Wed·Dec 7, 2022Wednesday·December 7, 2022

1. 01*

   Lattice QCD at non-zero temperature and density

   Frithjof Karsch🇩🇪

   Soon after the formulation of Quantum Chromodynamics in 1972 its regularization on Euclidean space-time lattices had been introduced by Kenneth Wilson. This paved ground for numerical studies of non-perturbative aspects of QCD, first shown by Michael Creutz. Ever since these first lattice QCD calculations the exploration of the QCD phase diagram and the thermodynamics of strong-interaction matter at non-zero temperature and density was pursued vigorously. In this brief review I try to highlight some of the results on QCD thermodynamics obtain during the last 42 years through lattice QCD calculations.

   hep-lathep-phhep-th7 citations
2. 02*

   Nuclear Transition in the Strong Coupling Limit

   Jangho Kim🇩🇪 · Pratitee Pattanaik🇩🇪 · Wolfgang Unger🇩🇪

   Lattice QCD at finite baryon chemical potential has the infamous sign problem which hinders Monte Carlo simulations. This can be remedied by a dual representation that makes the sign problem mild. In the strong coupling limit, the dual formulation with staggered quarks is well established. We have used this formulation to study the quark mass dependence of the baryon mass and the nuclear transition. This allows us to quantify the nuclear interaction. We have also compared our Monte Carlo results with mean field predictions.

   hep-latnucl-thPoS(2023)·1 citation
3. 03*

   Thermal phase transitions in rotating QCD with dynamical quarks

   V. V. Braguta🇷🇺 · A. Yu. Kotov🇷🇺 · A. A. Roenko🇷🇺 · D. A. Sychev🇷🇺

   Relativistic rotation causes a change of QCD critical temperatures. Various phenomenological and effective models predict a decrease of the critical temperatures in rotating QCD. Nevertheless, lattice simulations showed that the critical temperature in gluodynamics increases due to rotation. We extend the lattice study to the theory with dynamical fermions. We present the first lattice results for rotating QCD with $N_f=2$ dynamical clover-improved Wilson quarks. We also study separately the effect of rotation on gluonic and fermionic degrees of freedom. It is shown that separate rotations of gluons and fermions have opposite effects on the critical temperatures. In aggregate, the pseudo-critical temperatures in QCD increase with angular velocity. Dependence of the results on the pion mass is also discussed.

   hep-lathep-phhep-thPoS(2023)·36 citations
4. 04*

   Investigating $B_c$ semileptonic decays

   Francesco Loparco🇮🇹

   I present analyses of semileptonic $B_c$ decays. I first discuss the decays induced by $c\to \{s,d\}$ transitions, in particular $B_c\to B_a\bar{\ell }{\nu }_{\ell }$ and $B_c\to B_a^{\ast }(\to B_a\gamma )\bar{\ell }{\nu }_{\ell }$ decays, with $a=\{s,d\}$ and $\ell =\{e,\mu \}$, in the Standard Model and in the extension based on the low-energy Hamiltonian comprising the full set of $D=6$ semileptonic $c\to s,d$ operators with left-handed neutrinos.\\ Moreover, I consider $b\to c$ modes, with particular focus on the determination of the form factors parametrizing the $B_c\to J/\psi ,{\eta }_c$ matrix elements of the operators in a generalized low-energy $b\to c$ semileptonic Hamiltonian. In this case I consider an expansion in nonrelativistic \qcd\ together with an expansion in the inverse heavy-quark mass which allows the form factors to be expressed in terms of universal functions in a selected kinematical range.\\ The Heavy Quark Spin Symmetry is used for both analyses. In the first case, it allows the relevant hadronic matrix elements to be related and the lattice \qcd\ results on $B_c$ form factors to be exploited. Optimized observables are selected, and correlations among them is studied to identify the effects of the various operators in the extended low-energy Hamiltonian. In the second one, using as an input the lattice \qcd\ results for the $B_c\to J/\psi$ matrix element of the Standard Model operator, it is possible to obtain information on other form factors. The extrapolation to the full kinematical range is also presented.

   ↳ hep-phhep-exhep-latPoS(2022)·0 citations
5. 05*

   On the Proof of Chiral Symmetry Breaking from Anomaly Matching in QCD-like Theories

   Luca Ciambriello🇮🇹 · Roberto Contino🇮🇹 · Andrea Luzio🇮🇹 · Marcello Romano🇫🇷 · Ling-Xiao Xu🇮🇹

   We critically reconsider the argument based on 't Hooft anomaly matching that aims at proving chiral symmetry breaking in confining four-dimensional QCD-like theories with $N_c>2$ colors and $N_f$ flavors. The main line of reasoning relies on a property of the solutions of the anomaly matching and persistent mass equations called $N_f$-independence. In previous works, the validity of $N_f$-independence was assumed based on qualitative arguments, but it was never proven rigorously. We provide a detailed proof and clarify under which (dynamical) conditions it holds. Our results are valid for a generic spectrum of massless composite fermions including baryons and exotics.

   ↳ hep-thhep-lathep-phPRD(2024)·10 citations
6. 06*

   Virasoro Generators in the Fibonacci Model Tensor Network -- Tackling Finite Size Effects

   Xiangdong Zeng🇨🇳 · Ruoshui Wang🇺🇸 · Ce Shen🇨🇳 · Ling-Yan Hung🇨🇳

   In this paper, we extend the method implementing Virasoro operators in a tensor network we proposed in arXiv:2205.04500 and test it on the Fibonacci model, which is known to suffer from far more finite size effects. To pick up the "seed" state that would flow to the stress tensor in the thermodynamic limit, we make use of the topological idempotent that projects the transfer matrix to the trivial sector. Combined with an optimization method, the seed state can be identified. We demonstrate that the descendant states in the Fibonacci model can be correctly generated with this approximate stress tensor, giving further evidence that the method applies more generally.

   ↳ cond-mat.str-elhep-latPRB(2023)·4 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.