Latest in hep-lat

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The strong running coupling from the gauge sector of Domain Wall lattice QCD with physical quark massesFeb 21 2019We report on the first computation of the strong running coupling at the physical point (physical pion mass) from the ghost-gluon vertex, computed from lattice simulations with three flavors of Domain Wall fermions. We find $\alpha_{\overline{\rm MS}}(m_Z^2)=0.1172(11)$, ... More
Fermion Conformal Bootstrap in 4dFeb 15 2019We apply numerical conformal bootstrap techniques to the four-point function of a Weyl spinor in 4d non-supersymmetric CFTs. We find universal bounds on operator dimensions and OPE coefficients, including bounds on operators in mixed symmetry representations ... More
Theoretical predictions on polarization asymmetry for Drell-Yan process with spin-one deuteron and tensor-polarized structure function $b_1$Feb 13 2019We report recent theoretical progress on a polarization asymmetry in the proton-deuteron Drell-Yan process with a polarized-deuteron target and the tensor-polarized structure function $b_1$. Experimental measurements are possible at JLab for $b_1$ and ... More
Light Nuclei from Lattice QCD: Spectrum, Structure and ReactionsFeb 12 2019Lattice Quantum Chromodynamics (LQCD) studies of light nuclei have entered an era when first results on structure and reaction properties of light nuclei have emerged in recent years, complementing existing results on their lowest-lying spectra. Although ... More
Hadron tomography in meson-pair production and gravitational form factorsFeb 12 2019Generalized parton distributions (GPDs) are 3-dimensional (3D) structure functions for hadrons, and they are important for solving the proton spin puzzle including partonic orbital-angular-momentum contributions. The $s$-$t$ crossed quantities of the ... More
Effective long distance $q\bar{q} $ potential in holographic RG flowsFeb 12 2019We study the $q\bar{q}$ potential in strongly coupled non-conformal field theories with a non-trivial renormalization group flow via holography. We focus on the properties of this potential at an inter-quark separation $L$ large compared to the characteristic ... More
Hadronic-vacuum-polarization contribution to the muon's anomalous magnetic moment from four-flavor lattice QCDFeb 12 2019We calculate the contribution to the muon anomalous magnetic moment hadronic vacuum polarization from the connected diagrams of up and down quarks, omitting electromagnetism. We employ QCD gauge-field configurations with dynamical $u$, $d$, $s$, and $c$ ... More
Calculation of the non-perturbative strong coupling from first principlesFeb 11 2019The success of the screened massive expansion is investigated in the framework of a screened momentum-subtraction scheme for the running of the strong coupling in pure Yang-Mills theory. By the exact Slavnov-Taylor and Nielsen identities, a very predictive ... More
String breaking by light and strange quarks in QCDFeb 11 2019The energy spectrum of a system containing a static quark anti-quark pair is computed for a wide range of source separations using lattice QCD with $N_\mathrm{f}=2+1$ dynamical flavours. By employing a variational method with a basis including operators ... More
Meson Electromagnetic Form Factors from Lattice QCDFeb 11 2019Lattice QCD can provide a direct determination of meson electromagnetic form factors, making predictions for upcoming experiments at Jefferson Lab. The form factors are a reflection of the bound-state nature of the meson and so these calculations give ... More
Spectral estimators for finite non-commutative geometriesFeb 10 2019A finite non-commutative geometry consists of a fuzzy space together with a Dirac operator satisfying the axioms of a real spectral triple. This paper addreses the question of how to extract information about these geometries from the spectrum of the ... More
Nuclear Physics without High-Momentum Potentials: Constructing the Nuclear Effective Interaction Directly from Scattering ObservablesFeb 10 2019The traditional approach to nuclear physics encodes phase shift information in a nucleon-nucleon (NN) potential, producing a nucleon-level interaction that captures the sub-GeV consequences of QCD. A further reduction to the nuclear scale is needed to ... More
