Thu·Dec 15, 2022Thursday·December 15, 2022

1. 01*

   Simulating 2+1D Lattice Quantum Electrodynamics at Finite Density with Neural Flow Wavefunctions

   Zhuo Chen🇺🇸 · Di Luo🇺🇸 · Kaiwen Hu🇺🇸 · Bryan K. Clark🇺🇸

   We present a neural flow wavefunction, Gauge-Fermion FlowNet, and use it to simulate 2+1D lattice compact quantum electrodynamics with finite density dynamical fermions. The gauge field is represented by a neural network which parameterizes a discretized flow-based transformation of the amplitude while the fermionic sign structure is represented by a neural net backflow. This approach directly represents the $U(1)$ degree of freedom without any truncation, obeys Guass's law by construction, samples autoregressively avoiding any equilibration time, and variationally simulates Gauge-Fermion systems with sign problems accurately. In this model, we investigate confinement and string breaking phenomena in different fermion density and hopping regimes. We study the phase transition from the charge crystal phase to the vacuum phase at zero density, and observe the phase seperation and the net charge penetration blocking effect under magnetic interaction at finite density. In addition, we investigate a magnetic phase transition due to the competition effect between the kinetic energy of fermions and the magnetic energy of the gauge field. With our method, we further note potential differences on the order of the phase transitions between a continuous $U(1)$ system and one with finite truncation. Our state-of-the-art neural network approach opens up new possibilities to study different gauge theories coupled to dynamical matter in higher dimensions.

   hep-latcond-mat.str-elcs.LGphysics.comp-ph+119 citations
2. 02*

   Symmetry Breaking in an Extended-O(2) Model

   Leon Hostetler🇺🇸 · Ryo Sakai🇺🇸 · Jin Zhang🇺🇸 · Judah Unmuth-Yockey🇺🇸 · Alexei Bazavov🇺🇸 · Yannick Meurice🇺🇸

   Motivated by attempts to quantum simulate lattice models with continuous Abelian symmetries using discrete approximations, we consider an extended-O(2) model that differs from the ordinary O(2) model by an explicit symmetry breaking term. Its coupling allows to smoothly interpolate between the O(2) model (zero coupling) and a $q$-state clock model (infinite coupling). In the latter case, a $q$-state clock model can also be defined for non-integer values of $q$. Thus, such a limit can also be considered as an analytic continuation of an ordinary $q$-state clock model to non-integer $q$. The phase diagram of the extended-O(2) model in the infinite coupling limit was established in our previous work, where it was shown that for non-integer $q$, there is a second-order phase transition at low temperature and a crossover at high temperature. In this work, we investigate the model at finite values of the coupling using Monte Carlo and tensor methods. The results may be relevant for configurable Rydberg-atom arrays.

   hep-latcond-mat.stat-mechphysics.comp-phPoS(2022)·3 citations
3. 03*

   Disconnected contribution to the LO HVP term of muon g-2 from ETMC

   Constantia Alexandrou🇨🇾 · Simone Bacchio🇨🇾 · Petros Dimopoulos🇮🇹 · Jacob Finkenrath🇨🇾 · Roberto Frezzotti🇮🇹 · Giuseppe Gagliardi🇮🇹 · Marco Garofalo🇩🇪 · Kyriakos Hadjiyiannakou🇨🇾 · Bartosz Kostrzewa🇩🇪 · Karl Jansen🇩🇪 · Vittorio Lubicz🇮🇹 · Marcus Petschlies🇩🇪 and 4 other authors

   We present a lattice determination of the disconnected contributions to the leading-order hadronic vacuum polarization (HVP) to the muon anomalous magnetic moment in the so-called short and intermediate time-distance windows. We employ gauge ensembles produced by the Extended Twisted Mass Collaboration (ETMC) with $N_f=2+1+1$ flavours of Wilson twisted-mass clover-improved quarks with masses approximately tuned to their physical value. We take the continuum limit employing three lattice spacings at about 0.08, 0.07 and 0.06 fm.

