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B Meson Semileptonic Form Factors from Unquenched Lattice QCD: 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: the $s$ quark and t...
hep-lat
Compact Gauge Fields on Causal Dynamical Triangulations: a 2D case study: We discuss the discretization of Yang-Mills theories on Dynamical Triangulations in the compact formulation, with gauge fields living on the links of the dual graph associated with the triangulation, and the numerical investigation of the minimal...
hep-lat
Approximate forms of the density of states: We compare MC calculations of the density of states in SU(2) pure gauge theory with the weak and strong coupling expansions. Surprisingly, the range of validity of the two approximations overlap significantly, however the large order behavior of both expansions appear to be s...
hep-lat
$χ_{\textrm{top}}(T \gg T_{\textrm{c}})$ in pure-glue QCD through reweighting: We calculate the topological susceptibility at 2.5 Tc and 4.1 Tc in SU(3) pure Yang-Mills theory. We define topology with the help of gradient flow and we largely overcome the problem of poor statistics at high temperatures by applying a r...
hep-lat
Deconfinement transition and dimensional cross-over in the 3D gauge Ising model: We present a high precision Monte Carlo study of the finite temperature $Z_2$ gauge theory in 2+1 dimensions. The duality with the 3D Ising spin model allows us to use powerful cluster algorithms for the simulations. For temporal extensi...
hep-lat
Dirac-mode analysis for quark number density and its application for deconfinement transition: The quark number density at finite imaginary chemical potential is investigated in the lattice QCD using the Dirac-mode expansion. We find the analytical formula of the quark number density in terms of the Polyakov loop in ...
hep-lat
Recent Developments of Muon g-2 from Lattice QCD: One of the most promising quantities for the search of signatures of physics beyond the Standard Model is the anomalous magnetic moment $g-2$ of the muon, where a comparison of the experimental result with the Standard Model estimate yields a deviation of about $3.5~\si...
hep-lat
Towards corrections to the strong coupling limit of staggered lattice QCD: We report on the first steps of an ongoing project to add gauge observables and gauge corrections to the well-studied strong coupling limit of staggered lattice QCD, which has been shown earlier to be amenable to numerical simulations by the w...
hep-lat
Impact of Dynamical Fermions on the Centre Vortex Gluon Propagator: The impact of $SU(3)$ centre vortices on the Landau-gauge gluon propagator is calculated in the presence of dynamical fermions and compared to the pure Yang-Mills case. The presence of dynamical fermions is found to alter the behaviour of the centre vo...
hep-lat
Enumerating Copies in the First Gribov Region on the Lattice in up to four Dimensions: The covariant gauges are known to suffer from the Gribov problem: even after fixing a gauge non-perturbatively, there may still exist residual copies which are physically equivalent to each other, called Gribov copies. While the in...
hep-lat
Finite-volume effects in long-distance processes with massless leptonic propagators: In Ref. [1], a method was proposed to calculate QED corrections to hadronic self energies from lattice QCD without power-law finite-volume errors. In this paper, we extend the method to processes which occur at second-order in the we...
hep-lat
Phase diagram of two-dimensional SU($N$) super-Yang--Mills theory with four supercharges: We non-perturbatively study two-dimensional SU($N$) supersymmetric Yang--Mills theory with four supercharges and large $12 \leq N \leq 20$. Although this theory has no known holographic dual, we conduct numerical investigations ...
hep-lat
Lattice QCD Study of the Pentaquark Baryons: We study the spin $\frac12$ hadronic state in quenched lattice QCD to search for a possible $S=+1$ pentaquark resonance. Simulations are carried out on $8^3\times 24$, $10^3\times 24$, $12^3\times 24$ and $16^3\times 24$ lattices at $\beta$=5.7 at the quenched level with the...
hep-lat
Charmonium spectral functions from 2+1 flavour lattice QCD: Finite temperature charmonium spectral functions in the pseudoscalar and vector channels are studied in lattice QCD with 2+1 flavours of dynamical Wilson quarks, on fine isotropic lattices (with a lattice spacing of 0.057 fm), with a non-physical pion mass of ...