Confirming the Existence of the strong CP Problem in Lattice QCD with the Gradient FlowFeb 08 2019We calculate the electric dipole moment of the nucleon induced by the QCD theta term. We use the gradient flow to define the topological charge and use $N_f = 2+1$ flavors of dynamical quarks corresponding to pion masses of $700$, $570$, and $410$ MeV, ... More
Symmetries of spatial meson correlators in high temperature QCDFeb 08 2019Based on a complete set of $J = 0$ and $J=1$ spatial isovector correlation functions calculated with $N_F = 2$ domain wall fermions we identify an intermediate temperature regime of $T \sim 250 - 550$ MeV where chiral symmetry is restored but the correlators ... More
Heavy-quark spin and flavour symmetry partners of the X(3872) revisited: what can we learn from the one boson exchange model?Feb 08 2019Heavy-quark symmetry as applied to heavy hadron systems implies that their interactions are independent of their heavy-quark spin (heavy-quark spin symmetry) and heavy flavour contents (heavy flavour symmetry). In the molecular hypothesis the $X(3872)$ ... More
Natural discrete differential calculus in physicsFeb 08 2019We sharpen a recent observation by Tim Maudlin: differential calculus is a natural language for physics only if additional structure, like the definition of a Hodge dual or a metric, is given; but the discrete version of this calculus provides this additional ... More
Anisotropic pressure of deconfined QCD matter in presence of strong magnetic field within one-loop approximationFeb 07 2019Considering the general structure of the two point functions of quarks and gluons, we compute the free energy and pressure of a strongly magnetized hot and dense QCD matter created in heavy-ion collisions. In presence of strong magnetic field we found ... More
Anomalous magnetic moment of the muon with dynamical QCD+QEDFeb 05 2019The current $3.5\sigma$ discrepancy between experimental and Standard Model determinations of the anomalous magnetic moment of the muon $a_\mu=(g-2)/2$ can only be extended to the discovery $5\sigma$ regime through a reduction of both experimental and ... More
Galilean invariance restoration on the latticeFeb 04 2019We consider the breaking of Galilean invariance due to different lattice cutoff effects in moving frames and a nonlocal smearing parameter which is used in the construction of the nuclear lattice interaction. The dispersion relation and neutron-proton ... More
Energy shift of the three-particle system in a finite volumeFeb 04 2019Feb 06 2019Using the three-particle quantization condition recently obtained in the particle-dimer framework, the finite-volume energy shift of the two lowest three-particle scattering states is derived up to and including order $L^{-6}$. Furthermore, assuming that ... More
QED corrections to leptonic decay ratesFeb 01 2019RBC/UKQCD is preparing a calculation of leptonic decay rates including isospin breaking corrections. We use a perturbative approach to include NLO contributions from QED effects, following N. Carassco et al. We present preliminary results for a contribution ... More
Spectrum of light- and heavy-baryonsJan 31 2019A symmetry-preserving truncation of the strong-interaction bound-state equations is used to calculate the spectrum of ground-state $J=1/2^+$, $3/2^+$ $(qq^\prime q^{\prime\prime})$-baryons, where $q, q^\prime, q^{\prime\prime} \in \{u,d,s,c,b\}$, their ... More
JIMWLK evolution and small-x asymptotics of 2n-tuple Wilson line correlatorsJan 31 2019Feb 06 2019JIMWLK equation tells how gauge invariant higher order Wilson line correlators would evolve at high energy. In this article we present a convenient integro-differential form of this equation, for 2n-tuple correlator, where all real and virtual terms are ... More
Tensor renormalization group study of the non-Abelian Higgs model in two dimensionsJan 31 2019We study the $SU(2)$ gauge-Higgs model in two Euclidean dimensions using the tensor renormalization group (TRG) approach. We derive a tensor formulation for this model in the unitary gauge and compare the expectation values of different observables between ... More
The BRST-invariant vacuum state of the Gribov-Zwanziger theoryJan 31 2019We revisit the effective action of the Gribov-Zwanziger theory, taking into due account the BRST symmetry and renormalization (group invariance) of the construction. We compute at one loop the effective potential, showing the emergence of BRST-invariant ... More
