Nuclear Theory·nucl-th

Friday·August 2, 2024

13 papers—7 primary·6 cross-listed

08
Quantum Computing Universal Thermalization Dynamics in a (2+1)D Lattice Gauge Theory
Niklas Mueller🇺🇸 · Tianyi Wang🇺🇸 · Or Katz🇺🇸 · Zohreh Davoudi🇺🇸 · Marko Cetina🇺🇸
Simulating non-equilibrium phenomena in strongly-interacting quantum many-body systems, including thermalization, is a promising application of near-term and future quantum computation. By performing experiments on a digital quantum computer consisting of fully-connected optically-controlled trapped ions, we study the role of entanglement in the thermalization dynamics of a $Z_{2}$ lattice gauge theory in 2+1 spacetime dimensions. Using randomized-measurement protocols, we efficiently learn a classical approximation of non-equilibrium states that yields the gap-ratio distribution and the spectral form factor of the entanglement Hamiltonian. These observables exhibit universal early-time signals for quantum chaos, a prerequisite for thermalization. Our work, therefore, establishes quantum computers as robust tools for studying universal features of thermalization in complex many-body systems, including in gauge theories.
↳ quant-phhep-lathep-phnucl-thNature Commun.(2025)·60 citations
09
An alternative way to decipher the nature of the doubly charmed tetraquark $T_{cc} (3875)^{+}$ : its antiparticle $T_{c ˉ c ˉ} (3875)^{-}$ photoproduction off nuclei near threshold
E. Ya. Paryev🇷🇺
We study the inclusive photoproduction of $T_{c ˉ c ˉ} (3875)^{-}$ mesons (which are the antiparticles of the doubly charmed tetraquarks $T_{cc} (3875)^{+}$ discovered recently by the LHCb Collaboration) from nuclei in the near-threshold energy region within the nuclear spectral function approach by considering incoherent direct ( $γ p (n) \to D^{+} (D^{0}) T_{c ˉ c ˉ} (3875)^{-} Λ_{c}^{+}$ ) photon--nucleon $T_{c ˉ c ˉ} (3875)^{-}$ creation processes as well as five possible different scenarios for their internal structure with the main goal of clarifying the possibility to decipher this structure (and, hence, that of $T_{cc} (3875)^{+}$ ) in photoproduction via integral and differential observables. We calculate the absolute and relative excitation functions for $T_{c ˉ c ˉ} (3875)^{-}$ production off $^{12}$ C and $^{184}$ W target nuclei at near-threshold photon beam energies of 30--38 GeV, the absolute differential cross sections for their production off these target nuclei at laboratory polar angles of 0 $^{\circ}$ --10 $^{\circ}$ as well as the A and momentum dependences of the relative (transparency ratios) cross sections for $T_{c ˉ c ˉ} (3875)^{-}$ production at photon energy of 35 GeV within the adopted scenarios for the $T_{c ˉ c ˉ} (3875)^{-}$ meson intrinsic structure. We demonstrate that the absolute and relative observables considered show a certain sensitivity to these scenarios. Therefore, the measurement of such observables in future experiments at the proposed high-luminosity electron-ion colliders EIC and EicC in the US and China in the near-threshold energy region might shed light on the $T_{cc} (3875)^{+}$ internal structure.
↳ hep-phhep-exnucl-exnucl-thInt.J.Mod.Phys.A(2024)·3 citations
10
Second-order nonlocal shifts of scattered wave-packets: What can be measured by Goos-Hänchen and Imbert-Fedorov effects ?
K. Morawetz
The scattering of wavepackets with arbitrary energy dispersion on surfaces has been analyzed. Expanding up to second order in scattering shifts, it is found that besides the known Goos-Hänchen or Imbert-Fedorov spatial offset, as well as the Wigner delay time, new momentum and frequency shifts appear. Furthermore, the width of the scattered wave packet becomes modified as well, which can lead to a shrinking of pulses by multiple scattering. For a model of dielectric material characterized by a longitudinal and transverse dielectric function the shifts are calculated analytically. From the Goos-Hänchen and Imbert-Fedorov shifts one can access the longitudinal and transversal dielectric function. Perfectly aligned crystal symmetry axes with respect to scattering beam shows no Imbert-Fedorov effect. It is found that the Goos-Hänchen and Imbert-Fedorov effect are absent for homogeneous materials. Oppositely it is found that the Wigner delay time and the shrinking of the temporal pulse width allows to access the dielectric function independent on the beam geometry.
↳ physics.opticscond-mat.mtrl-scinucl-thquant-phRev.Phys.(2025)·0 citations
11
Fully strange tetraquark resonant states as the cousins of $X (6900)$
