Thu·Dec 2, 2021Thursday·December 2, 2021

1. 01*

   Dual Polyakov loop model at finite density: phase diagram and screening masses

   Oleg Borisenko🇺🇦 · Volodymyr Chelnokov🇩🇪 · Emanuele Mendicelli🇨🇦 · Alessandro Papa🇮🇹

   We consider a dual representation of an effective three-dimensional Polyakov loop model for the SU(3) theory at nonzero real chemical potential. This representation is free of the sign problem and can be used for numeric Monte-Carlo simulations. These simulations allow us to locate the line of second order phase transitions, that separates the region of first order phase transition from the crossover one. The behavior of local observables in different phases of the model is studied numerically and compared with predictions of the mean-field analysis. Our dual formulation allows us to study also Polyakov loop correlation functions. From these results, we extract the screening masses and compare them with large-N predictions.

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

   Thimble regularisation of YM fields: crunching a hard problem

   Francesco Di Renzo (Parma Univ. and INFN, Parma)🇮🇹 · Simran Singh (Parma Univ. and INFN, Parma)🇮🇹 · Kevin Zambello (Parma Univ. and INFN, Parma)🇮🇹

   Thimble regularisation of Yang Mills theories is still to a very large extent terra incognita. We discuss a couple of topics related to this big issue. 2d YM theories are in principle good candidates as a working ground. An analytic solution is known, for which one can switch from a solution in terms of a sum over characters to a form which is a sum over critical points. We would be interested in an explicit realisation of this mechanism in the lattice regularisation, which is actually quite hard to work out. A second topic is the inclusion of a topological term in the lattice theory, which is the prototype of a genuine sign problem for pure YM fields. For both these challenging problems we do not have final answers. We present the current status of our study.

   hep-lathep-thPoS(2022)·1 citation
3. 03*

   Equation of state of QCD at finite chemical potential from an alternative expansion scheme

   Paolo Parotto🇩🇪 · Szabolcs Borsanyi🇩🇪 · Zoltan Fodor🇩🇪 · Jana N. Guenther🇩🇪 · Ruben Kara🇩🇪 · Sandor D. Katz🇭🇺 · Attila Pasztor🇭🇺 · Claudia Ratti🇺🇸 · Kalman K. Szabo🇩🇪

   The equation of state of Quantum Chromodynamics (QCD) at finite density is currently known only in a limited range in the baryon chemical potential ${\mu }_B$. This is due to fundamental shortcomings of traditional methods such as Taylor expansion around ${\mu }_B=0$. In this contribution, we present an alternative scheme that displays substantially improved convergence over the Taylor expansion method. We calculate the alternative expansion coefficients in the continuum, and show our results for the thermodynamic observables up to ${\mu }_B/T\le 3.5$.

   hep-lathep-phnucl-thPoS(2022)·1 citation
4. 04*

   Isovector Axial Vector Form Factors of the Nucleon from Lattice QCD with $N_f=2+1$ $\mathcal{O}(a)$-improved Wilson Fermions

   Dalibor Djukanovic🇩🇪 · Georg von Hippel🇩🇪 · Jonna Koponen🇩🇪 · Harvey B. Meyer🇩🇪 · Konstantin Ottnad🇩🇪 · Tobias Schulz🇩🇪 · Hartmut Wittig🇩🇪

   We present the analysis of isovector axial vector nucleon form factors on a set of $N_f=2+1$ CLS ensembles with $\mathcal{O}(a)$-improved Wilson fermions and Lüscher-Weisz gauge action. The set of ensembles covers a pion mass range of $130-353$MeV with lattice spacings between $0.05$fm and $0.09$fm. In particular, the set includes a $L/a=96$ ensemble at the physical pion mass. For the purpose of the form factor extraction, we employ both the summed operator insertion method (summation method) and explicit two-state fits in order to account for excited-state contributions to the nucleon correlation functions. To describe the $Q^2$-behavior of the form factors, we perform $z$-expansion fits. Finally, we present HBChPT-inspired chiral and continuum extrapolations of the axial charge and radius.

