Nuclear Theory·nucl-th

Tuesday·June 30, 2020

21 papers—12 primary·9 cross-listed

01
Initial fluctuations and power spectrum of flow anisotropies in relativistic heavy-ion collisions
Shreyansh S. Dave🇮🇳 · Saumia P.S.🇷🇺 · Ajit M. Srivastava🇮🇳
Flow has emerged as a crucial probe for the properties of the thermalized medium produced in relativistic heavy-ion collisions. The evolution of initial state fluctuations leaves imprints on the power spectrum of flow coefficients. Therefore flow coefficients are a crucial probe of initial state fluctuations arising from the parton distributions of the colliding nuclei. This has a very strong correspondence with the physics of power spectrum of cosmic microwave background radiation (CMBR) anisotropies which directly probes initial inflationary fluctuations. Much work has been done to probe these interesting interconnections, in particular, in developing techniques for the measurements of higher flow coefficients. We present a short review of these developments. The effect of initial magnetic field on these features will also be reviewed. All this acquires special importance in view of upcoming electron-ion collider which will directly probe initial parton distribution of the colliding nucleus.
nucl-thhep-phnucl-exEur.Phys.J.ST(2021)·2 citations
02
A shell-model study of calcium isotopes towards their drip line
L. Coraggio · G. De Gregorio · A. Gargano · N. Itaco · T. Fukui · Y. Z. Ma · F. R. Xu
We report in this paper a study in terms of the nuclear shell model about the location of the calcium isotopes drip line. The starting point is considering the realistic two-body potential derived by Entem and Machleidt within chiral perturbation theory at next-to-next-to-next-to-leading order (N3LO), as well as a chiral three-body force at next-to-next-to-leading order (N2LO) whose structure and low-energy constants are consistent with the two-body potential. Then we construct the effective single-particle energies and residual interaction needed to diagonalize the shell-model Hamiltonian. The calculated two-neutron separation energies agree nicely with experiment until 56Ca, which is the heaviest isotope whose mass has been measured, and do not show any sign of two-neutron emission until 70Ca. We discuss the role of the choice of the model space in determining the neutron drip line, and also the dependence of the results on the parameters of the shell-model Hamiltonian.
nucl-thPRC(2020)·26 citations
03
Entrainment effects in neutron-proton mixtures within the nuclear-energy density functional theory. II. Finite temperatures and arbitrary currents
Valentin Allard · Nicolas Chamel
Mutual entrainment effects in hot neutron-proton superfluid mixtures are studied in the framework of the self-consistent nuclear energy-density functional theory. The local mass currents in homogeneous or inhomogeneous nuclear systems, which we derive from the time-dependent Hartree-Fock-Bogoliubov equations at finite temperatures, are shown to have the same formal expression as the ones we found earlier in the absence of pairing at zero temperature. Analytical expressions for the entrainment matrix are obtained for application to superfluid neutron-star cores. Results are compared to those obtained earlier using Landau's theory. Our formulas, valid for arbitrary temperatures and currents, are applicable to various types of functionals including the Brussels-Montreal series for which unified equations of state have been already calculated, thus laying the ground for a fully consistent microscopic description of superfluid neutron stars.
nucl-thastro-ph.HEPRC(2021)·12 citations
04
Precision determination of pion-nucleon coupling constants using effective field theory
P. Reinert🇩🇪 · H. Krebs🇩🇪 · E. Epelbaum🇩🇪
The pion-nucleon coupling constants determine the strength of the long-range nuclear forces and play a fundamental part in our understanding of nuclear physics. While the charged- and neutral-pion couplings to protons and neutrons are expected to be very similar, owing to the approximate isospin symmetry of the strong interaction, the different masses of the up- and down-quarks and electromagnetic effects may result in their slightly different values. Despite previous attempts to extract these coupling constants from different systems, our knowledge of their values is still deficient. In this Letter we present a precision determination of these fundamental observables with fully controlled uncertainties from neutron-proton and proton-proton scattering data using chiral effective field theory. To achieve this goal, we use a novel methodology based on the Bayesian approach and perform, for the first time, a full-fledged partial-wave analysis of nucleon-nucleon scattering up to the pion production threshold in the framework of chiral effective field theory, including a complete treatment of isospin-breaking effects and our own determination of mutually consistent data. The resulting values of the pion-nucleon coupling constants are accurate at the percent level and show no significant charge dependence. These results mark an important step towards developing a precision theory of nuclear forces and structure.
