English
Related papers

Related papers: Form factors for semi-leptonic B decays

200 papers

We present results for form factors of semileptonic decays of $D$ and $B$ mesons in 2+1 flavor lattice QCD using the MILC gauge configurations. With an improved staggered action for light quarks, we successfully reduce the systematic error…

We present updates for our nonperturbative lattice QCD calculations to determine semileptonic form factors for exclusive $B\to \pi\ell\nu$, $B\to D \ell\nu$, $B_s\to K\ell \nu$, and $B_s\to D_s\ell\nu$ decays. Our calculation is based on…

High Energy Physics - Lattice · Physics 2019-12-23 Jonathan Flynn , Ryan Hill , Andreas Jüttner , Amarjit Soni , Justus Tobias Tsang , Oliver Witzel

We present the status of our updated D- and B-meson decay-constant analysis, based on the MILC $N_f = 2+1$ asqtad gauge ensembles. Heavy quarks are incorporated using the Wilson clover action with the Fermilab interpretation. This analysis…

High Energy Physics - Lattice · Physics 2019-08-15 Andreas S. Kronfeld , Ethan T. Neil , James N. Simone , Ruth S. Van de Water

Precise theoretical predictions derived from the Standard Model are a key ingredient in searches for new physics in the flavor sector. The large mass and long lifetime of the $b$ quark make processes involving $b$ quarks of particular…

High Energy Physics - Phenomenology · Physics 2020-12-09 Jonathan M. Flynn , Ryan C. Hill , Andreas Jüttner , Amarjit Soni , J. Tobias Tsang , Oliver Witzel

We calculate the form factor f_+(q^2) for B-meson semileptonic decay in unquenched lattice QCD with 2+1 flavors of light sea quarks. We use Asqtad-improved staggered light quarks and a Fermilab bottom quark on gauge configurations generated…

We present results for the semi-leptonic and leptonic decays of B mesons. These non-perturbative matrix elements are important for constraining the CKM matrix. Results are presented for the pseudoscalar and vector decay constants, as well…

High Energy Physics - Lattice · Physics 2015-06-25 UKQCD Collaboration , C. M. Maynard

We present a calculation of the B -> pi l nu form factors with domain-wall light quarks and relativistic b-quarks on the lattice. We work with the 2+1 flavor domain-wall fermion and Iwasaki gauge-field ensembles generated by the RBC and…

High Energy Physics - Lattice · Physics 2013-11-06 Taichi Kawanai , Ruth S. Van de Water , Oliver Witzel

Semileptonic $B_s \to K \ell \nu$ decays provide an alternative $b$-decay channel to determine the CKM matrix element $|V_{ub}|$, and to obtain a $R$-ratio to investigate lepton-flavor-universality violations. Results for the CKM matrix…

High Energy Physics - Lattice · Physics 2023-06-21 Jonathan M. Flynn , Ryan C. Hill , Andreas Jüttner , Amarjit Soni , J. Tobias Tsang , Oliver Witzel

The measured partial widths of the semileptonic decays D to K l nu and D to pi l nu can be combined with the form factors calculated on the lattice to extract the CKM matrix elements |V_cs| and |V_cd|. The lattice calculations can be…

High Energy Physics - Lattice · Physics 2019-08-15 Jon A. Bailey , A. Bazavov , A. X. El-Khadra , Steven Gottlieb , R. D. Jain , A. S. Kronfeld , R. S. Van de Water , R. Zhou

Semileptonic $B_{(s)}$ decays are of great phenomenological interest because they allow to extract CKM matrix elements or test lepton flavour universality. Taking advantage of existing data, we explore extracting form factors for vector…

High Energy Physics - Lattice · Physics 2024-12-24 Anastasia Boushmelev , Matthew Black , Oliver Witzel

We present results from a lattice study of the semileptonic decay $\Lambda_b \to \Lambda_c l \nu_l $. We use $O(a^2, \alpha_s a^2)$ improved quenched lattices of the MILC collaboration, with lattice spacing $\sim 0.13$ fm. For the valence…

High Energy Physics - Lattice · Physics 2009-11-10 Steven Gottlieb , Sonali Tamhankar

We update the lattice calculation of the $B\to\pi$ semileptonic form factors, which have important applications to the CKM matrix element $|V_{ub}|$ and the $B\to\pi\ell^+\ell^-$ rare decay. We use MILC asqtad ensembles with $N_f=2+1$ sea…

Form factors relevant for semi-leptonic $B\to D,\ D^*$ decays are obtained in quenched lattice QCD. Tests of heavy-quark symmetry as well as determinations of the Isgur-Wise function and $|V_{cb}|$ are presented.

High Energy Physics - Lattice · Physics 2010-11-01 Laurent Lellouch

The Fermilab Lattice-MILC collaboration is completing a comprehensive program of heavy-light physics on the MILC (2+1)-flavor asqtad ensembles with lattice spacings as small as 0.045 fm and light-to-strange-quark mass ratios as low as 1/20.…

High Energy Physics - Lattice · Physics 2019-08-14 Si-Wei Qiu , Carleton DeTar , Daping Du , Andreas S. Kronfeld , Jack Laiho , Ruth S. Van de Water

We present results of a lattice computation of the matrix elements of the vector and axial-vector currents which are relevant for the semi-leptonic decays $D \rightarrow K$ and $D \rightarrow K^*$. The computations are performed in the…

High Energy Physics - Lattice · Physics 2012-08-27 UKQCD Collaboration

We present a (2+1)-flavor lattice QCD calculation of the form factor ratio between the semileptonic decays $\bar{B}^0_s \to D^+_sl^-\bar{\nu} $ and $\bar{B}^0 \to D^+l^-\bar{\nu} $. This ratio is an important theoretical input to the…

High Energy Physics - Lattice · Physics 2012-02-10 Daping Du , Carleton DeTar , Andreas Kronfeld , Jack Laiho , Yannick Meurice , Si-wei Qiu

We present the status of calculations of the form factors of the most relevant heavy-to-heavy and heavy-to-light decay channels. Using seven $N_f = 2+1+1$ HISQ ensembles, with lattice spacings ranging from 0.15 fm down to 0.06 fm, we…

The experimentally measured rates of the semileptonic decays K -> pi l nu and D -> K(pi) l nu can be combined with lattice calculations of the associated form factors to precisely extract the CKM matrix elements |V_{us}| and |V_{cs(d)}|. We…

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…

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