A5068458488- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Black Holes and Theoretical Physics
- Superconducting Materials and Applications
- Physics of Superconductivity and Magnetism
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Computational Physics and Python Applications
- Particle Accelerators and Free-Electron Lasers
- Particle accelerators and beam dynamics
- Medical Imaging Techniques and Applications
- Wireless Communication Networks Research
- Nuclear physics research studies
- Advanced Wireless Communication Techniques
- Algorithms and Data Compression
- Advanced Data Compression Techniques
- Iron-based superconductors research
- Cosmology and Gravitation Theories
- Noncommutative and Quantum Gravity Theories
- Advanced Algebra and Geometry
- semigroups and automata theory
- Advanced Graph Theory Research
- Spectral Theory in Mathematical Physics
- Induction Heating and Inverter Technology
University of Glasgow
2017-2023
Cornell University
2017-2022
University of Cambridge
2022
Johannes Gutenberg University Mainz
2022
Williams (United States)
2015-2018
William & Mary
2014-2018
University at Albany, State University of New York
2018
The Ohio State University
2011-2017
Rutgers, The State University of New Jersey
2017
Ohio Supercomputer Center
2017
We present the first unquenched lattice-QCD calculation of hadronic form factors for exclusive decay $\overline{B}\ensuremath{\rightarrow}D\ensuremath{\ell}\overline{\ensuremath{\nu}}$ at nonzero recoil. carry out numerical simulations on 14 ensembles gauge-field configurations generated with $2+1$ flavors asqtad-improved staggered sea quarks. The encompass a wide range lattice spacings (approximately 0.045 to 0.12 fm) and ratios light (up down) strange sea-quark masses ranging from 0.05...
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 entire physical $q^2$ range. Non-relativistic (NRQCD) bottom quarks Highly Improved Staggered Quark (HISQ) charm light are employed together with $N_f = 2+1$ MILC gauge configurations. A joint fit to our BaBar experimental data allows an extraction CKM matrix element $|V_{cb}|$. also determine phenomenologically interesting ratio $R(D) {\cal B}(B \tau \nu_\tau) /...
We calculate---for the first time in three-flavor lattice QCD---the hadronic matrix elements of all five local operators that contribute to neutral ${B}^{0}$- and ${B}_{s}$-meson mixing beyond Standard Model. present a complete error budget for each element also provide full set correlations among elements. corresponding bag parameters their correlations, as well specific combinations enter expression $B$-meson width difference. obtain most precise determination date SU(3)-breaking ratio...
We present the result of lattice QCD calculation scalar, vector and tensor form factors for $B\to K\ell^+\ell^-$ decay, across full physical range momentum transfer. use highly improved staggered quark (HISQ) formalism all valence quarks on eight ensembles gluon field configurations generated by MILC collaboration. These include four flavours HISQ in sea, with three having light $u/d$ at masses. In first fully relativistic these factors, we heavy-HISQ method. This allows us to determine as a...
We use HPQCD's recent lattice QCD determination of $B \to K$ scalar, vector and tensor form factors to determine Standard Model differential branching fractions for K \ell^+\ell^-$, $B\to \ell_1^+\ell_2^-$ K\nu \overline{\nu}$. These are calculated across the full $q^2$ range decay have smaller uncertainties than previous work, particularly at low $q^2$. For \ell^+ \ell^-$ we find fraction in region below squared $J/\psi$ mass exceed LHCb results, with tensions as high $4.2\sigma$ $B^+\to...
We calculate the leptonic decay constants of ${B}_{(s)}$ and ${D}_{(s)}$ mesons in lattice QCD using staggered light quarks Fermilab bottom charm quarks. compute heavy-light-meson correlation functions on MILC Asqtad-improved gauge configurations, which include effects three dynamical sea simulate with several values valence- sea-quark masses (down to $\ensuremath{\sim}{m}_{s}/10$) at spacings ($a\ensuremath{\approx}0.15$, 0.12, 0.09 fm) extrapolate physical up down quark continuum...
