We present an update for our ongoing calculation of $B$-meson semileptonic form factors, using the highly improved staggered quark (HISQ) action on FNAL-MILC $N_f=2+1+1$ HISQ gauge ensembles. We compute the scalar, vector, and tensor form factors for the $B \to \pi$, $B \to K$, $B_s \to K$, and $B_{(s)} \to D_{(s)}$ transitions . We have recently added data with $a \approx 0.03$ fm into our...
We present recent updates for $\epsilon_{K}$ determined directly from the standard model (SM) with lattice QCD inputs such as $\hat{B}_{K}$ , $|V_{cb}|$, $|V_{us}|$, $|V_{ud}|$, $\xi_{0}$, $\xi_{2}$, $\xi_{LD}$, $f_{K}$ , and $m_{c}$. We find that the standard model with exclusive $|V_{cb}|$ and other lattice QCD inputs describes only 2/3 of the experimental value of $|\epsilon_{K}|$ and does...
We consider the two-flavor Gross-Neveu model and compute the real time evolution of probabilities relevant to the calculation of the scattering phase shift with a digital quantum computer. We demonstrate the different intermediate steps of preparing the ground state, preparing a Gaussian wave packet and performing a Quantum Fourier transform on the quantum device. The phase shift is computed...
Generative models, in particular normalizing flows, have demonstrated exceptional performance in learning probability distributions across various domains of physics, including statistical mechanics, collider physics, and lattice field theory. In lattice field theory, using normalizing flows for accurately learning the Boltzmann distribution has been applied to a wide range of tasks, such as...
Lattice gauge fixing is necessary to compute gauge-variant quantities, for example those used in RI-MOM renormalization. Recently, gauge-variant observables have also been found to be more amenable to signal-to-noise optimization using contour deformations. These applications motivate systematic parameterization and exploration of gauge-fixing schemes. This work introduces a differentiable...
The pseudoscalar meson light cone distribution amplitudes (LCDAs) are essential non-perturbative inputs for a range of high-energy exclusive processes in quantum chromodynamics. In this poster, progress towards a determination of the second and fourth Mellin moments of pseudoscalar meson LCDAs by the HOPE Collaboration is reported.
We study the finite-temperature critical point of QCD in the heavy-quark region by a scaling study of the Binder cumulant on large lattices to determine the critical point in the thermodynamic limit with a high precision. We perform simulations on $N_t=6$ and 8 lattices with spatial volumes up to the aspect ratio $LT=N_s/N_t=18$ and 15, respectively. To enable simulations with large spatial...
While over the past few decades lattice QCD has provided information on the spectrum of glueballs, little is known about the structure of these exotic candidates. In this poster, we present preliminary results on the gravitational form factors of glueball states in pure Yang-Mills theory. We use $\mathcal{O}(10)$ million configurations with $\beta=5.95$, and a large set of interpolators, to...
The quantum field theories of the Higgs boson interacting with light vector particles offer a number of non-trivial features to study. Bound states, phase structure, dynamical mass generation, and the Higgs mechanism are among them. As light vector particles are dark matter candidates, a thorough understanding of the involved physics is crucial as experimental searches continue. It requires...
In this work we present ongoing work for the study of the two pole structure of the $\Lambda$ (1405) baryon at the $SU(3)$ point. We construct the interpolation operators from the direct product of the pseudo-scalar meson and baryon octets. In these combinations the singlet and octet representations of the $SU(3)$ symmetry are attractive, so we choose the states belonging to this...
We demonstrate the use of Bayesian fitting combined with a model averaging technique based on the Bayesian Akaike information criterion, with the intention to release a general purpose python package for typical correlator analysis coming from LFT. As examples we concentrate on two-point functions, one from a recent study on the Hubbard model and one on hadron correlators, extracting energies...
The investigation of $\mathbb{Z}_N$ lattice gauge theories was initially undertaken to gain insights into the phase structure of lattice gauge theories. It is established that for $N<5$, these theories exhibit two phases: an ordered, deconfining phase at low temperatures and a disordered, confining phase at high temperatures. For $N\geq 5$, an additional Coulomb phase emerges at intermediate...
The presence of GPU from different vendors demands the Lattice QCD codes to support multiple architectures. To this end, Open Computing Language (OpenCL) is a viable framework for writing portable code. It is of interest to find out how the OpenCL implementation performs as compared to the code based on a dedicated programming interface such as CUDA for Nvidia GPUs. We have developed an OpenCL...
Developed under the European Processor Initiaive (EPI) the STX stencil/tensor accelerator aims to achieve a 5-10x higher energy efficiency over general purpose compute units.
The architectue consists of specialiced MIMD compute units which are supported and controlled by RISC-V cores.
We describe a co-design effort between hardware, software, and application development focused around...
