Nuclear Theory·nucl-th

Tuesday·October 24, 2023

11 papers—2 primary·9 cross-listed

03
Simulating Scattering of Composite Particles
Michael Kreshchuk🇺🇸 · James P. Vary🇺🇸 · Peter J. Love🇺🇸
We develop a non-perturbative approach to simulating scattering on classical and quantum computers, in which the initial and final states contain a fixed number of composite particles. The construction is designed to mimic a particle collision, wherein two composite particles are brought in contact. The initial states are assembled via consecutive application of operators creating eigenstates of the interacting theory from vacuum. These operators are defined with the aid of the Møller wave operator, which can be constructed using such methods as adiabatic state preparation or double commutator flow equation. The approach is well-suited for studying strongly coupled systems in both relativistic and non-relativistic settings. For relativistic systems, we employ the language of light-front quantization, which has been previously used for studying the properties of individual bound states, as well as for simulating their scattering in external fields, and is now adopted to the studies of scattering of bound state systems. For simulations on classical computers, we describe an algorithm for calculating exact (in the sense of a given discretized theory) scattering probabilities, which has cost (memory and time) exponential in momentum grid size. Such calculations may be interesting in their own right and can be used for benchmarking results of a quantum simulation algorithm, which is the main application of the developed framework. We illustrate our ideas with an application to the $ϕ^{4}$ theory in $1 + 1 D$ .
↳ quant-phhep-thnucl-th22 citations
04
Isospin-dependence of the charge-changing cross-section shaped by the charged-particle evaporation process
J.W. Zhao · B.-H. Sun · I. Tanihata · S. Terashima · A. Prochazka · J.Y. Xu · L.H. Zhu · J. Meng · J. Su · K.Y. Zhang · L.S. Geng · L.C. He and 17 other authors
We present the charge-changing cross sections (CCCS) of $^{11 - 15}$ C, $^{13 - 17}$ N, and $^{15, 17 - 18}$ O at around 300 MeV/nucleon on a carbon target, which extends to $p$ -shell isotopes with $N < Z$ for the first time. The Glauber model, which considers only the proton distribution of projectile nuclei, underestimates the cross sections by more than 10\%. We show that this discrepancy can be resolved by considering the contribution from the charged-particle evaporation process (CPEP) following projectile neutron removal. Using nucleon densities from the deformed relativistic Hartree-Bogoliubov theory in continuum, we investigate the isospin-dependent CPEP contribution to the CCCS for a wide range of neutron-to-proton separation energy asymmetry. Our calculations, which include the CPEP contribution, agree well with existing systematic data and reveal an ``evaporation peak" at the isospin symmetric region where the neutron-to-proton separation energy is close to zero. These results suggest that analysis beyond the Glauber model is crucial for accurately determining nuclear charge radii from CCCSs.
↳ nucl-exnucl-thPLB(2023)·25 citations
05
Spin asymmetry and dipole moments in $τ$ -pair production with ultraperipheral heavy ion collisions
Ding Yu Shao🇨🇳 · Bin Yan🇨🇳 · Shu-Run Yuan🇨🇳 · Cheng Zhang🇨🇳
The anomalous magnetic (MDM) and electric (EDM) dipole moments of the $τ$ lepton serve as crucial indicators of new physics beyond the Standard Model. Leveraging azimuthal angular asymmetry as a novel tool in ultraperipheral collisions (UPCs), we attain unparalleled precision in the study of these key properties. Driven by the highly linear polarization of coherent photons, this method uniquely enables both the MDM and EDM to contribute to the $cos 2 ϕ$ angular distribution in similar magnitudes. Importantly, our approach substantially narrows the parameter space, excluding more than half of it compared to expected UPC-based measurements reliant solely on the total cross-section. This method not only provides improved constraints but also minimizes the need for additional theoretical assumptions.
↳ hep-phhep-exnucl-exnucl-thSCPMA(2024)·45 citations
06
Strangelets at finite temperature: nucleon emission rates, interface and shell effects
Hao-Song You🇨🇳 · Huai-Min Chen🇨🇳 · Jian-Feng Xu🇨🇳 · Cheng-Jun Xia🇨🇳 · Guang-Xiong Peng🇨🇳 · Ren-Xin Xu🇨🇳