nucl-thhep-lathep-phnucl-exPRL(2021)·67 citations
05
Constraints from GW170817 on the bulk viscosity of neutron star matter and the r-mode instability
T. R. Routray🇮🇳 · S. P. Pattnaik🇮🇳 · C. Gonzalez-Boquera🇪🇸 · X. Viñas🇪🇸 · M. Centelles🇪🇸 · B. Behera🇮🇳
We perform a systematic study of the dependence of the r-mode phenomenology in normal fluid pulsar neutron stars on the symmetry energy slope parameter $L$ . An essential ingredient in this study is the bulk viscosity, which is evaluated consistently for several equations of state corresponding to different values of the slope parameter $L$ . Direct Urca processes, which are allowed from a critical $L$ -value onwards, enhance the bulk viscosity and have large influence on the $r$ -mode features, such as the instability boundary and spin-down properties of newborn neutron stars. The magnitude of the changes in the $r$ -mode properties induced by the direct Urca processes are driven by the $L$ -value of the equation of state and the mass of the pulsar. The study has been done by using a family of equations of state of $β$ -equilibrated neutron star matter obtained with the finite range simple effective interaction, which provides realistic results for nuclear matter and finite nuclei properties. These equations of state predict the same properties in symmetric nuclear matter and have the same value of the symmetry energy parameter, $E_{s} (ρ_{0})$ , but differ in the slope parameter $L$ . The range chosen for the variation of $L$ is decided from the tidal deformability data extracted from the GW170817 event and the maximum mass constraint.
nucl-thastro-ph.HEastro-ph.SR5 citations
06
Conformal Symmetry in nuclear structure
Panagioti E Georgoudis🇫🇷
The purpose of this paper is to introduce the unitary limit as applied in systems of cold atoms into collective states of heavy, even-even nuclei and to identify a related physical example. This is accompanied by the determination of observables of conformal symmetry in nuclear structure. A Hamiltonian is defined that governs the scattering process of an incident pair of two slow neutrons onto a heavy, even-even target nucleus in the framework of the Interacting Boson Model of nuclear structure. A unitary pair-collective state interaction is introduced along with the effective range expansion of a pair-collective state scattering length. The solutions to the coupled channels equations provide a scattering state for the two neutrons that couples with intermediate states of the $A + 2 n$ compound nucleus. The unitary limit manifests itself when the intermediate states correspond to pair-collective state resonances the positions of which coincide with the energies of IBM states of the closed channels. The position and the width of each resonance is measurable via the fluctuation of the cross section which tunes the pair-collective state scattering length. Conformal symmetry is represented in a tower of equally spaced states that emerges at the unitary limit from two-boson excitations on the IBM state of the closed channel. These tower states are experimentally testable as a regularity pattern of fluctuations of the cross section, in terms of regular positions and widths. The manifestation of the unitary limit and conformal symmetry via fluctuations of the cross section indicates the $A + 2 n$ compound nucleus as a physical laboratory for the examination of the BCS-BEC crossover, of an underlying critical point and of algebras with infinite number of generators.