Simulation of adiabatic methods on a quantum computer has been successfully used to prepare ground states of gauge theories. However, this process requires a high number of quantum gates, which is inaccessible in the NISQ era. An alternative approach is to use variational methods, which utilise a hybrid of classical and quantum computation. We show how a particular example, the Quantum...
HiRep allows flexible simulations of higher representations of Wilson Fermions with various actions and gauge groups and a range of inverters and integrators. This is particularly important for enabling evaluations of observables relevant to phenomenological inputs for Beyond-the-Standard-Model physics from lattice field theory. We present progress on the GPU porting of available features.
We report our current status of lattice calculation of proton decay matrix elements on the PACS configurations of $64^4$ volume with lattice spacing $a=0.085$ fm at physical point for 2+1 flavor QCD. We carefully study the various systematic effects, especially for the renormalization scheme, and show the comparison with the previous results.
Semiconductor spin qubits are ideal for scalable quantum computing due to their long coherence times and compatibility with existing semiconductor fabrication technology. For quantum simulation of lattice gauge theories, the encoding of fermionic d.o.f. into qubits becomes complicated in higher dimensions. Furthermore, encoding with bosonic d.o.f. in a digital scheme introduces additional...
Low Mode Average (LMA) is a technique to improve the quality of the signal-to-noise ratio in the long time separation of Euclidean correlation functions. We report on its beneficial impact in computing the vector-vector light connected two-point correlation functions $V_{kk}(t)$ and derived physical quantities in the mixed action lattice setup adopted by ETMC. We focus on preliminary results...
The convergence property of iterative solvers strongly depends on the spectrum of Dirac operator. For most of the standard algorithms to work, the real part of the spectrum should be positive. The domain-wall operator does not satisfy this condition, and this is one the reasons for difficulty in applying the multi-grid algorithms. In this presentation, we examine several preconditioning...
We report the status of the ensemble generation effort of the Extended Twisted Mass Collaboration towards controlled continuum and infinite volume extrapolations for a variety of physical observables through simulations employing $N_f=2+1+1$ Wilson clover twisted mass fermions at physical quark masses using five lattice spacings. We further give an update on the status of the tmLQCD software...
We simulate QCD with 3 Quark flavours for the case of an external magnetic field and imaginary chemical potential in the temperature range of the crossover. This poster clarifies how to match experimental conditions, i.e bringing the system into strangeness neutrality as well as predicting the new simulation parameters for runs with increasing imaginary chemical potential by comparing...
Karsten-Wilczek (KW) and Borici-Creutz (BC) fermions show a near-degeneracy similar to staggered fermions. In the eigenvalue spectrum this near-degeneracy is simpler to quantify than in spectroscopic quantities. Therefore we determine the low-lying eigenvalues of these fermion operators at a fixed flow time (either in lattice or physical units) in the quenched Schwinger model and study the...
To compare the results from different calculations of the leading-order HVP contribution to the muonโs anomalous magnetic moment, either using lattice QCD or phenomenological input, it has been found useful to use window observables. We report blinded results on the connected QED contributions to the short distance and intermediate windows. The calculations use the highly-improved staggered...
We compute the spectra of open flux tubes formed between a static quark-antiquark pair for various $SU(N)$ gauge groups in the large-N limit, focusing on different symmetries. Specifically, we present spectra up to N=6 and for eight different symmetries of the flux tube. In this study, we employed an anisotropic Wilson action, a large number of suitable operators, and solved the generalized...
We study possible discretizations of the action of supersymmetric QCD. Supersymmetry is broken on the lattice and improved lattice formulations should reduce the amount of fine-tuning required to recover it in the continuum limit. The discrepancy between the conventional scalar field discretization and the Wilson fermion discretization contributes to the breaking of supersymmetry. We...
The width of a hadronic decay to two particles can be studied from ratios of three and two point functions if the initial and final states in the matrix elements are degenerate. In our work, we rederive this method to study the vector-charmonium decay $\psi(3770)\to\bar{D}D$, we discuss the specific systematics that we found, and present preliminary results. Furthermore, we study the width as...
We present the preliminary results for a study of exotic states using 6-stout smeared ensembles approaching the physical point. Benchmarks for the optimal distillation parameters and number of sources are presented in order to maximize the signal while keeping the total computational resources low.
The runs are all preformed with resources at JSC. We use the latest architectures to show the...
The family of SU(2) theories with matter transforming in the adjoint representation has attracted interest from many angles. The 2-flavour theory, known as Minimal Walking Technicolor, has a body of evidence pointing to it being in the conformal window with anomalous dimension $\gamma_*\approx 0.3$. Perturbative calculations would suggest that the 1-flavour theory should be confining and...
