PaperPanorama

Nuclear Theory·nucl-th

Monday·January 30, 2023

7 papers—1 primary·6 cross-listed

All7Primary1Cross-lists6
  1. 01

    Next-generation multi-fluid hydrodynamic model for RHIC BES

    Jakub Cimerman🇨🇿 · Iurii Karpenko🇨🇿 · Boris Tomasik🇨🇿 · Pasi Huovinen🇵🇱

    We have developed a next-generation hybrid event-by-event three-fluid hydrodynamic model, suitable for simulations of heavy-ion collisions in the energy range from few up to tens of GeV per colliding NN pair. At such energies the interpenetration time of the nuclei is of the same order as the lifetime of the system, however this model treats the initial phase hydrodynamically. Thanks to that it is more sensitive to the Equation of State than 1-fluid models with initial states being parametrised or generated by transport approach. Hence, our model is well designed for simulations at collision energies, at which matter in vicinity of the QCD critical endpoint is expected. The construction of the model is explained and basic observables like hadron spectra in rapidity and transverse momentum, as well as elliptic flow are calculated.

    nucl-thhep-phPRC(2023)·30 citations
  2. 02

    Particle Interferometry in a Moat Regime

    Fabian Rennecke🇩🇪 · Robert D. Pisarski🇺🇸 · Dirk H. Rischke🇩🇪

    Dense strongly interacting matter can exhibit regimes with spatial modulations, akin to crystalline phases. In this case particles can have a moat spectrum with minimal energy at nonzero momentum. We show that particle interferometry is a sensitive probe of such a regime in heavy-ion collisions. To this end, we develop a field-theoretical formalism that relates particle spectra to in-medium real-time correlation functions of quantum fields on curved hypersurfaces of spacetime. This is then applied to the study of Bose-Einstein correlations in a moat regime in heavy-ion collisions. The resulting two-particle spectra exhibit peaks at nonzero average pair momentum, in contrast to the two-particle spectra in a normal phase, which peak at zero momentum. These peaks lead to non-trivial structures in the ratio of two-particle correlation functions, which should be experimentally measurable if the resolution in the direction of average pair momentum is sufficiently large. We propose these structures in the correlation-function ratios as clear signature of a moat regime and spatially modulated phases in quantum chromodynamics (QCD).

    ↳ hep-phnucl-exnucl-thPRD(2023)·38 citations
  3. 03

    Eigenvalues of the QCD Dirac matrix with improved staggered quarks in the continuum limit

    Olaf Kaczmarek🇩🇪 · Ravi Shanker🇮🇳 · Sayantan Sharma🇮🇳

    We calculate the eigenmodes of the Highly Improved Staggered Quark (HISQ) matrix near the chiral crossover transition in QCD with flavors with the aim to gain more insights into its temperature dependence. On performing the continuum extrapolation, we do not observe any gap opening up in the infrared part of the eigenvalue density of the QCD Dirac operator; instead we observe a peak. The existence of the peak and oscillations of the infrared eigenmodes can be understood in terms of an interacting ensemble of instantons. From the properties of the continuum extrapolated eigenspectrum we further show that the anomalous part of the chiral symmetry is not effectively restored simultaneously along with its non-singlet counterpart. We provide an explanation for this observation, further showing interesting connections between the anomalous restoration and the change in the infrared part of the eigenvalue distribution.

    ↳ hep-lathep-phnucl-thPRD(2023)·27 citations
  4. 04

    Non-Abelian Anyons and Non-Abelian Vortices in Topological Superconductors

    Yusuke Masaki🇯🇵 · Takeshi Mizushima🇯🇵 · Muneto Nitta🇯🇵

    Anyons are particles obeying statistics of neither bosons nor fermions. Non-Abelian anyons, whose exchanges are described by a non-Abelian group acting on a set of wave functions, are attracting a great attention because of possible applications to topological quantum computations. Braiding of non-Abelian anyons corresponds to quantum computations. The simplest non-Abelian anyons are Ising anyons which can be realized by Majorana fermions hosted by vortices or edges of topological superconductors, quantum Hall states, spin liquids, and dense quark matter. While Ising anyons are insufficient for universal quantum computations, Fibonacci anyons present in quantum Hall states can be used for universal quantum computations. Yang-Lee anyons are non-unitary counterparts of Fibonacci anyons. Another possibility of non-Abelian anyons (of bosonic origin) is given by vortex anyons, which are constructed from non-Abelian vortices supported by a non-Abelian first homotopy group, relevant for certain nematic liquid crystals, superfluid He, spinor Bose-Einstein condensates, and high density quark matter. Finally, there is a unique system admitting two types of non-Abelian anyons, Majorana fermions (Ising anyons) and non-Abelian vortex anyons. That is superfluids (spin-triplet, -wave paring of neutrons), expected to exist in neutron star interiors as the largest topological quantum matter in our universe.

