Mon·Nov 21, 2022Monday·November 21, 2022

1. 01*

   Meson screening mass at finite chemical potential

   Rishabh Thakkar🇮🇳 · Prasad Hegde🇮🇳

   Knowledge of the screening masses at finite chemical potential can provide insight into the nature of the QCD phase diagram. However, lattice studies at finite chemical potential suffer from the well-known issue of the sign problem, which has made the calculation of observables such as screening correlators and screening masses at finite chemical potential quite challenging. One way to proceed is by expanding the observable in a Taylor series in the chemical potential and hence calculating the finite-density corrections to the observable. In this talk, we will use this approach to calculate the screening mass of the pseudoscalar meson at finite temperatures and chemical potential by expanding the screening correlator in a Taylor series in the chemical potential. We will present our results for the second derivative of the screening mass w.r.t. the chemical potential. Our calculation was done on $64^3\times 8$ lattices generated using the (2+1) HISQ/tree action.

   hep-latPoS(2023)·5 citations
2. 02*

   Three-particle Lellouch-Lüscher formalism in moving frames

   Fabian Müller🇩🇪 · Jin-Yi Pang🇨🇳 · Akaki Rusetsky🇩🇪 · Jia-Jun Wu🇨🇳

   A manifestly relativistic-invariant Lellouch-Lüscher formalism for the three-particle decays is proposed. Similarly to ref.[1], the formalism is based on the use of the non-relativistic effective Lagrangians. Manifest Lorentz invariance is guaranteed, as in ref.[2], by choosing the quantization axis along the total four-momentum of the three-particle system. A systematic inclusion of the higher-order derivative couplings, as well as higher partial waves is addressed.

   hep-lathep-phnucl-thJHEP(2023)·30 citations
3. 03*

   QCD confronts heavy-flavor and exotic hadrons

   Sasa Prelovsek🇸🇮

   A review of QCD-based theory approaches to study the heavy-flavor and exotic hadrons is given. The focus is on the results from lattice QCD and from lattice QCD complemented by effective field theories. Both approaches are first briefly introduced and applied in few examples. Then the status of various hadrons sectors is presented.

   hep-lathep-phEPJ Web Conf.(2022)·1 citation
4. 04*

   Equation of state from complex Langevin simulations

   Felipe Attanasio🇩🇪 · Benjamin Jäger🇩🇰 · Felix P.G. Ziegler🇬🇧

   We use complex Langevin simulations to study the QCD phase diagram with two light quark flavours. In this study, we use Wilson fermions with an intermediate pion mass of $\sim 480$MeV. By studying thermodynamic quantities, in particular at lower temperatures, we are able to describe the equation of state.

   hep-latEPJ Web Conf.(2022)·1 citation
5. 05*

   Magnetic catalysis in the $1$-flavor Gross-Neveu model in $2+1$ dimensions

   Michael Mandl🇩🇪 · Julian J. Lenz🇩🇪 · Andreas Wipf🇩🇪

   We investigate the Gross-Neveu model in $2+1$ dimensions in a constant and homogeneous magnetic field using one reducible flavor of overlap fermions. Our lattice simulations suggest that the magnetic catalysis phenomenon, i.e., an increase of the chiral condensate with the magnetic field, is present for all temperatures below the chiral phase transition, in accordance with predictions from mean-field and beyond-mean-field calculations.

   hep-lathep-thPoS(2023)·4 citations
6. 06*

   The density of states method in Yang-Mills theories and first order phase transitions

   David Mason🇬🇧 · Biagio Lucini🇬🇧 · Maurizio Piai🇬🇧 · Enrico Rinaldi🇯🇵 · Davide Vadacchino🇬🇧

   Extensions of the standard model that lead to first-order phase transitions in the early universe can produce a stochastic background of gravitational waves, which may be accessible to future detectors. Thermodynamic observables at the transition, such as the latent heat, can be determined by lattice simulations, and then used to predict the expected signatures in a given theory. In lattice calculations, the emergence of metastabilities in proximity of the phase transition may make the precise determination of these observables quite challenging, and may lead to large uncontrolled numerical errors. In this contribution, we discuss as a prototype lattice calculation the first order deconfinement transition that arises in the strong SU(3) Yang-Mills sector. We adopt the novel logarithmic linear relaxation method, which can provide a determination of the density of states of the system with exponential error suppression. Thermodynamic observables can be reconstructed with a controlled error, providing a promising direction for accurate model predictions in the future.

   hep-latEPJ Web Conf.(2022)·13 citations
7. 07*

   Origin of the Proton Mass

   Craig D. Roberts🇨🇳

   Atomic nuclei lie at the core of everything visible; and at the first level of approximation, their atomic weights are simply the sum of the masses of all the neutrons and protons (nucleons) they contain. Each nucleon has a mass $m_N\approx 1\mathrm{GeV}\approx 2000$-times the electron mass. The Higgs boson -- discovered at the large hadron collider in 2012, a decade ago -- produces the latter, but what generates the nucleon mass? This is a pivotal question. The answer is widely supposed to lie within quantum chromodynamics (QCD), the strong-interaction piece of the Standard Model. Yet, it is far from obvious. In fact, removing Higgs-boson couplings into QCD, one arrives at a scale invariant theory, which, classically, can't support any masses at all. This contribution sketches forty years of developments in QCD, which suggest a solution to the puzzle, and highlight some of the experiments that can validate the picture.

