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Related papers: B -> D* l nu with 2+1 flavors

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We compute the zero-recoil form factor for the semileptonic decay $\bar{B}^0\to D^{*+}\ell^-\bar{\nu}$ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. We use an improved staggered…

We present the results of a lattice computation of the form factors for B^0 ->pi^- l^+nu_l decays near zero-recoil. These results will allow a determination of the CKM matrix element |Vub| when measurements of the differential decay rate…

High Energy Physics - Lattice · Physics 2014-11-17 UKQCD Collaboration , K. C. Bowler , L. Del Debbio , J. M. Flynn , L. Lellouch , V. Lesk , C. M. Maynard , J. Nieves , D. G. Richards

We study the $B \to Kl^+l^-$ semileptonic decay process in three-flavor lattice QCD. We analyze several ensembles generated by the MILC collaboration at different lattice spacings and sea-quark masses. We use the asqtad improved staggered…

We report on form factors for the B->K l^+ l^- semi-leptonic decay process. We use several lattice spacings from a=0.12 fm down to 0.06 fm and a variety of dynamical quark masses with 2+1 flavors of asqtad quarks provided by the MILC…

We present a lattice QCD calculation of the $B \rightarrow D l \nu$ semileptonic decay form factors $f_+(q^2)$ and $f_0(q^2)$ for the entire physical $q^2$ range. Non-relativistic QCD (NRQCD) bottom quarks and Highly Improved Staggered…

High Energy Physics - Lattice · Physics 2016-06-14 Heechang Na , Chris M. Bouchard , G. Peter Lepage , Chris Monahan , Junko Shigemitsu

Sufficient control of transition form factors is a vital ingredient for the precision flavor programs including the nearer term searches at the Large Hadron Collider (LHC) and the forthcoming Belle II experiment. We improve on existing…

High Energy Physics - Phenomenology · Physics 2014-06-03 Christian Hambrock , Gudrun Hiller , Stefan Schacht , Roman Zwicky

We discuss preliminaries of a calculation of the form factors for the semileptonic decays B -> pi lv, B_s -> K lv, and B -> K ll. We simulate with NRQCD heavy and HISQ light valence quarks on the MILC 2+1 dynamical asqtad configurations.…

High Energy Physics - Lattice · Physics 2012-12-14 C. M. Bouchard , G. Peter Lepage , Chris J. Monahan , Heechang Na , Junko Shigemitsu

We show that a combined analysis of $B\to K\nu\bar\nu$ and $B\to Kl^+l^-$ allows for new physics tests practically free of form factor uncertainties. Residual theory errors are at the level of several percent. Our study underlines the…

High Energy Physics - Phenomenology · Physics 2009-11-30 M. Bartsch , M. Beylich , G. Buchalla , D. -N. Gao

We discuss how the combined analysis of $B\to K\nu\bar\nu$ and $B\to Kl^+l^-$ can provide us with new physics tests practically free of form factor uncertainties. Residual theory errors are at the level of several percent. This study…

High Energy Physics - Phenomenology · Physics 2011-04-05 Gerhard Buchalla

We calculate the form factors for the semileptonic decays $B_s\to K\ell\nu$ and $B\to K\ell\ell$ with lattice QCD. We work at several lattice spacings and a range of light quark masses, using the MILC 2+1-flavor asqtad ensembles. We use the…

We present an update of the Fermilab Lattice and MILC Collaborations project to compute the form factors for semileptonic $B_{(s)}$-meson decays. Our calculation uses the highly improved staggered quark (HISQ) action for sea and valence…

We discuss our ongoing effort to calculate form factors for several B and Bs semileptonic decays. We have recently completed the first unquenched calculation of the form factors for the rare decay B -> K ll. Extrapolated over the full…

High Energy Physics - Lattice · Physics 2013-10-14 C. M. Bouchard , G. Peter Lepage , Chris J. Monahan , Heechang Na , Junko Shigemitsu

We give an update on simulation results for the decay constants f_B, f_{B_s}, f_D and f_{D_s}. These decay constants are important for precision tests of the standard model, in particular entering as inputs to the global CKM unitarity…

We present the status of our ongoing calculation of the zero-recoil form factor for the semileptonic decay $\bar{B}^0\rightarrow D^{*+}l^-\bar{\nu}$ using lattice QCD with 2+1+1 flavours of highly improved staggered quarks in the sea (the…

High Energy Physics - Lattice · Physics 2017-01-11 Judd Harrison , Christine Davies , Matthew Wingate

We present the first unquenched lattice-QCD calculation of the form factors for the decay $B\rightarrow D^\ast\ell\nu$ at nonzero recoil. Our analysis includes 15 MILC ensembles with $N_f=2+1$ flavors of asqtad sea quarks, with a strange…

The form factors and the branching ratio of the "B -> a_1 l nu" decay are calculated in framework of QCD sum rules. A comparison of our results on form factors and branching ratio with the results from constituent quark model is presented.

High Energy Physics - Phenomenology · Physics 2009-10-31 T. M. Aliev , M. Savci

We discuss the matching procedure for heavy-light 4-quark operators using the Fermilab method for heavy quarks and staggered fermions for light quarks. These ingredients enable us to construct the continuum-limit operator needed to…

High Energy Physics - Lattice · Physics 2010-11-05 Richard Todd Evans , Elvira Gamiz , Aida El-Khadra , Andreas Kronfeld

We present preliminary results from our analysis of the form factors for the $\overline{B}\rightarrow D^\ast\ell\overline{\nu}$ decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with $N_f=2+1$ flavors of sea quarks…

High Energy Physics - Lattice · Physics 2017-10-27 A. Vaquero Avilés-Casco , C. DeTar , D. Du , A. El-Khadra , A. S. Kronfeld , J. Laiho , R. S. Van de Water

The semileptonic process, B --> \pi l \nu, is studied via full QCD Lattice simulations. We use unquenched gauge configurations generated by the MILC collaboration. These include the effect of vacuum polarization from three quark flavors:…

High Energy Physics - Lattice · Physics 2014-11-17 Emel Gulez , Alan Gray , Matthew Wingate , Christine T. H. Davies , G. Peter Lepage , Junko Shigemitsu

We present a calculation of f_B and of the form factors for the semi-leptonic decay B -> D l nu in the quenched approximation to QCD. Results are generated on lattices at beta = 6.2, using an O(a)-improved fermion action, with the clover…

High Energy Physics - Lattice · Physics 2015-06-25 UKQCD Collaboration , David Richards