The Isoscalar Mesons and Exotic States in Light Front Holographic QCDJan 31 2019In this article a systematic quantitative analysis of all isoscalar bosonic states is performed in the framework of supersymmetric light front holographic QCD. It is shown that the spectra of the $\eta$ and $h$ mesons can be well described if one additional ... More
Lattice-Friendly Gauge Completion of a Composite Higgs with Top PartnersJan 29 2019We give an explicit example of a composite Higgs model with a pseudo-Nambu-Goldstone Higgs in which the top Yukawa coupling is generated via the partial compositeness mechanism. This mechanism requires composite top partners which are relatively light ... More
Lattice-Friendly Gauge Completion of a Composite Higgs with Top PartnersJan 29 2019Feb 13 2019We give an explicit example of a composite Higgs model with a pseudo-Nambu-Goldstone Higgs in which the top Yukawa coupling is generated via the partial compositeness mechanism. This mechanism requires composite top partners which are relatively light ... More
Electromagnetic and strong isospin-breaking corrections to the muon $g - 2$ from Lattice QCD+QEDJan 28 2019We present a lattice calculation of the leading-order electromagnetic and strong isospin-breaking corrections to the hadronic vacuum polarization (HVP) contribution to the anomalous magnetic moment of the muon. We employ the gauge configurations generated ... More
A novel mechanism for dynamical generation of elementary fermion mass: lattice evidenceJan 28 2019We establish from first principles the existence of a non-perturbative mechanism leading to elementary particle mass generation in models with gauge fields, fermions and scalars if an exact invariance forbids power divergent fermion masses and fermionic ... More
Review on Lattice QCD Studies for Muon g-2 with Hadron Vacuum PolarizationJan 25 2019Lattice QCD (LQCD) studies for the hadron vacuum polarization (HVP) and its contribution to the muon anomalous magnetic moment (muon g-2) are reviewd. There currently exists more than 3-sigma deviations in the muon g-2 between the BNL experiment with ... More
$D$ meson Semileptonic Decay Form Factors at $q^2 = 0$Jan 25 2019We discuss preliminary results for the vector form factors $f_+^{\{\pi,K\}}$ at zero-momentum transfer for the decays $D\to\pi\ell\nu$ and $D\to K \ell\nu$ using MILC's $N_f = 2+1+1$ HISQ ensembles at four lattice spacings, $a \approx 0.042, 0.06, 0.09$, ... More
Test of factorization for the long-distance effects from charmonium on $B\to K\ell^+\ell^-$Jan 25 2019We report on a calculation of the charmonium contribution to the decay $B \rightarrow K\ell^+\ell^-$ using lattice simulations with 2+1 flavors of Mobius domain wall fermions. We focus on the region of $q^2$ below the $J/\psi$ resonance and test the factorization ... More
The density of states approach to the sign problemJan 22 2019Approaches to the sign problem based on the density of states have been recently revived by the introduction of the LLR algorithm, which allows us to compute the density of states itself with exponential error reduction. In this work, after a review of ... More
Ratio of strange to $u/d$ momentum fraction in disconnected insertionsJan 22 2019The ratio of the strange momentum fraction $\langle x\rangle_{s+\bar{s}}$ to that of $u/d$ in the disconnected insertion is calculated on the lattice with overlap fermions on four domain wall fermion ensembles. These ensembles cover three lattice spacings, ... More
Lattice QCD determination of neutron-antineutron matrix elements with physical quark massesJan 22 2019Matrix elements of six-quark operators are needed to extract new physics constraints from experimental searches for neutron-antineutron oscillations. This work presents in detail the first lattice quantum chromodynamics calculations of the necessary neutron-antineutron ... More
The fate of the doubly heavy spin$-3/2$ baryons in dense mediumJan 22 2019Feb 01 2019We investigate the behavior of the doubly heavy spin$-3/2$ baryons in cold nuclear matter. In particular, we study the variations of the spectroscopic parameters of the ground state $\Xi^*_{QQ'}$ and $\Omega^*_{QQ'}$ particles, with $ Q $ and $ Q' $ being ... More