The axial charge of the nucleon, $g_A$, has been computed extensively on the lattice. However, the axial charges for other octet baryons (hyperons) such as the $\Sigma$ and $\Xi$ baryons are less well known experimentally and theoretically. Here we present results from our updated analysis of the isovector axial, scalar and tensor charges, as well as first results for the second Mellin moments...
Variational Quantum Eigensolvers (VQEs) are a powerful class of hybrid quantum-classical algorithms designed to approximate the ground state of a quantum system described by its Hamiltonian. VQEs hold promise for various applications, including lattice field theory and quantum chemistry.
However, the inherent noise present in Noisy Intermediate-Scale Quantum (NISQ) devices poses a significant...
In this poster, we report on our investigation of two specific systems that are hard to simulate with ordinary Monte Carlo methods: the transverse Ising model with an imaginary magnetic field (CTIM) and the quantum harmonic oscillator in a complex cubic potential (CQHO). We focus on understanding the quantum phase transition in CTIM with varying field strengths, and the PT-symmetry breaking in...
We present the current development status and plans for the tooling for a user-friendly and modern interface for the International Lattice Data Grid (ILDG), that is being developed as part of the PUNCH4NFDI project.
In particular, we'd like to present the current web-based UI for searching ensembles in the Metadata Catalog and for generating the XML (templated) metadata files, which are...
The confinement/deconfinement phase transition of QCD at finite densities is still numerically inaccessible by classical computations. The exponential speedup of quantum computers could avoid this issue, but their current physical implementations are subjected to quantum noise. In my poster, I will present a novel quantum error mitigation scheme based on the BBGKY hierarchy, applicable to any...
In this poster, we will present our implementation strategy of domain decomposition techniques for the Dirac operator within QUDA. We are developing a generic 4-dimensional domain decomposition aiming to support algorithms such as Red-Black Schwartz Alternating Procedure (SAP), time-slice domains and multilevel algorithms. We will also discuss how we plan to support preconditioned operators,...
The long-term goal of this project is the non-perturbative renormalization of the energy-momentum tensor in the 2d O(3) nonlinear sigma model using different methods which have been developed for QCD applications.
As a first step, we have identified all operators that mix with the energy-momentum tensor once a lattice discretization is employed, that is all which are compatible with power...
We report the results of Fourier-accelerated HMC simulations of 2D SU(N) X SU(N) principal chiral models for N = 2, 3, 4, 6, 9. These models share several key properties with 4D QCD, for example asymptotic freedom and dynamical mass generation. Even for modest correlation lengths, we find integrated autocorrelation times are decreased by an order of magnitude relative to standard HMC, with...
The lattice computation of the one-particle irreducible ghost-gluon Green function in the Landau gauge is revisited with a set of large gauge ensembles. The large statistical ensembles enable a precision determination of this Green function over a wide range of momenta, accessing its IR and UV properties with a control on the lattice effects.
Fixed point (FP) lattice actions are classically perfect, i.e., they have continuum classical properties unaffected by discretization effects. They have suppressed lattice artefacts and therefore provide a possible way to extract continuum physics with coarser lattices, allowing to circumvent problems with critical slowing down and topological freezing towards the continuum limit. We use...
Radial quantization would be the ideal formalism for studying strongly-coupled conformal and near-conformal quantum field theories but it requires the ability to perform lattice calculations on static, curved manifolds, specifically a very long cylinder whose cross section is a sphere. Smoothly discretizing the surface of a sphere requires a graph with unequal edge lengths. The geometry of...
Recent years have seen significant progress in numerical lattice studies of supersymmetric gauge theories, exploiting formulations that exactly preserve a supersymmetry sub-algebra at non-zero lattice spacing. These investigations remain computationally demanding, especially in the large-$N$ limit of the SU($N$) gauge group. Three-dimensional theories offer a promising balance between...
We study the 3D Ising model in the infinite volume limit
$N_{x,y,z}\to\infty$ by means of numerical simulations. We determine $T_c$
as well as the critical exponents $\alpha,\beta,\gamma$ and $\nu$, based
on finite-size scaling and histogram reweighting techniques. In addition,
we study a "dimensionally reduced" scenario where $N_z$ is kept fixed
(e.g. at 2, 4, 8), while the limit...
Propagators of massless scalar fields have been computed on configurations of Euclidean dynamical triangulations (EDT) in the collapsed phase. They are used to calculate -- up to an integration constant -- the scale factor of a rotational invariant metric. This scale factor is non-zero at the origin, which we assume to be caused by the presence of the well-known singular structure in the...
The one-loop matching between the overlinee coupling and the MS coupling is done in two steps. First, we
calculate the relation of the overlinee coupling to a renormalised lattice coupling. Combination with
the known one-loop relation between the lattice and the MS couplings then yields the desired result.