    ↳ cond-mat.supr-concond-mat.mes-hallhep-phhep-th+1in Encyclopedia of Condensed Matter Physi…·13 citations
  5. 05

    Neutrinos from dense environments : Flavor mechanisms, theoretical approaches, observations, and new directions

    M. Cristina Volpe🇫🇷

    Neutrino masses and mixings produce vacuum oscillations, an established quantum mechanical phenomenon. In matter, the Mikheev-Smirnov-Wolfenstein effect, due to neutrino interactions with the background particles, triggers resonant flavor modification. In dense environments, such as core-collapse supernovae or compact mergers, sizable neutrino-neutrino interactions, shock waves and turbulence impact the neutrino flavor content under a variety of phenomena. Theoretical approaches of neutrino propagation range from the mean-field approximation to the full quantum kinetic equations. Intriguing connections have been uncovered between weakly interacting dense neutrino gases and other many-body systems and domains, from condensed matter and nuclear physics to quantum computing. Besides the intrinsic theoretical interest, establishing how neutrinos change flavor contributes to answer the longstanding open questions of how massive stars explode and of the r-process sites. It is also important for future observations of core-collapse supernova neutrinos and of the diffuse supernova neutrino background that should be discovered in the foreseeable future.

    ↳ hep-phastro-ph.SRhep-exnucl-thRMP(2024)·159 citations
  6. 06

    Electromagnetic Form Factors and Charge Radii of Pseudoscalar and Scalar Mesons: A Comprehensive Contact Interaction Analysis

    R. J. Hernández-Pinto🇲🇽 · L. X. Gutiérrez-Guerrero🇲🇽 · A. Bashir🇲🇽 · M. A. Bedolla🇲🇽 · I. M. Higuera-Angulo🇲🇽

    We carry out a comprehensive survey of electromagnetic form factors of all light, heavy and heavy-light ground-state pseudoscalar and scalar mesons. Our analysis is based upon a Schwinger-Dyson equations treatment of a vector vector contact interaction. It incorporates confinement and ensures axial vector and vector Ward-Takahashi identities are satisfied along with the corresponding corollaries such as the Goldberger-Treiman relations. The algebraic simplicity of the model allows us to compute the form factors at arbitrarily large virtualities of the probing photon momentum squared with relative ease. Wherever possible and insightful, we compare our results for the electromagnetic form factors and the charge radii with those obtained earlier through Schwinger-Dyson equations, lattice and with experimental observations available. We also comment on the scope and shortcomings of the model.

    ↳ hep-phnucl-thPRD(2023)·36 citations
  7. 07

    A modular perspective to the jet suppression from a small to large radius in very high transverse momentum jets

    Manaswini Priyadarshini🇮🇳 · Om Shahi🇮🇳 · Vaishnavi Sathe🇮🇳 · Prabhakar Palni🇮🇳

    In this work, we expand the scope of the JETSCAPE framework to investigate the dependence of the jet nuclear modification factor, , on the jet radius parameter () for broader area jet cones, going all the way up to = 1.0. This study presents a comprehensive analysis of high- inclusive jets extending up to 1 TeV to probe the quark-gluon plasma medium at much shorter distance scales. It focuses on quenching effects observed in the quark-gluon plasma formed during Pb-Pb collisions at = 5.02 TeV, particularly for the most-central (0-10\%) collisions. Jet-medium interactions represent a pivotal domain of both theoretical and experimental QGP studies, with various models offering different assumptions to describe these phenomena. To illustrate this modular approach, this work computes the nuclear modification factor for inclusive jets via coupling of the MATTER model (which simulates the high virtuality phase of the parton evolution) with the LBT model (which simulates the low virtuality phase of the parton evolution). Additionally, the two successful energy loss models: MARTINI and AdS/CFT are employed to characterize the jet-suppression effectively within the JETSCAPE framework. The results are compared with the experimental data from the ATLAS and CMS detectors, covering jet transverse momentum () ranging from 100 GeV to 1 TeV for ATLAS and 300 GeV to 1 TeV for CMS. The predictions made by the JETSCAPE are consistent in the high range as well as for extreme jet cone sizes, showing deviation within 10-25\%. Our major focus is on calculating the double ratio () as a function of jet-R and jet-, where the experimental results align well with predictions from the JETSCAPE framework.

    ↳ hep-phnucl-thPRD(2025)·0 citations

Affiliations

first authorsco-authorsvia INSPIRE