   hep-latPoS(2022)·7 citations
5. 05*

   Recent progress on nucleon form factors

   Dalibor Djukanovic🇩🇪

   The form factors of the nucleon provide key information on nucleon properties. When confronted with precisely measured observables from experiments, they serve as benchmark quantities for lattice calculations. On the other hand lattice determinations may serve as vital theory input for the interpretation of experiments, e.g. in neutrino-nucleus scattering. I review recent progress in the calculation of nucleon form factors on the lattice and its relevance to future experiments.

   hep-lathep-phnucl-thPoS(2022)·11 citations
6. 06*

   Flavor number dependence of QCD at finite density by the complex Langevin method

   Yusuke Namekawa🇯🇵 · Yuhma Asano🇯🇵 · Yuta Ito🇯🇵 · Takashi Kaneko🇯🇵 · Hideo Matsufuru🇯🇵 · Jun Nishimura🇯🇵 · Asato Tsuchiya🇯🇵 · Shoichiro Tsutsui🇯🇵 · Takeru Yokota🇯🇵

   We discuss the flavor number dependence of QCD at low temperature and high density by the complex Langevin method. In our previous work, the complex Langevin method is confirmed to satisfy the criterion for correct convergence in certain regions, such as ${\mu }_{\mathrm{q}}/T=5.2-7.2$ on $8^3\times 16$ and ${\mu }_{\mathrm{q}}/T=1.6-9.6$ on $16^3\times 32$ using $N_{\mathrm{f}}=4$ staggered fermion at $\beta =5.7$. We extend this study to more realistic flavor cases, $N_{\mathrm{f}}=2,2+1,3$, using Wilson fermions. We present the flavor number dependence of the validity regions of the complex Langevin method and the quark number.

   hep-lathep-phPoS(2022)·7 citations
7. 07*

   Coulomb corrections to pi-pi scattering

   Norman Christ🇺🇸 · Xu Feng🇨🇳 · Joseph Karpie🇺🇸 · Tuan Nguyen🇺🇸

   The relationship between finite volume multi-hadron energy levels and matrix elements and two particle scattering phase shifts and decays is well known, but the inclusion of long range interactions such as QED is non-trivial. Inclusion of QED is an important systematic error correction to $K\to \pi \pi$ decays. In this talk, we present a method of including a truncated, finite-range Coulomb interaction in a finite-volume lattice QCD calculation. We show how the omission caused by the truncation can be restored by an infinite-volume analytic calculation so that the final result contains no power-law finite-volume errors beyond those usually present in Luscher's finite-volume phase shift determination. This approach allows us to calculate the QED corrected infinite-volume phase shift for $\pi \pi$ scattering in Coulomb gauge, a necessary ingredient to $K\to \pi \pi$, while neglecting the transverse radiation for now.

   hep-latPoS(2022)·3 citations
8. 08*

   Holography for Ising spins on the hyperbolic plane

   Muhammad Asaduzzaman🇺🇸 · Simon Catterall🇺🇸 · Jay Hubisz🇺🇸 · Roice Nelson🇺🇸 · Judah Unmuth-Yockey🇺🇸

   Motivated by the AdS/CFT correspondence, we use Monte Carlo simulation to investigate the Ising model formulated on tessellations of the two-dimensional hyperbolic disk. We focus in particular on the behavior of boundary-boundary correlators, which exhibit power-law scaling both below and above the bulk critical temperature indicating scale invariance of the boundary theory at any temperature. This conclusion is strengthened by a finite-size scaling analysis of the boundary susceptibility which yields a scaling exponent consistent with the scaling dimension extracted from the boundary correlation function. This observation provides evidence that the connection between continuum boundary conformal symmetry and isometries of the bulk hyperbolic space survives for simple interacting field theories even when the bulk is approximated by a discrete tessellation.