\subsection{The basic calculation}
Expand $\overline{g}(L)$ the running coupling...
Following from LDIC survey performed last year in May and June 2023, we show more information about the preferences regarding online or in person workshops and connect them to diversity concerns. People with disabilities, women and non-binary respondents, and ethnic and religious minorities express the opinion that online workshops are more inclusive. However, we find a slight effect that the...
Full QCD+QED simulations allow to evaluate isospin breaking corrections to hadron masses. With the openQxD code, we are able to perform these simulations employing C-periodic boundary conditions, implemented through a doubling of the physical lattice along one spatial direction.
The use of these boundary conditions introduces non-zero Wick contractions between two quark or two antiquark...
In this talk I will present new blinded lattice results for the intermediate-distance window observable of the anomalous muon magnetic moment. Results are obtained on several staggered ensembles covering lattice spacings down to a ~ 0.048 fm. I will discuss the details of the continuum extrapolation and of other sources of systematic uncertainties.
We presents the status of our program to generate $n_f=2+1$ quark flavor gauge configurations using stabilized Wilson fermions within OpenLat. Updates on our ongoing production at the four lattice spacings $a=0.12, 0.094, 0.077$ and $0.064$ fm are shown and, aside from the flavor symmetric point, advancements in going towards physical pion masses are discussed. High-statistics ensembles are...
Modern measurement workflows require the iterative solution of hundreds or thousands of linear systems with unique sources but a constant discrete Dirac fermion stencil. Algorithmically batching multiple independent linear solves with a fixed stencil improves compute throughput by exposing additional data parallelism and increasing data reuse. The multiplicative benefit of utilizing batched...
Recently, confining strongly coupled models have been considered as dark matter candidates, and to predict the gravitational wave spectrum from a possible early universe phase transition, the nucleation rate is needed as an input. The nucleation rate of a confinement transition for strongly coupled theories has not so far been determined from lattice, but is instead often estimated using...
In this study, we present an analysis of the weak and strong scaling behaviours of normalizing flow methods applied to SU(2) and SU(3) gauge theories. We investigate the performance of these normalizing flows across varying lattice volumes and spacings, providing insights into their scalability and computational demands. Additionally, we perform an automated hyper-parameter optimization...
In multilevel integration, the correlation functions are decomposed into factors that depend only on fields localized into lattice subdomains so that they can be independently integrated. Although the standard formulation of the LQCD action is not local in the presence of fermions, past studies have shown approximations of the quark propagator and the fermionic determinant dependent on the...
In JHEP 04 (2024) 126 [arXiv:2402.06561] we recently proposed an out-of-equilibrium setup to reduce the large auto-correlations of the topological charge in two-dimensional CP$^{N-1}$ models. Our proposal consists of performing open-boundaries simulations at equilibrium, and gradually switching on periodic boundary conditions out-of-equilibirum. Our setup allows to exploit the reduced...
In two dimensions $U(N_c)$ gauge theories on a torus exhibit a non-trivial topological structure (both on the lattice and in the continuum). Like in 4D $SU(3)$ gauge theories the phase spaces are divided into topological sectors, characterized by a topological index (a.k.a. "topological charge"). These sectors are separated by action barriers, which diverge if the lattice spacing is taken...
We investigate the step scaling approach in compact pure U(1) lattice gauge theory in 2+1 dimensions combining Monte Carlo and quantum computing methods. We present results for the step scaling deep into the small gauge coupling region and discuss the non-perturbative matching between Monte Carlo and quantum computing simulations.
Random matrix theory was first examined in the context of nuclear physics to investigate properties of heavy atom nucleus spectra. This theory is suited for an application to machine learning algorithms, specifically to study the properties of their weight matrices.
In this presentation, we report the effect of varying the learning rate and the batch size used in the stochastic gradient...
We compute the vector, scalar, and tensor form factors for the $B\to \pi$, $B\to K$, and $B_s\to K$ amplitudes, which are needed to describe semileptonic $B$-meson decay rates for both the charged and neutral current cases. We use the highly improved staggered quark (HISQ) action for the sea and light valence quarks. The bottom quark is described by the clover action in the Fermilab...
We study an application of supervised learning to infer two-point lattice correlation functions at one input mass from correlator data computed at a different target mass. Learning across the mass parameters could potentially reduce the cost of expensive calculations involved in light Dirac inversions, which can be a computational bottleneck for performing simulations of quantum chromodynamics...
The use of generative models to learn and sample complex distributions is increasingly common in computational physics. Many generative approaches are being used with a view to improving algorithms for complex lattice systems like QCD. One such generative model is the Variational Autoencoder, which can simplify a complex distribution by identifying the distribution with a Gaussian in a latent...
