Mon·Nov 22, 2021Monday·November 22, 2021

1. 01*

   The static force from generalized Wilson loops using gradient flow

   Viljami Leino🇩🇪 · Nora Brambilla🇩🇪 · Julian Mayer-Steudte🇩🇪 · Antonio Vairo🇩🇪

   We explore a novel approach to compute the force between a static quark-antiquark pair with the gradient flow algorithm on the lattice. The approach is based on inserting a chromoelectric field in a Wilson loop. The renormalization issues, associated with the finite size of the chromoelectric field on the lattice, can be solved with the use of gradient flow. We compare numerical results for the flowed static potential to our previous measurement of the same observable without a gradient flow.

   hep-lathep-phhep-thEPJ Web Conf.(2022)·14 citations
2. 02*

   Another look at the Landau gauge three-gluon vertex

   Guilherme T. R. Catumba🇪🇸 · Orlando Oliveira🇵🇹 · Paulo J. Silva🇵🇹

   We revisit the computation of the three-gluon vertex in the Landau gauge using lattice QCD simulations with large physical volumes of $\sim$ (6.5 fm)${}^4$ and $\sim$ (8 fm)${}^4$ and large statistical ensembles. For the kinematical configuration analysed, that is described by a unique form factor, an evaluation of the lattice artefacts is also performed. Particular attention is given to the low energy behaviour of vertex and its connection with evidence (or lack of it) of infrared ghost dominance.

   hep-latEPJ Web Conf.(2022)·11 citations
3. 03*

   Chromoelectric and chromomagnetic correlators at high temperature from gradient flow

   Julian Mayer-Steudte🇩🇪 · Nora Brambilla🇩🇪 · Viljami Leino🇩🇪 · Peter Petreczky🇺🇸

   The heavy quark diffusion coefficient is encoded in the spectral functions of the chromoelectric and the chromomagnetic correlators that are calculable on the lattice. We study the chromoelectric and the chromomagnetic correlator in the deconfined phase of SU(3) gauge theory using Symanzik flow at two temperatures $1.5T_c$ and $10000T_c$, with $T_c$ being the phase transition temperature. To control the lattice discretization errors and perform the continuum limit we use several temporal lattice extents $N_t=16,20,24$ and 28. We observe that the flow time dependence of the chromomagnetic correlator is quite different from chromoelectric correlator most likely due to the anomalous dimension of the former as has been pointed out recently in the literature.

   hep-lathep-phhep-thnucl-thPoS(2022)·8 citations
4. 04*

   HotQCD on Multi-GPU Systems

   Luis Altenkort🇩🇪 · Dennis Bollweg🇩🇪 · David Anthony Clarke🇩🇪 · Olaf Kaczmarek🇩🇪 · Lukas Mazur🇩🇪 · Christian Schmidt🇩🇪 · Philipp Scior🇺🇸 · Hai-Tao Shu🇩🇪

   We present $\text{SIMULATeQCD}$, HotQCD's software for performing lattice QCD calculations on GPUs. Started in late 2017 and intended as a full replacement of the previous single GPU lattice QCD code used by the HotQCD collaboration, our software has been developed into an extensive framework for lattice QCD calculations distributed on multiple GPUs over many compute nodes. The code is built on C++, CUDA, and MPI and leverages modern C++ language features to provide high-level data structures, objects, and algorithms that allow users to express lattice QCD calculations in an intuitive way without sacrificing performance. Implemented algorithms range from gradient flow, correlator measurements, and mixed precision conjugate gradient solvers all the way to full HISQ gauge field configuration generation using RHMC. After successful deployment in large-scale computing projects, we want to share the result of our efforts with the lattice QCD community by making it publicly available. In these proceedings, we will present some of the key features of our code, demonstrate its ease of use, and show benchmarks of performance critical kernels on state-of-the-art supercomputers.

   hep-latPoS(2022)·37 citations
5. 05*

   Probing New Physics with heavy hadron decays

   Pietro Colangelo🇮🇹 · Fulvia De Fazio🇮🇹 · Francesco Loparco🇮🇹

   The increasing number of flavour anomalies calls for the investigation of new processes where tensions similar to the observed ones could emerge. Observables sensitive to physics beyond the Standard Model need to be identified. We discuss the inclusive semileptonic decays of polarized beauty baryons, computed through the heavy quark expansion at $\mathcal{O}(1/m_b^3)$ and at the leading order in ${\alpha }_s$. We account for New Physics interactions in a model-independent way, extending the Standard Model $b\to U\ell {\bar{\nu }}_{\ell }$ low energy Hamiltonian (with $U=u,c$ and $\ell =e,\mu ,\tau$) with the inclusion of the full set of D=6 semileptonic operators with left-handed neutrinos. We identify a set of promising observables, the study of which can be included in the physics programmes of future facilities, such as FCC-e.

