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The first, to our knowledge, calculation of neutrinoless double beta decay ($0\nu\beta\beta$-decay) matrix elements within the self-consistent renormalised Quasiparticle Random Phase Approximation (SRQRPA) is presented. The contribution…

Nuclear Theory · Physics 2009-02-18 A. Bobyk , W. A. Kaminski , F. Simkovic

In this work we compute the leading logarithmic corrections to the b -> s gamma decay in a dimensional scheme which does not require any definition of the gamma5 matrix. The scheme does not exhibit unconsistencies and it is therefore a…

High Energy Physics - Phenomenology · Physics 2009-10-28 G. Cella , G. Curci , G. Ricciardi , A. Vicere'

The element |V_{ub}| of the quark mixing matrix can be extracted with small theoretical uncertainties by combining weighted integrals over the endpoint regions of the lepton spectrum in B -> X_u l nu decays and the photon spectrum in B ->…

High Energy Physics - Phenomenology · Physics 2014-11-17 Matthias Neubert

A lattice quantum chromodynamics (LQCD) calculation of the nuclear matrix element relevant to the $nn\to ppee\overline{\nu}_e\overline{\nu}_e$ transition is described in detail, expanding on the results presented in Ref. [1]. This matrix…

In this work we study the effects of new-physics (NP) operators with different Lorentz structures on the inclusive $B \to X_c\tau \bar{\nu}$ decay and make predictions for the ratio of total decay rates $R(X_c)=\frac{\Gamma(B \to X_c\tau…

High Energy Physics - Phenomenology · Physics 2018-05-31 Saeed Kamali , Ahmed Rashed , Alakabha Datta

We report on progress towards including next-to-leading order (NLO) radiative corrections to the subleading-power factorization formula for the $Q_1^{q}-Q_{7\gamma}$ interference contribution in $\bar{B}\to X_s\gamma$ at large photon…

High Energy Physics - Phenomenology · Physics 2025-10-22 Riccardo Bartocci , Philipp Böer , Tobias Hurth

We calculate the two-loop QCD mixing of the dimension-five flavor-changing operators that arise in the Standard Model after integrating out the $W$, $Z$ and Higgs bosons and the top-quark, i.e.~the mixing among gluonic and photonic magnetic…

High Energy Physics - Phenomenology · Physics 2011-07-19 M. Misiak , M. Muenz

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

It is possible to employ virtual decay paths, including two-particle transfer, to calculate the nuclear matrix element of neutrinoless double-beta decay under the closure approximation, in addition to the true double-beta path. In the…

Nuclear Theory · Physics 2016-03-02 Jun Terasaki

The goal of the SIMBA collaboration is to provide a global fit to the available measurements of inclusive B -> X_s gamma and B -> X_u l nu decays. By performing a global fit one is able to simultaneously determine the relevant…

High Energy Physics - Phenomenology · Physics 2013-03-06 Florian U. Bernlochner , Heiko Lacker , Zoltan Ligeti , Iain W. Stewart , Frank J. Tackmann , Kerstin Tackmann

We calculate the three-loop master integrals of Ref. [1] [arXiv:1709.02160] in analytic form. This allows us to present the fermionic contributions to the $\Delta B=2$ Wilson coefficients of the $B$-$\bar B$ decay matrix in…

High Energy Physics - Phenomenology · Physics 2022-07-06 Artyom Hovhannisyan , Ulrich Nierste

We give a recurrence relation for two-loop integrals encountered in the effective field theory of an infinitely heavy quark, Q, interacting with gluons and Nl massless quarks, q, from which we obtain exact two-loop results, in any dimension…

High Energy Physics - Phenomenology · Physics 2010-11-01 D. J. Broadhurst , A. G. Grozin

Under the framework of the Bethe-Salpeter (B.S.) wave functions and the Mandelstam formalism as well, to make ``instantaneous approximation'' to a transition matrix element (a current operator sandwiched between two bound-states of double…

High Energy Physics - Phenomenology · Physics 2011-07-19 Chao-Hsi Chang , Yu-Qi Chen

The nuclear matrix elements $M^{0\nu}$ of the neutrinoless double beta decay ($0\nu\beta\beta$) of most nuclei with known $2\nu\beta\beta$-decay rates are systematically evaluated using the Quasiparticle Random Phase Approximation (QRPA)…

Nuclear Theory · Physics 2009-11-11 Vadim Rodin , Amand Faessler , Fedor Simkovic , Petr Vogel

We present a leading-order pQCD calculation of the helicity-flip $\Delta\to N\gamma^*$ matrix element $G_0$ (Coulomb quadrupole amplitude $C2$), taking into account the transverse momenta of the quarks and the contribution from the gluons.…

High Energy Physics - Phenomenology · Physics 2009-11-10 Ahmad Idilbi , Xiangdong Ji , Jian-Ping Ma

Soft-QCD effects of quark-level form factors in $\gamma\gamma$ decay of $B_s$-mesons via $D{\bar D}$ intermediate states, suggested by Ellis et al, are examined in the "Salpeter" model [reinterpreted in terms of the Markov-Yukawa…

High Energy Physics - Phenomenology · Physics 2009-10-31 A. N. Mitra

We analyze uncertainties in the theoretical prediction for the inclusive branching ratio $BR[B \rightarrow X_s \gamma]$. We find that the dominant uncertainty in the leading order expression comes from its $\mu$-dependence. We discuss a…

High Energy Physics - Phenomenology · Physics 2011-07-19 A. J. Buras , M. Misiak , M. Muenz , S. Pokorski

We explore the theoretical feasibility of extracting V_ub from two ratios built from B meson inclusive partial decays, R_1 = Gamma(b-> u cbar s)/3Gamma(b -> c l nu), and R_2 = [Gamma(b -> c X) - Gamma(b -> cbar X)]/Gamma(b -> c ubar d). We…

High Energy Physics - Phenomenology · Physics 2010-11-23 Junegone Chay , Adam F. Falk , Michael Luke , Alexey A. Petrov

Using the parallel/orthogonal space method, we calculate the planar two-loop three-point diagram and two rotated reduced planar two-loop three-point diagrams. Together with the crossed topology, these diagrams are the most complicated ones…

High Energy Physics - Phenomenology · Physics 2009-01-07 Stefan Groote , Markus M. Knodel

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