We present a lattice-QCD calculation of the $B\to\pi\ell\nu$ semileptonic form factors and new determination CKM matrix element $|V_{ub}|$. use MILC asqtad 2+1-flavor lattice configurations at four spacings light-quark masses down to 1/20 physical strange-quark mass. extrapolate continuum using staggered chiral perturbation theory in hard-pion SU(2) limits. employ model-independent $z$ parameterization our from large-recoil momentum full kinematic range. introduce functional method propagate...
We compute the zero-recoil form factor for semileptonic decay ${\overline{B}}^{0}\ensuremath{\rightarrow}{D}^{*+}{\ensuremath{\ell}}^{\ensuremath{-}}\overline{\ensuremath{\nu}}$ (and modes related by isospin and charge conjugation) using lattice QCD with three flavors of sea quarks. use an improved staggered action light valence quarks (the MILC asqtad configurations), Fermilab heavy Our calculations incorporate higher statistics, finer spacings, lighter quark masses than our 2008 work. As a...
We compute the leptonic decay constants ${f}_{{D}^{+}}$, ${f}_{{D}_{s}}$, and ${f}_{{K}^{+}}$ quark-mass ratios ${m}_{c}/{m}_{s}$ ${m}_{s}/{m}_{l}$ in unquenched lattice QCD using experimentally determined value of ${f}_{{\ensuremath{\pi}}^{+}}$ for normalization. use MILC highly improved staggered quark ensembles with four dynamical flavors---up, down, strange, charm---and both physical unphysical values light sea-quark masses. The pions removes need a chiral extrapolation, thereby...
We compute the form factors for $B \to Kl^+l^-$ semileptonic decay process in lattice QCD using gauge-field ensembles with 2+1 flavors of sea quark, generated by MILC Collaboration. The span spacings from 0.12 to 0.045 fm and have multiple sea-quark masses help control chiral extrapolation. asqtad improved staggered action is used light valence quarks, clover Fermilab interpretation heavy $b$ quark. present results $f_+(q^2)$, $f_0(q^2)$, $f_T(q^2)$, where $q^2$ momentum transfer, together a...
We calculate, for the first time using unquenched lattice QCD form factors, standard model differential branching fractions $d\mathcal{B}/d{q}^{2}(B\ensuremath{\rightarrow}K{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}})$ $\ensuremath{\ell}=e$, $\ensuremath{\mu}$, $\ensuremath{\tau}$ and compare with experimental measurements by Belle, BABAR, CDF, LHCb. report on $\mathcal{B}(B\ensuremath{\rightarrow}K{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}})$ in ${q}^{2}$...
We calculate, for the first time using unquenched lattice QCD, form factors rare decay $B\ensuremath{\rightarrow}K{\ensuremath{\ell}}^{+}{\ensuremath{\ell}}^{\ensuremath{-}}$ in and beyond Standard Model. Our QCD calculation utilizes a nonrelativistic formulation $b$ valence quarks highly improved staggered quark light quarks. employ MILC $2+1$ asqtad ensembles. The factor results, based on $z$ expansion, are valid over full kinematic range of ${q}^{2}$. construct ratios ${f}_{0}/{f}_{+}$...
We report the first lattice QCD calculation of form factors for standard model tree-level decay $B_s\to K \ell\nu$. In combination with future measurement, this will provide an alternative exclusive semileptonic determination $|V_{ub}|$. compare our results previous calculations, make predictions differential rates and branching fractions, predict ratio fractions between K\tau\nu$ K\mu\nu$. also present rate forward-backward asymmetries, polarization calculate potentially useful ratios K$...