hep-lat
Lattice QCD results at finite T and μ: We propose a method to study lattice QCD at finite temperature (T) and chemical potential (\mu). We test the method and compare it with the Glasgow method using n_f=4 staggered QCD with imaginary \mu. The critical endpoint (E) of QCD on the Re(\mu)-T plane is located. We use n_f=2...
hep-lat
Complex spacing ratios of the non-Hermitian Dirac operator in universality classes AI$^\dagger$ and AII$^\dagger$: We consider non-Hermitian Dirac operators in QCD-like theories coupled to a chiral U(1) potential or an imaginary chiral chemical potential. We show that in the continuum they fall into the recently disc...
hep-lat
Light Hadron Masses from Lattice QCD: This article reviews lattice QCD results for the light hadron spectrum. We give an overview of different formulations of lattice QCD, with discussions on the fermion doubling problem and improvement programs. We summarize recent developments in algorithms and analysis techniques, t...
hep-lat
Hopping Parameter Analysis of Leptonic and Semi-Leptonic Heavy-Light Decays: We study leptonic and semi-leptonic decays of D and B mesons. Use of the Hopping Parameter Expansion (HPE) for two-point functions allows us continuously to vary the pseudoscalar mass from below m_D up towards m_B. We compute the pseudoscala...
hep-lat
Hadron correlators with improved fermions: We investigate point-to-point correlation functions for various mesonic and baryonic channels using the ${\cal O}(a)$-improved Wilson action due to Sheikholeslami and Wohlert. We consider propagators to both time slices 0 and 1. We find that discretisation effects are more pro...
hep-lat
Practical methods for a direct calculation of $ΔI=1/2$ $K$ to $ππ$ Decay: A direct calculation of the complex $\Delta I=1/2$ kaon decay amplitude is notoriously difficult because of the presence of disconnected graphs. Here we describe and demonstrate two practical methods to defeat this problem: the EigCG algorithm ...
hep-lat
The Mellin moments $\langle x \rangle$ and $\langle x^2 \rangle$ for the pion and kaon from lattice QCD: We present a calculation of the pion quark momentum fraction, $\langle x \rangle$, and its third Mellin moment $\langle x^2 \rangle$. We also obtain directly, for the first time, $\langle x \rangle$ and $\langle x...
hep-lat
Chiral Limit of Staggered Fermions at Strong Couplings: A Loop Representation: The partition function of two dimensional massless staggered fermions interacting with U(N) gauge fields is rewritten in terms of loop variables in the strong coupling limit. We use this representation of the theory to devise a non-local M...
hep-lat
Extending the eigCG algorithm to nonsymmetric Lanczos for linear systems with multiple right-hand sides: The technique that was used to build the EigCG algorithm for sparse symmetric linear systems is extended to the nonsymmetric case using the BiCG algorithm. We show that, similarly to the symmetric case, we can bui...
hep-lat
Status of Lattice QCD Determination of Nucleon Form Factors and their Relevance for the Few-GeV Neutrino Program: Calculations of neutrino-nucleus cross sections begin with the neutrino-nucleon interaction, making the latter critically important to flagship neutrino oscillation experiments, despite limited measuremen...
hep-lat
String breaking mechanisms induced by magnetic and electric condensates: The normal confining phase of gauge theories is characterised by the condensation of magnetic monopoles and center vortices. Sometimes in coupled gauge system one finds another phase with simultaneous condensation of electric and magnetic charges....
hep-lat
Finite-size scaling for the left-current correlator with non-degenerate quark masses: We study the volume dependence of the left-current correlator with non-degenerate quark masses to next-to-leading order in the chiral expansion. We consider three possible regimes: all quark masses are in the $\epsilon$-regime, all ...
hep-lat
Four-loop logarithms in 3d gauge + Higgs theory: We discuss the logarithmic contributions to the vacuum energy density of the three-dimensional SU(3) + adjoint Higgs theory in its symmetric phase, and relate them to numerical Monte Carlo simulations. We also comment on the implications of these results for perturbative...
hep-lat
Monopoles and hadron spectrum in quenched QCD: We report the preliminary results of the studies of hadron spectrum under the background of abelian and monopole gauge fields in quenched Wilson SU(3) QCD. Abelian gauge fields alone reproduce the same chiral limit as in the full case. Critical hopping parameter $\kappa_c$...
