We review the level of welcomeness that members of the lattice field theory community feel based on the results of a survey performed in May and June 2023. While respondents reported generally high levels of feeling welcome at the lattice conference, women and people with diverse gender identities, sexual orientations, ethnic backgrounds and religious affiliations feel less included and have...
In this study we present lattice results on the QCD $\beta$-function in the presence of a quark mass. The $\beta$-function is calculated to three loops in perturbation theory and for improved lattice actions; it is extracted from the renormalization of the coupling constant $Z_g$. The background field method is used to compute $Z_g$, where it is simply related to the background gluon field...
We report basic properties of our new configuration set.We calculated the topological charge, the mass spectra for hadrons, and so on.The lattice spacing, $a^{-1}=2.339$[GeV], is fixed using the Omega baryon mass.
The ``Sphaleron Rate'' (imaginary linear-in-frequency part of the topological density retarded Green's function) determines the real-time relaxation rate of axial quark number for light quarks in a hot medium, and is relevant in heavy-ion collisions and electroweak baryogenesis. We recently showed how it can be determined in pure-glue QCD via standard Euclidean simulations, via a novel...
We report recent progress in data analysis on the two point correlation functions
which will be used to obtain form factors for the semileptonic decays $B_{(s)} \to D_{(s)}\ell\nu$.
We use a MILC HISQ ensemble ($a=0.12fm$ and $m_\pi = 310 MeV$) to produce the measurement data
using the HISQ light quarks and Oktay-Kronfeld (OK) action for the heavy quarks($N_f=2+1+1$ flavor).
We...
We present recent progress in evaluatinging $\varepsilon_K$, the indirect
CP violation parameter in the neutral kaon system, calculated using
lattice QCD inputs directly from the standard model.
We report recent progress on data analysis for 2-point correlation functions with HYP-smeared staggered quarks. We use the sequential Bayesian fitting method. We present how to obtain a good initial guess using the Newton method. We report results of fitting 2-point correlation functions, including the excited states, for $P \times P$ and $P \times A$ operators.
Workflow management has become an important topic in many research communities. Here, we focus on the particular aspect of provenance tracking. We follow the W3C PROV standard and formulate a provenance model for Lattice QCD that includes the ensemble-generation and the measurement parts of the Lattice QCD workflow. Since many important provenance questions in our community require extensions...
How and when do people become physicists? Are they always certain about their career choice? What are physicists like outside work? A team of physics students and faculty aim to answer these questions through the “My Journey as a Physicist” podcast. In each episode, a student host(s) interviews professional physicists to learn about their professional journey of how they ended up where they...
We examine the renormalized lattice spacing anisotropy in SU(2) Yang-Mills theory. We determine the physical anisotropy by performing anisotropic Wilson flow. Our preliminary findings indicate that, at high bare anisotropies, the physical anisotropy reaches a plateau. Further increase of the bare anisotropy results in a slight increase of the lattice spacings. Our findings can be then applied...
Here we present a lattice QCD determination of the first few Mellin moments of the pion distribution amplitude by analyzing the quasi-DA matrix elements using a lattice spacing of $a=0.836 \; \text{fm}$. Our work differs from previous work in that we use domain-wall fermions in order to respect chiral symmetry and that calculations are performed at the physical pion mass. First, we analyze...
The extraction of the QCD coupling via non-perturbative decoupling methods has been recently shown to be a compelling strategy for high-precision determinations [Eur. Phys. J. C 82 (2022) 12, 1092]. One of the key ingredients of this strategy is the determination of a (finite-volume) non-perturbative massive coupling at large values of the quark-mass, $M$. Robust continuum limit extrapolations...
Ab-initio calculations of real-time evolution for lattice gauge theory have very interesting potential applications but present challenging computational aspects.
We show that tensor renormalization group methods developed in the context of Euclidean-time lattice field theory can be applied to calculation of Trotterized evolution operators at real time. We discuss the optimization of...
General positivity constraints linking various powers of observables in energy eigenstates can be used to sharply locate acceptable regions for the energy eigenvalues, provided that efficient recursive methods are available to calculate the matrix elements. These recursive methods are derived by looking at the commutation relations of the observables with the Hamiltonian. We discuss how this...
The Pauli strings appearing in the decomposition of an operator can be can be grouped into commuting families, reducing the number of quantum circuits needed to measure the expectation value of the operator. We detail an algorithm to completely partition the full set of Pauli strings acting on any number of qubits into the minimal number of sets of commuting families, and we provide python...
Multilevel integration schemes are easy to couple with distillation, our current approach for computing highly optimized interpolating fields for hadrons. The locality of the distillation basis in the time direction can be exploited in accelerating the propagator computations with domain decomposition. Currently, we are exploring the use of asymmetric domain decomposition schemas in which the...
Numerous studies have demonstrated that the rapid decline in the efficiency of traditional sampling algorithms caused by Critical Slowing Down can be alleviated or even sidestepped completely using flow-based sampling. Such approaches trade off a reduction in autocorrelation times with an increase in the cost of generating new field configurations and an up-front training cost. The...
