Nuclear Theory·nucl-th

Monday·October 25, 2021

7 papers—1 primary·6 cross-listed

01
Cumulants: It's More Than You Think
Agnieszka Sorensen🇺🇸 · Dmytro Oliinychenko🇺🇸 · Volker Koch🇺🇸 · Larry McLerran🇺🇸
Cumulants of baryon number are given considerable attention in analyses of heavy-ion collision experiments as possible signatures of the QCD critical point. In this work, we show that the values of the lowest three cumulants can also be utilized to recover information about the isothermal speed of sound and its logarithmic derivative with respect to the baryon number density. This result provides a new method for obtaining information about fundamental properties of nuclear matter studied in heavy-ion collisions, with consequences for both the search for the QCD critical point and neutron star studies. While the approximations and the model comparison we considered apply to experiments at low energies, the approach itself can be used at any collision energy provided that measurements of cumulants of baryon number distribution as well as their temperature dependence are available.
nucl-thnucl-exPoS(2022)·0 citations
02
The $γ π \to π π$ anomaly from lattice QCD and dispersion relations
Malwin Niehus🇩🇪 · Martin Hoferichter🇨🇭 · Bastian Kubis🇩🇪
We propose a formalism to extract the $γ π \to π π$ chiral anomaly $F_{3 π}$ from calculations in lattice QCD performed at larger-than-physical pion masses. To this end, we start from a dispersive representation of the $γ^{(*)} π \to π π$ amplitude, whose main quark-mass dependence arises from the $π π$ scattering phase shift and can be derived from chiral perturbation theory via the inverse-amplitude method. With parameters constrained by lattice calculations of the $P$ -wave phase shift, we use this combination of dispersion relations and effective field theory to extrapolate two recent $γ^{(*)} π \to π π$ calculations in lattice QCD to the physical point. Our formalism allows us to extract the radiative coupling of the $ρ (770)$ meson and, for the first time, the chiral anomaly $F_{3 π} = 38 (16) (11) GeV^{- 3}$ . The result is consistent with the chiral prediction albeit within large uncertainties, which will improve in accordance with progress in future lattice-QCD computations.
↳ hep-phhep-exhep-latnucl-thJHEP(2021)·35 citations
03
Chiral anomalous processes in magnetospheres of pulsars and black holes
E. V. Gorbar🇺🇦 · I. A. Shovkovy🇺🇸
We propose that chirally asymmetric plasma can be produced in the gap regions of the magnetospheres of pulsars and black holes. We show that, in the case of supermassive black holes situated in active galactic nuclei, the chiral charge density and the chiral chemical potential are very small and unlikely to have any observable effects. In contrast, the chiral asymmetry produced in the magnetospheres of magnetars can be substantial. It can trigger the chiral plasma instability that, in turn, can lead to observable phenomena in magnetars. In particular, the instability should trigger circularly polarized electromagnetic radiation in a wide window of frequencies, spanning from radio to near-infrared. As such, the produced chiral charge has the potential to affect some features of fast radio bursts.
↳ astro-ph.HEhep-phnucl-thEPJC(2022)·17 citations
04
State mixing and masses of the $π^{0}$ , $η$ and $η^{'}$ mesons from $n_{f} = 1 + 1 + 1$ lattice QCD+QED
Z. R. Kordov🇦🇺 · R. Horsley🇬🇧 · W. Kamleh🇦🇺 · Z. Koumi🇦🇺 · Y. Nakamura🇯🇵 · H. Perlt🇩🇪 · P. E. L. Rakow🇬🇧 · G. Schierholz🇩🇪 · H. Stüben🇩🇪 · R. D. Young🇦🇺 · J. M. Zanotti🇦🇺
We present a lattice analysis of the light pseudoscalar mesons with consideration for the mixing between the flavour-neutral states $π^{0}$ , $η$ and $η^{'}$ . We extract the masses and flavour compositions of the pseudoscalar meson nonet in $n_{f} = 1 + 1 + 1$ lattice QCD+QED around an SU(3)-flavour symmetric point, and observe flavour-symmetry features of the extracted data, along with preliminary extrapolation results for the flavour compositions at the physical point. A key result of this work is the observed mass splitting between the $π^{0}$ and $η$ on our ensembles, which is found to exhibit behaviour that is simply related to the corresponding flavour compositions.
