Mon·Dec 13, 2021Monday·December 13, 2021

1. 01*

   Comparison of topology changing update algorithms

   Timo Eichhorn🇩🇪 · Christian Hoelbling🇩🇪

   In modern lattice simulations, conventional update algorithms do not allow for tunneling between topological sectors at fine lattice spacings. We compare the viability of multiple less commonly used algorithms (metadynamics, instanton updates, and multiscale thermalization) with respect to proper sampling of all topological sectors in the Schwinger model. We briefly comment on the prospects of applying these methods to 4-dimensional SU(3) simulations.

   hep-latPoS(2022)·16 citations
2. 02*

   Tensor Charges and their Impact on Physics Beyond the Standard Model

   R. E. Smail🇦🇺 · R. Horsley🇬🇧 · Y. Nakamura🇯🇵 · H. Perlt🇩🇪 · D. Pleiter🇸🇪 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben🇩🇪 · R. D. Young🇦🇺 · J. M. Zanotti🇦🇺

   The nucleon tensor charge, $g_T$, is an important quantity in the search for beyond the Standard Model tensor interactions in neutron and nuclear $\beta$-decays as well as the contribution of the quark electric dipole moment (EDM) to the neutron EDM. We present results from the QCDSF/UKQCD/CSSM collaboration for the tensor charge, $g_T$, using lattice QCD methods and the Feynman-Hellmann theorem. We use a flavour symmetry breaking method to systematically approach the physical quark mass using ensembles that span three lattice spacings.

   hep-latPoS(2022)·2 citations
3. 03*

   Non-perturbative thermal QCD at all temperatures: the case of mesonic screening masses

   Mattia Dalla Brida🇨🇭 · Leonardo Giusti🇮🇹 · Tim Harris🇬🇧 · Davide Laudicina🇮🇹 · Michele Pepe🇮🇹

   We present a strategy based on the step-scaling technique to study non-perturbatively thermal QCD up to very high temperatures. As a first concrete application, we compute the flavour non-singlet meson screening masses at 12 temperatures covering the range from $T\sim 1$ GeV up to $\sim 160$ GeV in the theory with three massless quarks. The calculation is carried out by Monte Carlo simulations on the lattice by considering large spatial extensions in order to have negligible finite volume effects. For each temperature we have simulated 3 or 4 values of the lattice spacing, so as to perform the continuum limit extrapolation with confidence at a few permille accuracy. Chiral symmetry restoration manifests itself in our results through the degeneracy of the vector and the axial vector channels and of the scalar and the pseudoscalar ones. In the entire range of temperatures explored, the meson screening masses deviate from the free theory result, $2\pi T$, by at most a few percent. These deviations, however, cannot be explained by the known leading term in the QCD coupling constant $g$ up to the highest temperature, where other contributions are still very relevant. In particular the vector-pseudoscalar mass splitting turns out to be of $O(g^4)$ in the entire range explored, and it remains clearly visible up to the highest temperature, where the two screening masses are still significantly different within our numerical precision. The pattern of different contributions that we have found explains why it has been difficult in the past to match non-perturbative lattice results at $T\sim 1$ GeV with the analytic behaviour at asymptotically high temperatures.

   hep-lathep-exhep-phnucl-thJHEP(2022)·50 citations
4. 04*

   Localization at the quenched SU(3) phase transition

   Tamas G. Kovacs (Eotvos U. and Debrecen, Inst. Nucl. Res.)🇭🇺

   It is known that the deconfining transition of QCD is accompanied by the appearance of localized eigenmodes at the low end of the Dirac spectrum. In the quenched case localization appears exactly at the critical temperature of deconfinement. In the present work, using quenched simulations exactly at the critical temperature, we show that the localization properties of low Dirac modes change abruptly between the confined and deconfined phase. This means that in the real Polyakov loop sector, the mobility edge has a discontinuity at the critical temperature. In contrast, in the complex sector, there is no such discontinuity at $T_c$, even the lowest Dirac modes remain delocalized at the critical temperature in the deconfined phase.