nucl-thNPA(2021)·4 citations
07
Medium effects on $Ξ^{-}$ production in the nuclear ( $K^{-}$ , $K^{+}$ ) reaction
Toru Harada🇯🇵 · Yoshiharu Hirabayashi🇯🇵
We study theoretically medium effects on $Ξ^{-}$ production in the ( $K^{-}$ , $K^{+}$ ) reaction, using the optimal Fermi-averaging procedure which describes the Fermi motion of a nucleon on the on-energy-shell $K^{-} p \to K^{+} Ξ^{-}$ reaction condition in nuclei. The result shows the strong energy and angular dependence of the in-medium $K^{-} p \to K^{+} Ξ^{-}$ cross section,which affects significantly the shape and magnitude of the production spectrum for $Ξ^{-}$ hypernuclear states in the ( $K^{-}$ , $K^{+}$ ) reaction on a nuclear target.The application to the $Ξ^{-}$ quasi-free production via the ( $K^{-}$ , $K^{+}$ ) reaction on a $^{12}$ C target is also discussed in a Fermi gas model.
nucl-thhep-thnucl-exPRC(2020)·4 citations
08
Extending Standard Atomic Kernel Model with New Interpretation of Strong Forces
Dr Ing Hongguang Yang · Dr ret nat Weidong Yang
This paper gives an extended model of the atomic nucleus - we call it the YY model, which allows a new description for strong forces from the well-known Standard Model. The forces that hold the nucleus together (protons and neutrons) can be expressed in a new way. Based on the YY model, more structural description details for an atomic nucleus will be possible than is the case with the conventional description. The YY model is compatible with the standard model. However, it allows for very delicate considerations when modelling the distribution of protons and neutrons within or around an atomic nucleus. Furthermore, it can explain many subatomic processes in an elegant way. The YY model predicts some subatomic aspects that can be explored in a deeper step. Our approach also includes a native common root for the description of macrophysics (space, dark matter and cosmology). Following a model-driven approach - a methodology widely used in computer science and informatics - the investigations in this paper will completely dispense with mathematical formulations. In addition, energy balances in the transformations are left out. Many different aspects that can be derived from this new mechanism can then be verified. We hope to gain the confidence of many other physicists in the YY model. They could make detailed theoretical and experimental verifications by adding additional descriptive elements and linking the YY model to the known quantum field theories and the widely accepted big bang theories for space and cosmology, especially for research on dark matter.
nucl-thhep-ph0 citations
09
Observable signatures of initial state momentum anisotropies in nuclear collisions
Giuliano Giacalone🇫🇷 · Bjoern Schenke🇺🇸 · Chun Shen🇺🇸
We show that the correlation between the elliptic momentum anisotropy, $v_{2}$ , and the average transverse momentum, $[p_{T}]$ , at fixed multiplicity in small system nuclear collisions carries information on the origin of the observed momentum anisotropy. A calculation using a hybrid IP-Glasma+\textsc{Music}+UrQMD model that includes contributions from final state response to the initial geometry as well as initial state momentum anisotropies of the Color Glass Condensate, predicts a characteristic sign change of the correlator $ρ^(v_{2}^{2}, [p_{T}])$ as a function of charged particle multiplicity in p+Au and d+Au collisions at $s = 200 GeV$ , and p+Pb collisions at $s = 5.02 TeV$ . This sign change is absent in calculations without initial state momentum anisotropies. The model further predicts a qualitative difference between the centrality dependence of $ρ^(v_{2}^{2}, [p_{T}])$ in Au+Au collisions at $s = 200 GeV$ and Pb+Pb collisions at $s = 5.02 TeV$ , with only the latter showing a sign change in peripheral events. Predictions for O+O collisions at different collision energy show a similar behavior. Experimental observation of these distinct qualitative features of $ρ^(v_{2}^{2}, [p_{T}])$ in small and large systems would constitute strong evidence for the presence and importance of initial state momentum anisotropies predicted by the Color Glass Condensate effective theory.
