Nuclear Theory·nucl-th

Wednesday·August 28, 2024

14 papers—7 primary·7 cross-listed

08
Long Range Energy-energy Correlator at the LHC
Yuxun Guo🇺🇸 · Xiaohui Liu🇨🇳 · Feng Yuan🇺🇸
We study the forward-backward azimuthal angular correlations of hadrons in association with multi-particle production in the central rapidity region in proton-proton collisions at the LHC. We apply the nucleon energy-energy correlator framework, where the spinning gluon distribution introduces a nontrivial $cos (2 ϕ)$ asymmetries. We will demonstrate that the fundamental helicity structure of QCD amplitudes predicts a unique power counting rule: $cos (2 ϕ)$ asymmetry starts at $O (α_{s}^{2})$ order for dijet, $O (α_{s})$ for three jet and $O (1)$ for four (and more) jet productions. Our results will help us to understand the long standing puzzle of nearside ridge behavior observed in high multiplicity events of $pp$ collisions at the LHC.
↳ hep-phhep-exnucl-exnucl-thPRD(2025)·11 citations
09
The impact of dark matter on tidal signatures in neutron star mergers with Einstein Telescope
Hauke Koehn · Edoardo Giangrandi · Nina Kunert · Rahul Somasundaram · Violetta Sagun · Tim Dietrich
If dark matter (DM) accumulates inside neutron stars (NS), it changes their internal structure and causes a shift of the tidal deformability from the value predicted by the dense-matter equation of state (EOS). In principle, this shift could be observable in the gravitational-wave (GW) signal of binary neutron star (BNS) mergers. We investigate the effect of fermionic, non-interacting DM when observing a large number of GW events from DM-admixed BNSs with the precision of the proposed Einstein telescope (ET). Specifically, we study the impact on the recovery of the baryonic EOS and whether DM properties can be constrained. For this purpose, we create event catalogues of BNS mock events with DM fraction up to 1%, from which we reconstruct the posterior uncertainties with the Fisher matrix approach. Using this data, we perform joint Bayesian inference on the baryonic EOS, DM particle mass, and DM particle fraction in each event. Our results reveal that when falsely ignoring DM effects, the EOS posterior is biased towards softer EOSs, though the offset is rather small. Further, we find that within our assumptions of our DM model and population, ET will likely not be able to test the presence of DM in BNSs, even when combining many events and adding Cosmic Explorer (CE) to the next-generation detector network. Likewise, the potential constraints on the DM particle mass will remain weak because of degeneracies with the fraction and EOS.
↳ astro-ph.HEgr-qcnucl-thPRD(2024)·26 citations
10
Effect of quark anomalous magnetic moment on neutral dense quark matter under magnetic field
Mamiya Kawaguchi🇨🇳 · Irfan Siddique🇨🇳 · Mei Huang🇨🇳
We discuss the effect of the quark anomalous magnetic moment (AMM) on the neutral dense quark matter under magnetic fields based on the Nambu-Jona-Lasinio (NJL) model at finite baryon density. To address its correlation with the chiral symmetry, we consider a simplified situation: the model includes the two-quark flavors under constant magnetic fields, and incorporates the effective interaction of the quark AMM linked to the spontaneous chiral symmetry breaking. We then examine the equation of state (EoS) in cases with and without magnetization for anatomizing the thermodynamic quantities. Without the magnetization, a small magnetic field stiffens the EoS, but with increasing the magnetic field, the EoS tends to soften. The stiffness of the EoS is found to be influenced by the magnetic effect on the critical chemical potential of the chiral phase transition and the quark number density at this critical point. As a result, the mass and radius of the neutral dense quark matter increase with the small magnetic field but turn to decrease as the magnetic field further increases. By including the quark AMM, the critical chemical potential is decreased and the quark number density takes a smaller value. Thus, for the stronger magnetic fields, the quark AMM suppresses the softening effect of the magnetic field on the EoS, leading to increased mass and radius compared to when the quark AMM is absent. In contrast, for the small magnetic field, the contribution of the quark AMM to the EoS is marginal. When the magnetization is taken into account, the magnetic effect on the stiffness of the EoS is overshadowed by the contribution of the magnetization, and the significance of the quark AMM also becomes invisible in the mass-radius relation.
↳ hep-phnucl-thEPJC(2025)·8 citations
11
A multi-band study of pulsar glitches with Fermi-LAT and Parkes
P. Liu · J.-P. Yuan · M.-Y. Ge · W.-T. Ye · S.-Q. Zhou · S.-J. Dang · Z.-R. Zhou · E. Gügercinoğlu · Z. H. Tu · P. Wang · A. Li · D. Li · N. Wang
Pulsar glitch is a phenomenon characterized by abrupt changes in the spin period over less than a minute. We present a comprehensive analysis of glitches in four gamma-ray pulsars by combining the timing observation data from \textit{Fermi} Large Area Telescope (\textit{Fermi}-LAT) and Parkes 64 m radio telescope. The timing data of five pulsars, namely PSRs J1028 $-$ 5819, J1420 $-$ 6048, J1509 $-$ 5850, J1709 $-$ 4429 (B1706 $-$ 44) and J1718 $-$ 3825, are examined over 14 yr of observations for each. A total of 12 glitches are identified in four pulsars, including a previously unreported glitch. That is, a new small glitch is identified for PSR J1718 $-$ 3825 in MJD $\sim$ 59121(8), with a fractional glitch size of $Δ ν / ν \sim 1.9 (2) \times 1 0^{- 9}$ . For PSR J1420 $-$ 6048, our investigation confirms the presence of two linear recovery terms during the evolution of $ν ˙$ following glitches 4, 6 and 8. Moreover, an