Wed·Oct 6, 2021Wednesday·October 6, 2021

1. 01*

   Critical dynamics of relativistic diffusion

   Dominik Schweitzer🇩🇪 · Sören Schlichting🇩🇪 · Lorenz von Smekal🇩🇪

   We study the dynamics of self-interacting scalar fields with $Z_2$ symmetry governed by a relativistic Israel-Stuart type diffusion equation in the vicinity of a critical point. We calculate spectral functions of the order parameter in mean-field approximation as well as using first-principles classical-statistical lattice simulations in real-time. We observe that the spectral functions are well-described by single Breit-Wigner shapes. Away from criticality, the dispersion matches the expectations from the mean-field approach. At the critical point, the spectral functions largely keep their Breit-Wigner shape, albeit with non-trivial power-law dispersion relations. We extract the characteristic time-scales as well as the dynamic critical exponent $z$, verifying the existence of a dynamic scaling regime. In addition, we derive the universal scaling functions implied by the Breit-Wigner shape with critical power-law dispersion and show that they match the data. Considering equations of motion for a system coupled to a heat bath as well as an isolated system, we perform this study for two different dynamic universality classes, both in two and three spatial dimensions.

   hep-latcond-mat.stat-mechhep-phnucl-thNPB(2022)·25 citations
2. 02*

   Annihilation diagram contribution to charmonium masses

   Renqiang Zhang🇨🇳 · Wei Sun🇨🇳 · Feiyu Chen🇨🇳 · Ying Chen🇨🇳 · Ming Gong🇨🇳 · Xiangyu Jiang🇨🇳 · Zhaofeng Liu🇨🇳

   In this work, we generate gauge configurations with $N_f=2$ dynamical charm quarks on anisotropic lattices. The mass shift of $1S$ and $1P$ charmonia owing to the charm quark annihilation effect can be investigated directly in a manner of unitary theory. The distillation method is adopted to treat the charm quark annihilation diagrams at a very precise level. For $1S$ charmonia, the charm quark annihilation effect almost does not change the $J/\psi$ mass, but lifts the ${\eta }_c$ mass by approximately 3-4 MeV. For $1P$ charmonia, this effect results in positive mass shifts of approximately 1 MeV for ${\chi }_{c1}$ and $h_c$, but decreases the ${\chi }_{c2}$ mass by approximately 3 MeV. We have not obtain a reliable result for the mass shift of ${\chi }_{c0}$. In addition, it is observed that the spin averaged mass of the spin-triplet $1P$ charmonia is in a good agreement with the $h_c$, as expected by the non-relativistic quark model and measured by experiments.

   hep-lathep-exCPC(2022)·12 citations
3. 03*

   The Evolution of Lattice Field Theory: a Statistical Study

   Wolfgang Bietenholz🇲🇽

   Researchers working in lattice field theory constitute an established community since the early 1990s, and around the same time the online open-access e-print repository arXiv was created. The fact that this field has a specific arXiv section, hep-lat, provides a unique opportunity for a statistical study of its evolution over the last three decades. We present data for the number of entries, $E$, published papers, $P$, and citations, $C$, in total and separated by nations. We compare them to 6 other arXiv sections, and to socio-economic indices of the nations involved, namely the Gross Domestic Product (GDP) and the Education Index (EI). We present rankings, which are based either on the Hirsch Index $H$, or on the linear combination $\Sigma =E+P+0.05C$. We consider both extensive and intensive national statistics, i.e. absolute and relative to the population or to the GDP.

   hep-latphysics.hist-phPoS(2022)·2 citations
4. 04*

   Phase diagram and Higgs phases of 3D lattice SU(Nc) gauge theories with multiparameter scalar potentials

   Claudio Bonati🇮🇹 · Alessio Franchi🇮🇹 · Andrea Pelissetto🇮🇹 · Ettore Vicari🇮🇹

   We consider three-dimensional lattice SU(Nc) gauge theories with degenerate multicomponent (Nf>1) complex scalar fields that transform under the fundamental representation of the gauge SU(Nc) group and of the global U(Nf) invariance group, interacting with the most general quartic potential compatible with the global (flavor) and gauge (color) symmetries. We investigate the phase diagrams, identifying the low-temperature Higgs phases and their global and gauge symmetries, and the critical behaviors along the different transition lines. In particular, we address the role of the quartic scalar potential, which determines the Higgs phases and the corresponding symmetry-breaking patterns. Our study is based on the analysis of the minimum-energy configurations and on numerical Monte Carlo simulations. Moreover, we investigate whether some of the transitions observed in the lattice model can be related to the behavior of the renormalization-group flow of the continuum field theory with the same symmetries and field content around its stable charged fixed points. For Nc=2, numerical results are consistent with the existence of charged critical behaviors for Nf > Nf*, with 20 < Nf* < 40.

   ↳ cond-mat.stat-mechhep-latPRE(2021)·20 citations
5. 05*

   Circuit realization of tilted Dirac cone: A platform for fabrication of curved spacetime geometry on a chip

   A. Motavassal🇮🇷 · S. A. Jafari🇮🇷

   We present a LC circuit model that supports tilted {\it Dirac cone} in its spectrum. The tilt of the Dirac cone is specified by the parameters of the model consisting of mutual inductance between the neighboring sites and a capacitance C0 at every lattice site. These parameters can be completely measured by impedance spectroscopy. Given that a tilted Dirac cone can be described by a background spacetime metric, the impedance spectroscopy can perfectly provide (local) information about the metric of the spacetime. Non-uniform spatial dependence of the mutual inductance or capacitance induces non-trivial geometrical structure on the emergent spacetime.