nucl-thhep-phnucl-exPRL(2020)·72 citations
10
Insights on pion production mechanism and symmetry energy at high density
Yangyang Liu🇨🇳 · Yongjia Wang🇨🇳 · Ying Cui🇨🇳 · Chen-Jun Xia🇨🇳 · Zhuxia Li🇨🇳 · Yongjing Chen🇨🇳 · Qingfeng Li🇨🇳 · Yingxun Zhang🇨🇳
The $N Δ \to N N$ cross sections, which take into account the $Δ$ -mass dependence of M-matrix and momentum $p_{N Δ}$ , are applied on the calculation of pion production within the framework of the UrQMD model. Our study shows that UrQMD calculations with the $Δ$ -mass dependent $N Δ \to N N$ cross sections enhance the pion multiplicities and decrease the $π^{-} / π^{+}$ ratios. By analyzing the time evolution of the pion production rate and the density in the overlapped region for Au+Au at the beam energy of 0.4A GeV, we find that the pion multiplicity probes the symmetry energy in the region of 1-2 times normal density. The process of pion production in the reaction is tracked including the loops of $N N \leftrightarrow N Δ$ and $Δ \leftrightarrow N π$ , our calculations show that the sensitivity of $π^{-} / π^{+}$ to symmetry energy is weakened after 4-5 N- $Δ$ - $π$ loops in the pion production path, while the $π^{-} / π^{+}$ ratio in reactions at near threshold energies remains its sensitivity to the symmetry energy. By comparing the calculations to the FOPI data, we obtain a model dependent conclusion on the symmetry energy and the symmetry energy at two times normal density is $S (2 ρ_{0})$ =38-73 MeV within $1 σ$ uncertainties. Under the constraints of tidal deformability and maximum mass of neutron star, the symmetry energy at two times normal density is reduced to $48 - 58$ MeV and slope of symmetry energy $L = 54 - 81$ MeV, and it is consistent with the constraints from ASY-EOS flow data.
nucl-thnucl-exPRC(2021)·42 citations
11
Systematic Analysis of Flow Distributions
Hadi Mehrabpour🇮🇷
The information of the event-by-event fluctuations is extracted from flow harmonic distributions and cumulants, which can be done experimentally. In this work, we employ the standard method of Gram-Charlier series with the normal kernel to find such distribution, which is the generalization of recently introduced flow distributions for the studies of the event-by-event fluctuations. Also, we introduce a new set of cumulants $j_{n} {2 k}$ which have more information about the fluctuations compared with other known cumulants. The experimental data imply that not only all of the information about the event-by-event fluctuations of collision zone properties and different stages of the heavy-ion process are not encoded in the radial flow distribution $p (v_{n})$ , but also the observables describing harmonic flows can generally be given by the joint distribution $P (v_{1}, v_{2}, ...)$ . In such a way, we first introduce a set of joint cumulants $K_{nm}$ , and then we find the flow joint distribution using these joint cumulants. Finally, we show that the Symmetric Cumulants $S C (2, 3)$ and $S C (2, 4)$ obtained from ALICE data are explained by the combinations $K_{22} + \frac{1}{2} K_{04} - K_{31}$ and $K_{22} + 4 K_{11}^{2}$ .
nucl-thhep-phnucl-exPRC(2020)·5 citations
12
Nucleon Polarizabilities and Compton Scattering as a Playground for Chiral Perturbation Theory
Franziska Hagelstein (AEC Bern)🇨🇭
I give a summary of recent results on nucleon polarizabilities, with emphasis on chiral perturbation theory. The predictive calculations of Compton scattering off the nucleon are compared to recent empirical determinations and lattice QCD calculations of the polarizabilities, thereby testing chiral perturbation theory in the single-baryon sector.