   hep-lathep-thphysics.comp-phPRD(2022)·19 citations
9. 09*

   A physicist-friendly reformulation of the Atiyah-Patodi-Singer index (on a lattice)

   Hidenori Fukaya🇯🇵

   The Atiyah-Singer index theorem on a closed manifold is well understood and appreciated in physics. On the other hand, the Atiyah-Patodi-Singer index, which is an extension to a manifold with boundary, is physicist-unfriendly, in that it is formulated with a nonlocal boundary condition. Recently we proved that the same index as APS is obtained from the domain-wall fermion Dirac operator. Our theorem indicates that the index can be expressed without any nonlocal conditions, in such a physicist-friendly way that application to the lattice gauge theory is straightforward. The domain-wall fermion provides a natural mathematical foundation for understanding the bulk-edge correspondence of the anomaly inflow.

   hep-lathep-thPoS(2022)·0 citations
10. 10*

    Correlated Dirac eigenvalues around the transition temperature on $N_{\tau }=8$ lattices

    Heng-Tong Ding🇨🇳 · Wei-Ping Huang🇨🇳 · Min Lin🇨🇳 · Swagato Mukherjee🇺🇸 · Peter Petreczky🇺🇸 · Yu Zhang🇯🇵

    We investigate the criticality of chiral phase transition manifested in the first and second order derivatives of Dirac eigenvalue spectrum with respect to light quark mass in (2+1)-flavor lattice QCD. Simulations are performed at temperatures from about 137 MeV to 176 MeV on $N_{\tau }=8$ lattices using the highly improved staggered quarks and the tree-level improved Symanzik gauge action. The strange quark mass is fixed to its physical value $m_s^{\text{phy}}$ and the light quark mass is set to $m_s^{\text{phy}}/40$ which corresponds to a Goldstone pion mass $m_{\pi }=110$ MeV. We find that in contrast to the case at $T\simeq 205$ MeV $m_l^{-1}\partial \rho (\lambda ,m_l)/\partial m_l$ is no longer equal to ${\partial }^2\rho (\lambda ,m_l)/\partial m_l^2$ and ${\partial }^2\rho (\lambda ,m_l)/\partial m_l^2$ even becomes negative at certain low temperatures. This means that as temperature getting closer to $T_c$ $\rho (\lambda ,m_l)$ is no longer proportional to $m_l^2$ and thus dilute instanton gas approximation is not valid for these temperatures. We demonstrate the temperature dependence can be factored out in $\partial \rho (\lambda ,m_l)/\partial m_l$ and ${\partial }^2\rho (\lambda ,m_l)/\partial m_l^2$ at $T\in [137,153]$ MeV, and then we propose a feasible method to estimate the power $c$ given $\rho \propto m_l^c$.

    hep-latnucl-thPoS(2022)·6 citations
11. 11*

    Deep inelastic scattering off quark-gluon plasma and its photon emissivity

    Marco Cè🇨🇭 · Tim Harris🇬🇧 · Harvey B. Meyer🇩🇪 · Arianna Toniato🇩🇪 · Csaba Török🇩🇪

    The photon emissivity of quark-gluon plasma probes the interactions in the medium and differs qualitatively between a weakly coupled and a strongly coupled plasma in the soft-photon regime. The photon emissivity is given by the product of kinematic factors and a spectral function associated with the two-point correlator of the electromagnetic current at lightlike kinematics. A certain Euclidean correlator at imaginary spatial momentum can be calculated in lattice QCD and is given by an integral over the relevant spectral function at lightlike kinematics. I present a first exploratory lattice calculation of this correlator. Secondly, I show how Euclidean correlators at imaginary spatial momenta can also be used to probe the regime of deep inelastic scattering off quark-gluon plasma, which reveals its parton distribution function.