Yao Ma🇨🇳 · Wei-Lin Wu🇨🇳 · Lu Meng🇩🇪 · Yan-Ke Chen🇨🇳 · Shi-Lin Zhu🇨🇳
We conduct systematic calculations of the S-wave fully strange systems with ``normal" $(J^{P C} = 0^{++}, 1^{+-}, 2^{++})$ and ``exotic" $(J^{P C} = 0^{+-}, 1^{++}, 2^{+-})$ C-parities, which are the strange analogue of the fully charmed tetraquark state $X (6900)$ . Within a constituent quark potential model, we employ the Gaussian expansion method to solve the four-body Schrödinger equation and the complex scaling method to identify resonant states. We obtain a series of resonant states and zero-width states in the mass range of 2.7 to 3.3 GeV, with their widths ranging from less than 1 MeV to about 50 MeV. Their rms radii strongly indicate that they are compact tetraquark states. Among these states, the $T_{4 s, 2^{++}} (2714)$ may be the most likely one to be observed experimentally. We urge the experimental exploration of the $2^{++}$ $ss s ˉ s ˉ$ state around 2.7 GeV in the $ϕϕ$ channel. Since the lowest S-wave $ss s ˉ s ˉ$ state is around 2.7 GeV, the compact P-wave $ss s ˉ s ˉ$ states are expected to be heavier. Hence, $ϕ (2170)$ and $X (2370)$ are unlikely to be compact tetraquark states.
↳ hep-phhep-exhep-latnucl-thPRD(2024)·17 citations
12
Hot and Dense QCD Shear Viscosity at (almost) NLO
Isabella Danhoni🇩🇪 · Guy D. Moore🇩🇪
The next-to-leading order weak-coupling shear viscosity of QCD was computed 6 years ago. However, these results have never been applied at finite baryon chemical potential $μ$ , even though intermediate-energy heavy ion collisions and merging neutron stars may explore the Quark-Gluon Plasma in a regime where baryon chemical potentials are large. Here, we extend the next-to-leading order shear viscosity calculations to finite $μ$ , and we show that, while the convergence of the weak-coupling expansion is questionable for achievable plasmas, it is somewhat better at $μ > T$ than at $μ = 0$ .
↳ hep-phhep-thnucl-thJHEP(2024)·9 citations
13
Investigating the role of nuclear parameters on oscillation modes in hot Neutron Stars
Nilaksha Barman🇮🇳 · Bikram Keshari Pradhan🇮🇳 · Debarati Chatterjee🇮🇳
Recent studies have revealed that certain nuclear parameters are more dominant than others in governing global neutron star properties, such as its structure or oscillation mode characteristics. Although neutron stars can in general assumed to be cold, in astrophysical scenarios such as newly born neutron stars or remnants of binary neutron star mergers, finite temperature effects play a non-negligible role. In this work, we perform a consistent and systematic investigation of the role of nuclear parameters and thermal effects on neutron star properties and fluid oscillation modes within a full general relativistic scheme. We impose constraints on the parameter space of the relativistic mean field model using state-of-the-art information from terrestrial experiments and multi-messenger astrophysical data. We find effective nucleon mass to be the most important nuclear parameter controlling astrophysical observables of hot neutron stars, similar to the cold beta equilibrated matter. However, we conclude that the interplay among saturation properties and astrophysical observables depends not only on the thermal configurations considered but also on the constraints imposed. We also investigated the role of nuclear saturation parameters on some universal relations for hot NSs which are important in gravitational wave asteroseismology. Our investigation confirmed that these relations are mostly insensitive to nuclear saturation properties and mainly affected by variation of charge fraction in the star.
↳ astro-ph.HEgr-qcnucl-thPRD(2025)·10 citations

Affiliations

first authorsco-authorsvia INSPIRE

Quantum Computing Universal Thermalization Dynamics in a (2+1)D Lattice Gauge Theory

An alternative way to decipher the nature of the doubly charmed tetraquark Tcc​(3875)+: its antiparticle Tcˉcˉ​(3875)− photoproduction off nuclei near threshold

Second-order nonlocal shifts of scattered wave-packets: What can be measured by Goos-Hänchen and Imbert-Fedorov effects ?

Fully strange tetraquark resonant states as the cousins of X(6900)

Hot and Dense QCD Shear Viscosity at (almost) NLO

Investigating the role of nuclear parameters on oscillation modes in hot Neutron Stars

Affiliations

An alternative way to decipher the nature of the doubly charmed tetraquark $T_{cc} (3875)^{+}$ : its antiparticle $T_{c ˉ c ˉ} (3875)^{-}$ photoproduction off nuclei near threshold

Fully strange tetraquark resonant states as the cousins of $X (6900)$