nucl-thhep-lathep-phnucl-exSymmetry(2020)·13 citations
13
Excitation Functions of Tsallis-like Parameters in High-Energy Nucleus-Nucleus Collisions
Li-Li Li🇨🇳 · Fu-Hu Liu🇨🇳 · Khusniddin K. Olimov🇺🇿
The transverse momentum spectra of charged pions, kaons, and protons produced at mid-rapidity in central nucleus-nucleus (AA) collisions at high energies are analyzed by considering particles to be created from two participant partons which are assumed to be contributors from the collision system. Each participant (contributor) parton is assumed to contribute to the transverse momentum by a Tsallis-like function. The contributions of the two participant partons are regarded as the two components of transverse momentum of the identified particle. The experimental data measured in high-energy AA collisions by international collaborations are studied. The excitation functions of kinetic freeze-out temperature and transverse flow velocity are extracted. The two parameters increase quickly from $\approx 3$ to $\approx 10$ GeV (exactly from 2.7 to 7.7 GeV) and then slowly at above 10 GeV with the increase of collision energy. In particular, there is a plateau from near 10 GeV to 200 GeV in the excitation function of kinetic freeze-out temperature.
↳ hep-phhep-exnucl-exnucl-thEntropy(2021)·31 citations
14
A Dyson-Schwinger model beyond isospin limit prepared for investigating U_A(1)-breaking temperature dependence
Davor Horvatić🇭🇷 · Dalibor Kekez🇭🇷 · Dubravko Klabučar🇭🇷
Motivated by our earlier findings of sensitive quark-flavor dependence of QCD topological susceptibility on products of current quark masses and corresponding condensates, we allow the breaking of isospin symmetry. For the purpose of future investigations of U_A(1) symmetry breaking and restoration at T > 0, we perform (at T = 0) refitting of the quark-mass parameters of a phenomenologically successful effective model of low-energy QCD. It belongs to the class of separable-interaction models within the Dyson-Schwinger approach to the quark-antiquark substructure of mesons.
↳ hep-phnucl-thEur.Phys.J.ST(2020)·3 citations
15
FeynOnium: Using FeynCalc for automatic calculations in Nonrelativistic Effective Field Theories
Nora Brambilla🇩🇪 · Hee Sok Chung🇩🇪 · Vladyslav Shtabovenko🇩🇪 · Antonio Vairo🇩🇪
We present new results on FeynOnium, an ongoing project to develop a general purpose software toolkit for semi-automatic symbolic calculations in nonrelativistic Effective Field Theories (EFTs). Building upon FeynCalc, an existing Mathematica package for symbolic evaluation of Feynman diagrams, we have created a powerful framework for automatizing calculations in nonrelativistic EFTs (NREFTs) at tree- and 1-loop level. This is achieved by exploiting the novel features of FeynCalc that support manipulations of Cartesian tensors, Pauli matrices and nonstandard loop integrals. Additional operations that are common in nonrelativistic EFT calculations are implemented in a dedicated add-on called FeynOnium. While our current focus is on EFTs for strong interactions of heavy quarks, extensions to other systems that admit a nonrelativistic EFT description are planned for the future. All our codes are open-source and publicly available. Furthermore, we provide several example calculations that demonstrate how FeynOnium can be employed to reproduce known results from the literature.