hep-lat
Nucleon to $Δ$ and $Δ$ form factors in Lattice QCD: We present recent lattice QCD results on the electroweak nucleon to $\Delta$ transition and $\Delta$ form factors using dynamical fermion gauge configurations with a lowest pion mass of about 300 MeV, with special emphasis in the determination of the sub-dominant quad...
hep-lat
Hadron-Hadron Interactions from Imaginary-time Nambu-Bethe-Salpeter Wave Function on the Lattice: Imaginary-time Nambu-Bethe-Salpeter (NBS) wave function is introduced to extend our previous approach for hadron-hadron interactions on the lattice. Scattering states of hadrons with different energies encoded in the NBS...
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Higgs and W boson spectrum from lattice simulations: The spectrum of energy levels is computed for all available angular momentum and parity quantum numbers in the SU(2)-Higgs model, with parameters chosen to match experimental data from the Higgs-W boson sector of the standard model. Several multi-boson states are obs...
hep-lat
Systematics of the HAL QCD Potential at Low Energies in Lattice QCD: The $\Xi\Xi$ interaction in the $^1$S$_0$ channel is studied to examine the convergence of the derivative expansion of the non-local HAL QCD potential at the next-to-next-to-leading order (N$^2$LO). We find that (i) the leading order potential from th...
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Distributing the chiral and flavour components of Dirac-Kahler fermions across multiple lattices: We use a specific implementation of discrete differential geometry to describe Dirac-Kahler fermions in such a way that we can separate their chiral and flavour components. The formulation introduces additional lattices ...
hep-lat
Correlation functions in lattice formulations of quantum gravity: We compare different models of a quantum theory of four-dimensional lattice gravity based on Regge's original proposal. From Monte Carlo simulations we calculate two-point functions between geometrical quantities and estimate the masses of the correspond...
hep-lat
Lattice QCD study of baryon-baryon interactions in the (S,I)=(-2,0) system using the coupled-channel formalism: We investigate baryon-baryon interactions with strangeness $S=-2$ and isospin I=0 system from Lattice QCD. In order to solve this system, we prepare three types of baryon-baryon operators ($\Lambda-\Lambda$...
hep-lat
Chiral Phase Transition in Lattice QCD with Wilson Quarks: The nature of the chiral phase transition in lattice QCD is studied for the cases of 2, 3 and 6 flavors with degenerate Wilson quarks, mainly on a lattice with the temporal direction extension $N_t=4$. We find that the chiral phase transition is continuous for ...
hep-lat
New Algorithm of the Finite Lattice Method for the High-temperature Expansion of the Ising Model in Three Dimensions: We propose a new algorithm of the finite lattice method to generate the high-temperature series for the Ising model in three dimensions. It enables us to extend the series for the free energy of the s...
hep-lat
Chebyshev and Backus-Gilbert reconstruction for inclusive semileptonic $B_{(s)}$-meson decays from Lattice QCD: We present a study on the nonperturbative calculation of observables for inclusive semileptonic decays of $B_{(s)}$ mesons using lattice QCD. We focus on the comparison of two different methods to analyse t...
hep-lat
Numerical tests of the electroweak phase transition and thermodynamics of the electroweak plasma: The finite temperature phase transition in the SU(2) Higgs model at a Higgs boson mass $M_H \simeq 34$ GeV is studied in numerical simulations on four-dimensional lattices with time-like extensions up to $L_t=5$. The eff...
hep-lat
Systematics of the HAL QCD Potential at Low Energies in Lattice QCD: The $\Xi\Xi$ interaction in the $^1$S$_0$ channel is studied to examine the convergence of the derivative expansion of the non-local HAL QCD potential at the next-to-next-to-leading order (N$^2$LO). We find that (i) the leading order potential from th...
hep-lat
Absolute X-distribution and self-duality: Various models of QCD vacuum predict that it is dominated by excitations that are predominantly self-dual or anti-self-dual. In this work we look at the tendency for self-duality in the case of pure-glue SU(3) gauge theory using the overlap-based definition of the field-strengt...