We present our ongoing work on the distribution amplitudes of the charmonia states $\eta_c(1s)$ and $J/\psi(1s)$. We use the so-called pseudo approach developed by A. Radyushkin in a set of three CLS $N_f=2$ ensembles at three different lattice spacings between $0.08~\text{fm}$ and $0.05~\text{fm}$ and a pion mass around $270~\text{MeV}$. The resulting momentum distributions can be studied in...
This work presents a study of Wuppertal smearing, comparing different mesons and kinematic configurations.
We propose a parametrization of the optimal smearing radius in terms of the reduced masses of the mesons, giving, at the same time, an estimate of the efficiency of the smearing in suppressing the excited states.
The relation between Momentum Smearing and ordinary Wuppertal smearing...
Hadronic scattering amplitudes determined in Lattice QCD using Lüscher’s formalism depend crucially on the finite-volume energy spectrum. This work presents some of the technical details of the determination of such spectra within the study of the two-poles nature of the $\Lambda(1405)$ from Lattice QCD. Starting with the extraction of energy states from correlation functions, the GEVP...
In this poster, I present preliminary results from the Fermilab Lattice and MILC collaborations on the nucleon axial charge and nucleon axial and vector form factors with the HISQ action for both valence and 2+1+1 sea quarks. For the nucleon axial charge, we compute correlators across four physical mass ensembles with approximate lattice spacings of 0.15, 0.12, 0.09, and 0.06 fm, and perform...
Normalizing flow based methods for sampling lattice gauge theories has shown some recent progress. Here, we present rudimentary results for observables with finite temperature on small lattices in 2+1 dimensions.
The phase diagram of QCD at finite density remains largely unknown due to the sign problem. We propose a 1+1 dimensional model which mimics some of the features of QCD in order to study how quantum computers can avoid the sign problem and allow computations at the finite density. The model is a Z(3) gauge theory coupled to 3 flavors of staggered fermions, and it features baryon-like...
We present results on three-particle scattering in the (1+1)-dimensional O(3) non-linear sigma model using lattice-determined finite-volume energies and the relativistic-field-theory (RFT) finite-volume formalism. We focus on the isospin-3 and isospin-2 three-particle channels, and perform lattice computations for four different volumes with three values of the lattice spacing each. The...
While Wick rotation to Euclidean spacetime is necessary for lattice QCD calculations, the subsequent rotation back to Minkowski spacetime from discrete correlator data is an ill-posed problem. In this proof-of-concept calculation, we compute correlation functions necessary for computing the hadronic tensor of the pion using existing ensembles generated by the MILC collaboration and $N_f=2+1+1$...
The Landau gauge four-gluon vertex is studied using high
statistical lattice simulations for several momentum configurations.
Furthermore, the outcome of the lattice QCD simulations are compared
with calculations performed with continuum Schwinger-Dyson equations.
Normalizing flow based methods for efficient sampling in lattice gauge theories have shown impressive progress. We have extended these methods to generate ensembles for SU(3) in 2+1 dimensions at a range of temporal extents. Preliminary results for observables are presented and future prospectives for finite temperature simulations are discussed
We present a new take on low-mode averaging, where the dimension of the low-mode subspace is multiplied by exploiting local coherence of low modes. The fraction of the quark propagator captured by this subspace can easily be volume averaged or sampled excessively and reaches gauge variance with lower computational cost than the traditional methods. The remainder piece can be sampled...
We present an evaluation of the glueball spectrum for configurations produced with $N_f=1$ dynamical fermions as a function of the $m_{\rm PCAC}$ mass. We obtained masses of states that fall into the irreducible representations of the octagonal group of rotations in combination with the quantum numbers of charge conjugation $C$ and parity $P$. Due to the low signal to noise ratio,...
In lattice QCD calculations, the trace of operator products involving the inverse Dirac operator is often necessary for evaluating various observables, such as cumulants of the chiral order parameter and conserved charge fluctuations. Since the Dirac operator is represented by a large sparse matrix on the lattice, the exact calculation of the trace is typically impractical. Instead, it is...
Two analysis techniques, the generalized eigenvalue method (GEM) or Prony's method (PM), are commonly used to analyze statistical estimates of correlation functions produced in lattice quantum field theory calculations. GEM takes full advantage of the matrix structure of correlation functions but only considers individual pairs of time separations when much more data exists. PM can be...
Python is a particularly appealing language to carry out data analysis, owing in part to its user-friendly character as well as its access to well maintained and powerful libraries like NumPy and SciPy. Still, for the purpose of analyzing data in a lattice QCD context, some desirable functionality is missing from these libraries. Moreover, scripting languages tend to be slower than compiled...
Common to many analysis pipelines in lattice field theory is the need to fit data to a model that is determined partially by a finite number of model parameters. Familiar examples include analyses of finite-size scaling and ground state spectroscopy. We propose a Bayesian fit method that utilizes a neural network to approximate the component of such models that is a priori unknown. The...
We use a regular tessellation of AdS$_2$ based on the (2,3,7) triangle group, with an extension to Euclidean AdS$_3$, to study the AdS/CFT correspondence. Perturbative calculations are verified and initial tests of monte carlo calculations for non-perturbative $𝜙^4$ theory exhibit critical phenomena on the boundary.