PaperPanorama

Nuclear Theory·nucl-th

Friday·December 13, 2024

12 papers6 primary·6 cross-listed

  1. 07

    Jet substructure of light and heavy flavor jets at RHIC

    Zhuoheng Yang🇺🇸 · Oleh Fedkevych🇺🇸 · Roli Esha🇺🇸

    Jet substructure studies at the Large Hadron Collider have been used to constrain parton distribution functions, test perturbative QCD, measure the strong-coupling constant, and probe the properties of the quark-gluon plasma. We extend these studies to lower energies at the Relativistic Heavy Ion Collider that would additionally allow us to test existing models of non-perturbative physics. In this study, we present a PYTHIA8-based Monte Carlo study of substructure of jets produced in collisions at 200 GeV. The selection criteria is adapted for a feasible measurement at sPHENIX. We consider different types of jet substructure observables such as jet angularities and primary Lund Plane with a special focus on suppression of collinear radiation around emitting heavy quark known as a dead cone effect.

    hep-phnucl-exnucl-thPRC(2026)·1 citation
  2. 08

    Off-shell vertices in heavy particle effective theories and

    Michele Papucci🇺🇸 · Ryan Plestid🇺🇸

    We study the modifications to decay amplitudes in heavy to heavy semileptonic decays with multiple hadrons in the final state due to intermediate heavy hadrons being off-shell or having a finite width. Combining Heavy Hadron Chiral Perturbation Theory (HHPT) with a BCFW on-shell factorization formula, we show that these effects induce corrections to the standard results computed in the narrow-width approximation and therefore are important in extracting form factors from data. A combination of perturbative unitarity, analyticity, and reparameterization invariance fully determine these corrections in terms of known Isgur-Wise functions without the need to introduce new form factors. In doing so, we develop a novel technique to compute the boundary term at complex infinity in the BCFW formula for theories with derivatively coupled scalars. While we have used the decay as an example, these techniques can generally be applied to effective field theories with (multiple) distinct reference vectors.

    hep-phnucl-thJHEP(2025)·2 citations
  3. 09

    Chiral phase transition: effective field theory and holography

    Yanyan Bu🇨🇳 · Zexin Yang🇨🇳

    We consider the chiral phase transition relevant for QCD matter at finite temperature but with vanishing baryon density. Presumably, the chiral phase transition is of second order for two-flavor QCD in the chiral limit. Near the transition temperature, we apply the Schwinger-Keldysh formalism and construct a low-energy effective field theory for the system, in which fluctuations and dissipations are systematically captured. The dynamical variables involve the chiral charge densities and order parameter (chiral condensate). Via the holographic Schwinger-Keldysh technique, the effective action is further confirmed within a modified AdS/QCD model. With higher-order terms suitably neglected, the stochastic equations derived from the effective field theory resemble those of model F in the Hohenberg-Halperin classification. Within the effective field theory, we briefly discuss the spontaneous breaking of chiral symmetry and Goldstone modes.

    hep-thcond-mat.mes-hallhep-phnucl-thPRD(2025)·4 citations
  4. 10

    Magnetic polarisability of octet baryons near the physical quark-mass point

    Thomas Kabelitz🇦🇺 · Waseem Kamleh🇦🇺 · Derek Leinweber🇦🇺

    The magnetic polarisabilities of octet baryons are calculated close to the physical quark-mass point using the background field method in lattice QCD. This first calculation draws on the identification and elimination of exceptional configurations that have hindered previous attempts. The origin of the exceptional configuration problem lies in the use of a Wilson-type fermion action on electro-quenched gauge field configurations, where the dynamical-fermion gauge-field generation algorithm the electric charges of the quarks. Changes in the fermion determinant that would suppress some gauge fields in the background magnetic field are neglected, leaving improbable gauge fields that generate large additive mass renormalisations which manifest as significant outliers in correlation-function distributions. An algorithm for the systematic identification and removal of these exceptional configurations is described. We find the light up and down quarks to be problematic, particularly the up quark with its larger electric charge. The heavier mass of the strange quark protects the hyperon correlation functions to some extent. However, these also benefit from the removal of exceptional configurations. In many cases, the magnetic polarisability is calculated with good precision. We find our results to be in accord with the behaviour anticipated by chiral perturbation theory.

    hep-lathep-phnucl-thPRD(2025)·0 citations
  5. 11

    Exploring the chiral magnetic effect in isobar collisions through Chiral Anomaly Transport

    Zilin Yuan🇨🇳 · Anping Huang🇨🇳 · Guannan Xie🇨🇳 · Wen-Hao Zhou🇨🇳 · Guo-Liang Ma🇨🇳 · Mei Huang🇨🇳

    We investigate the signal of the chiral magnetic effect (CME) in Au+Au collisions and isobar collisions of and in the newly developed chiral anomaly transport (CAT) module based on the state-of-the-art model a multiphase transport (AMPT). Our numerical simulation results for the ratio charge correlation in Ru+Ru and Zr+Zr collisions are close to the latest experimental data. The simulation shows that the CME signal is larger in Ru+Ru collisions than that in Zr+Zr collisions, while the background is smaller, and the upper limit of the CME signal is in the isobar collisions.

    hep-phnucl-thPRC(2025)·7 citations
  6. 12

    A harmonic oscillator in nonadditive statistics and a novel transverse momentum spectrum in high-energy collisions

    Trambak Bhattacharyya🇵🇱 · Maciej Rybczyński🇵🇱 · Grzegorz Wilk🇵🇱 · Zbigniew Włodarczyk🇵🇱

    It is widely observed that particles produced in high-energy collisions follow a power-law distribution. One such power-law distribution used extensively in the phenomenological studies owes its origin to nonadditive statistics proposed by C. Tsallis. In this article, we derive a novel nonadditive generalization of the conventional Bose-Einstein distribution using a single-mode harmonic oscillator. The approach taken in this paper eliminates the need of a regularization procedure proposed in previous works. We observe that the spectra of the bosonic particles like the pions and kaons produced in high-energy collisions are well-described by the nonadditive bosonic distribution derived in this paper.

    hep-phhep-exnucl-thPLB(2025)·2 citations

Affiliations

first authorsco-authorsvia INSPIRE