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Related papers: B--> eta' X_s in the Standard Model

200 papers

We use a factorization theorem from the soft-collinear effective theory along with heavy quark symmetry to make model independent predictions for B-> D^(*)M where M={eta,eta',phi, omega}. Gluon production of these isosinglet mesons is…

High Energy Physics - Phenomenology · Physics 2010-04-05 Andrew E. Blechman , Sonny Mantry , Iain W. Stewart

An analysis of the rare B decays $B\to K^{(*)}\nu\bar\nu$ is presented both within the SM and beyond. The SM predictions for the branching ratios are updated and uncertainties reduced. For the NP analysis both a model independent approach…

High Energy Physics - Phenomenology · Physics 2014-10-22 Jennifer Girrbach-Noe

The QCD-induced $W^\pm \gamma$ production channels in association with two jets are computed at next-to-leading order QCD accuracy. The W bosons decay leptonicly and full off-shell and finite width effects as well as spin correlations are…

High Energy Physics - Phenomenology · Physics 2015-07-15 Francisco Campanario , Matthias Kerner , Le Duc Ninh , Dieter Zeppenfeld

The next-to-next-to-next-to-leading order (N^3LO) Hamiltonian of potential nonrelativistic QCD is derived. The complete matching of the Hamiltonian and the contribution from the ultrasoft dynamical gluons relevant for perturbative…

High Energy Physics - Phenomenology · Physics 2015-06-25 B. A. Kniehl , A. A. Penin , V. A. Smirnov , M. Steinhauser

We study the rare radiative leptonic decays $B_s\to\ell^+\ell^-\gamma$ ($\ell=e,\mu,\tau$) within the Standard Model, considering both the structure-dependent amplitude and bremsstrahlung. In the framework of the covariant confined quark…

High Energy Physics - Phenomenology · Physics 2019-02-06 Stanislav Dubnička , Anna Z. Dubničková , Mikhail A. Ivanov , Andrej Liptaj , Pietro Santorelli , Chien-Thang Tran

The gluino-induced contribution to the decay $b \to s \gamma$ is investigated in supersymmetric frameworks with generic sources of flavour violation. It is emphasized that the operator basis of the standard model effective Hamiltonian is…

High Energy Physics - Phenomenology · Physics 2016-09-06 Daniel Wyler , Francesca Borzumati

We calculate the branching ratio of $\Lambda_b \to \Lambda \gamma$ in the standard model using the PQCD method. The predicted branching ratio $B(\Lambda_b \to \Lambda \gamma)$ is about $(4.3\sim 8.6)\times 10^{-8}$, with reasonable…

High Energy Physics - Phenomenology · Physics 2009-11-11 Xiao-Gang He , Tong Li , Xue-Qian Li , Yu-Ming Wang

We present a next-to-leading order (NLO) QCD corrections to $B_c\to \eta_c$ and $B_c\to J/\psi$ tensor form factors within nonrelativistic QCD (NRQCD) framework. The full analytical results for $B_c$ to S-wave charmonium tensor form factors…

High Energy Physics - Phenomenology · Physics 2022-06-29 Wei Tao , Zhen-Jun Xiao , Ruilin Zhu

We calculate semileptonic form factors for the decays $B_c \to \eta_c \, l \nu$ and $B_c \to J/\psi \, l \nu$ over the entire $q^2$ range, using a highly improved lattice quark action for charm at several lattice spacings down to $a=0.045$…

High Energy Physics - Lattice · Physics 2016-11-08 Brian Colquhoun , Christine Davies , Jonna Koponen , Andrew Lytle , Craig McNeile

In this talk I give an introduction to methods used to give a model independent description of QCD effects in B-decays. I discuss three useful expansions: mb/mW << 1 for the electroweak Hamiltonian, LambdaQCD/mb << 1 for Heavy Quark…

High Energy Physics - Phenomenology · Physics 2007-05-23 Iain W. Stewart

In this paper, we calculate the branching ratios and CP-violating asymmetries for $B_{s} \to (\rho^0,\omega, \phi) \eta^{(\prime)}$ decays in the perturbative QCD (pQCD) factorization approach. Numerically we found that (a) the pQCD…

High Energy Physics - Phenomenology · Physics 2007-05-23 Xin-fen Chen , Dong-qin Guo , Zhen-jun Xiao

Using $(2+1)$-flavor lattice QCD, we compute the 10 form factors describing the $\Lambda_b \to \Lambda$ matrix elements of the $b \to s$ vector, axial vector, and tensor currents. The calculation is based on gauge field ensembles generated…

High Energy Physics - Lattice · Physics 2021-08-12 William Detmold , Stefan Meinel

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

We investigate the processes $e^+e^-\to \eta_c+\gamma$ and $e^+e^-\to \chi_{cJ}+\gamma$ at B factories within the NRQCD factorization framework, computing the corresponding helicity amplitudes through $\mathcal{O}(\alpha_s^2)$. The…

High Energy Physics - Phenomenology · Physics 2025-12-05 Cong Li , Wen-Long Sang , Hong-Fei Zhang

We review the theoretical understanding of the branching ratio and photon-energy spectrum in B -> Xs gamma decays at next-to-leading order in QCD, including consistently the effects of Fermi motion. For the Standard Model, we obtain B(B ->…

High Energy Physics - Phenomenology · Physics 2007-05-23 Matthias Neubert

I review recent progresses in heavy quarks physics on the lattice. I focus on decay constants and form factors relevant for the extraction of CKM matrix elements from experimental data. B-\bar{B} mixing is also discussed. In the last part…

High Energy Physics - Lattice · Physics 2009-01-06 Michele Della Morte

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

We directly fit the QCD dimensional transmutation parameter, Lambda MS-bar, to experimental data on e+e- jet observables, making use of next-to-leading order (NLO) perturbative calculations. In this procedure there is no need to mention,…

High Energy Physics - Phenomenology · Physics 2009-10-31 S. J. Burby , C. J. Maxwell

Within the nonrelativistic QCD (NRQCD) factorization framework, we compute the long-awaited ${\mathcal O}(\alpha_s^2)$ correction for the exclusive double charmonium production process at $B$ factories, {\it i.e.}, $e^+e^-\to J/\psi+\eta_c$…

High Energy Physics - Phenomenology · Physics 2022-11-28 Feng Feng , Yu Jia , Zhewen Mo , Wen-Long Sang , Jia-Yue Zhang

The standard Large Deviation Theory (LDT) is mathematically illustrated by the Boltzmann-Gibbs factor which describes the thermal equilibrium of short-range-interacting many-body Hamiltonian systems, the velocity distribution of which is…

Statistical Mechanics · Physics 2021-12-24 Ugur Tirnakli , Constantino Tsallis , Nihat Ay