The semileptonic decay channel B -> D tau nu is sensitive to the presence of a scalar current, such as that mediated by charged-Higgs boson. Recently BaBar experiment reported first observation exclusive nu, finding an approximately 2-sigma disagreement with Standard-Model prediction for ratio R(D)=BR(B->D nu)/BR(B->D l nu), where l=e,mu. We compute this branching fractions using hadronic form factors computed in unquenched lattice QCD and obtain R(D) = 0.316(12)(7), errors are statistical...
The Feynman-Hellmann theorem can be derived from the long Euclidean-time limit of correlation functions determined with functional derivatives partition function. Using this insight, we fully develop an improved method for computing matrix elements external currents utilizing only two-point functions. Our applies to any bilinear current, including nonzero momentum transfer, flavor-changing, and two or more current insertion elements. ability identify control all systematic uncertainties in...
We calculate form-factor ratios between the semileptonic decays \bar{B}->D^+\ell^-\bar{\nu} and \bar{B}_s->D_s^+\ell^-\bar{\nu} with lattice QCD. These are a key theoretical input in new strategy to determine fragmentation fractions of neutral B decays, which needed for measurements BR(B^0_s-> \mu^+\mu^-). use MILC ensembles gauge configurations 2+1 flavors sea quarks at two spacings approximately 0.12 fm 0.09 fm. model-independent z-parametrization extrapolate our simulation results small...
The rare decay B→πℓ^{+}ℓ^{-} arises from b→d flavor-changing neutral currents and could be sensitive to physics beyond the standard model. Here, we present first ab initio QCD calculation of B→π tensor form factor f_{T}. Together with vector scalar factors f_{+} f_{0} our companion work [J. A. Bailey et al., Phys. Rev. D 92, 014024 (2015)], these parametrize hadronic contribution semileptonic decays in any extension We obtain total branching ratio BR(B^{+}→π^{+}μ^{+}μ^{-})=20.4(2.1)×10^{-9}...
We present progress on the calculation of scalar, vector, and tensor form factors for following meson decays: $B\rightarrow\pi$, $B_s\rightarrow K$, $D\rightarrow\pi$ $D_s\rightarrow K$. This uses MILC HISQ gluon field ensembles with valence quarks. generate correlator data varying lattice spacings, some as small 0.044 fm. Some have a strange-to-light quark mass ratio 5:1 others use physical light mass. The fully-relativistic, heavy-HISQ approach is used heavy quark, simulation masses...
We present progress on the calculation of scalar, vector, and tensor form factors for following meson decays: $𝐵 \rightarrow \pi$, $𝐵_𝑠 𝐾$, $𝐷 \pi$ $𝐷_𝑠 𝐾$. This uses MILC HISQ gluon field ensembles with valence quarks. generate correlator data varying lattice spacings, some as small 0.044 fm. Some have a strange-to-light quark mass ratio 5:1 others use physical light mass. The fully-relativistic, heavy-HISQ approach is used heavy quark, simulation masses ranging from charm to near bottom....
Received 1 October 2013DOI:https://doi.org/10.1103/PhysRevD.88.079901© 2013 American Physical Society
We calculate the kaon semileptonic form factor f+(0) from lattice QCD, working, for first time, at physical light-quark masses. use gauge configurations generated by MILC Collaboration with Nf=2+1+1 flavors of sea quarks, which incorporate effects dynamical charm quarks as well those up, down, and strange. employ data three spacings to extrapolate continuum limit. Our result, f+(0)=0.9704(32), where error is total statistical plus systematic uncertainty added in quadrature, most precise...
We report on a lattice QCD calculation of the nucleon axial charge, $g_A$, using Möbius Domain-Wall fermions solved dynamical $N_f=2+1+1$ HISQ ensembles after they are smeared gradient-flow algorithm. The is performed with three pion masses, $m_π\sim\{310,220,130\}$ MeV. Three spacings ($a\sim\{0.15,0.12,0.09\}$ fm) used heaviest mass, while coarsest two middle mass and only spacing near physical mass. On $m_π\sim220$ MeV, $a\sim0.12$ fm point, dedicated volume study $m_πL \sim...