hep-lat
Center Projection With and Without Gauge Fixing: We consider projections of SU(2) lattice link variables onto Z(2) center and U(1) subgroups, with and without gauge-fixing. It is shown that in the absence of gauge-fixing, and up to an additive constant, the static quark potential extracted from projected variables agre...
hep-lat
Lattice gauge-fixing for generic covariant gauges: We propose a method which allows the generalization of the Landau lattice gauge-fixing procedure to generic covariant gauges. We report preliminary numerical results showing how the procedure works for $SU(2)$ and $SU(3)$. We also report numerical results showing that ...
hep-lat
Twisted mass ensemble generation on GPU machines: We present how we ported the Hybrid Monte Carlo implementation in the tmLQCD software suite to GPUs through offloading its most expensive parts to the QUDA library. We discuss our motivations and some of the technical challenges that we encountered as we added the requi...
hep-lat
Evidence for fine tuning of fermionic modes in lattice gluodynamics: We consider properties of zero and near-zero fermionic modes in lattice gluodynamics. The modes are known to be sensitive to the topology of the underlying gluonic fields in the quantum vacuum state of the gluodynamics. We find evidence that these mod...
hep-lat
Towards the continuum limit of nucleon form factors at the physical point using lattice QCD: We present results for the axial charge and root-mean-square (RMS) radii of the nucleon obtained from 2+1 flavor lattice QCD at the physical point with a large spatial extent of about 10 fm. Our calculations are performed wit...
hep-lat
Non-perturbative renormalization of quark mass in Nf=2+1 QCD with the Schroedinger functional scheme: We present an evaluation of the quark mass renormalization factor for Nf=2+1 QCD. The Schroedinger functional scheme is employed as the intermediate scheme to carry out non-perturbative running from the low energy to...
hep-lat
The Status of D-Theory: Field theories are usually quantized by performing a path integral over configurations of classical fields. This is the case both in perturbation theory and in Wilson's nonperturbative lattice field theory. D-theory is an alternative nonperturbative formulation of field theory in which classical...
hep-lat
On-shell representations of two-body transition amplitudes: single external current: This work explores scattering amplitudes that couple two-particle systems via a single external current insertion, $2+\mathcal{J}\to 2$. Such amplitudes can provide structural information about the excited QCD spectrum. We derive an ...
hep-lat
Quenched charmonium near the continuum limit: We study relativistic charmonium on very fine quenched lattices (beta=6.4 and 6.6). We concentrate on the calculation of the hyperfine splitting between eta_c and J/psi, aiming for a controlled continuum extrapolation of this quantity. Results for the eta_c and J/psi wave f...
hep-lat
Lattice QCD Study for Confinement and Hadrons: Using SU(3) lattice QCD, we perform the detailed studies of the three-quark and the multi-quark potentials. From the accurate calculation for more than 300 different patterns of 3Q systems, the static ground-state 3Q potential $V_{\rm 3Q}^{\rm g.s.}$ is found to be well de...
hep-lat
Lattice QCD study of a five-quark hadronic molecule: We compute the ground-state energies of a heavy-light K-Lambda like system as a function of the relative distance r of the hadrons. The heavy quarks, one in each hadron, are treated as static. Then, the energies give rise to an adiabatic potential Va(r) which we use ...
hep-lat
Weak universality induced by $Q=\pm 2e$ charges at the deconfinement transition of a (2+1)-d $U(1)$ lattice gauge theory: Matter-free lattice gauge theories (LGTs) provide an ideal setting to understand confinement to deconfinement transitions at finite temperatures, which is typically due to the spontaneous breakdow...
hep-lat
A quark action for very coarse lattices: We investigate a tree-level O(a^3)-accurate action, D234c, on coarse lattices. For the improvement terms we use tadpole-improved coefficients, with the tadpole contribution measured by the mean link in Landau gauge. We measure the hadron spectrum for quark masses near that of ...
hep-lat
Controlling sign problems in spin models using tensor renormalization: We consider the sign problem for classical spin models at complex $\beta =1/g_0^2$ on $L\times L$ lattices. We show that the tensor renormalization group method allows reliable calculations for larger Im$\beta$ than the reweighting Monte Carlo metho...
hep-lat
Lee-Yang zeroes in the one flavour massive lattice Schwinger model: We study the partition function of the model formulated with Wilson fermions with only one species, both analytically and numerically. At strong coupling we construct the solution for lattice size up to $8\times 8$, a polynomial in the hopping paramete...
