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In the heavy quark limit, the form factors for semileptonic and rare radiative B decays into light mesons are related by heavy quark spin symmetry. Here we compute the leading corrections of order \Lambda/m_Q to these symmetry relations,…

High Energy Physics - Phenomenology · Physics 2009-11-07 Benjamin Grinstein , Dan Pirjol

The infinite mass effective theory, when a heavy quark mass tends to infinity, and Chiral perturbation theory at the quark level, based on the extended Nambu -- Jona -- Lasinio model with linear realization of chiral $U(3)\times U(3)$…

High Energy Physics - Phenomenology · Physics 2016-09-01 F. Hussain , A. N. Ivanov , N. I. Troitskaya

The form factors for semi-leptonic B decays, $\bar{B}\to\pi l\bar{\nu}_l$, are calculated under collinear factorization approach. The end-point divergences are regularized by a $\xi$-regularization, where $\xi$ means the collinear fraction…

High Energy Physics - Phenomenology · Physics 2009-01-05 Tsung-Wen Yeh

We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral…

High Energy Physics - Phenomenology · Physics 2024-12-13 Michele Papucci , Ryan Plestid

We show how radiative QCD corrections calculated in terms of quarks can be incorporated at the hadron level in inclusive semileptonic B-meson decays. The bound state effects are described by a momentum distribution function of the $b$…

High Energy Physics - Phenomenology · Physics 2011-09-13 Changhao Jin , Emmanuel A. Paschos

We present a quenched calculation of the form factors of the semileptonic weak decay $B \to \pi l \bar{\nu}$ with $O(1/m_Q)$ NRQCD heavy quark and Wilson light quark on a $16^3 \times 32$ lattice at $\beta=5.8$. The form factors are…

High Energy Physics - Lattice · Physics 2009-10-30 H. Matsufuru , S. Hashimoto , K-I. Ishikawa , T. Onogi , N. Yamada

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

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 O(alpha_s^2) corrections to the decay t-->bW in the limit of a very large top quark mass, m_t >> m_W. We find that the O(alpha_s^2) effects decrease the top quark decay width Gamma_t by about 2%: Gamma_t =…

High Energy Physics - Phenomenology · Physics 2009-10-31 Andrzej Czarnecki , Kirill Melnikov

The renormalization factor and O(a) improvement coefficient of four-quark operators are calculated perturbatively for the improved Wilson fermion action with clover term and the Iwasaki gauge action. With an application to the $K\to\pi\pi$…

High Energy Physics - Lattice · Physics 2015-06-04 Yusuke Taniguchi

We derive factorization theorems for Lambda_QCD/mb power corrections to inclusive B-decays in the endpoint region, where mX^2 ~mb Lambda_QCD. In B-> Xu e nu our results are for the full triply differential rate. A complete enumeration of…

High Energy Physics - Phenomenology · Physics 2011-01-27 Keith S. M. Lee , Iain W. Stewart

We develop the perturbative QCD formalism for inclusive semileptonic $B$ meson decays, which includes Sudakov suppression from the resummation of large radiative corrections near the high end of charged lepton energy. Transverse degrees of…

High Energy Physics - Phenomenology · Physics 2014-11-17 Hsiang-nan Li , Hoi-Lai Yu

We study inclusive semi-leptonic (B -> X_c \ell \nu) decay using the power counting m_c ~ \sqrt{Lambda_{QCD} m_b}. Assuming this scaling for the charm-quark mass, the decay kinematics can be chosen to access the shape-function region even…

High Energy Physics - Phenomenology · Physics 2009-11-11 H. Boos , Th. Feldmann , T. Mannel , B. D. Pecjak

We calculate the electroweak and finite width corrections to the decay of an unpolarized top quark into a bottom quark and a $ W $-gauge boson where the helicities of the $ W $ are specified as longitudinal, transverse-plus and…

High Energy Physics - Phenomenology · Physics 2011-03-23 H. S. Do , S. Groote , J. G. Körner , M. C. Mauser

We compute 2-loop QCD corrections to the hard coefficient functions which arise in the factorization formula for B -> X_u l nu decays in the shape-function region. Our calculation provides the last missing piece required for a NNLO analysis…

High Energy Physics - Phenomenology · Physics 2009-02-23 Guido Bell

We report the final results of the ALPHA collaboration for some B-physics observables: $f_B$, $f_{B_s}$ and $m_b$. We employ CLS configurations with 2 flavors of $O(a)$ improved Wilson fermions in the sea and pion masses ranging down to 190…

High Energy Physics - Lattice · Physics 2013-09-05 F. Bernardoni , B. Blossier , J. Bulava , M. Della Morte , P. Fritzsch , N. Garron , A. Gerardin , J. Heitger , G. von Hippel , H. Simma , R. Sommer

We present a new theoretical framework for the study of $B\to X_u \ell \nu$ decays, which includes all known perturbative and non-perturbative contributions and a description of leading and subleading Fermi motion effects. The perturbative…

High Energy Physics - Phenomenology · Physics 2008-11-26 P. Giordano

We compute the complete supersymmetric QCD corrections to the Wilson coefficients of the magnetic and chromomagnetic operators, relevant in the calculation of b -> s gamma decays, in the MSSM with Minimal Flavor Violation. We investigate…

High Energy Physics - Phenomenology · Physics 2011-07-18 G. Degrassi , P. Gambino , P. Slavich

The decay width of b to c,c,c,l,nu has been computed as an expansion in limit (1- 3*(m_c/m_b)) << 1 with zero lepton invariant mass. Considering O(alpha_s^2) corrections to b to c,l,nu with zero invariant lepton mass, inclusion of our…

High Energy Physics - Phenomenology · Physics 2007-05-23 Matthew Dowling , Alexey Pak

We calculate the $O(\alpha_s^2)$ heavy flavor corrections to charged current deep-inelastic scattering at large scales $Q^2 \gg m^2$. The contributing Wilson coefficient are given as convolutions between massive operator matrix elements and…

High Energy Physics - Phenomenology · Physics 2014-02-21 Johannes Blümlein , Alexander Hasselhuhn , Torsten Pfoh