    hep-lathep-phPoS(2022)·8 citations
12. 12*

    Machine learning Hadron Spectral Functions in Lattice QCD

    Shi-Yang Chen🇨🇳 · Heng-Tong Ding🇨🇳 · Fei-Yi Liu🇨🇳 · Gabor Papp🇭🇺 · Chun-Bin Yang🇨🇳

    Hadron spectral functions carry all the information of hadrons and are encoded in the Euclidean two-point correlation functions. The extraction of hadron spectral functions from the correlator is a typical ill-posed inverse problem and infinite number of solutions to this problem exists. We propose a novel neural network (sVAE) based on the Variation Auto-Encoder (VAE) and Bayesian theorem. Inspired by the maximum entropy method (MEM) we construct the loss function of the neural work such that it includes a Shannon-Jaynes entropy term and a likelihood term. The sVAE is then trained to provide the most probable spectral functions. For the training samples of spectral function we used general spectral functions produced from the Gaussian Mixture Model. After the training is done we performed the mock data tests with input spectral functions consisting 1) only a free continuum, 2) only a resonance peak, 3) a resonance peak plus a free continuum and 4) a NRQCD motivated spectral function. From the mock data test we find that the sVAE in most cases is comparable to the maximum entropy method in the quality of reconstructing spectral functions and even outperforms the MEM in the case where the spectral function has sharp peaks with insufficient number of data points in the correlator. By applying to temporal correlation functions of charmonium in the pseudoscalar channel obtained in the quenched lattice QCD at 0.75 $T_c$ on $128^3\times 96$ lattices and $1.5$ $T_c$ on $128^3\times 48$ lattices, we find that the resonance peak of ${\eta }_c$ extracted from both the sVAE and MEM has a substantial dependence on the number of points in the temporal direction ($N_{\tau }$) adopted in the lattice simulation and $N_{\tau }$ larger than 48 is needed to resolve the fate of ${\eta }_c$ at 1.5 $T_c$.

    hep-latcs.LGhep-phhep-th+1PoS(2022)·4 citations
13. 13*

    Correlated Dirac Eigenvalues and Axial Anomaly in Chiral Symmetric QCD

    Heng-Tong Ding🇨🇳 · Sheng-Tai Li🇨🇳 · Swagato Mukherjee🇺🇸 · Akio Tomiya🇺🇸 · Xiao-Dan Wang🇨🇳 · Yu Zhang🇯🇵

    We investigate the Dirac eigenvalue spectrum ($\rho (\lambda ,m_l)$) to study the microscopic origin of axial anomaly in high temperature phase of QCD. We propose novel relations between the derivatives (${\partial }^n\rho (\lambda ,m_l)/\partial m_l^n$) of the Dirac eigenvalue spectrum with respect to the quark mass ($m_l$) and the $(n+1)$-point correlations among the eigenvalues ($\lambda$) of the massless Dirac operator. Based on these relations, we present lattice QCD results for ${\partial }^n\rho (\lambda ,m_l)/\partial m_l^n$ ($n=1,2,3$) with $m_l$ corresponding to pion masses $m_{\pi }=160-55$ MeV, and at a temperature of about 1.6 times the chiral phase transition temperature. Calculations were carried out using (2+1)-flavors of highly improved staggered quarks and the tree-level Symanzik gauge action with the physical strange quark mass, three lattice spacings $a=0.12,0.08,0.06$ fm, and lattices having aspect ratios $4-9$. We find that $\rho (\lambda \to 0,m_l)$ develops a peaked structure. This peaked structure, which arises due to non-Poisson correlations within the infrared part of the Dirac eigenvalue spectrum, becomes sharper as $a\to 0$, and its amplitude is proportional to $m_l^2$. After continuum and chiral extrapolations, we find that the axial anomaly remains manifested in two-point correlation functions of scalar and pseudo-scalar mesons in the chiral limit. We demonstrate that the behavior of $\rho (\lambda \to 0,m_l)$ is responsible for it.

