Thu·Sep 23, 2021Thursday·September 23, 2021

1. 01*

   Monopole-like configurations in the O(3) spin model at the upper critical dimension

   Marco Panero🇮🇹 · Antonio Smecca🇮🇹

   We present a high-precision Monte Carlo study of the O(3) spin theory on the lattice in four dimensions. This model exhibits interesting dynamical features, in particular in the broken-symmetry phase, where suitable boundary conditions can be used to enforce monopole-like topological excitations. We investigate the Euclidean time propagation and the features of these excitations close to the critical point, where our numerical results show an excellent quantitative agreement with analytic predictions derived from purely quantum-field-theoretical tools by G. Delfino. We conclude by commenting on the implications of our findings for a conjectured violation of Derrick's theorem at the quantum level and on the consequences in various areas of physics, ranging from condensed matter to astro-particle physics.

   hep-latPoS(2022)·1 citation
2. 02*

   102 PFLOPS Lattice QCD quark solver on Fugaku

   Ken-Ichi Ishikawa🇯🇵 · Issaku Kanamori🇯🇵 · Hideo Matsufuru🇯🇵 · Ikuo Miyoshi🇯🇵 · Yuta Mukai🇯🇵 · Yoshifumi Nakamura🇯🇵 · Keigo Nitadori🇯🇵 · Miwako Tsuji🇯🇵

   We present results on the world's first over 100 PFLOPS single precision lattice QCD quark solver on the japanese new supercomputer Fugaku. We achieve a factor 38 time speedup from the supercomputer K on the same problem size, $192^4$, with 102 PFLOPS, 10% floating-point operation efficiency against single precision floating-point operation peak. The evaluation region is the single precision BiCGStab for a Clover-Wilson Dirac matrix with Schwarz Alternating Procedure domain decomposition preconditioning using Jacobi iteration for the local domain matrix inversion.

   hep-latComput.Phys.Commun.(2023)·15 citations
3. 03*

   Quark and gluon momentum fractions in the pion from $N_f=2+1+1$ lattice QCD

   Constantia Alexandrou🇨🇾 · Simone Bacchio🇨🇾 · Georg Bergner🇩🇪 · Jacob Finkenrath🇨🇾 · Andrew Gasbarro🇨🇭 · Kyriakos Hadjiyiannakou🇨🇾 · Karl Jansen🇩🇪 · Bartosz Kostrzewa🇩🇪 · Konstantin Ottnad🇩🇪 · Marcus Petschlies🇩🇪 · Ferenc Pittler🇨🇾 · Fernanda Steffens🇩🇪 · Carsten Urbach🇩🇪 · Urs Wenger🇨🇭

   We perform the first full decomposition of the pion momentum into its gluon and quark contributions. We employ an ensemble generated by the Extended Twisted Mass Collaboration with $N_f=2+1+1$ Wilson twisted mass clover fermions at maximal twist tuned to reproduce the physical pion mass. We present our results in the $\overline{\mathrm{MS}}$ scheme at $2\text{gev}$. We find ${\text{avgx}}_{u+d}=0.601(28)$, ${\text{avgx}}_s=0.059(13)$, ${\text{avgx}}_c=0.019(05)$, and ${\text{avgx}}_g=0.52(11)$ for the separate contributions, respectively, whose sum saturates the momentum sum rule.

   hep-lathep-phPRL(2021)·18 citations
4. 04*

   Chiral theory of $\rho$-meson gravitational form factors

   E. Epelbaum🇩🇪 · J. Gegelia🇩🇪 · U.-G. Meißner🇩🇪 · M. V. Polyakov🇩🇪

   The low-energy chiral effective field theory of vector mesons and Goldstone bosons in external gravitational field is considered. The energy-momentum tensor is obtained and the gravitational form factors of the $\rho$-meson are calculated up to next-to-leading order in the chiral expansion. This amounts to considering tree-level and one-loop order diagrams. The chiral expansion of the form factors at zero momentum transfer as well as of the slope parameters is worked out. Also, the long-range behaviour of the energy and internal force distributions is obtained and analysed.

   ↳ hep-phhep-lathep-thnucl-thPRD(2022)·21 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.