↳ hep-phcond-mat.str-elhep-lathep-th+1JHEP(2020)·23 citations
16
Theoretical study of the $Ω (2012)$ state in the $Ω_{c}^{0} \to π^{+} Ω (2012)^{-} \to π^{+} (K ˉ Ξ)^{-}$ and $π^{+} (K ˉ Ξ π)^{-}$ decays
Chun-Hua Zeng🇨🇳 · Jun-Xu Lu🇨🇳 · En Wang🇨🇳 · Ju-Jun Xie🇨🇳 · Li-Sheng Geng🇨🇳
We report on a theoretical study of the newly observed $Ω (2012)$ resonance in the nonleptonic weak decays of $Ω_{c}^{0} \to π^{+} K ˉ Ξ^{*} (1530) (η Ω) \to π^{+} (K ˉ Ξ)^{-}$ and $π^{+} (K ˉ Ξ π)^{-}$ via final-state interactions of the $K ˉ Ξ^{*} (1530)$ and $η Ω$ pairs. The weak interaction part is assumed to be dominated by the charm quark decay process: $c (ss) \to (s + u + d ˉ) (ss)$ , while the hadronization part takes place between the $sss$ cluster from the weak decay and a quark-antiquark pair with the quantum numbers $J^{P C} = 0^{++}$ of the vacuum, produces a pair of $K ˉ Ξ^{*} (1530)$ and $η Ω$ . Accordingly, the final $K ˉ Ξ^{*} (1530)$ and $η Ω$ states are in pure isospin $I = 0$ combinations, and the $Ω_{c}^{0} \to π^{+} K ˉ Ξ^{*} (1530) (η Ω) \to π^{+} (K ˉ Ξ)^{-}$ decay is an ideal process to study the $Ω (2012)$ resonance. With the final-state interaction described in the chiral unitary approach, up to an arbitrary normalization, the invariant mass distributions of the final state are calculated, assuming that the $Ω (2012)$ resonance with spin-parity $J^{P} = 3/ 2^{-}$ is a dynamically generated state from the coupled channels interactions of the $K ˉ Ξ^{*} (1530)$ and $η Ω$ in $s$ -wave and $K ˉ Ξ$ in $d$ -wave. We also calculate the ratio, $R_{K ˉ Ξ}^{K ˉ Ξ π} = Br [Ω_{c}^{0} \to π^{+} Ω (2012)^{-} \to π^{+} (K ˉ Ξ π)^{-}] / Br [Ω_{c}^{0} \to π^{+} Ω (2012)^{-} \to π^{+} (K ˉ Ξ)^{-}$ ]. The proposed mechanism can provide valuable information on the nature of the $Ω (2012)$ and can in principle be tested by future experiments.
↳ hep-phhep-exnucl-exnucl-thPRD(2020)·35 citations
17
In medium properties of axion within a Polyakov loop enhanced Nambu-Jona-Lasinio model
Arpan Das🇵🇱 · Hiranmaya Mishra🇮🇳 · Ranjita K. Mohapatra🇮🇳
We estimate the axion properties i.e. its mass, topological susceptibility and the self-coupling within the framework of Polyakov loop enhanced Nambu-Jona-Lasinio (PNJL) model at finite temperature and quark chemical potential. PNJL model, where quarks couple simultaneously to the chiral condensate and to a background temporal quantum chromodynamics (QCD) gauge field, includes two important features of QCD phase transition, i.e. deconfinement and chiral symmetry restoration. The Polyakov loop in PNJL model plays an important role near the critical temperature. We have shown significant difference in the axion properties calculated in PNJL model compared to the same obtained using Nambu-Jona-Lasinio (NJL) model. We find that both the mass of the axion and its self-coupling are correlated with the chiral transition as well as the confinement-deconfinement transition. We have also estimated the axion properties at finite chemical potential. Across the QCD transition temperature and/or quark chemical potential axion mass and its self-coupling also changes significantly. Since the PNJL model includes both the fermionic sector and the gauge fields, it can give reliable estimates of the axion properties, i.e. it's mass and the self-coupling in a hot and dense QCD medium. We also compare our results with the lattice QCD results whenever available.
↳ hep-phnucl-thPRD(2021)·19 citations
18
Pileup corrections on higher-order cumulants
Toshihiro Nonaka🇯🇵 · Masakiyo Kitazawa🇯🇵 · ShinIchi Esumi🇯🇵
We propose a method to remove the contributions of pileup events from higher-order cumulants and moments of event-by-event particle distributions. Assuming that the pileup events are given by the superposition of two independent single-collision events, we show that the true moments in each multiplicity bin can be obtained recursively from lower multiplicity events. In the correction procedure the necessary information are only the probabilities of pileup events. Other terms are extracted from the experimental data. We demonstrate that the true cumulants can be reconstructed successfully by this method in simple models. Systematics on trigger inefficiencies and correction parameters are discussed.
