Tue·Nov 16, 2021Tuesday·November 16, 2021

1. 01*

   Light-cone PDFs and GPDs from Lattice QCD

   Martha Constantinou🇺🇸

   In this article, we review recent lattice calculations on the $x$-dependence of PDFs and GPDs from lattice QCD.

   hep-lat0 citations
2. 02*

   The 't Hooft-Veneziano limit of the Polyakov loop models

   O. Borisenko🇺🇦 · V. Chelnokov🇩🇪 · S. Voloshyn🇺🇦

   The broad class of U(N) and SU(N) Polyakov loop models on the lattice are solved exactly in the combined large N, Nf limit, where N is a number of colors and Nf is a number of quark flavors, and in any dimension. In this 't Hooft-Veneziano limit the ratio N/Nf is kept fixed. We calculate both the free energy and various correlation functions. The critical behavior of the models is described in details at finite temperatures and non-zero baryon chemical potential. Furthermore, we prove that the calculation of the N-point (baryon) correlation function reduces to the geometric median problem in the confinement phase. In the deconfinement phase we establish an existence of the complex masses and an oscillating decay of correlations in a certain region of parameters.

   hep-lathep-thPoS(2022)·8 citations
3. 03*

   A chiralspin symmetry in QCD in Minkowski space-time

   Marco Catillo🇨🇭

   In this paper, we look how to construct in Minkowski space-time a new type of \textit{chiralspin} group transformation of the spinor fields, similar to the one discovered by recent works of \textit{Glozman et al.} in the context of high temperature QCD and truncated studies in lattice calculations. Afterwards, we prove the invariance of free massless fermionic action under such group transformations, as well the invariance of the Hamiltonian of free massless fermions. At the end, the possible presence of a symmetry driven by such new \textit{chiralspin} group at high temperature QCD, also at non zero chemical potential, is discussed.

   hep-latPRD(2022)·1 citation
4. 04*

   Progress on Meson-Baryon Scattering

   Colin Morningstar🇺🇸 · John Bulava🇩🇪 · Andrew D. Hanlon🇺🇸 · Ben Hörz🇺🇸 · Daniel Mohler🇩🇪 · Amy Nicholson🇺🇸 · Sarah Skinner🇺🇸 · André Walker-Loud🇺🇸

   Progress in computing various meson-baryon scattering amplitudes is presented on a single ensemble from the Coordinated Lattice Simulations (CLS) consortium with $m_{\pi }=200$ MeV and $N_f=2+1$ dynamical fermions. The finite-volume Lüscher approach is employed to determine the lowest few partial waves from ground- and excited-state energies computed from correlation matrices rotated in a single pivot using a generalized eigenvector solution. This analysis requires evaluating matrices of correlation functions between single- and two-hadron interpolating operators which are projected onto definite spatial momenta and finite-volume irreducible representations. The stochastic LapH method is used to estimate all needed quark propagators. Preliminary results are presented for $I=\frac{1}{2},\frac{3}{2}$ $N\pi$ amplitudes including the $\Delta (1232)$ resonance and the $I=0$ $S$-wave amplitude with unit strangeness relevant for the $\Lambda (1405)$.

   hep-latPoS(2022)·14 citations
5. 05*

   The static force from generalized Wilson loops

   Viljami Leino🇩🇪 · Nora Brambilla🇩🇪 · Owe Philipsen🇩🇪 · Christian Reisinger🇩🇪 · Antonio Vairo🇩🇪 · Marc Wagner🇩🇪

   Recently a method to compute the static force with lattice gauge theory using an insertion of a chromoelectric field into a Wilson loop was proposed. We explore this method using the multilevel algorithm and discuss the renormalization of the chromoelectric field on the lattice.

   hep-lathep-phhep-thPoS(2022)·4 citations
6. 06*

   Vacuum correlators at short distances from lattice QCD

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

   We propose a method to help control cutoff effects in the short-distance contribution to integrated correlation functions, such as the hadronic vacuum polarization (HVP), using the corresponding screening correlators computed at finite temperature. The strategy is investigated with Wilson fermions at leading order, which reveals a logarithmically-enhanced lattice artifact in the short-distance contribution, whose coefficient is determined at this order. We then perform a numerical study with $N_{\mathrm{f}}=2$ O($a$)-improved Wilson fermions and a temperature $T\approx 250\mathrm{MeV}$, with lattice spacings down to $a\approx 0.03\mathrm{fm}$, which suggests good control can be achieved on the short-distance contribution to the HVP and the Adler function at large virtuality. Finally, we put forward a scheme to compute the complete HVP function at arbitrarily large virtualities using a step-scaling in the temperature.