We investigate the properties of strangelets at finite temperature $T$ , where an equivparticle model is adopted with both the linear confinement and leading-order perturbative interactions accounted for using density-dependent quark masses. The shell effects are examined by solving the Dirac equations for quarks in the mean-field approximation, which diminish with temperature as the occupation probability of each single-particle levels fixed by the Fermi-Dirac statistics, i.e., shell dampening. Consequently, instead of decreasing with temperature, the surface tension extracted from a liquid-drop formula increases with $T$ until reaching its peak at $T \approx 20$ -40 MeV with vanishing shell corrections, where the formula roughly reproduces the free energy per baryon of all strangelets. The curvature term, nevertheless, decreases with $T$ despite the presence of shell effects. The neutron and proton emission rates are fixed microscopically according to the external nucleon gas densities that are in equilibrium with strangelets, which generally increase with $T$ ( $≲ 50$ MeV) for stable strangelets but decrease for those that are unstable against nucleon emission at $T = 0$ . The energy, free energy, entropy, charge-to-mass ratio, strangeness per baryon, and root-mean-square radius of $β$ -stable strangelets obtained with various parameter sets are presented as well. The results indicated in this work are useful for understanding the products of binary compact star mergers and heavy-ion collisions.
↳ hep-phnucl-thPRD(2024)·5 citations
07
Unified description of the $Q s q ˉ q ˉ$ molecular bound states, molecular resonances and compact tetraquark states in the quark potential model
Yan-Ke Chen🇨🇳 · Wei-Lin Wu🇨🇳 · Lu Meng🇩🇪 · Shi-Lin Zhu🇨🇳
We calculate the mass spectrum of the $Q s q ˉ q ˉ$ $(Q = c, b)$ tetraquark states with $J^{P} = (0, 1, 2)^{+}$ using the AL1 quark potential model, which successfully describes the conventional hadron spectrum. We employ the Gaussian expansion method to solve the four-body Schrödinger equation, and use the complex scaling method to identify the resonances. With the notation $T_{Q s, I (J)}^{Theo.} (M)$ , we find several near-threshold bound states and resonances, including $T_{cs, 0 (0)}^{Theo.} (2350)$ , $T_{cs, 0 (0)}^{Theo.} (2906)$ , $T_{b s, 0 (0)}^{Theo.} (5781)$ , $T_{b s, 0 (1)}^{Theo.} (5840)$ , and $T_{b s, 0 (0)}^{Theo.} (6240)$ which are close to the $D K ˉ$ , $D^{*} K ˉ^{*}$ , $B ˉ K ˉ$ , $B ˉ^{*} K ˉ$ and $B ˉ^{*} K ˉ^{*}$ thresholds, respectively. Furthermore, their spatial structures clearly support their molecular natures. The resonance $T_{cs, 0 (0)}^{Theo.} (2906)$ has a mass of $2906$ MeV, a width of $20$ MeV, and quantum numbers $I (J^{P}) = 0 (0^{+})$ , which may serve as a good candidate for the experimental $T_{cs 0} (2900)$ state. We strongly urge the experimental search of the predicted states.
↳ hep-phhep-exhep-latnucl-thPRD(2024)·24 citations
08
One-neutron transfer reaction in the $^{18}$ O + $^{48}$ Ti collision at 275 MeV
O. Sgouros🇮🇹 · M. Cutuli🇮🇹 · F. Cappuzzello🇮🇹 · M. Cavallaro🇮🇹 · D. Carbone🇮🇹 · C. Agodi🇮🇹 · G. De Gregorio🇮🇹 · A. Gargano🇮🇹 · R. Linares🇧🇷 · G. A. Brischetto🇮🇹 · D. Calvo🇮🇹 · E. R. Chavez Lomeli🇲🇽 and 20 other authors
The present article reports new data on the $^{48}$ Ti( $^{18}$ O, $^{17}$ O) $^{49}$ Ti reaction at 275 MeV incident energy as part of the systematic research pursued within the NUMEN project. Supplementary measurements of the same reaction on $^{16}$ O and $^{27}$ Al targets were also performed in order to estimate the background arising from the use of a composite target (TiO $_{2}$ + $^{27}$ Al). These data were analyzed under the same theoretical framework as those obtained with the titanium target in order to reinforce the conclusions of our analysis. Differential cross-section angular distribution measurements for the $^{17}$ O $^{8 +}$ ejectiles were performed in a wide angular range by using the MAGNEX large acceptance magnetic spectrometer. The experimental results were analyzed within the distorted-wave and coupled-channels Born Approximation frameworks. The optical potentials at the entrance and exit channels were calculated in a double folding approach adopting the São Paulo potential, and the spectroscopic amplitudes for the projectile and target overlaps were obtained from large-scale shell model calculations. The differential cross-sections are well-described by the theoretical calculations, where a weak coupling to collective excitations of projectile and target is inferred. The sensitivity of transfer cross-sections on different model spaces adopted in nuclear structure calculations, is also discussed.