hep-lat
Order a improved renormalization constants: We present non-perturbative results for the constants needed for on-shell $O(a)$ improvement of bilinear operators composed of Wilson fermions. We work at $\beta=6.0$ and 6.2 in the quenched approximation. The calculation is done by imposing axial and vector Ward identities o...
hep-lat
B, Bs, K and pi weak matrix elements with physical light quarks: Calculations of pseudoscalar decay constants of B, Bs, K and pi mesons with physical light quarks are presented. We use HISQ ensembles that include u,d,s and c sea quarks at three lattice spacings. HISQ is used for the valence light quarks and a radiative...
hep-lat
Phase structure of two-color QCD at real and imaginary chemical potentials; lattice simulations and model analyses: We investigate the phase structure of two-color QCD at both real and imaginary chemical potentials mu, performing lattice simulations and analyzing the data with the Polyakov-loop extended Nambu--Jona-L...
hep-lat
Monopoles and Spatial String Tension in the High Temperature Phase of SU(2) QCD: We studied a behavior of monopole currents in the high temperature (deconfinement) phase of abelian projected finite temperature SU(2) QCD in maximally abelian gauge. Wrapped monopole currents closed by periodic boundary play an importan...
hep-lat
The QCD equation of state in background magnetic fields: We determine the equation of state of 2+1-flavor QCD with physical quark masses, in the presence of a constant (electro)magnetic background field on the lattice. To determine the free energy at nonzero magnetic fields we develop a new method, which is based on an...
hep-lat
Landau gauge gluon and ghost propagators from two-flavor lattice QCD at T > 0: In this contribution we extend our unquenched computation of the Landau gauge gluon and ghost propagators in lattice QCD at non-zero temperature. The study was aimed at providing input for investigations employing continuum functional meth...
hep-lat
Fermionic observables in Numerical Stochastic Perturbation Theory: We present technical details of fermionic observables computations in NSPT. In particular we discuss the construction of composite operators starting from the inverse Dirac operator building block, the subtraction of UV divergences and the treatment of ...
hep-lat
Lattice calculation of SU(3) flavor breaking ratios in B - anti-B mixing: We present an unquenched lattice calculation for the SU(3) flavor breaking ratios of the heavy-light decay constants and the $\Delta B = 2$ matrix elements. The calculation was performed on $16^3 \times 32$ lattices with two dynamical flavors of ...
hep-lat
Duality and scaling in 3-dimensional scalar electrodynamics: Three-dimensional scalar electrodynamics, with a local U(1) gauge symmetry, is believed to be dual to a scalar theory with a global U(1) symmetry, near the phase transition point. The conjectured duality leads to definite predictions for the scaling exponents...
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Correlation Functions of Hadron Currents in the QCD Vacuum Calculated in Lattice QCD: Point-to-point vacuum correlation functions for spatially separated hadron currents are calculated in quenched lattice QCD on a $16^3\times 24$ lattice with $6/g^2=5.7$. The lattice data are analyzed in terms of dispersion relations...
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Delta I = 3/2, K to Pi Pi Decays with a Nearly Physical Pion Mass: The Delta I = 3/2 K to Pi Pi decay amplitude is calculated on RBC/UKQCD 32^3 x 64, L_s=32 dynamical lattices with 2+1 flavors of domain wall fermions using the DSDR and Iwasaki gauge action. The calculation is performed with a single pion mass (m_pi=141...
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Simulating lattice QCD at finite temperature and zero quark mass: We simulate lattice QCD with an irrelevant chiral 4-fermion interaction which allows us to simulate at zero quark mass. This enables us to study the finite-temperature chiral-symmetry-restoring phase transition for 2 massless quark flavours, which is bel...
hep-lat
Spectroscopy in finite density lattice field theory: An exploratory study in the relativistic Bose gas: We analyze 2-point functions in the relativistic Bose gas on the lattice, i.e., a charged scalar phi-4 field with chemical potential mu. Using a generalized worm algorithm we perform a Monte Carlo simulation in a d...
