Search results for "lattice [space-time]"
showing 10 items of 692 documents
LOW-ENERGY QCD II — STATUS OF LATTICE CALCULATIONS
2013
The current status of lattice calculations is reviewed, with a particular emphasis on the question whether lattice simulations have matured to a stage where there is full interaction with experiment. Particular examples include the hadron spectrum, mesonic form factors and decay constants, the axial charge of the nucleon, and the hadronic vacuum polarization contribution to the muon (g-2).
Model discriminating power ofμ→econversion in nuclei
2009
13 pages, 12 figures, 1 table.-- PACS nrs.: 13.35.Bv; 11.30.Hv.-- ArXiv pre-print available at: http://arxiv.org/abs/0904.0957
Constituent-quark model description of triply heavy-baryon nonperturbative lattice QCD data
2015
This paper provides results for the spectra of triply charmed and bottom baryons based on a constituent quark model approach. We take advantage of the assumption that potential models are expected to describe triply heavy baryons to a similar degree of accuracy as the successful results obtained in the charmonium and bottomonium sectors. The high precision calculation of the ground state and positive and negative parity excited states recently reported by nonperturbative lattice QCD provides us with a unique opportunity to confront model predictions with data. This comparison may also help to build a bridge between two difficult to reconcile lattice QCD results, namely, the lattice SU(3) QC…
Charmonium properties in hot quenched lattice QCD
2012
We study the properties of charmonium states at finite temperature in quenched QCD on large and fine isotropic lattices. We perform a detailed analysis of charmonium correlation and spectral functions both below and above $T_c$. Our analysis suggests that both S wave states ($J/\psi$ and $\eta_c$) and P wave states ($\chi_{c0}$ and $\chi_{c1}$) disappear already at about $1.5 T_c$. The charm diffusion coefficient is estimated through the Kubo formula and found to be compatible with zero below $T_c$ and approximately $1/\pi T$ at $1.5 T_c\lesssim T\lesssim 3 T_c$.
The physics of glueballs
2008
Glueballs are particles whose valence degrees of freedom are gluons and therefore in their description the gauge field plays a dominant role. We review recent results in the physics of glueballs with the aim set on phenomenology and discuss the possibility of finding them in conventional hadronic experiments and in the Quark Gluon Plasma. In order to describe their properties we resort to a variety of theoretical treatments which include, lattice QCD, constituent models, AdS/QCD methods, and QCD sum rules. The review is supposed to be an informed guide to the literature. Therefore, we do not discuss in detail technical developments but refer the reader to the appropriate references.
Study of the D0→K−μ+νμ Dynamics and Test of Lepton Flavor Universality with D0→K−ℓ+νℓ Decays
2019
Using e^{+}e^{-} annihilation data of 2.93 fb^{-1} collected at center-of-mass energy sqrt[s]=3.773 GeV with the BESIII detector, we measure the absolute branching fraction of D^{0}→K^{-}μ^{+}ν_{μ} with significantly improved precision: B_{D^{0}→K^{-}μ^{+}ν_{μ}}=(3.413±0.019_{stat}±0.035_{syst})%. Combining with our previous measurement of B_{D^{0}→K^{-}e^{+}ν_{e}}, the ratio of the two branching fractions is determined to be B_{D^{0}→K^{-}μ^{+}ν_{μ}}/B_{D^{0}→K^{-}e^{+}ν_{e}}=0.974±0.007_{stat}±0.012_{syst}, which agrees with the theoretical expectation of lepton flavor universality within the uncertainty. A study of the ratio of the two branching fractions in different four-momentum tra…
5 QCD on the Lattice
2008
Since Wilson’s seminal papers of the mid-1970s, the lattice approach to Quantum Chromodynamics has become increasingly important for the study of the strong interaction at low energies, and has now turned into a mature and established technique. In spite of the fact that the lattice formulation of Quantum Field Theory has been applied to virtually all fundamental interactions, it is appropriate to discuss this topic in a chapter devoted to QCD, since by far the largest part of activity is focused on the strong interaction. Lattice QCD is, in fact, the only known method which allows ab initio investigations of hadronic properties, starting from the QCD Lagrangian formulated in terms of quark…
Extraction of heavy-quark-expansion parameters from unquenched lattice data on pseudoscalar and vector heavy-light meson masses
2017
We present a precise lattice computation of pseudoscalar and vector heavy-light meson masses for heavy-quark masses ranging from the physical charm mass up to $\ensuremath{\simeq}4$ times the physical $b$-quark mass. We employ the gauge configurations generated by the European Twisted Mass Collaboration (ETMC) with ${N}_{f}=2+1+1$ dynamical quarks at three values of the lattice spacing ($a\ensuremath{\simeq}0.062,0.082,0.089\text{ }\text{ }\mathrm{fm}$) with pion masses in the range ${M}_{\ensuremath{\pi}}\ensuremath{\simeq}210--450\text{ }\text{ }\mathrm{MeV}$. The heavy-quark mass is simulated directly on the lattice up to $\ensuremath{\simeq}3$ times the physical charm mass. The interpol…
Accelerating Ab Initio Nucleon Structure Calculations with All-Mode-Averaging on Gordon
2014
The composition of nucleons has long been known to be sub-atomic particles called quarks and gluons, which interact through the strong force and theoretically can be described by Quantum Chromodynamics (QCD). Lattice QCD (LQCD), in which the continuous space-time is translated into grid points on a four-dimensional lattice and ab initio Monte Carlo simulations are performed, is by far the only model-independent method to study QCD with controllable errors. We report the successful application of a novel algorithm, All-Mode-Averaging, in the LQCD calculations of nucleon internal structure on the Gordon supercomputer our award of roughly 6 million service units through XSEDE. The application …
Heavy-hadron interactions from Lattice QCD
2018
I review recent progress in heavy hadron spectroscopy and from ab-initio Lattice QCD calculations.After motivating lattice calculations for heavy-hadrons by contrasting recent LHCb results charmed and doubly-charmed baryons with lattice predictions, selected resultsfrom scattering calculations for heavy-light mesons and for charmonia are presented.I close with a discussion of recent Lattice QCD predictions of explicitlyexotic doubly-heavy states.