↳ hep-lathep-phnucl-thPRD(2021)·14 citations
05
Static quark anti-quark interactions at non-zero temperature from lattice QCD
Dibyendu Bala🇩🇪 · Olaf Kaczmarek🇩🇪 · Rasmus Larsen🇳🇴 · Swagato Mukherjee🇺🇸 · Gaurang Parkar🇳🇴 · Peter Petreczky🇺🇸 · Alexander Rothkopf🇳🇴 · Johannes Heinrich Weber🇩🇪
We study the interactions of a static quark antiquark pair at non-zero temperature using realistic 2+1 flavor lattice QCD calculations. The study consists of two parts: the first investigates the properties of Wilson line correlators in Coulomb gauge and compares to predictions of hard-thermal loop perturbation theory. As a second step we extract the spectral functions underlying the correlators using four conceptually different methods: spectral function fits, a HTL inspired fit for the correlation function, Padé rational approximation and the Bayesian BR spectral reconstruction. We find that our high statistics Euclidean lattice data are amenable to different hypotheses for the shapes of the spectral function and we compare the implications of each analysis method for the existence and properties of a well defined ground state spectral peak.
↳ hep-lathep-phnucl-thPRD(2022)·80 citations
06
Multi-Particle Tunneling Transport at Strongly-Correlated Interfaces
Hiroyuki Tajima · Daigo Oue · Mamoru Matsuo
We elucidate the multi-particle transport of pair- and spin-tunnelings in strongly correlated interfaces. Not only usual single-particle tunneling but also interaction-induced multi-particle tunneling processes naturally arise from a conventional microscopic model without any empirical parameters, through the overlap of the many-body wave functions around the interface. We demonstrate how anomalous tunneling currents occur in a strongly interacting system due to the pair-tunneling process which we derived microscopically. Our formulation is useful for junction systems in various disciplines, including atomtronics, spintronics, and nuclear reactions.
↳ cond-mat.quant-gascond-mat.mes-hallcond-mat.str-elcond-mat.supr-con+1PRA(2022)·4 citations
07
Quantifying modeling uncertainties when combining multiple gravitational-wave detections from binary neutron star sources
Nina Kunert · Peter T. H. Pang · Ingo Tews · Michael W. Coughlin · Tim Dietrich
With the increasing sensitivity of gravitational-wave detectors, we expect to observe multiple binary neutron-star systems through gravitational waves in the near future. The combined analysis of these gravitational-wave signals offers the possibility to constrain the neutron-star radius and the equation of state of dense nuclear matter with unprecedented accuracy. However, it is crucial to ensure that uncertainties inherent in the gravitational-wave models will not lead to systematic biases when information from multiple detections are combined. To quantify waveform systematics, we perform an extensive simulation campaign of binary neutron-star sources and analyse them with a set of four different waveform models. Based on our analysis with about 38 simulations, we find that statistical uncertainties in the neutron-star radius decrease to $\pm 250 m$ ( $2%$ at $90%$ credible interval) but that systematic differences between currently employed waveform models can be twice as large. Hence, it will be essential to ensure that systematic biases will not become dominant in inferences of the neutron-star equation of state when capitalizing on future developments.
↳ astro-ph.HEgr-qcnucl-thPRD(2022)·42 citations

Affiliations

first authorsco-authorsvia INSPIRE

Cumulants: It's More Than You Think

The γπ→ππ anomaly from lattice QCD and dispersion relations

Chiral anomalous processes in magnetospheres of pulsars and black holes

State mixing and masses of the π0, η and η′ mesons from nf​=1+1+1 lattice QCD+QED

Static quark anti-quark interactions at non-zero temperature from lattice QCD

Multi-Particle Tunneling Transport at Strongly-Correlated Interfaces

Quantifying modeling uncertainties when combining multiple gravitational-wave detections from binary neutron star sources

Affiliations

The $γ π \to π π$ anomaly from lattice QCD and dispersion relations

State mixing and masses of the $π^{0}$ , $η$ and $η^{'}$ mesons from $n_{f} = 1 + 1 + 1$ lattice QCD+QED