   hep-lathep-phhep-thPoS(2022)·9 citations
5. 05*

   First Lattice QCD Study of Proton Twist-3 GPDs

   Shohini Bhattacharya🇺🇸 · Krzysztof Cichy🇵🇱 · Martha Constantinou🇺🇸 · Jack Dodson🇸🇪 · Andreas Metz🇺🇸 · Aurora Scapellato🇺🇸 · Fernanda Steffens🇩🇪

   We present first results on selected twist-3 quark GPDs using the quasi-distribution method. This approach relates lattice QCD data and light-cone distribution functions using Large Momentum Effective Theory (LaMET). We calculate quark-antiquark correlators of boosted nucleons coupled to non-local operators with vector and axial Dirac structure, which is transverse to the momentum boost. We use three values of the momentum boost, namely 0.83, 1.25, 1.67 GeV. The GPDs are defined in the symmetric (Breit) frame, which we implement here with 4-vector momentum transfer squared of 0, 0.69 and 1.39 GeV 2 , all at zero skewness. The calculation is performed using one ensemble of two degenerate light, a strange and a charm quark ($N_f$ = 2 + 1 + 1) of maximally twisted mass fermions with a clover term, corresponding to a pion mass of 260 MeV.

   hep-lathep-phnucl-thPoS(2022)·25 citations
6. 06*

   Quantum Error Correction with Gauge Symmetries

   Abhishek Rajput🇺🇸 · Alessandro Roggero🇺🇸 · Nathan Wiebe🇨🇦

   Quantum simulations of Lattice Gauge Theories (LGTs) are often formulated on an enlarged Hilbert space containing both physical and unphysical sectors in order to retain a local Hamiltonian. We provide simple fault-tolerant procedures that exploit such redundancy by combining a phase flip error correction code with the Gauss' law constraint to correct one-qubit errors for a ${\mathbb{Z}}_2$ or truncated U(1) LGT in 1+1 and 2+1 dimensions with a link flux cutoff of $1$. Unlike existing work on detecting violations of Gauss' law, our circuits are fault tolerant and the overall error correction scheme outperforms a naïve application of the $[5,1,3]$ code. The constructions outlined can be extended to LGT systems with larger cutoffs and may be of use in understanding how to hybridize error correction and quantum simulation for LGTs in higher space-time dimensions and with different symmetry groups.

   ↳ quant-phhep-latnpj Quantum Inf.(2023)·52 citations
7. 07*

   Neural quantum states for supersymmetric quantum gauge theories

   Xizhi Han🇺🇸 · Enrico Rinaldi🇯🇵

   Supersymmetric quantum gauge theories are important mathematical tools in high energy physics. As an example, supersymmetric matrix models can be used as a holographic description of quantum black holes. The wave function of such supersymmetric gauge theories is not known and it is challenging to obtain with traditional techniques. We employ a neural quantum state ansatz for the wave function of a supersymmetric matrix model and use a variational quantum Monte Carlo approach to discover the ground state of the system. We discuss the difficulty of including bosonic particles and fermionic particles, as well as gauge degrees of freedom.

   ↳ hep-thhep-latquant-ph6 citations
8. 08*

   Hadronic vacuum polarization contributions to the muon $g$-2 in the space-like region

   Elisa Balzani🇮🇹 · Stefano Laporta🇮🇹 · Massimo Passera🇮🇹

   We present simple analytic expressions to compute the hadronic vacuum polarization contribution to the muon $g$-2 in the space-like region up to next-to-next-to-leading order. These results can be employed in lattice QCD calculations of this contribution as well as in space-like determinations based on scattering data, like that expected from the proposed MUonE experiment at CERN.

   ↳ hep-phhep-latPLB(2022)·31 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.