SVE-enabling Lattice QCD CodesJan 22 2019Optimization of applications for supercomputers of the highest performance class requires parallelization at multiple levels using different techniques. In this contribution we focus on parallelization of particle physics simulations through vector instructions. ... More
Implementing the three-particle quantization condition including higher partial wavesJan 21 2019We present an implementation of the relativistic three-particle quantization condition including both $s$- and d-wave two-particle channels. For this, we develop a systematic expansion about threshold of the three-particle divergence-free K matrix, $\mathcal{K}_{\mathrm{df,3}}$, ... More
Settling the $Z_c(4600)$ in the charged charmonium-like familyJan 21 2019Very recently LHCb reported the evidence of a new charged charmonium-like structure in the $J/\psi \pi^-$ invariant mass spectrum near 4600 MeV. In this work we investigate this structure together with three other charged charmonium-like states, the $Z_c(3900)$, ... More
Paramagnetic squeezing of a uniformly expanding quark-gluon plasma in and out of equilibriumJan 21 2019The plasma of quarks and gluons created in ultrarelativistic heavy-ion collisions turns out to be paramagnetic. In the presence of a background magnetic field, this paramagnetism thus leads to a pressure anisotropy, similar to anisotropies appearing in ... More
Quark mass determinations with the RI-SMOM scheme and HISQ actionJan 21 2019Lattice QCD provides several avenues for the high precision determination of quark masses. Using the RI-SMOM scheme applied to lattice calculations with the HISQ action, we obtain mass renormalisation factors that we use to provide strange and charm quark ... More
SMOM - $\overline{MS}$ Matching for $B_K$ at Two-loop OrderJan 21 2019The Kaon bag parameter, $B_K$, is a key non-perturbative ingredient in the search for new physics through CP-violation. It parameterizes the QCD hadronic matrix element of the effective weak $\Delta S=2$ four-quark operator which can only be computed ... More
Conformal fields and operator product expansion in critical quantum spin chainsJan 18 2019We propose a variational method for identifying lattice operators in a critical quantum spin chain with scaling operators in the underlying conformal field theory (CFT). In particular, this allows us to build a lattice version of the primary operators ... More
Strong coupling constant and heavy quark masses in 2+1 flavor QCDJan 18 2019We present a determination of the strong coupling constant and heavy quark masses in 2+1-flavor QCD using lattice calculations of the moments of the pseudo-scalar quarkonium correlators at several values of the heavy valence quark mass with Highly Improved ... More
Quantum simulation of scattering in the quantum Ising modelJan 17 2019Feb 04 2019We discuss real time evolution for the quantum Ising model in one spatial dimension with $N_s$ sites. In the limit where the nearest neighbor interactions $J$ in the spatial directions are small, there is a simple physical picture where qubit states can ... More
Calculation of Nucleon Electric Dipole Moments Induced by Quark Chromo-Electric Dipole Moments and the QCD $θ$-termJan 16 2019Electric dipole moments (EDMs) of nucleons and nuclei, which are sought as evidence of CP violation, require lattice calculations to connect constraints from experiments to limits on the strong CP violation within QCD or CP violation introduced by new ... More
Reconstructing parton distribution functions from Ioffe time data: from Bayesian methods to Neural NetworksJan 16 2019The computation of the parton distribution functions (PDF) or distribution amplitudes (DA) of hadrons from first principles lattice QCD constitutes a central open problem. In this study, we present and evaluate the efficiency of a selection of methods ... More
Spectral representation of lattice gluon and ghost propagators at zero temperatureJan 16 2019We consider the analytic continuation of Euclidean propagator data obtained from 4D simulations to Minkowski space. In order to perform this continuation, the common approach is to first extract the K\"all\'en-Lehmann spectral density of the field. Once ... More
The Discrete Langevin Machine: Bridging the Gap Between Thermodynamic and Neuromorphic SystemsJan 16 2019A formulation of Langevin dynamics for discrete systems is derived as a new class of generic stochastic processes. The dynamics simplify for a two-state system and suggest a novel network architecture which is implemented by the Langevin machine. The ... More