   hep-latPoS(2023)·2 citations
4. 04*

   Setting the Scale Using Baryon Masses with Isospin-Breaking Corrections

   Alexander M. Segner🇩🇪 · Andrew D. Hanlon🇺🇸 · Andreas Risch🇩🇪 · Hartmut Wittig🇩🇪

   We present the status of an ongoing project aimed at the inclusion of isospin-breaking corrections arising from the non-degeneracy of the light quark masses and electromagnetic interactions in calculations of the low-lying octet and decuplet baryon masses. Our ultimate goal is to perform a precision determination of the lattice scale including isospin-breaking effects. We apply the perturbative formalism to isospin-symmetric $N_f=2+1$ CLS ensembles. We show results on baryon masses up to leading order in isospin-breaking corrections on two ensembles with $m_{\pi }\approx 290\text{MeV}$ and $m_{\pi }\approx 215\text{MeV}$ at a lattice spacing of $a\approx 0.076\text{fm}$.

   hep-latPoS(2023)·4 citations
5. 05*

   Gauge generation and dissemination in OpenLat

   Francesca Cuteri🇩🇪 · Anthony Francis🇹🇼 · Patrick Fritzsch🇮🇪 · Giovanni Pederiva🇩🇪 · Antonio Rago🇩🇰 · Andrea Shindler🇺🇸 · Andre Walker-Loud🇺🇸 · Savvas Zafeiropoulos🇫🇷

   In this contribution we report the status and plans of the open lattice initiative to generate and share new gauge ensembles using the stabilised Wilson fermion framework. The production strategy is presented in terms of a three stage plan alongside summaries of the data management as well as access policies. Current progress in completing the first stage of generating ensembles at four lattice spacings at the flavor symmetric point is given.

   hep-latPoS(2023)·12 citations
6. 06*

   Hausdorff dimension of fermions on a random lattice

   Mattia Varrone🇬🇧 · William E V Barker🇬🇧

   Geometric properties of lattice quantum gravity in two dimensions are studied numerically via Monte Carlo on Euclidean Dynamical Triangulations. A new computational method is proposed to simulate gravity coupled with fermions, which allows the study of interacting theories on a lattice, such as non-Riemannian gravity models. This was tested on Majorana spinors, where we obtained a Hausdorff dimension dW = 4.22 +/- 0.03, consistent with the bounds from the literature 4.19 < dH < 4.21.

   hep-latNPB(2024)·0 citations
7. 07*

   Effective Hamiltonians and Counterterms for Hamiltonian Truncation

   Joan Elias Miro🇮🇹 · James Ingoldby🇮🇹

   We outline a procedure for applying Hamiltonian Truncation to Quantum Field Theories (QFTs) that have UV divergences. To do this, we derive a novel representation of an Effective Hamiltonian which makes manifest some of its important properties (e.g. the non-perturbative matching of the spectra between the UV theory and the theory described by the Effective Hamiltonian). We check the consistency of our procedure using Conformal Perturbation Theory. Finally we comment on how the Effective Hamiltonian, which incorporates non-local interactions, describes a local QFT.

   ↳ hep-thcond-mat.stat-mechhep-lathep-phJHEP(2023)·18 citations
8. 08*

   Gravitational transition form factors of $N\to \Delta$ via QCD light-cone sum rules

   U. Özdem🇹🇷 · K. Azizi🇮🇷

   We present the first direct calculation on the gravitational form factors (GFFs) of the $N\to \Delta$ transition using an analytic method, the QCD light-cone sum rules. The matrix element of the quark part of the energy momentum tensor current sandwiched between the nucleon and $\Delta$ states are parameterized in terms of five independent conserved and four independent non-conserved GFFs, for calculation of which we use the distribution amplitudes (DAs) of the on-shell nucleon expanded in terms of functions with different twists. We present the results for two sets of light-cone input parameters. The results indicate that the behavior of the form factors with respect to $Q^2$ are described by multipole fit functions. Our results may be checked by other phenomenological models including the Lattice QCD as well as future related experiments.

   ↳ hep-phhep-exhep-latJHEP(2023)·19 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.