hep-lat
A computational system for lattice QCD with overlap Dirac quarks: We outline the essential features of a Linux PC cluster which is now being developed at National Taiwan University, and discuss how to optimize its hardware and software for lattice QCD with overlap Dirac quarks. At present, the cluster constitutes of 30...
hep-lat
Infrared fixed point in SU(2) gauge theory with adjoint fermions: We apply Schrodinger-functional techniques to the SU(2) lattice gauge theory with N_f=2 flavors of fermions in the adjoint representation. Our use of hypercubic smearing enables us to work at stronger couplings than did previous studies, before encounter...
hep-lat
A new strategy for evaluating the LO HVP contribution to $(g-2)_μ$ on the lattice: A highly physical model of the subtracted $I=1$ vector polarization, obtained using a dispersive representation with precise hadronic $\tau$ decay data as input, is used to investigate systematic issues in the lattice evaluation of the...
hep-lat
Atomic Bose Condensation and the Lattice: I show how interaction corrections to the Bose condensation temperature of an atomic gas can be computed using a combination of perturbative effective field theory and lattice techniques.
hep-lat
The Landshoff-Nachtmann Pomeron on the Lattice: We investigate the Landshoff-Nachtmann two-gluon-exchange model of the Pomeron using gluon propagators computed in the Landau gauge within quenched lattice QCD calculations. We first determine an effective gluon-quark coupling by constraining the Pomeron-quark coupling to...
hep-lat
Display of probability densities for data from a continuous distribution: Based on cumulative distribution functions, Fourier series expansion and Kolmogorov tests, we present a simple method to display probability densities for data drawn from a continuous distribution. It is often more efficient than using histograms...
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The vector and axial vector current in Wilson ChPT: We construct the vector and axial vector currents in Wilson Chiral Perturbation Theory (WChPT), the low-energy effective theory for lattice QCD with Wilson fermions. Our construction is slightly different compared to ChPT in continuum QCD, where the currents are ess...
hep-lat
Glueball matrix elements: a lattice calculation and applications: We compute the matrix elements of the energy-momentum tensor between glueball states and the vacuum in SU(3) lattice gauge theory and extrapolate them to the continuum. These matrix elements may play an important phenomenological role in identifying glue...
hep-lat
Lattice Simulations using OpenACC compilers: OpenACC compilers allow one to use Graphics Processing Units without having to write explicit CUDA codes. Programs can be modified incrementally using OpenMP like directives which causes the compiler to generate CUDA kernels to be run on the GPUs. In this article we look at ...
hep-lat
Approaching the chiral point in two-flavour lattice simulations: We investigate the behaviour of the pion decay constant and the pion mass in two-flavour lattice QCD, with the physical and chiral points as ultimate goal. Measurements come from the ensembles generated by the CLS initiative using the O(a)-improved Wilson...
hep-lat
Critical exponents of a three dimensional O(4) spin model: By Monte Carlo simulation we study the critical exponents governing the transition of the three-dimensional classical O(4) Heisenberg model, which is considered to be in the same universality class as the finite-temperature QCD with massless two flavors. We use...
hep-lat
(1+1)-dimensional Baryons from the SU(N) Color-Flavor Transformation: The color-flavor transformation, an identity that connects two integrals, each of which is over one of a dual pair of Lie groups acting in the fermionic Fock space, is extended to the case of the special unitary group. Using this extension, a toy mod...
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JLQCD IroIro++ lattice code on BG/Q: We describe our experience on the multipurpose C++ code IroIro++ designed for JLQCD to run on the BG/Q installation at KEK. We discuss some details on the performance improvements specific for the IBM Blue Gene Q.
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The spin content of the proton in quenched QCD: We present preliminary results on the proton spin structure function at zero momentum, in the quenched approximation. Our calculation makes use of a nonperturbative means of determining the multiplicative renormalization of the topological charge density.
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Degeneracy of vector-channel spatial correlators in high temperature QCD: We study spatial isovector meson correlators in $N_f=2$ QCD with dynamical domain-wall fermions on $32^3\times 8$ lattices at temperatures up to 380 MeV with various quark masses. We measure the correlators of spin-one isovector operators includi...