Reweighting Lefschetz ThimblesJan 16 2019We present a novel reweighting technique to calculate the relative weights in the Lefschetz thimble decomposition of a path integral. Our method is put to work using a $U(1)$ one-link model providing for a suitable testing ground and sharing many features ... More
$B_s\to D_s^{(*)}lν$ Form Factors with Heavy HISQ QuarksJan 15 2019We present progress on an ongoing calculation of the $B_s\to D_s^{(*)} l \nu$ form factors calculated on the $n_f=2+1+1$ MILC ensembles and using the Highly Improved Staggered Quark action for all valence quarks. We perform the calculation at a range ... More
The strange quark contribution to the spin of the nucleonJan 15 2019Quark line disconnected matrix elements of an operator, such as the axial current, are difficult to compute on the lattice. The standard method uses a stochastic estimator of the operator, which is generally very noisy. We discuss and develop further ... More
Nonperturbative Casimir Effects in Field Theories: aspects of confinement, dynamical mass generation and chiral symmetry breakingJan 15 2019The Casimir effect is a quantum phenomenon rooted in the fact that vacuum fluctuations of quantum fields are affected by the presence of physical objects and boundaries. Since the energy spectrum of the vacuum fluctuations depends on distances between ... More
Insight into thermal modifications of quarkonia from a comparison of continuum-extrapolated lattice results to perturbative QCD$^{\dagger}$Jan 14 2019In this work, we strive to gain insight into thermal modifications of charmonium and bottomonium bound states as well as the heavy quark diffusion coefficient. The desired information is contained in the spectral function which can not be calculated on ... More
Pion Valence Quark Distribution from Matrix Element Calculated in Lattice QCDJan 13 2019We present the first exploratory lattice QCD calculation of the pion valence quark distribution, using a lattice calculable, renormalizable, and factorizable matrix element obtained through spatially-separated current-current correlations in coordinate ... More
Spectrum and structure of octet and decuplet baryons and their positive-parity excitationsJan 10 2019A continuum approach to the three valence-quark bound-state problem in quantum field theory is used to compute the spectrum and Poincar\'e-covariant wave functions for all flavour-$SU(3)$ octet and decuplet baryons and their first positive-parity excitations. ... More
Six-loop $\varepsilon$ expansion study of three-dimensional $n$-vector model with cubic anisotropyJan 09 2019Jan 31 2019The six-loop expansions of the renormalization-group functions of $\varphi^4$ $n$-vector model with cubic anisotropy are calculated within the minimal subtraction (MS) scheme in $4 - \varepsilon$ dimensions. The $\varepsilon$ expansions for the cubic ... More
$B_s\to K\ellν$ decay from lattice QCDJan 08 2019We use lattice QCD to calculate the form factors $f_+(q^2)$ and $f_0(q^2)$ for the semileptonic decay $B_s\to K\ell\nu$. Our calculation uses six MILC asqtad 2+1 flavor gauge-field ensembles with three lattice spacings. At the smallest and largest lattice ... More
Variational analysis of low-lying states in supersymmetric Yang-Mills theoryJan 08 2019Jan 17 2019We have calculated the masses of bound states numerically in N = 1 supersymmetric Yang-Mills theory with gauge group SU(2). Using the suitably optimised variational method with an operator basis consisting of smeared Wilson loops and mesonic operators, ... More
Phenomenological view on baryon-baryon potentials from lattice QCD simulationsJan 07 2019A qualitative discussion on the range of the potentials as they result from the phenomenological meson-exchange picture and from lattice simulations by the HAL QCD Collaboration is presented. For the former pion- and/or $\eta$-meson exchange are considered ... More
Kondo QCD effect in stellar matterJan 06 2019Light ($u$, $d$ and $s$)\ quark matter containing charm impurities is studied. These impurities, which induce a Kondo phase, are added to the Lagrangian density and the equation of state (EOS) is then derived. The effects of the Kondo phase on the mass-ratio ... More