   hep-lathep-phPoS(2021)·6 citations
7. 07*

   Introducing vortices in the continuum using direct and indirect methods

   Zahra Asmaee🇮🇷 · Sedigheh Deldar🇮🇷 · Motahareh Kiamari🇮🇷

   Inspired by direct and indirect maximal center gauge methods which confirm the existence of vortices in lattice calculations and by using the connection formalism, we show that under some appropriate gauge transformations vortices and chains appear in the QCD vacuum of the continuum limit. In the direct method, by applying center gauge transformation and \textquotedblleft center projection,\textquotedblright QCD is reduced to a gauge theory including vortices, which corresponds to the non-trivial first homotopy group ${\Pi }_1\left(\text{SO}(3)\right)=Z_2.$ On the other hand, using the indirect method, in addition to the center gauge transformation and \textquotedblleft center projection,\textquotedblright an initial step called Abelian gauge transformation and then Abelian projection are applied. Therefore, instead of single vortices, chains that contain monopoles and vortices appear in the theory.

   hep-lathep-phPRD(2022)·4 citations
8. 08*

   Accurate relativistic chiral nucleon-nucleon interaction up to NNLO

   Jun-Xu Lu🇨🇳 · Chun-Xuan Wang🇨🇳 · Yang Xiao🇨🇳 · Li-Sheng Geng🇨🇳 · Jie Meng🇨🇳 · Peter Ring🇩🇪

   We construct a relativistic chiral nucleon-nucleon interaction up to the next-to-next-to-leading order in covariant baryon chiral perturbation theory. We show that a good description of the $np$ phase shifts up to $T_{\mathrm{lab}}=200$ MeV and even higher can be achieved with a ${\tilde{\chi }}^2/d.o.f.$ less than 1. Both the next-to-leading order results and the next-to-next-to-leading order results describe the phase shifts equally well up to $T_{\mathrm{lab}}=200$ MeV, but for higher energies, the latter behaves better, showing satisfactory convergence. The relativistic chiral potential provides the most essential inputs for relativistic ab initio studies of nuclear structure and reactions, which has been in need for almost two decades.

   ↳ nucl-thhep-lathep-phnucl-exPRL(2022)·69 citations
9. 09*

   QCD Static Force in Gradient Flow

   Nora Brambilla🇩🇪 · Hee Sok Chung🇩🇪 · Antonio Vairo🇩🇪 · Xiang-Peng Wang🇩🇪

   We compute the QCD static force and potential using gradient flow at next-to-leading order in the strong coupling. The static force is the spatial derivative of the static potential: it encodes the QCD interaction at both short and long distances. While on the one side the static force has the advantage of being free of the $O({\Lambda }_{\mathrm{QCD}})$ renormalon affecting the static potential when computed in perturbation theory, on the other side its direct lattice QCD computation suffers from poor convergence. The convergence can be improved by using gradient flow, where the gauge fields in the operator definition of a given quantity are replaced by flowed fields at flow time $t$, which effectively smear the gauge fields over a distance of order $\sqrt{t}$, while they reduce to the QCD fields in the limit $t\to 0$. Based on our next-to-leading order calculation, we explore the properties of the static force for arbitrary values of $t$, as well as in the $t\to 0$ limit, which may be useful for lattice QCD studies.

   ↳ hep-phhep-lathep-thnucl-thJHEP(2022)·10 citations
10. 10*

    Efficient Representation for Simulating U(1) Gauge Theories on Digital Quantum Computers at All Values of the Coupling

    Christian W. Bauer🇺🇸 · Dorota M. Grabowska🇨🇭

    We derive a representation for a lattice U(1) gauge theory with exponential convergence in the number of states used to represent each lattice site that is applicable at all values of the coupling. At large coupling, this representation is equivalent to the Kogut-Susskind electric representation, which is known to provide a good description in this region. At small coupling, our approach adjusts the maximum magnetic field that is represented in the digitization as in this regime the low-lying eigenstates become strongly peaked around zero magnetic field. Additionally, we choose a representation of the electric component of the Hamiltonian that gives minimal violation of the canonical commutation relation when acting upon low-lying eigenstates, motivated by the Nyquist-Shannon sampling theorem. For (2+1) dimensions with 4 lattice sites the expectation value of the plaquette operator can be calculated with only 7 states per lattice site with per-mille level accuracy for all values of the coupling constant.

    ↳ hep-phhep-latquant-phPRD(2023)·105 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.