Phenomenology · Physics 2008-11-26 Michael Gronau , Yuval Grossman , Ze'ev Surujon , Jure Zupan

We compute next-to-next-to-leading order corrections to the decay width difference of mass eigenstates and the charge-parity (CP) asymmetry $a_{\rm fs}$ in flavour-specific decays of neutral $B$ mesons. We include both current-current and…

High Energy Physics - Phenomenology · Physics 2026-04-01 Ulrich Nierste , Pascal Reeck , Vladyslav Shtabovenko , Matthias Steinhauser

We have calculated the decay amplitude for the process $K_{S}$ $\to$ $\gamma \gamma$ at one loop order in chiral perturbation theory. As a new improvement we have included the weak mass term which is only relevant for processes with…

High Energy Physics - Phenomenology · Physics 2009-07-20 Karim Ghorbani

The dominant contribution to the inclusive decays of $B$ mesons into the charm-strangeness mesons $D_s$ and $D_s^{\ast}$ is expected to be given by the partonic process $b \to c+(D_s^-,D_s^{\ast -})$. We determine the nonperturbative…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. Fischer , S. Groote , J. G. Körner , M. C. Mauser

We reconsider the prediction of the semileptonic branching ratio of B mesons, using a recent calculation of the radiative corrections with account for finite quark masses in nonleptonic decays and taking into account 1/m_b^2 corrections.…

High Energy Physics - Phenomenology · Physics 2009-10-28 E. Bagan , Patricia Ball , V. M. Braun , P. Gosdzinsky

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 study constraints on the CP violating phase $\gamma$ in the Kobayashi-Maskawa model using available experimental data. We first follow the conventional method to up date the constraint on $\gamma$ by performing a $\chi^2$ analysis using…

High Energy Physics - Phenomenology · Physics 2014-11-17 X. -G. He , Y. -K. Hsiao , J. -Q. Shi , Y. -L. Wu , Y. -F. Zhou

The MSbar charm quark mass is determined to be m_c(m_c)=1224+-17+-54 MeV from a global fit to inclusive B meson decay data, where the first error is experimental, and includes the uncertainty in alpha_s, and the second is an estimate of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Andre H. Hoang , Aneesh V. Manohar

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 calculate the complete NNLO QCD corrections to the charm contribution of the rare decay K+ -> pi+ nu nu-bar. We encounter several new features, which were absent in lower orders. We discuss them in detail and present the results for the…

High Energy Physics - Phenomenology · Physics 2016-06-29 Andrzej J. Buras , Martin Gorbahn , Ulrich Haisch , Ulrich Nierste

The renormalization-scale ($\mu$) dependence of the two-loop inclusive semileptonic $b\to c\ell^-\bar\nu_\ell$ decay rate is shown to be significant in the pole mass scheme, and the decay rate is shown to be poorly convergent in the MS-bar…

High Energy Physics - Phenomenology · Physics 2011-01-25 M. R. Ahmady , F. A. Chishtie , V. Elias , A. H. Fariborz , D. G. C. McKeon , T. N. Sherry , T. G. Steele

The recent LHCb angular analysis of the exclusive decay B->K^*mu+mu- has indicated significant deviations from the Standard Model expectations. Accurate predictions can be achieved at large K*-meson recoil for an optimised set of…

High Energy Physics - Phenomenology · Physics 2015-06-22 Sébastien Descotes-Genon , Lars Hofer , Joaquim Matias , Javier Virto

About 2.9 fb$^{-1}$ data set had been collected with the BESIII detector at the BEPCII collider. Taking advantages of data near open-charm threshold, we present preliminary results on leptonic and semileptonic charm-meson decays, as well as…

High Energy Physics - Experiment · Physics 2015-06-11 Hai-Bo Li

Two-body non-leptonic charmed decays $B_{(s)} \to D_{(s)}P$, $D_{(s)}^*P$, $D_{(s)}V$ and $D_{(s)}^*V$ are analyzed in perturbative QCD approach, where $P$ and $V$ denote the light pseudoscalar meson and vector meson, respectively. We test…

High Energy Physics - Phenomenology · Physics 2008-11-26 Run-Hui Li , Cai-Dian Lü , Hao Zou

We study the contributions to the branching ratios of $B_{s(d)}\to \gamma \gamma$ decay in the sequential fourth generation model (SM4). We find that the theoretical values of the branching ratios, ${\rm BR}(B_{s(d)}\to\gamma\gamma)$,…

High Energy Physics - Phenomenology · Physics 2011-01-26 H. Chen , W. Huo

The B -> X_s gamma branching ratio is currently measured with around 5% accuracy. Further improvement is expected from Belle II. To match such a precision on the theoretical side, evaluation of O(alpha_s^2) corrections to the partonic decay…

High Energy Physics - Phenomenology · Physics 2023-12-11 M. Czaja , M. Czakon , T. Huber , M. Misiak , M. Niggetiedt , A. Rehman , K. Schönwald , M. Steinhauser