Localization and topology in high temperature QCDJan 03 2019At high temperature part of the spectrum of the quark Dirac operator is known to consist of localized states. This comes about because around the crossover temperature to the quark-gluon plasma localized states start to appear at the low end of the spectrum ... More
Lattice QCD and Three-particle Decays of ResonancesJan 02 2019Most strong-interaction resonances have decay channels involving three or more particles, including many of the recently discovered $X$, $Y$ and $Z$ resonances. In order to study such resonances from first principles using lattice QCD, one must understand ... More
$B\to D^\ast\ellν$ at non-zero recoilJan 01 2019We present preliminary blinded results from our analysis of the form factors for $B\rightarrow D^\ast\ell\nu$ decay at non-zero recoil. Our analysis includes 15 MILC asqtad ensembles with $N_f=2+1$ flavors of sea quarks and lattice spacings ranging from ... More
Updates on Nucleon Form Factors from Clover-on-HISQ Lattice FormulationDec 31 2018Updates on results for the electric, magnetic and axial vector form factors are presented. The data analyzed cover high statistics measurements on 11 ensembles generated with 2+1+1 flavors of HISQ fermions by the MILC collaboration. The data cover the ... More
Improving the Kinetic Couplings in Lattice Non-Relativistic QCDDec 30 2018We improve the non-relativistic QCD (NRQCD) action by comparing the dispersion relation to that of the continuum through $\mathcal{O}(p^6)$ in perturbation theory. The one-loop matching coefficients of the $\mathcal{O}(p^4)$ kinetic operators are determined, ... More
Symmetries and Interactions from Lattice QCDDec 28 2018Precision experimental tests of the Standard Model of particle physics (SM) are one of our best hopes for discovering what new physics lies beyond the SM (BSM). Key in the search for new physics is the connection between theory and experiment. Forging ... More
Essential elements for nuclear bindingDec 28 2018How does nuclear binding emerge from first principles? Our current best understanding of nuclear forces is based on a systematic low-energy expansion called chiral effective field theory. However, recent {\it ab initio} calculations of nuclear structure ... More
Lattice study of supersymmetry breaking in N=2 supersymmetric quantum mechanicsDec 27 2018We study supersymmetry breaking from a lattice model of N=2 supersymmetric quantum mechanics using the direct computational method proposed in arXiv:1803.07960. The vanishing Witten index is realized as a numerical result in high precision. The expectation ... More
Form factors of two-hadron states from a covariant finite-volume formalismDec 26 2018In this work we develop a Lorentz-covariant version of the previously derived formalism for relating finite-volume matrix elements to $\textbf 2 + \mathcal J \to \textbf 2$ transition amplitudes. We also give various details relevant for the implementation ... More
Proton and neutron electromagnetic form factors from lattice QCDDec 26 2018The electromagnetic form factors of the proton and the neutron are computed within lattice QCD using simulations of maximally twisted mass fermions with masses fixed to their physical values. We analyse two new ensembles of $N_f=2$ and $N_f=2+1+1$ and ... More
New charged resonance $Z_{c}^{-}(4100)$: the spectroscopic parameters and widthDec 25 2018Feb 05 2019The mass, coupling and width of the newly observed charged resonance $ Z_{c}^{-}(4100)$ are calculated by treating it as a scalar four-quark system with a diquark-antidiquark structure. The mass and coupling of the state $ Z_{c}^{-}(4100)$ are calculated ... More
Baryonic susceptibilities, quark-diquark models and quark-hadron duality at finite temperatureDec 21 2018Fluctuations of conserved charges such as baryon number, electric charge and strangeness may provide a test for completeness of states in lattice QCD for three light flavours. We elaborate on the idea that the corresponding susceptibilities can be saturated ... More
Proton decay matrix element on the lattice with physical pion massDec 21 2018Proton decay is one of possible signatures of baryon number violation, which has to exist to explain the baryon asymmetry and the existence of nuclear matter. Proton decays must be mediated through effective low-energy baryon number violating operators ... More