   ↳ hep-phhep-exhep-latnucl-ex+1EPJ Web Conf.(2023)·25 citations
8. 08*

   Electromagnetic form factors of the $B_c$-like tetraquarks: molecular and diquark-antidiquark pictures

   Ulaş Özdem🇹🇷

   In this study, we use the molecular and diquark-antidiquark tetraquark pictures to investigate magnetic and quadrupole moments of the $B_c$-like ground state tetraquarks with the QCD light-cone sum rules with quantum numbers $J^P=1^{+}$. In the numerical analysis, to obtain the magnetic and quadrupole moments of $B_c$-like tetraquark states molecular and diquark-antidiquark forms of interpolating currents, and photon distribution amplitudes have been used. The magnetic moments are acquired as ${\mu }_{Z_{uc\bar{u}\bar{b}}}^{Mol}=1.18_{-0.40}^{+0.52}{\mu }_N$, ${\mu }_{Z_{uc\bar{u}\bar{b}}}^{Di}=3.05_{-0.95}^{+1.19}{\mu }_N$, ${\mu }_{Z_{dc\bar{d}\bar{b}}}^{Mol}=0.32_{-0.10}^{+0.18}{\mu }_N$, and ${\mu }_{Z_{dc\bar{d}\bar{b}}}^{Di}=2.38_{-0.75}^{+0.95}{\mu }_N$. The hadrons' magnetic and quadrupole moments are another fundamental observable as their mass, which provides information on the underlying quark structure and dynamics. The results obtained in both pictures are quite different from each other. Any experimental measurement of the magnetic moments can provide an understanding of the internal structure of these states. We get nonzero but small values for the quadrupole moments of $B_c$-like tetraquark states showing non-spherical charge distributions. Hopefully, the examinations given in this study will be helpful to an experimental search of them, which will be an interesting research subject.

   ↳ hep-phhep-exhep-latPLB(2023)·21 citations
9. 09*

   QuantumFDTD -- A computational framework for the relativistic Schrödinger equation

   Rafael L. Delgado🇪🇸 · Sebastian Steinbeißer🇩🇪 · Michael Strickland🇺🇸 · Johannes H. Weber🇩🇪

   We extend the publicly available quantumfdtd code. It was originally intended for solving the time-independent three-dimensional Schrödinger equation via the finite-difference time-domain (FDTD) method and for extracting the ground, first, and second excited states. We (a) include the case of the relativistic Schrödinger equation and (b) add two optimized FFT-based kinetic energy terms for the non-relativistic case. All the three new kinetic terms are computed using Fast Fourier Transform (FFT). We release the resulting code as version 3 of quantumfdtd. Finally, the code now supports arbitrary external file-based potentials and the option to project out distinct parity eigenstates from the solutions. Our goal is quark models used for phenomenological descriptions of QCD bound states, described by the three-dimensional Schrödinger equation. However, we target any field where solving either the non-relativistic or the relativistic three-dimensional Schrödinger equation is required.

   ↳ hep-phhep-latphysics.comp-phquant-phEPJ Web Conf.(2022)·0 citations
10. 10*

    Dispersive formalism for the nuclear structure correction ${\delta }_{\mathrm{NS}}$ to the $\beta$ decay rate

    Chien-Yeah Seng🇺🇸 · Mikhail Gorchtein🇩🇪

    We analyze the axial $\gamma W$-box diagram for $I(J^P)=1(0^{+})$ nuclei and provide a dispersion representation of the nuclear-structure correction ${\delta }_{\text{NS}}$ including its energy-dependent part. We also summarize useful isospin rotation formula and representations in nuclear theory that could facilitate the calculation of the parity-odd nuclear structure function $F_3(\nu ,Q^2)$. They provide a rigorous theory framework for the future, high-precision calculation of the nuclear structure correction ${\delta }_{\text{NS}}$ necessary for the extraction of the Cabibbo-Kobayashi-Maskawa matrix element $|V_{ud}|$ from superallowed nuclear $\beta$ decays.

    ↳ nucl-thhep-exhep-lathep-ph+1PRC(2023)·41 citations
11. 11*

    The hybrid nonet of ${\pi }_1(1600)$ and ${\eta }_1(1855)$: analysis and predictions for the kaonic members

    Vanamali Shastry🇵🇱

    The hybrid mesons form a part of the exotic spectrum of the standard model. The recent observation of the isoscalar hybrid, called the ${\eta }_1(1855)$, provides an important step towards the completion of the $1^{-+}$ nonet. In the present work, we analyze the masses and two-body decays of the members of this nonet using a model hadronic Lagrangian. The isovector ${\pi }_1(1600)$ has been studied extensively - both experimentally and on lattice. We use the available experimental and lattice data to extract the coupling constants. Using these parameters, we analyze the possible decay channels for the hybrid kaons.

    ↳ hep-phhep-exhep-latPoS(2022)·4 citations
12. 12*

    Gauge theory geography: charting a path between semiclassical islands

    Erich Poppitz🇨🇦 · F David Wandler🇨🇦

    We study two semiclassical limits of $SU(2)$ Yang-Mills theory on a spatial torus with a 't Hooft twist: the ``femtouniverse,'' where all ${\mathbb{T}}^3$ directions are small, and deformed Yang-Mills theory on ${\mathbb{T}}^2\times {\mathbb{S}}^1$, with small ${\mathbb{S}}^1$ and large or infinite ${\mathbb{T}}^2$. Carefully defining the symmetries, we show that the classical ground states, while different, have the same transformation properties under the 1-form center symmetry and parity. We argue that this is behind the identical multi-branch $\theta$-dependent vacuum structure of these theories. We then calculate the one-loop potential for the ${\mathbb{S}}^1$-holonomy in the presence of twists on ${\mathbb{T}}^2$. We use it to study the quantum stability of the semiclassical ground states in gauge theories with massive or massless adjoint fermions on spatial ${\mathbb{T}}^2\times {\mathbb{S}}^1$, with a twist in the ${\mathbb{T}}^2$. The results point towards some interesting features worthy of further study.

    ↳ hep-thhep-latJHEP(2023)·17 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.