Tue·Nov 15, 2022Tuesday·November 15, 2022

1. 01*

   Confinement-deconfinement transition in $SU(3)$-Higgs theory

   Sanatan Digal🇮🇳 · Vinod Mamale🇮🇳 · Sabiar Shaikh🇮🇳

   We study lattice cutoff effects on the confinement-deconfinement transition and the $Z_3$ symmetry in $SU(3)$-Higgs theory in $3+1$ dimensions. The Higgs in this study is a complex triplet with vanishing bare mass and quartic coupling. The lattice cutoff is regulated by varying the number of temporal lattice sites, $N_{\tau }$. Our results show that the nature of the confinement-deconfinement transition depends on $N_{\tau }$. For $N_{\tau }=2$ the transition is found to be the end point of a first-order transition and is first order for $N_{\tau }\ge 3$. The distributions of the Polyakov loop and other observables, sensitive to the $Z_3$ symmetry, show that the strength of $Z_3$ explicit breaking decreases with $N_{\tau }$. Up to $T\simeq 2T_c$, the free energy difference between $Z_3$ states decreases with $N_{\tau }$, suggesting the realization of $Z_3$ symmetry in the continuum limit.

   hep-lathep-phnucl-thPRD(2023)·0 citations
2. 02*

   Four-dimensional domain decomposition for the factorization of the fermion determinant

   Matteo Saccardi🇮🇹 · Leonardo Giusti🇮🇹

   The non-local dependence of the fermion determinant on the gauge field limits our ability of simulating Quantum Chromodynamics on the lattice. Here we present a factorization of the gauge field dependence of the fermion determinant based on an overlapping four-dimensional domain decomposition of the lattice. The resulting action is block-local in the gauge and in the auxiliary bosonic fields. Possible applications are multi-level integration, master field simulations, and more efficient parallelizations of Monte Carlo algorithms and codes.

   hep-latPoS(2023)·3 citations
3. 03*

   Aspects of scaling and scalability for flow-based sampling of lattice QCD

   Ryan Abbott🇺🇸 · Michael S. Albergo🇺🇸 · Aleksandar Botev🇬🇧 · Denis Boyda🇺🇸 · Kyle Cranmer🇺🇸 · Daniel C. Hackett🇺🇸 · Alexander G. D. G. Matthews🇬🇧 · Sébastien Racanière🇬🇧 · Ali Razavi🇬🇧 · Danilo J. Rezende🇬🇧 · Fernando Romero-López🇺🇸 · Phiala E. Shanahan🇺🇸 · Julian M. Urban🇺🇸

   Recent applications of machine-learned normalizing flows to sampling in lattice field theory suggest that such methods may be able to mitigate critical slowing down and topological freezing. However, these demonstrations have been at the scale of toy models, and it remains to be determined whether they can be applied to state-of-the-art lattice quantum chromodynamics calculations. Assessing the viability of sampling algorithms for lattice field theory at scale has traditionally been accomplished using simple cost scaling laws, but as we discuss in this work, their utility is limited for flow-based approaches. We conclude that flow-based approaches to sampling are better thought of as a broad family of algorithms with different scaling properties, and that scalability must be assessed experimentally.

   hep-latcond-mat.stat-mechcs.LGEPJA(2023)·53 citations
4. 04*

   Screened massive expansion of Schwinger-Dyson equations

   Fabio Siringo🇮🇹

   A general formal derivation of the screened massive expansion is provided by Schwinger-Dyson equations. Some known issues of the expansion are clarified and a more general framework is established for a natural extension of the method to two-loop or to amplitudes which are not directly defined by a generating functional. For instance, a one-loop screened expansion is given for the effective gauge-parameter-independent gluon propagator which arises from the pinch-technique.

   ↳ hep-phhep-lathep-thPRD(2023)·4 citations
5. 05*

   A novel approach to semileptonic heavy-to-light $B$ decays through the Dispersive Matrix method

   Guido Martinelli🇮🇹 · Silvano Simula🇮🇹 · Ludovico Vittorio🇫🇷

   In this contribution we analyse the heavy-to-light $B$ decays through the Dispersive Matrix method, which can be applied to any semileptonic decays of hadrons once lattice QCD computations of the hadronic Form Factors and of the relevant susceptibilities are available. We will explicitly discuss the application of the Dispersive Matrix approach to both $B\to \pi \ell {\nu }_{\ell }$ and $B_s\to K\ell {\nu }_{\ell }$ decays. As usual in our analysis strategy, only LQCD computations of the FFs at high values of the momentum transfer will be used to determine the shape of the FFs in the whole kinematical range without making any assumption on their momentum dependence. Then, the experimental data will be used only to obtain our final exclusive determinations of $|V_{ub}|$. In this way, our calculation of the FFs allows to obtain pure theoretical estimates of several quantities of phenomenological interest, for instance the $\tau /\mu$ ratio of the differential decay rates $R_{\pi (K)}^{\tau /\mu }$, which is an important tool for testing Lepton Flavour Universality. We will also present a summary of all the results obtained so far for semileptonic $B$ decays within the Dispersive Matrix approach.

   ↳ hep-phhep-exhep-latPoS(2023)·1 citation

* 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.