exponential recovery process was identified after glitch 8, with a recovery fraction ( $Q$ ) of $Q = 0.0131 (5)$ and a corresponding timescale of $τ_{d} = 100 (6)$ d. Regarding the fourth glitch of PSR J1709 $-$ 4429, our analysis reveals the presence of two exponential recovery terms with degree of recovery and decay time-scales $Q$ 1 = 0.0104(5), $τ_{d1} = 72 (4)$ d and $Q$ 2 = 0.006(1), $τ_{d2} = 4.2 (6)$ d, respectively. For the remaining previously reported glitches, we also refine the glitch epochs and recovery process through precise fitting of the timing data. We discuss how multi-band data of glitches can help better characterize the glitch recoveries and constrain the underlying physics of glitch events. Our findings demonstrate that the accumulation of observational data reveals the rich complexity of the glitch phenomenon, aiding in the search for a well-established interpretation.
↳ astro-ph.HEnucl-thMNRAS(2025)·10 citations
12
Speed of sound bounds and first-order phase transitions in compact stars
P. Laskos-Patkos · G.A. Lalazissis · Sibo Wang · Jie Meng · Peter Ring · Ch.C. Moustakidis
In the present study, we employ three distinct, physically motivated speed of sound bounds to construct hybrid models, where the high-density phase is described by the maximally stiff equation of state. In particular, we consider the bounds related to special relativity, relativistic kinetic theory and conformality. The low-density hadronic phase is described by a state-of-the-art microscopic relativistic Brueckner-Hartree-Fock theory. This work aims to access the effect of the different speed of sound constraints on the relevant parameter space of the key parameters of first-order phase transitions by utilizing recent astronomical data. This involves a systematic analysis that also includes two distinct schemes for the construction of hybrid models (abrupt and smooth). Finally, a relevant discussion is conducted on the possible occurrence of a thermodynamic inconsistency that is related to the stability of the high-density phase over hadronic matter at large densities.
↳ astro-ph.HEgr-qcnucl-thPRC(2025)·21 citations
13
Simultaneously Constraining the Neutron Star Equation of State and Mass Distribution through Multimessenger Observations and Nuclear Benchmarks
Bhaskar Biswas · Stephan Rosswog
With ongoing advancements in nuclear theory and experimentation, together with a growing body of neutron star (NS) observations, a wealth of information on the equation of state (EOS) for matter at extreme densities has become accessible. Here, we utilize a hybrid EOS formulation that combines an empirical parameterization centered around the nuclear saturation density with a generic three-segment piecewise polytrope model at higher densities. We incorporate data derived from chiral effective field theory ( $χ$ EFT), perturbative quantum chromodynamics (pQCD), and from experiments such as PREX-II and CREX. Furthermore, we examine the influence of a total of 129 NS mass measurements up to April 2023, as well as simultaneous mass and radius measurements derived from the X-ray emission from surface hot spots on NSs. Additionally, we consider constraints on tidal properties inferred from the gravitational waves emitted by coalescing NS binaries. To integrate this extensive and varied array of constraints, we utilize a hierarchical Bayesian statistical framework to simultaneously deduce the EOS and the distribution of NS masses. We find that incorporating data from $χ$ EFT significantly tightens the constraints on the EOS of NSs near or below the nuclear saturation density. However, constraints derived from pQCD computations and nuclear experiments such as PREX-II and CREX have minimal impact.
↳ astro-ph.HEgr-qcnucl-thPRD(2025)·30 citations
14
Compact object of HESS J1731-347 and its implication on neutron star matter
Prasanta Char · Bhaskar Biswas
In this work, we investigate the impact of the possibility of a small, subsolar mass compact star, such as the recently reported central compact object of HESS J1731-347, on the equation of state (EOS) of neutron stars. We have used a hybrid approach to the nuclear EOS developed recently where the matter around nuclear saturation density is described by a parametric expansion in terms of nuclear empirical parameters and represented in an agnostic way at higher density using piecewise polytropes. We have incorporated the inputs provided by the latest neutron skin measurement experiments from PREX-II and CREX, simultaneous mass-radius measurements of pulsars PSR J0030+0451 and PSR J0740+6620, and the gravitational wave events GW170817 and GW190425. The main results of the study show the effect of HESS J1731-347 on the nuclear parameters and neutron star observables. Our analysis yields the slope of symmetry energy $L = 45.7 1_{- 22.11}^{+ 38.18}$ MeV, the radius of a $1.4 M_{⊙}$ star, $R_{1.4} = 12.1 8_{- 0.88}^{+ 0.71}$ km, and the maximum mass of a static star, $M_{max} = 2.1 4_{- 0.17}^{+ 0.26} M_{⊙}$ within $90%$ confidence interval, respectively.
↳ astro-ph.HEnucl-thPRD(2026)·13 citations

Affiliations

first authorsco-authorsvia INSPIRE

Long Range Energy-energy Correlator at the LHC

The impact of dark matter on tidal signatures in neutron star mergers with Einstein Telescope

Effect of quark anomalous magnetic moment on neutral dense quark matter under magnetic field

A multi-band study of pulsar glitches with Fermi-LAT and Parkes

Speed of sound bounds and first-order phase transitions in compact stars

Simultaneously Constraining the Neutron Star Equation of State and Mass Distribution through Multimessenger Observations and Nuclear Benchmarks

Compact object of HESS J1731-347 and its implication on neutron star matter

Affiliations