    hep-lathep-phhep-thnucl-thPoS(2022)·4 citations
14. 14*

    Multigrid Solver on Fugaku

    Ken-Ichi Ishikawa🇯🇵 · Issaku Kanamori🇯🇵 · Hideo Matsufuru🇯🇵

    We report an implementation of a multigrid solver for the Clover fermion on supercomputer Fugaku, which uses A64FX CPU with Arm architecture. On Fugaku, a highly optimized implementation of BiCGStab solver with domain decomposed preconditioner for the Clover fermion, called QCD Wide SIMD library (QWS), is available. We use the preconditioner in QWS as a smoother of the multigrid solver. Our implementation shows reasonably good scaling and performance. The code is developed by using Bridge++ code framework and its extension.

    hep-latPoS(2022)·3 citations
15. 15*

    Estimating the thermal photon production rate using lattice QCD

    Csaba Török🇩🇪 · Marco Cè🇨🇭 · Tim Harris🇬🇧 · Ardit Krasniqi🇩🇪 · Harvey B. Meyer🇩🇪 · Arianna Toniato🇩🇪

    We present results for the photon emission rate determined from the transverse channel vector correlator at fixed spatial momentum using two flavors of dynamical Wilson fermions at $T\sim$250 MeV. We estimate the transverse channel spectral function using the continuum extrapolated correlator by applying various fit ansätze with a smooth matching to the NLO perturbative result. We confront our estimate based on this channel with the latest results of our collaboration based on the difference of the transverse and longitudinal channels.

    hep-latPoS(2021)·2 citations
16. 16*

    Towards the determination of sigma terms for the baryon octet on $N_{\mathrm{f}}=2+1$ CLS ensembles

    Pia Leonie Jones Petrak🇩🇪 · Gunnar Bali🇩🇪 · Sara Collins🇩🇪 · Jochen Heitger🇩🇪 · Daniel Jenkins🇩🇪 · Simon Weishäupl🇩🇪 · Thomas Wurm🇩🇪

    A lot of progress has been made in the determination of nucleon sigma terms. In this work we consider the sigma terms of the other octet baryons as well. These are determined on CLS gauge field ensembles employing the Lüscher-Weisz gluon action and the Sheikholeslami-Wohlert fermion action with $N_{\mathrm{f}}=2+1$. The ensembles have pion masses ranging from $410\mathrm{MeV}$ down to the physical value and lattice spacings covering a range between $0.09\mathrm{fm}$ and $0.04\mathrm{fm}$. We present some preliminary results for $a\approx 0.06$ fm along a trajectory where the sum of the sea quark masses is kept constant, focusing on the quark mass dependence. We discuss multi-state fits to tackle the well-known problem of excited state contamination and detail how we analyse connected and disconnected contributions.

    hep-latPoS(2022)·4 citations
17. 17*

    The complex potential from 2+1 flavor QCD using HTL inspired approach

    Dibyendu Bala🇩🇪 · Olaf Kaczmarek🇩🇪 · Rasmus Larsen🇳🇴 · Swagato Mukherjee🇺🇸 · Gaurang Parkar🇳🇴 · Peter Petreczky🇺🇸 · Alexander Rothkopf🇳🇴 · Johannes Heinrich Weber🇩🇪

    We have studied finite temperature complex static quark-antiquark potentials for 2+1 flavor QCD using highly improved staggered action with physical strange quark masses and light quark masses corresponding to a pion mass of 161 MeV. We calculated the potential using Wilson line correlators fixed in Coulomb gauge. For the extraction, we have used HTL motivated parametrization of the correlators. We found that the real part of the potential is screened above the crossover temperature and it's close to singlet free energies, whereas the imaginary part is increasing with both distance and temperature.