Avoiding Ergodicity Problems in Lattice Discretizations of the Hubbard ModelDec 21 2018The Hubbard model arises naturally when electron-electron interactions are added to the tight-binding descriptions of many condensed matter systems. For instance, the two-dimensional Hubbard model on the honeycomb lattice is central to the ab initio description ... More
Topological Susceptibility and $η'$ Meson Mass from $N_f=2$ Lattice QCD at the Physical PointDec 20 2018In this paper we explore the computation of topological susceptibility and $\eta'$ meson mass in $N_f=2$ flavour QCD using lattice techniques with physical value of the pion mass as well as larger pion mass values. We observe that the physical point can ... More
SU(3)-breaking ratios for $D_{(s)}$ and $B_{(s)}$ mesonsDec 20 2018We present results for the $SU(3)$ breaking ratios of decay constants $f_{D_s}/f_D$ and $f_{B_s}/f_B$ and - for the first time with physical pion masses - the ratio of bag parameters $B_{B_s}/B_{B_d}$, as well as the ratio $\xi$, forming the ratio of ... More
Consistency between Lüscher's finite volume method and HAL QCD method for two-baryon systems in lattice QCDDec 20 2018There exist two methods to study two-baryon systems in lattice QCD: the direct method which extracts eigenenergies from the plateaux of the temporal correlator and the HAL QCD method which extracts observables from the non-local potential associated with ... More
Nucleon generalized form factors from two-flavor lattice QCDDec 19 2018We determine the generalized form factors, which correspond to the second Mellin moment (i.e., the first $x$-moment) of the generalized parton distributions of the nucleon at leading twist. The results are obtained within lattice QCD calculations with ... More
Chiral crossover in QCD at zero and non-zero chemical potentialsDec 19 2018We present results for pseudo-critical temperatures of QCD chiral crossovers at zero and non-zero values of baryon ($B$), strangeness ($S$), electric charge ($Q$), and isospin ($I$) chemical potentials $\mu_{X=B,Q,S,I}$. The results were obtained using ... More
Update on $B\to D^\ast \ell ν$ form factor at zero-recoil using the Oktay-Kronfeld actionDec 18 2018We present an update on the calculation of $\bar{B}\to D^\ast \ell \bar{\nu}$ semileptonic form factor at zero recoil using the Oktay-Kronfeld bottom and charm quarks on $N_f=2+1+1$ flavor HISQ ensembles generated by the MILC collaboration. Preliminary ... More
Split Grid and Block Lanczos Algorithm for Efficient Eigenpair GenerationDec 17 2018Jan 07 2019The increasing imbalance between the computing capabilities of individual nodes and the internode bandwidth makes it highly desirable for any Lattice QCD algorithm to minimize the amount of internode communication. One of the relatively new methods for ... More
Charmonium resonances from 2+1 flavor CLS latticesDec 17 2018Many exotic charmonium resonances have been identified recently in experiment, however their nature and properties are mostly unknown. Algorithmic and theoretical progress in lattice calculations has enabled reliable numerical investigation of the spectrum ... More
Supersymmetric QCD: Renormalization and Mixing of Composite OperatorsDec 17 2018We study $4$-dimensional SQCD with gauge group $SU(N_c)$ and $N_f$ flavors of chiral super-multiplets on the lattice. We perform extensive calculations of matrix elements and renormalization factors of composite operators in Perturbation Theory. In particular, ... More
Machine Learning as a universal tool for quantitative investigations of phase transitionDec 17 2018The problem of identifying the phase of a given system for a certain value of the temperature can be reformulated as a classification problem in Machine Learning. Taking as a prototype the Ising model and using the Support Vector Machine as a tool to ... More
Numerical evidence of conformal phase transition in graphene with long-range interactionsDec 16 2018Using state of the art Hybrid-Monte-Carlo (HMC) simulations we carry out an unbiased study of the competition between spin-density wave (SDW) and charge-density wave (CDW) order in suspended graphene. We determine that the realistic inter-electron potential ... More
SU(N) polynomial integrals and some applicationsDec 14 2018We use the method of the Weingarten functions to evaluate SU(N) integrals of the polynomial type. As an application we calculate various one-link integrals for lattice gauge and spin SU(N) theories.
