Nuclear Theory·nucl-th

Tuesday·July 30, 2024

16 papers—8 primary·8 cross-listed

01
Causality and stability in relativistic hydrodynamic theory -- a choice to be endured
Sayantani Bhattacharyya · Sukanya Mitra · Shuvayu Roy
In this work, it has been indicated that the key features requisite for preserving causality and stability of the popularly existing relativistic hydrodynamic theories, can be translated into each other. It has been shown here, that a generic `fluid frame transformation' including all orders of gradient corrections can recast a stable-causal hydrodynamic theory that (i) only includes fundamental fluid variables (velocity and temperature) but requires to be in a general hydrodynamic frame other than the Landau or Eckart, to a theory that is (ii) pathology free in Landau frame but needs newer degrees of freedom. Since frame choice provides the first principle field definitions and degrees of freedom indicate the number of conserved quantities, the causality and stability of a theory seem to require a consensus between the two unless the derivative correction goes to infinity. The key finding of this work is to indicate a connection between these different formalisms, that lead to a causal and stable hydrodynamic theory.
nucl-thgr-qchep-phhep-thPLB(2024)·12 citations
02
On the determination of the $D$ meson width in the nuclear medium with the transparency ratio
Victor Montesinos🇪🇸 · Natsumi Ikeno🇯🇵 · Eulogio Oset🇪🇸 · Miguel Albaladejo🇪🇸 · Juan Nieves🇪🇸 · Laura Tolos🇪🇸
We have studied the feasibility of the experimental determination of the width of a $D$ meson in a nuclear medium by using the method of the nuclear transparency. The cross section for inclusive production of a $D^{+}$ in different nuclei is evaluated, taking care of the $D^{+}$ absorption in the nucleus, or equivalently, the survival probability of the $D^{+}$ in its way out of the nucleus from the point of production. We use present values of the in medium width of $D$ mesons and calculate ratios of the cross sections for different nuclei to the $^{12} C$ nucleus as reference. We find ratios of the order of $0.6$ for heavy nuclei, a large deviation from unity, which indicates that the method proposed is adequate to measure this relevant magnitude, so far only known theoretically.
nucl-thhep-phPLB(2025)·5 citations
03
Correlation between alpha-decay half-lives and symmetry energy
Yong-Beom Choi · Hana Gil · Chang Ho Hyun · Chang-Hwan Lee
We study the alpha-decay half-lives of 84 <= Z <= 92 even-even nuclei in the semiclassical WKB approximation framework using the density-dependent cluster model and the density distribution described by various Korea-IBS-Daegu-SKKU (KIDS) models. Main goal of this work is to find a correlation between the alpha-decay half-lives and the stiffness of the symmtery energy. Parameters of KIDS model are determined to reproduce the nuclear data (energy and charge radii of 40Ca, 48Ca and 208Pb) and the neutron star observations including constraints by NICER, tidal deformability from GW170817, and the maximum mass limit of neutron star observations. We use the KIDS models (A-D) which have distinctive values for the parameters controlling the stiffness of the nuclear matter equation of state. We find that the alpha-decay half-lives increase systematically from KIDS-A model to KIDS-D model. This implies a correlation between the alpha-decay half-lives and the symmetry energy. We find that the correlation can be understood from the dependence of the particle distribution in the core and the surface region on the symmetry energy.
nucl-thPRC(2025)·4 citations
04
Neutrinoless double-beta decay in a finite volume from relativistic effective field theory
Y. L. Yang🇨🇳 · P. W. Zhao🇨🇳
The neutrinoless double-beta decay process $nn \to pp ee$ within the light Majorana-exchange scenario is studied using the relativistic pionless effective field theory (EFT) in finite-volume cubic boxes with the periodic boundary conditions. Using the low-energy two-nucleon scattering observables from lattice QCD available at $m_{π} = 300$ , 450, 510, and 806 MeV, the leading-order $nn \to pp ee$ transition matrix elements are predicted and their volume dependence is investigated. The predictions for the $nn \to pp ee$ transition matrix elements can be directly compared to the lattice QCD calculations of the $nn \to pp ee$ process at the same pion masses. In particular for the matrix element at $m_{π} = 806$ MeV, the predictions with relativistic pionless EFT are confronted to the recent first lattice QCD evaluation. Therefore, the present results are expected to play a crucial role in the benchmark between the nuclear EFTs and the upcoming lattice QCD calculations of the $nn \to pp ee$ process, which would provide a nontrivial test on the predictive power of nuclear EFTs on neutrinoless double-beta decay.
hep-latnucl-thPRD(2025)·5 citations
05
