A5010334790- Quantum Chromodynamics and Particle Interactions
- Particle physics theoretical and experimental studies
- High-Energy Particle Collisions Research
- Advanced Data Storage Technologies
- Physics of Superconductivity and Magnetism
- Black Holes and Theoretical Physics
- Scientific Computing and Data Management
- Algorithms and Data Compression
- Distributed and Parallel Computing Systems
- Atomic and Subatomic Physics Research
- Parallel Computing and Optimization Techniques
- Superconducting Materials and Applications
- Theoretical and Computational Physics
- Cosmology and Gravitation Theories
- Pulsars and Gravitational Waves Research
- Particle Detector Development and Performance
- Topological Materials and Phenomena
- Spectroscopy and Laser Applications
- Quantum and electron transport phenomena
- Solid-state spectroscopy and crystallography
- Particle Accelerators and Free-Electron Lasers
- Medical Imaging Techniques and Applications
- Computational Physics and Python Applications
- Quantum Mechanics and Applications
- Dark Matter and Cosmic Phenomena
Columbia University
2014-2023
University of Regensburg
2023
University of Southampton
2014
University of Edinburgh
2014
Trinity College Dublin
2014
Tata Institute of Fundamental Research
2014
University of Reading
2014
Peking University
2010
University of Connecticut
2009
Lawrence Livermore National Laboratory
2009
We review lattice results related to pion, kaon, $D$-meson, $B$-meson, and nucleon physics with the aim of making them easily accessible nuclear particle communities. More specifically, we report on determination light-quark masses, form factor $f_+(0)$ arising in semileptonic $K \to \pi$ transition at zero momentum transfer, as well decay constant ratio $f_K/f_\pi$ its consequences for CKM matrix elements $V_{us}$ $V_{ud}$. Furthermore, describe obtained some low-energy constants...
We present results on the equation of state in QCD with two light quark flavors and a heavier strange quark. Calculations improved staggered fermions have been performed lattices temporal extent ${N}_{\ensuremath{\tau}}=4$ 6 line constant physics almost physical mass values; pion is about 220 MeV, adjusted to its value. High statistics large are obtained for bulk thermodynamic observables, i.e. pressure, energy entropy density, at vanishing chemical potential wide range temperatures,...
We calculate the equation of state in $2+1$ flavor QCD at finite temperature with physical strange quark mass and almost light masses using lattices temporal extent ${N}_{\ensuremath{\tau}}=8$. Calculations have been performed two different improved staggered fermion actions, asqtad p4 actions. Overall, we find good agreement between results obtained these $O({a}^{2})$ discretization schemes. A comparison earlier calculations on coarser is to quantify systematic errors current studies state....
We report on the first lattice calculation of QCD phase transition using chiral fermions with physical quark masses. This uses 2+1 flavors, spatial volumes between (4 fm)(3) and (11 temperatures 139 196 MeV. Each temperature is calculated at a single spacing corresponding to temporal Euclidean extent N(t) = 8. The disconnected susceptibility, χ(disc) shows pronounced peak whose position height depend sensitively mass. find no metastability near which does not change when 5 fm increased 10...
We present a detailed calculation of the transition temperature in QCD with two light and one heavier (strange) quark mass on lattices temporal extent ${N}_{\ensuremath{\tau}}=4$ 6. Calculations improved staggered fermions have been performed for various to strange ratios range, $0.05\ensuremath{\le}{\stackrel{^}{m}}_{l}/{\stackrel{^}{m}}_{s}\ensuremath{\le}0.5$, fixed close its physical value. From combined extrapolation chiral (${\stackrel{^}{m}}_{l}\ensuremath{\rightarrow}0$) continuum...
We have simulated QCD using 2+1 flavors of domain wall quarks on a $(2.74 {\rm fm})^3$ volume with an inverse lattice scale $a^{-1} = 1.729(28)$ GeV. The up and down (light) are degenerate in our calculations we used four values for the ratio light quark masses to strange (heavy) mass simulations: 0.217, 0.350, 0.617 0.884. measured pseudoscalar meson decay constants, kaon bag parameter $B_K$ vector couplings. SU(2) chiral perturbation theory, which assumes only small, SU(3) theory...