Numerical Implementation of Gauge-Fixed Fourier AccelerationDec 14 2018In hybrid Monte Carlo evolution, by imposing a physical gauge condition, simple Fourier acceleration can be used to generate conjugate momenta and potentially reduce critical slowing down. This modified gauge evolution algorithm does not change the gauge-independent ... More
First results for charm physics with a tmQCD valence actionDec 13 2018We present preliminary results in the charm sector from a mixed-action setup, in which CLS $N_f=2+1$ ensembles are combined with a Wilson twisted mass valence action. We study the continuum and chiral limits of charm quark observables such as the decay ... More
Three-quark potentials in an $SU(3)$ effective Polyakov loop modelDec 13 2018Feb 06 2019Three-quark potentials are studied in great details in the three-dimensional $SU(3)$ pure gauge theory at finite temperature, for the cases of static sources in the fundamental and adjoint representations. For this purpose, the corresponding Polyakov ... More
Results for the mass difference between the long- and short- lived K mesons for physical quark massesDec 13 2018The two neutral kaon states in nature, the $K_L$ (long-lived) and $K_S$ (short-lived) mesons, are the two time-evolution eigenstates of the $K^0 - \overline{K^0}$ mixing system. The prediction of their mass difference $\Delta m_K$ based on the Standard ... More
Fourier acceleration, the HMC algorithm and renormalizabilityDec 13 2018The analysis developed by L\"uscher and Schaefer of the Hybrid Monte Carlo (HMC) algorithm is extended to include Fourier acceleration. We show for the $\phi^4$ theory that Fourier acceleration substantially changes the structure of the theory for both ... More
Beyond the Standard Model Kaon Mixing with Physical MassesDec 12 2018Dec 15 2018We present results from a calculation of beyond the standard model (BSM) kaon mixing including data physical with light quark masses. We simulate $N_f=2+1$ QCD with Iwasaki gauge and domain wall fermion action on 8 ensembles, spanning 3 lattice spacings ... More
Charmed baryons in nuclear matterDec 12 2018We study the temperature and baryon density dependence of the masses of the lightest charmed baryons $\Lambda_c$, $\Sigma_c$ and $\Sigma^*_c$. We also look at the effects of the temperature and baryon density on the binding energies of the $\Lambda_c ... More
Fate of a recent conformal fixed point and $β$-function in the SU(3) BSM gauge theory with ten massless flavorsDec 10 2018SU(3) gauge theory with $N_f$ fermions in the fundamental representation serves as a theoretical testing ground for possible infrared conformal behavior, which could play a role in BSM composite Higgs models. We use lattice simulations to study the 10-flavor ... More
Meson-baryon scattering up to the next-to-next-to-leading order in covariant baryon chiral perturbation theoryDec 10 2018We study the scattering of a pseudoscalar meson off one ground state octet baryon in covariant baryon chiral perturbation theory (BChPT) up to the next-to-next-to-leading order. The inherent power counting breaking terms are removed within extended-on-mass-shell ... More
Isovector and flavor diagonal charges of the nucleon from 2+1+1 flavor QCDDec 09 2018We present high-statistics results for the isovector and flavor diagonal charges of the proton using 11 ensembles of 2+1+1 flavor HISQ fermions. In the isospin symmetric limit, results for the neutron are given by the $u \leftrightarrow d$ interchange. ... More
The hadronic vacuum polarization contribution to $(g-2)_μ$ from $2+1$ flavours of O($a$) improved Wilson quarksDec 09 2018We report on our ongoing project to determine the leading-order hadronic vacuum polarisation contribution to the muon $g-2$, using ensembles with $N_f=2+1$ flavours of O($a$) improved Wilson quarks generated by the CLS effort, with pion masses down to ... More
Entanglement Suppression and Emergent Symmetries of Strong InteractionsDec 07 2018Entanglement suppression in the strong interaction $S$-matrix is shown to be correlated with approximate spin-flavor symmetries that are observed in low-energy baryon interactions, the Wigner $SU(4)$ symmetry for two flavors and an $SU(16)$ symmetry for ... More