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Testing universality and the fractional power prescription for the staggered fermion determinant: In [Phys.Rev.Lett.92:162002 (2004), hep-lat/0312025] expressions for the continuous Euclidean time limits of various lattice fermion determinants were derived and compared in order to test universality expectations in La...
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A multigrid accelerated eigensolver for the Hermitian Wilson-Dirac operator in lattice QCD: Eigenvalues of the Hermitian Wilson-Dirac operator are of special interest in several lattice QCD simulations, e.g., for noise reduction when evaluating all-to-all propagators. In this paper we present a Davidson-type eigensol...
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Investigating the critical properties of beyond-QCD theories using Monte Carlo Renormalization Group matching: Monte Carlo Renormalization Group (MCRG) methods were designed to study the non-perturbative phase structure and critical behavior of statistical systems and quantum field theories. I adopt the 2-lattice mat...
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Progress on the QCD deconfinement critical point for $N_\text{f}=2$ staggered fermions: The global center symmetry of quenched QCD at zero baryonic chemical potential is broken spontaneously at a critical temperature $T_c$ leading to a first-order phase transition. Including heavy dynamical quarks breaks the center s...
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QCD Thermodynamics: Recent results on QCD thermodynamics are presented. The nature of the T>0 transition is determined, which turns out to be an analytic cross-over. The absolute scale for this transition is calculated. The temperature dependent static potential is given. The results were obtained by using a Symanzik i...
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A Wilson-Majorana Regularization for Lattice Chiral Gauge Theories: We discuss the regularization of chiral gauge theories on the lattice introducing only physical degrees of freedom. This is obtained by writing the Wilson term in a Majorana form, at the expense of the U(1) symmetry related to fermion number conservati...
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Fighting topological freezing in the two-dimensional CP$^{N-1}$ model: We perform Monte Carlo simulations of the CP$^{N-1}$ model on the square lattice for $N=10$, $21$, and $41$. Our focus is on the severe slowing down related to instantons. To fight this problem we employ open boundary conditions as proposed by L\"us...
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Numerical study of lattice index theorem usingimproved cooling and overlap fermions: We investigate topological charge and the index theorem on finite lattices numerically. Using mean field improved gauge field configurations we calculate the topological charge Q using the gluon field definition with ${\cal O}(a^4)$-...
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The pi-N Sigma term - an evaluation using staggered fermions: A lattice calculation of the pi-N sigma term is described using dynamical staggered fermions. Preliminary results give a sea term comparable in magnitude to the valence term.
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CP violation and Kaon weak matrix elements from Lattice QCD: In this short review, I present the recent lattice computations of kaon weak matrix elements relevant to $K \to \pi\pi$ decays and neutral kaon mixing. These matrix elements are key to the theoretical determination of the CP violation parameters $\epsilon$ an...
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Anatomy of the sign-problem in heavy-dense QCD: QCD at finite densities of heavy quarks is investigated using the density-of-states method. The phase factor expectation value of the quark determinant is calculated to unprecedented precision as a function of the chemical potential. Results are validated using those from...
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Finite-Size Scaling at Phase Coexistence: {}From a finite-size scaling (FSS) theory of cumulants of the order parameter at phase coexistence points, we reconstruct the scaling of the moments. Assuming that the cumulants allow a reconstruction of the free energy density no better than as an asymptotic expansion, we find...
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Correlation Function in Ising Models: We simulated the fourier transform of the correlation function of the Ising model in two and three dimensions using a single cluster algorithm with improved estimators. The simulations are in agreement with series expansion and the available exact results in $d=2$, which shows, tha...
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Quark orbital dynamics in the proton from Lattice QCD -- from Ji to Jaffe-Manohar orbital angular momentum: Given a Wigner distribution simultaneously characterizing quark transverse positions and momenta in a proton, one can directly evaluate their cross-product, i.e., quark orbital angular momentum. The aforementio...
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The topological structures in strongly coupled QGP with chiral fermions on the lattice: The nature of chiral phase transition for two flavor QCD is an interesting but unresolved problem. One of the most intriguing issues is whether or not the anomalous U(1) symmetry in the flavor sector is effectively restored along ...
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High performance Beowulf computer for lattice QCD: We describe the construction of a high performance parallel computer composed of PC components, as well as the performance test in lattice QCD.
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