We present results for several light hadronic quantities ($f_\pi$, $f_K$, $B_K$, $m_{ud}$, $m_s$, $t_0^{1/2}$, $w_0$) obtained from simulations of 2+1 flavor domain wall lattice QCD with large physical volumes and nearly-physical pion masses at two spacings. perform a short, O(3)%, extrapolation in mass to the values by combining our new data simultaneous chiral/continuum `global fit' number other ensembles heavier masses. use $m_\pi$, $m_K$ $m_\Omega$ determine quark scale - all are outputs...
We present physical results obtained from simulations using 2+1 flavors of domain wall quarks and the Iwasaki gauge action at two values lattice spacing $a$, ($a^{-1}$=\,1.73\,(3)\,GeV $a^{-1}$=\,2.28\,(3)\,GeV). On coarser lattice, with $24^3\times 64\times 16$ points, analysis ref.[1] is extended to approximately twice number configurations. The ensembles on finer $32^3\times are new. explain how we use data several for a range quark masses in combined continuum-chiral fits order obtain...
We report the first lattice QCD calculation of complex kaon decay amplitude $A_0$ with physical kinematics, using a $32^3\times 64$ volume and single spacing $a$, $1/a= 1.3784(68)$ GeV. find Re$(A_0) = 4.66(1.00)(1.26) \times 10^{-7}$ GeV Im$(A_0) -1.90(1.23)(1.08) 10^{-11}$ GeV, where error is statistical second systematic. The value in approximate agreement experimental result: 3.3201(18) while can be used to compute direct CP violating ratio...
We compute the standard Euclidean window of hadronic vacuum polarization using multiple independent blinded analyses. improve continuum and infinite-volume extrapolations dominant quark-connected light-quark isospin-symmetric contribution address additional subleading systematic effects from sea-charm quarks residual chiral-symmetry breaking first principles. find ${a}_{\mathrm{\ensuremath{\mu}}}^{\mathrm{W}}=235.56(65)(50)\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}10}$, which is...
We analyze baryon number, strangeness and electric charge fluctuations as well their correlations in QCD at high temperature. present results obtained from lattice calculations performed with an improved staggered fermion action (p4-action) two values of the cut-off almost physical up down quark masses a value for strange mass. compare these results, ideal gas temperature hadron resonance model low find that are described by former already temperatures about 1.5 times transition At...
We calculate the QCD equation of state for temperatures corresponding to transition region with physical mass values two degenerate light quark flavors and a strange using an improved staggered fermion action (p4-action) on lattices temporal extent ${N}_{\ensuremath{\tau}}=8$. compare our results previous calculations performed at twice larger masses as well obtained from resonance gas model calculation. also discuss deconfining chiral aspects in terms renormalized Polyakov loop, strangeness...
We present new results for the amplitude ${A}_{2}$ a kaon to decay into two pions with isospin $I=2$: $\mathrm{Re}{A}_{2}=1.50(4{)}_{\text{stat}}(14{)}_{\text{syst}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}\text{ }\text{ }\mathrm{GeV}$; $\mathrm{Im}{A}_{2}=\ensuremath{-}6.99(20{)}_{\text{stat}}(84{)}_{\text{syst}}\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}\text{ }\mathrm{GeV}$. These were obtained from ensembles generated at physical quark masses (in limit)...
We present physical results for a variety of light hadronic quantities obtained via combined analysis three $2+1$ flavour domain wall fermion ensemble sets. For two our sets we used the Iwasaki gauge action with $\ensuremath{\beta}=2.13$ (${a}^{\ensuremath{-}1}=1.75(4)\text{ }\text{ }\mathrm{GeV}$) and $\ensuremath{\beta}=2.25$ (${a}^{\ensuremath{-}1}=2.31(4)\text{ lattice sizes ${24}^{3}\ifmmode\times\else\texttimes\fi{}64$ ${32}^{3}\ifmmode\times\else\texttimes\fi{}64$ respectively,...
We present results on both the restoration of spontaneously broken chiral symmetry and effective anomalously U(1)_A in finite temperature QCD at zero chemical potential using lattice QCD. employ domain wall fermions lattices with fixed temporal extent N_\tau = 8 spatial N_\sigma 16 a range T 139 - 195 MeV, corresponding to spacings \approx 0.12 0.18 fm. In these calculations, we include two degenerate light quarks strange quark pion mass m_\pi 200 MeV. The is set near its physical value....