   ↳ cond-mat.str-elcond-mat.dis-nngr-qchep-lat+1PRB(2021)·9 citations
6. 06*

   Peaks of sound velocity in two color dense QCD: quark saturation effects and semishort range correlations

   Toru Kojo🇨🇳 · Daiki Suenaga🇯🇵

   We discuss stiffening of dense matter in two color QCD (QC${}_2$D) where hadrons are mesons and diquark baryons. We study two models which describe a transition of matter from the Bose-Einstein-Condensation regime at low density to the Bardeen-Cooper-Schrieffer regime at high density. The first model is based on coherent states of diquarks, and the second is the Nambu-Jona-Lasinio model with diquark pairing terms. We particularly focus on how quark states are occupied as baryon density increases. We find that, due to the occupied quark levels, the ideal gas picture of diquarks breaks down at density significantly less than the density where baryon cores overlap. The saturation of quark states at low momenta stiffens equations of state. We also study the effects of interactions which depend on the quark occupation probability. We argue that equations of state become very stiff when the bulk part of the quark Fermi sea has the effective repulsion but the Fermi surface enjoys the attractive correlations. This disparity for different momentum domains is possible due to the strong channel dependence in gluon exchanges with momentum transfer of $0.2-1$ GeV. These concepts can be transferred from QC${}_2$D to QCD in any numbers of colors.

   ↳ hep-phastro-ph.HEhep-latnucl-thPRD(2022)·54 citations
7. 07*

   Anomalies and phases of strongly-coupled chiral gauge theories: recent developments

   Stefano Bolognesi🇮🇹 · Kenichi Konishi🇮🇹 · Andrea Luzio🇮🇹

   After many years of investigations, our understanding of the dynamics of strongly-coupled chiral gauge theories is still quite unsatisfactory today. Conventional wisdom about strongly-coupled gauge theories, successfully applied to QCD, is not always as useful in chiral gauge theories. Recently some new ideas and techniques have been developed, which involve concepts of generalized symmetries, of gauging a discrete center symmetry, and of generalizing the 't Hooft anomaly matching constraints to include certain mixed symmetries. This new development has been applied to chiral gauge theories, leading to many interesting, sometimes quite unexpected, results. For instance, in the context of generalized Bars-Yankielowicz and generalized Georgi-Glashow models, these new types of anomalies give a rather clear indication in favor of the dynamical Higgs phase, against confining, flavor symmetric vacua. Another closely related topics is strong anomaly and the effective low-energy action representing it. It turns out that they have significant implications on the phase of chiral gauge theories, giving indications consistent with the findings based on the generalized anomalies. Some striking analogies and contrasts between the massless QCD and chiral gauge theories seem to emerge from these discussions. The aim of this work is to review these developments.

   ↳ hep-thhep-lathep-phInt.J.Mod.Phys.A(2022)·19 citations
8. 08*

   Lossy compression of statistical data using quantum annealer

   Boram Yoon🇺🇸 · Nga T.T. Nguyen🇺🇸 · Chia Cheng Chang🇯🇵 · Ermal Rrapaj🇺🇸

   We present a new lossy compression algorithm for statistical floating-point data through a representation learning with binary variables. The algorithm finds a set of basis vectors and their binary coefficients that precisely reconstruct the original data. The optimization for the basis vectors is performed classically, while binary coefficients are retrieved through both simulated and quantum annealing for comparison. A bias correction procedure is also presented to estimate and eliminate the error and bias introduced from the inexact reconstruction of the lossy compression for statistical data analyses. The compression algorithm is demonstrated on two different datasets of lattice quantum chromodynamics simulations. The results obtained using simulated annealing show 3.5 times better compression performance than the algorithms based on a neural-network autoencoder and principal component analysis. Calculations using quantum annealing also show promising results, but performance is limited by the integrated control error of the quantum processing unit, which yields large uncertainties in the biases and coupling parameters. Hardware comparison is further studied between the previous generation D-Wave 2000Q and the current D-Wave Advantage system. Our study shows that the Advantage system is more likely to obtain low-energy solutions for the problems than the 2000Q.

   ↳ quant-phhep-latstat.MLSci.Rep.(2022)·9 citations
9. 09*

   Analytical structure of the equation of state at finite density: Resummation versus expansion in a low energy model

   Swagato Mukherjee🇺🇸 · Fabian Rennecke🇩🇪 · Vladimir V. Skokov🇺🇸

   For theories plagued with a sign problem at finite density, a Taylor expansion in the chemical potential is frequently used for lattice gauge theory based computations of the equation of state. Recently, in arXiv:2106.03165, a new resummation scheme was proposed for such an expansion that resums contributions of correlation functions of conserved currents to all orders in the chemical potential. Here, we study the efficacy of this resummation scheme using a solvable low energy model, namely the mean-field quark-meson model. After adapting the scheme for a mean-field analysis, we confront the results of this scheme with the direct solution of the model at finite density as well as compare with results from Taylor expansions. We study to what extent the two methods capture the analytical properties of the equation of state in the complex chemical potential plane. As expected, the Taylor expansion breaks down as soon as the baryon chemical potential reaches the radius of convergence defined by the Yang-Lee edge singularity. Encouragingly, the resummation not only captures the location of the Yang-Lee edge singularity accurately, but is also able to describe the equation of state for larger chemical potentials beyond the location of the edge singularity for a wide range of temperatures.

   ↳ hep-phhep-lathep-thnucl-thPRD(2022)·29 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.