↳ nucl-exnucl-thPRC(2023)·15 citations
09
On the generalized Friedrichs-Lee model with multiple discrete and continuous states
Zhiguang Xiao🇨🇳 · Zhi-Yong Zhou🇨🇳
In this study, we present several improvements of the non-relativistic Friedrichs-Lee model with multiple discrete and continuous states and still retain its solvability. Our findings establish a solid theoretical basis for the exploration of resonance phenomena in scenarios involving multiple interfering states across various channels. The scattering amplitudes associated with the continuum states naturally adhere to coupled-channel unitarity, rendering this framework particularly valuable for investigating hadronic resonant states appearing in multiple coupled channels. Moreover, this generalized framework exhibits a wide-range applicability, enabling investigations into resonance phenomena across diverse physical domains, including hadron physics, nuclear physics, optics, and cold atom physics, among others.
↳ hep-phmath-phmath.MPnucl-th+1CPC(2025)·7 citations
10
Electromagnetic Properties of Indium Isotopes Elucidate the Doubly Magic Character of $^{100}$ Sn
J. Karthein🇺🇸 · C.M. Ricketts🇬🇧 · R.F. Garcia Ruiz🇺🇸 · J. Billowes🇬🇧 · C.L. Binnersley🇬🇧 · T.E. Cocolios🇧🇪 · J. Dobaczewski🇬🇧 · G.J. Farooq-Smith🇧🇪 · K.T. Flanagan🇬🇧 · G. Georgiev🇫🇷 · W. Gins🇧🇪 · R.P. de Groote🇧🇪 and 15 other authors
Our understanding of nuclear properties in the vicinity of $^{100}$ Sn, suggested to be the heaviest doubly magic nucleus with equal numbers of protons (Z=50) and neutrons (N=50), has been a long-standing challenge for experimental and theoretical nuclear physics. Contradictory experimental evidence exists on the role of nuclear collectivity in this region of the nuclear chart. Using precision laser spectroscopy, we measured the ground-state electromagnetic moments of indium (Z=49) isotopes approaching the N=50 neutron number down to 101In, and nuclear charge radii of 101-131In spanning almost the complete range between the two major neutron closed-shells at N=50 and N=82. Our results for both nuclear charge radii and quadrupole moments reveal striking parabolic trends as a function of the neutron number, with a clear reduction toward these two neutron closed-shells, thus supporting a doubly magic character of $^{100}$ Sn. Two complementary nuclear many-body frameworks, density functional theory and ab initio methods, elucidate our findings. A detailed comparison with our experimental results exposes deficiencies of nuclear models, establishing a benchmark for future theoretical developments.
↳ nucl-exnucl-thphysics.atom-phNat.Phys.(2024)·40 citations
11
Probing Transverse Momentum Dependent Structures with Azimuthal Dependence of Energy Correlators
Zhong-Bo Kang🇺🇸 · Kyle Lee🇺🇸 · Ding Yu Shao🇨🇳 · Fanyi Zhao🇺🇸
We study the azimuthal angle dependence of the energy-energy correlators $⟨ E (n^_{1}) E (n^_{2})⟩$ in the back-to-back region for $e^{+} e^{-}$ annihilation and deep inelastic scattering (DIS) processes with general polarization of the proton beam. We demonstrate that the polarization information of the beam and the underlying partons from the hard scattering is propagated into the azimuthal angle dependence of the energy-energy correlators. In the process, we define the Collins-type EEC jet functions and introduce a new EEC observable using the lab-frame angles in the DIS process. Furthermore, we extend our formalism to explore the two-point energy correlation between hadrons with different quantum numbers $S_{i}$ in the back-to-back limit $⟨ E_{S_{1}} (n^_{1}) E_{S_{2}} (n^_{2})⟩$ . We find that in the Operator Product Expansion (OPE) region the nonperturbative information is entirely encapsulated by a single number. Using our formalism, we present several phenomenological studies that showcase how energy correlators can be used to probe transverse momentum dependent structures.
↳ hep-phhep-exnucl-exnucl-thJHEP(2024)·51 citations

Affiliations

first authorsco-authorsvia INSPIRE