   ↳ hep-phhep-exhep-latPoS(2022)·0 citations
6. 06*

   Analysis of autocorrelation times in Neural Markov Chain Monte Carlo simulations

   Piotr Białas🇵🇱 · Piotr Korcyl🇵🇱 · Tomasz Stebel🇵🇱

   We provide a deepened study of autocorrelations in Neural Markov Chain Monte Carlo (NMCMC) simulations, a version of the traditional Metropolis algorithm which employs neural networks to provide independent proposals. We illustrate our ideas using the two-dimensional Ising model. We discuss several estimates of autocorrelation times in the context of NMCMC, some inspired by analytical results derived for the Metropolized Independent Sampler (MIS). We check their reliability by estimating them on a small system where analytical results can also be obtained. Based on the analytical results for MIS we propose a new loss function and study its impact on the autocorelation times. Although, this function's performance is a bit inferior to the traditional Kullback-Leibler divergence, it offers two training algorithms which in some situations may be beneficial. By studying a small, $4\times 4$, system we gain access to the dynamics of the training process which we visualize using several observables. Furthermore, we quantitatively investigate the impact of imposing global discrete symmetries of the system in the neural network training process on the autocorrelation times. Eventually, we propose a scheme which incorporates partial heat-bath updates which considerably improves the quality of the training. The impact of the above enhancements is discussed for a $16\times 16$ spin system. The summary of our findings may serve as a guidance to the implementation of Neural Markov Chain Monte Carlo simulations for more complicated models.

   ↳ cond-mat.stat-mechcs.LGhep-latstat.MLPRE(2023)·13 citations
7. 07*

   Gauge Enhanced Quantum Criticality Between Grand Unifications: Categorical Higher Symmetry Retraction

   Juven Wang🇺🇸 · Yi-Zhuang You🇺🇸

   Prior work [arXiv:2106.16248] shows that the Standard Model (SM) naturally arises near a gapless quantum critical region between Georgi-Glashow (GG) $su(5)$ and Pati-Salam (PS) $su(4)\times su(2)\times su(2)$ models of quantum vacua (in a phase diagram or moduli space), by implementing a modified $so(10)$ Grand Unification (GUT) with a Spin(10) gauge group plus a new discrete Wess-Zumino Witten term matching a 4d nonperturbative global mixed gauge-gravity $w_2{w}_3$ anomaly. In this work, we include Barr's flipped $su(5)$ model into the quantum landscape, showing these four GUT-like models arise near the quantum criticality near SM. Highlights include: First, we find the precise GG or flipped $u(5)$ gauge group requires to redefine a Lie group U(5)${}_{\hat{q}}$ with $\hat{q}=2$ or $3$ (instead of non-isomorphic analog $\hat{q}=1$ or 4), and different $\hat{q}$ are related by multiple covering. Second, we show that the GG and flipped $u(5)$ are two different symmetry-breaking vacua of the same order parameter separated by a first-order Landau-Ginzburg transition. We also show that analogous 3+1d deconfined quantum criticalities, both between GG and PS, and between the flipped $u(5)$ and PS, are beyond Landau-Ginzburg paradigm. Third, topological quantum criticality occurs by tuning between the 15n vs 16n scenarios. Fourth, we explore the generalized higher global symmetries in the SM and GUTs. Gauging the ${\mathbb{Z}}_2$ flip symmetry between GG and flipped $u(5)$ models, leads to a potential categorical higher symmetry that is a non-invertible global symmetry: within a gauge sector $(u(1)\times u(1))⋊{\mathbb{Z}}_2$, the fusion rule of 2d topological surface operator splits. However, the un-Higgs Spin(10) at UV retracts this categorical symmetry.

   ↳ hep-thcond-mat.str-elhep-lathep-ph+270 citations

* Reconstructed cohort: no mailing for this day survives in the archive. Papers are grouped by their submission times and arXiv's announcement cut-off, assuming announcement without delay; positions follow identifier order. Validated at ~91% exact-day agreement against the archived era.