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As a successive work to [Phys.Rev.D 102 (2020), 034034], we derive the $1/m_Q$ corrections to chiral effective Lagrangian for heavy-light mesons from QCD under proper approximations. The low energy constants in the effective Lagrangian are…

High Energy Physics - Phenomenology · Physics 2020-12-08 Qing-Sen Chen , Hui-Feng Fu , Yong-Liang Ma , Qing Wang

We discuss in detail the calculation of the leading order QCD corrections to the Effective Hamiltonian which governs $b \rightarrow s\, \gamma$ and $b \rightarrow s \, g$ transitions in three different regularization schemes (HV, NDR and…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Ciuchini , E. Franco , L. Reina , L. Silvestrini

We calculate the $\Lambda_b \to \Lambda_c \ell \nu$ form factors and decay rates for all possible $b\to c \ell\bar\nu$ four-Fermi interactions beyond the Standard Model, including nonzero charged lepton masses and terms up to order…

High Energy Physics - Phenomenology · Physics 2019-03-27 Florian U. Bernlochner , Zoltan Ligeti , Dean J. Robinson , William L. Sutcliffe

We compute the decay rate of the Standard Model Higgs boson to bottom quarks to order $\alpha\alpha_s$. We apply the optical theorem and calculate the imaginary part of three-loop corrections to the Higgs boson propagator using asymptotic…

High Energy Physics - Phenomenology · Physics 2015-11-11 Luminita Mihaila , Barbara Schmidt , Matthias Steinhauser

We calculate the QCD corrected effective Hamiltonian for $B\bbar$--Mixing in heavy quark effective theory including corrections of the order $\Lambda_{QCD} / m_b$. The matrix elements of the subleading operators are estimated using the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Wolfgang Kilian , Thomas Mannel

The enhancement $\Delta \Gamma (\Lambda_b)$ of the $\Lambda_b$ decay rate due to four-fermion processes of weak scattering and Pauli interference is calculated within the quark model. An estimate of the relative $bu$ wave function at zero…

High Energy Physics - Phenomenology · Physics 2009-10-28 Jonathan L. Rosner

We consider an effective field theory for the nonleptonic decay in which a heavy quark decays into a pair of a heavy quark and antiquark having a small relative velocity and one relativistic (massless) quark. This effective theory is a…

High Energy Physics - Phenomenology · Physics 2008-11-26 C. Bobeth , B. Grinstein , M. Savrov

In the framework of a 2HDM effective lagrangian for the MSSM, we analyse important phenomenological aspects associated with quantum soft SUSY-breaking effects that modify the relation between the bottom mass and the bottom Yukawa coupling.…

High Energy Physics - Phenomenology · Physics 2008-11-26 M. Carena , D. Garcia , U. Nierste , C. E. M. Wagner

Corrections of $O(\alpha_s^2)$ to the decay of the top quark into a W boson and a bottom quark are calculated. The method is based on an expansion of the top quark propagator for small external momentum, q, as compared to the top quark…

High Energy Physics - Phenomenology · Physics 2016-08-25 K. G. Chetyrkin , R. Harlander , T. Seidensticker , M. Steinhauser

We extend previous analyses of the supersymmetric loop correction to the charged Higgs couplings to include the coupling $H^{\pm}\chi^{\mp}\chi^0$. The analysis completes the previous analyses where similar corrections were computed for…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tarek Ibrahim , Pran Nath , Anastasios Psinas

The calculation of the one-loop induced decay rate b -> s \gamma is improved by including radiative corrections to the charged Higgs mass and to the charged-Higgs-fermion-fermion vertex. It is shown how the radiative corrections modify the…

High Energy Physics - Phenomenology · Physics 2009-10-22 Marco A. Diaz

We present upgraded theoretical predictions for inclusive and exclusive radiative decays of {\it B} mesons. Our results include those next-to-leading order corrections that have already been computed. Our best estimates in the Standard…

High Energy Physics - Phenomenology · Physics 2009-10-28 M. Ciuchini , E. Franco , G. Martinelli , L. Reina , L. Silvestrini

We discuss a general strategy to compute the coefficients of QCD chiral Lagrangian by using the lattice regularization of QCD with Wilson fermions. This procedure requires the introduction of an effective Lagrangian for lattice QCD as an…

High Energy Physics - Lattice · Physics 2009-10-28 A. R. Levi , V. Lubicz , C. Rebbi

The calculation of the $O(\a_s)$ virtual corrections to the matrix element of the inclusive decay $b \to s \gamma$ is reported. These contributions drastically reduce the large renormalization scale dependence of the leading logarithmic…

High Energy Physics - Phenomenology · Physics 2007-05-23 Christoph Greub , Tobias Hurth

We give the first accurate results for $B$ and $B_s$ meson masses from lattice QCD including the effect of $u$, $d$ and $s$ sea quarks, and we improve an earlier value for the $B_c$ meson mass. By using the Highly Improved Staggered Quark…

We compute the dimension 6 effective Lagrangian arising from the tree level integration of an arbitrary number of bulk fermions in models with warped extra dimensions. The coefficients of the effective operators are written in terms of…

High Energy Physics - Phenomenology · Physics 2012-03-14 Adrian Carmona , Jose Santiago

We give a summary about the various contributions which have to be calculated in order to obtain the next-to-leading logarithmic result for the branching ratio $BR(B \to X_s \gamma)$. Combining all these ingredients, which were obtained by…

High Energy Physics - Phenomenology · Physics 2016-11-03 C. Greub , T. Hurth

We compute the QCD corrections to the decay rate difference in the $B_s-\bar B_s$ system, $\Delta\Gamma_{B_s}$, in the next-to-leading logarithmic approximation using the heavy quark expansion approach. Going beyond leading order in QCD is…

High Energy Physics - Phenomenology · Physics 2009-10-09 M. Beneke , G. Buchalla , C. Greub , A. Lenz , U. Nierste

We derive the mass correction lagrangian of the heavy meson effective theory by using the projection operator method. The next leading order of the mass correction and the first order of the chiral expansion are given explicitely.We also…

High Energy Physics - Phenomenology · Physics 2016-09-01 Tsung-Wen Yeh , Chien-er Lee

The B -> X_s l+ l- decay rate is known at the next-to-next-to-leading order in QCD. It is proportional to alpha_em (mu)^2 and has a +- 4% scale uncertainty before including the O(alpha_em log(M_W^2/m_b^2)) electromagnetic corrections. We…

High Energy Physics - Phenomenology · Physics 2011-10-13 T. Huber , E. Lunghi , M. Misiak , D. Wyler