↳ physics.data-anhep-phnucl-exnucl-thNucl.Instrum.Meth.A(2020)·18 citations
19
Hawking radiation from acoustic black holes in relativistic heavy ion collisions
Arpan Das🇮🇳 · Shreyansh S. Dave🇮🇳 · Oindrila Ganguly🇮🇳 · Ajit M. Srivastava🇮🇳
We propose a new analogue model of gravity - the evolving quark gluon plasma (QGP) produced in relativistic heavy ion collisions. This quark gluon plasma is the "most inviscid" fluid known. Such low kinematic viscosity is believed to reflect strongly correlated nature for QGP in these experiments. Hence, it may provide a good example of a quantum fluid naturally suited to studies of acoustic Hawking radiation. Due to rapid longitudinal expansion, presence of a sonic horizon is also naturally guaranteed here, though, in general, this horizon is not static. Using Ultra relativistic quantum molecular dynamics (UrQMD) simulations, we show that, under certain conditions, the longitudinal velocity of the plasma, near the sonic horizon, can become time independent for a short span during the evolution of the system. During this period, we can have a conformally static acoustic metric with a (conformal) Killing horizon coinciding with the apparent horizon. An asymptotic observer will then see a thermal flux of phonons, constituting the Hawking radiation, coming from the horizon. For the relatively low energy collision considered here, where the resulting QCD system is governed by non-relativistic hydrodynamics, we estimate the Hawking temperature to be about 4-5 MeV (with the temperature of the QCD fluid being about 135 MeV). We discuss the experimental signatures of this Hawking radiation in terms of a thermal component in the rapidity dependence of the transverse momentum distribution of detected particles. We also discuss extension to ultra-relativistic case which should lead to a higher Hawking temperature, along with the effects of dynamical horizon leading to blue/red shift of the temperature.
↳ gr-qchep-phhep-thnucl-ex+1PLB(2021)·7 citations
20
Fermion and Photon gap-equations in Minkowski space within the Nakanishi Integral Representation method
Cédric Mezrag🇮🇹 · Giovanni Salmè🇮🇹
The approach based on the Nakanishi integral representation of n-leg transition amplitudes is extended to the treatment of the self-energies of a fermion and an (IR-regulated) vector boson, in order to pave the way for constructing a comprehensive application of the technique to both gap- and Bethe-Salpeter equations, in Minkowski space. The achieved result, namely a 6-channel coupled system of integral equations, eventually allows one to determine the three Källén-Lehman weights for fully dressing the propagators of fermion and photon. A first consistency check is also provided. The presented formal elaboration points to embed the characteristics of the non-perturbative regime at a more fundamental level. It yields a viable tool in Minkowski space for the phenomenological investigation of strongly interacting theories, within a QFT framework where the dynamical ingredients are made transparent and under control.
↳ hep-phnucl-thEPJC(2021)·26 citations
21
Out of equilibrium Chiral Vortical Effect in Holography
Sergio Morales-Tejera🇪🇸 · Karl Landsteiner🇪🇸
We study the chiral vortical effect far from equilibrium in a strongly coupled holographic field theory. Rotation is represented as a perturbation via a gravito-magnetic field on top of a five-dimensional charged AdS Vaidya metric. We also introduce a momentum relaxation mechanism by linear scalar field backgrounds and study the CVE dynamics as function of the charges, temperature and momentum relaxation. The far from equilibrium behavior shows that the CVE builds up with a significant delay in time compared to the quasi instantaneous equilibration of the background metric. We also pay special attention to the effects of the gravitational contribution to the axial anomaly in the CVE of the axial current. We develop an analytic estimate of this delay and also compute the quasi-normal modes near equilibrium which determine the late time ring down.
↳ hep-thhep-phnucl-thPRD(2020)·8 citations

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