    hep-latPoS(2022)·1 citation
18. 18*

    Charm physics with a tmQCD mixed action

    A. Bussone🇩🇪 · A. Conigli🇪🇸 · J. Frison🇩🇪 · G. Herdoíza🇪🇸 · C. Pena🇪🇸 · D. Preti🇮🇹 · J.Á. Romero🇪🇸 · J. Ugarrio🇪🇸

    We report on our ongoing determination of the charm quark mass and the masses and decay constants of various charmed mesons, obtained within a mixed-action setup. We employ $N_f=2+1$ CLS ensembles combined with a Wilson twisted mass valence action that eliminates the leading $O(a)$ effects from our target observables. Alongside our preliminary results, we will discuss an exploration of GEVP techniques aimed at optimizing the precision in view of the extension of the computation to heavier quark masses. We study the chiral-continuum extrapolation of decay constants for charm quark observables and the renormalized charm quark mass.

    hep-latPoS(2022)·5 citations
19. 19*

    Finite-Size Scaling at fixed Renormalization-Group invariant

    Francesco Parisen Toldin🇩🇪

    Finite-size scaling at fixed renormalization-group invariant is a powerful and flexible technique to analyze Monte Carlo data at a critical point. It consists in fixing a given renormalization-group invariant quantity to a given value, thereby trading its statistical fluctuations with those of a parameter driving the transition. One remarkable feature is the observed significant improvement of statistical accuracy of various quantities, as compared to a standard analysis. We review the method, discussing in detail its implementation, the error analysis, and a previously introduced covariance-based optimization. Comprehensive benchmarks on the Ising model in two and three dimensions show large gains in the statistical accuracy, which are due to cross-correlations between observables. As an application, we compute an accurate estimate of the inverse critical temperature of the improved O(2) ${\varphi }^4$ model on a three-dimensional cubic lattice.

    ↳ cond-mat.stat-mechhep-latPRE(2022)·4 citations
20. 20*

    Noisy Bayesian optimization for variational quantum eigensolvers

    Giovanni Iannelli🇩🇪 · Karl Jansen🇩🇪

    The variational quantum eigensolver (VQE) is a hybrid quantum-classical algorithm used to find the ground state of a Hamiltonian using variational methods. In the context of this Lattice symposium, the procedure can be used to study lattice gauge theories (LGTs) in the Hamiltonian formulation. Bayesian optimization (BO) based on Gaussian process regression (GPR) is a powerful algorithm for finding the global minimum of a cost function, e.g. the energy, with a very low number of iterations using data affected by statistical noise. This work proposes an implementation of GPR and BO specifically tailored to perform VQE on quantum computers already available today.

    ↳ quant-phhep-latPoS(2022)·18 citations
21. 21*

    Nonlinearity of the non-Abelian lattice gauge field theory according to the spectra of Kolmogorov-Sinai entropy and complexity

    Agnes Fulop🇭🇺

    Yang-Mills fields are an important part of the non-Abelian space theory describing the properties of quark-gluon plasma. The dynamics of the classical fields are given by the Hamiltonian equations of motion, which contain the member of the field strength tensor SU(2) \cite{1.}. This system exhibits chaotic behavior. The homogeneous Yang-Mills equation includes the quadratic part of the field strength tensor $F_{\mu \nu }^a$ expressed in Minkowski space, which was determined by the fields $A_{\mu }^a$. The dynamics of the classical Yang-Mills field equations arise from the Hamiltonian SU(2) field tensor so that the total energy remains constant and fulfills the Gaussian law. The microcanonical equations of motion are solved on a lattice $N^d$, which shows chaotic dynamics and we research the time-dependent entropy-energy relation on the lattice, which can be shown by the spectrum of Kolmogorov-Sinai entropy and the statistical complexity

    ↳ nlin.CDhep-latphysics.comp-phActa Univ. Sapientiae, Inform.(2021)·0 citations
22. 22*

