English
Related papers

Related papers: BSM Hadronic Matrix Elements for $\epsilon'/\epsil…

200 papers

We present $O(\alpha_s^2)$ QCD corrections to the fully-differential decay rate of a $b$-quark into inclusive semileptonic charmless final states. Our calculation provides genuine two-loop QCD corrections, beyond the…

High Energy Physics - Phenomenology · Physics 2015-06-12 Mathias Brucherseifer , Fabrizio Caola , Kirill Melnikov

We examine the semileptonic $B \to D^{(*)} \ell \nu_\ell$ and $B \to \pi \ell \nu_\ell$ decays adopting the unitarity-based Dispersive Matrix (DM) method, which allows to determine the shape of the relevant hadronic form factors (FFs) in…

High Energy Physics - Phenomenology · Physics 2022-03-31 G. Martinelli , M. Naviglio , S. Simula , L. Vittorio

We evaluate two-loop b -> s gamma matrix elements of all the four-quark operators containing no derivatives. Contrary to previous calculations, no expansion in the mass ratio mc/mb is performed, and all the possible Dirac and flavor…

High Energy Physics - Phenomenology · Physics 2009-11-07 Andrzej J. Buras , Andrzej Czarnecki , Mikolaj Misiak , Joerg Urban

We give a comprehensive account of the flavour physics of Beyond-Standard-Model (BSM) effects in $b \to c \bar{c} s$ transitions, considering the full set of 20 four-quark operators. We discuss the leading-order structure of their RG mixing…

High Energy Physics - Phenomenology · Physics 2023-07-13 S. Jäger , M. Kirk , A. Lenz , K. Leslie

We update the Standard Model predictions for the rare decays $K^+\to\pi^+\nu\bar\nu$ and $K_L\to\pi^0\nu\bar\nu$. In view of improved limits on $B_s$--$\bar B_s$ mixing we derive a stringent and theoretically clean Standard Model upper…

High Energy Physics - Phenomenology · Physics 2009-10-09 Gerhard Buchalla , Andrzej J. Buras

The decays $B_c^+ \to B_{a} \bar \ell \nu_\ell$ and $B_c^+ \to B_{a}^{*}(\to B_a \gamma) \bar \ell \nu_\ell$, with $a=s,d$ and $\ell=e,\mu$, are studied in the Standard Model (SM) and in the extension based on the low-energy Hamiltonian…

High Energy Physics - Phenomenology · Physics 2021-04-28 P. Colangelo , F. De Fazio , F. Loparco

We present a lattice-QCD calculation of the $B\to\pi\ell\nu$ semileptonic form factors and a new determination of the CKM matrix element $|V_{ub}|$. We use the MILC asqtad 2+1-flavor lattice configurations at four lattice spacings and…

I give a brief introduction to the scope of lattice QCD calculations in our effort to extract the fundamental parameters of the standard model. This goal is illustrated by two examples. First I discuss the extraction of CKM matrix elements…

High Energy Physics - Lattice · Physics 2007-05-23 Rajan Gupta

We use the recently calculated two--loop anomalous dimensions of current-current operators, QCD and electroweak penguin operators to construct the effective Hamiltonian for $\Delta S=1$ transitions beyond the leading logarithmic…

High Energy Physics - Phenomenology · Physics 2010-11-01 Andrzej J. Buras , Matthias Jamin , Markus E. Lautenbacher

We present a new analysis of the Delta I = 1/2 rule in K --> pi pi decays and the B_K parameter. We use the 1/N_c expansion within the effective chiral lagrangian for pseudoscalar mesons and compute the hadronic matrix elements at leading…

High Energy Physics - Phenomenology · Physics 2011-09-13 T. Hambye , G. O. Koehler , P. H. Soldan

Using special linear combinations of finite energy sum rules which minimize the contribution of the unknown continuum spectral function, we compute the decay constants of the pseudoscalar mesons B and B_s. In the computation, we employ the…

High Energy Physics - Phenomenology · Physics 2011-01-27 J. Bordes , J. Peñarrocha , K. Schilcher

We derive the four-fold angular distribution for the semileptonic decay $\bar{B}\to D_2^*(\to D \pi)\,\ell \bar{\nu}$ where $D_2^*$(2460) is a tensor meson. We start with the most general beyond the Standard Model (SM) dimension-six…

High Energy Physics - Phenomenology · Physics 2020-02-26 Rusa Mandal

We calculate the kaon mixing B-parameters for operators arising generically in theories of physics beyond the standard model. We use HYP-smeared improved staggered fermions on the $N_f = 2+1$ MILC asqtad lattices. Operator matching is done…

We calculate the B-parameters for operators arising in theories of new physics beyond the standard model (BSM) using HYP-smeared improved staggered fermions on the MILC asqtad lattices with N_f = 2+1 flavors. We use three different lattice…

In this short review, we present the current status about the theoretical and experimental studies for some important semileptonic decays of $B/B_s$ mesons. We firstly gave a brief introduction for the experimental measurements for $B/B_s…

High Energy Physics - Phenomenology · Physics 2014-08-01 Zhen-Jun Xiao , Ying-Ying Fan , Wen-Fei Wang , Shan Cheng

We study model-independently the implications of non-standard scalar and pseudoscalar interactions for the decays b ->s gamma, b -> s g, b -> s l^+l^- (l=e,mu) and B_s -> mu^+ mu^-. We find sizeable renormalization effects from scalar and…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Hiller , F. Krüger

Theoretical predictions for B decay rates are rewritten in terms of the Upsilon(1S) meson mass instead of the b quark mass, using a modified perturbation expansion. The theoretical consistency of this expansion is shown both at low and high…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andre H. Hoang , Zoltan Ligeti , Aneesh V. Manohar

This paper serves as an update of the previous work entitled ``Heavy-Flavor-Conserving Hadronic Weak Decays of Charmed and Bottom Baryons". We make an improvement on the bag wave functions by removing the center-of-mass motion of the bag.…

High Energy Physics - Phenomenology · Physics 2022-11-23 Hai-Yang Cheng , Chia-Wei Liu , Fanrong Xu

We compute the order 1/m_b^3 nonperturbative contributions to the inclusive differential B\to X_c\ell\bar\nu decay rate. They are parametrized by the expectation values of two local and four nonlocal dimension-six operators. We use our…

High Energy Physics - Phenomenology · Physics 2011-01-27 Martin Gremm , Anton Kapustin

We present progress on the calculation of scalar, vector, and tensor form factors for the following meson decays: $B\rightarrow\pi$, $B_s\rightarrow K$, $D\rightarrow\pi$ and $D_s\rightarrow K$. This calculation uses the MILC HISQ gluon…

High Energy Physics - Lattice · Physics 2025-02-03 Logan Roberts , Chris Bouchard , Olmo Francesconi , Will Parrott
‹ Prev 1 3 4 5 6 7 10 Next ›