We report on a study of the finite-temperature QCD transition region for temperatures between 139 and 196 MeV, with pion mass 200 MeV two space-time volumes: $2{4}^{3}\ifmmode\times\else\texttimes\fi{}8$ $3{2}^{3}\ifmmode\times\else\texttimes\fi{}8$, where larger volume varies in linear size 5.6 fm (at $T=139\text{ }\text{ }\mathrm{MeV}$) 4.0 $T=195\text{ }\mathrm{MeV}$). These results are compared an earlier calculation using same action quark masses but smaller,...
Quenched QCD simulations on three volumes ${8}^{3}\ifmmode\times\else\texttimes\fi{},$ ${12}^{3}\ifmmode\times\else\texttimes\fi{}$ and ${16}^{3}\ifmmode\times\else\texttimes\fi{}32$ couplings $\ensuremath{\beta}=5.7,$ 5.85 6.0 using domain wall fermions provide a consistent picture of quenched QCD. We demonstrate that the small induced effects chiral symmetry breaking inherent in this formulation can be described by residual mass ${(m}_{\mathrm{res}})$ whose size decreases as separation...
We present results for light meson masses and pseudoscalar decay constants from the first of a series lattice calculations with $2+1$ dynamical flavors domain wall fermions Iwasaki gauge action. The work reported here was done at fixed spacing about 0.12 fm on ${16}^{3}\ifmmode\times\else\texttimes\fi{}32$ lattice, which amounts to spatial volume $(2\text{ }\text{ }\mathrm{fm}{)}^{3}$ in physical units. number sites fifth dimension is 16, gives ${m}_{\mathrm{res}}=0.00308(4)$ these...
We present a calculation of the renormalization coefficients quark bilinear operators and K-Kbar mixing parameter B_K. The relating bare lattice to those in RI/MOM scheme are computed non-perturbatively then matched perturbatively MSbar scheme. calculated on RBC/UKQCD 2+1 flavor dynamical configurations. Specifically we use 16^3 x 32 volume, Iwasaki gauge action at beta=2.13 domain wall fermions with L_s=16.
We report on the first realistic ab initio calculation of a hadronic weak decay, that amplitude A(2) for kaon to decay into two π mesons with isospin 2. find ReA(2)=(1.436±0.063(stat)±0.258(syst))10(-8) GeV in good agreement experimental result and hitherto unknown imaginary part we ImA(2)=-(6.83±0.51(stat)±1.30(syst))10(-13) GeV. Moreover combining our ImA(2) values ReA(2), ReA(0), ε'/ε, obtain following value ratio ImA(0)/ReA(0) within standard model:...
We describe the computation of amplitude ${A}_{2}$ for a kaon to decay into two pions with isospin $I=2$. The results presented in [T. Blum et al., Phys. Rev. Lett. 108, 141601 (2012)] from an analysis 63 gluon configurations are updated 146 giving $\mathrm{Re}{A}_{2}=1.381(46{)}_{\mathrm{stat}}(258{)}_{\mathrm{syst}}{10}^{\ensuremath{-}8}\text{ }\text{ }\mathrm{GeV}$ and $\mathrm{Im}{A}_{2}=\ensuremath{-}6.54(46{)}_{\mathrm{stat}}(120{)}_{\mathrm{syst}}{10}^{\ensuremath{-}13}\text{...
We determine the neutral kaon mixing matrix element ${B}_{K}$ in continuum limit with $2+1$ flavors of domain wall fermions, using Iwasaki gauge action at two different lattice spacings. These fermions have near exact chiral symmetry and therefore avoid artificial operator mixing. introduce a significant improvement to conventional nonperturbative renormalization (NPR) method which bare elements are renormalized nonperturbatively regularization invariant momentum scheme (RI-MOM) then...
The large mass of the ninth pseudoscalar meson, $\eta^\prime$, is believed to arise from combined effects axial anomaly and gauge field topology present in QCD. We report a realistic, 2+1 flavor, lattice QCD calculation $\eta$ $\eta^\prime$ masses mixing which confirms this picture. physical eigenstates show small octet-singlet with angle $\theta = -14.1(2.8)^\circ$. Extrapolation light quark gives, statistical errors only, $m_\eta=573(6)$ MeV $m_{\eta^\prime}=947(142)$ MeV, consistent...