    Topological Mott Insulators and Discontinuous $U(1)$ $\theta$-Terms

    Michael A. DeMarco🇺🇸 · Ethan Lake🇺🇸 · Xiao-Gang Wen🇺🇸

    We introduce a lattice field theory that describes the transition between a superfluid (SF) and a bosonic topological Mott Insulator (tMI) -- a $U(1)$ symmetry protected topological phase labeled by an integer level $k$ and possessing an even integer $2k\frac{e^2}{h}$ quantized Hall conductance. Our model differs from the usual $2+1$d XY model by a topological term that vanishes on closed manifolds and in the absence of an applied gauge field, which implies that the critical exponents of the SF-tMI transition are identical to those of the well-studied $2+1$d XY transition. Our formalism predicts a "level-shift" symmetry: in the absence of an applied gauge field, the bulk correlation functions of all local operators are identical for models differing by the topological term. %, for example, near the SF-MI and SF-tMI transitions, and hence the extremely well-studied critical exponents of the $2+1$d XY model apply to the SF-tMI transition. In the presence of a background gauge field, the topological term leads to a quantized Hall response in the tMI phase, and we argue that this quantized Hall effect persists in the vicinity of the phase transition into the SF phase. Our formalism paves the way for other exact lattice descriptions of symmetry-protected-topological (SPT) phases, and mappings of critical exponents between transitions from symmetry-breaking to trivial states and transitions from symmetry-breaking to SPT states. A similar "level shift" symmetry should appear between all group cohomology SPT states protected by the same symmetry.

    ↳ cond-mat.str-elcond-mat.supr-conhep-lat3 citations
23. 23*

    Ground-state phase diagram of quantum link electrodynamics in $(2+1)$-d

    Tomohiro Hashizume🇬🇧 · Jad C. Halimeh🇮🇹 · Philipp Hauke🇮🇹 · Debasish Banerjee🇮🇳

    The exploration of phase diagrams of strongly interacting gauge theories coupled to matter in lower dimensions promises the identification of exotic phases and possible new universality classes, and it facilitates a better understanding of salient phenomena in Nature, such as confinement or high-temperature superconductivity. The emerging new techniques of quantum synthetic matter experiments as well as efficient classical computational methods with matrix product states have been extremely successful in one spatial dimension, and are now motivating such studies in two spatial dimensions. In this work, we consider a $\mathrm{U}(1)$ quantum link lattice gauge theory where the gauge fields, represented by spin-$\frac{1}{2}$ operators are coupled to a single flavor of staggered fermions. Using matrix product states on infinite cylinders with increasing diameter, we conjecture its phase diagram in $(2+1)$-d. This model allows us to smoothly tune between the $\mathrm{U}(1)$ quantum link and the quantum dimer models by adjusting the strength of the fermion mass term, enabling us to connect to the well-studied phases of those models. Our study reveals a rich phase diagram with exotic phases and interesting phase transitions to a potential liquid-like phase. It thus furthers the collection of gauge theory models that may guide future quantum-simulation experiments.

    ↳ cond-mat.str-elcond-mat.quant-gashep-latquant-phSciPost Phys.(2022)·23 citations
24. 24*

    Phase structure of 2+1-flavour QCD and the magnetic equation of state

    Fei Gao🇩🇪 · Jan M. Pawlowski🇩🇪

    We determine the chiral phase structure of $2+1$-flavour QCD in dependence of temperature and the light flavour quark mass with Dyson-Schwinger equations. Specifically, we compute the renormalised chiral condensate and its susceptibility. The latter is used to determine the (pseudo)critical temperature for general light current quark masses. In the chiral limit we obtain a critical temperature of about 141\,MeV. This result is in quantitative agreement with recent functional renormalisation group results in QCD, and is compatible with the respective lattice results. We also compute the order parameter potential of the light chiral condensate and map out the regime in the phase diagram which exhibits quasi-massless modes, and discuss the respective chiral dynamics.

    ↳ 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.