Meson-nucleus bound states in quark meson coupling model
Arpita Mondal🇮🇳 · Amruta Mishra🇮🇳
The formations of the $K (K ˉ)$ , $D (D ˉ)$ , and $B (B ˉ)$ meson-nucleus bound states in $^{16} O$ , $^{40} Ca$ , $^{90} Zr$ , $^{197} Au$ , and $^{208} Pb$ nucleus are investigated using the quark meson coupling model. The model relies on a mean field description of non-overlapping nucleon bags bound by the self-consistent interactions of scalar ( $σ$ , $δ$ ) and vector ( $ω$ , $ρ$ ) mesons with the (anti)quarks inside the bags, which is further extended to explore the properties of nuclei. We estimate the meson-nucleus bound state energies by solving the Klein-Gordon equations with the real potentials calculated self-consistently within the model, using a coordinate space approach. The calculations are carried out for different nuclear interactions. The effects of Coulomb interaction are considered in the present study for the charged mesons. Our study indicates the formation of rather deeply bound $B$ -mesic states at the very central region of the nuclei, compared to the $D$ and $K$ mesons, offering a more promising probe to explore subtle nuclear medium effects. The investigations of such bound states are of particular interest for the upcoming $P ˉ ANDA$ at FAIR, J-PARC-E29, and JLab experiments.
nucl-thhep-phPRC(2024)·10 citations
06
Investigation of kaonic atom optical potential by the high precision data of kaonic $^{3}$ He and $^{4}$ He atoms
J. Yamagata-Sekihara (Kyoto Sangyo U.)🇯🇵 · Y. Iizawa (Tokyo Inst. Tech.)🇯🇵 · D. Jido (Tokyo Inst. Tech.)🇯🇵 · N. Ikeno (Tottori U.)🇯🇵 · T. Hashimoto (Nishina Car., RIKEN and RIKEN)🇯🇵 · S. Okada (Chubu U. and RIKEN)🇯🇵 · S. Hirenzaki (Nara Women's U.)🇯🇵
We theoretically investigate kaonic atom states based on the latest high precision data of the $2 p$ states of the kaonic atoms in $^{3}$ He and $^{4}$ He (J-PARC E62). We consider the phenomenological form for the optical potential proportional to the nuclear density distributions and determine the potential parameters by the latest data. We find two sets of potential parameters for each of $K^{-} -^{3}$ He and $K^{-} -^{4}$ He that reproduce the data. We then extract the potential parameters consistent with the data of $^{3}$ He and $^{4}$ He atoms simultaneously. Using the potential, we investigate the structure of the kaonic atoms and kaonic nuclei for various nuclei up to Sn. We also report the optical potential parameters suited for the global description of the atomic data, the possible strong isospin dependence of the potential, and the different strength of the data of $K^{-} -^{3}$ He and $K^{-} -^{4}$ He in the restrictions on the potential parameters. In addition, we find that the study of the $1 s$ states of the kaonic helium atom is very interesting as a next step, and the determination of the orbital angular momenta of the kaonic nuclear states is helpful for the unified understandings of the atomic and nuclear bound states of kaon because of the mutual influence between the atomic and the nuclear states of kaon with the same orbital angular momentum.
nucl-thhep-exhep-phnucl-exPTEP(2025)·5 citations
07
Systematic study of complete fusion suppression for 6,7 Li nuclei using artificial neural network
D. Chattopadhyay
In recent decades, there has been a significant increase in the measurement of complete fusion cross-sections for various reactions, with particular emphasis on the reactions involving weakly bound projectile. It has been well established that the complete fusion cross-section involving weakly bound nuclei is suppressed at above barrier energies due to the breakup effect. Accurate determination of suppression factor is essential to understand the effect of breakup on complete fusion suppression. In this study, Feedforward Artificial Neural Network (ANN) methods based on Multilayer Perceptron is utilized to estimate the complete fusion suppression factor for reactions involving 6,7 Li projectile from the comparison of ANN predicted reduced fusion functions (F (x)) with the Universal Fusion Function(F0 (x)). Average suppression factor has been estimated as 0.68 and 0.74 for 6 Li and 7 Li induced reactions respectively. Normalized Mean Squared Error(NMSE) has been calculated as 1.85% for training and 1.92% for testing data of ANN for 6 Li case, while for 7 Li cases, the same is for 3.73% and 6.48% respectively. Present results have been compared with three other alternative methods Support Vector Regression, Random Forest Regression and Gaussian Process Regression. Relevant performance matrices has been estimated. It has been observed that, ANN algorithm is giving the better accuracy as compared with other. This results indicate that ANN might be an alternative tool for estimation of complete fusion suppression factor for weakly bound projectile.
nucl-th0 citations
08
Universal corrections to the superfluid gap in a cold Fermi gas
Silas R. Beane🇨🇭 · Zeno Capatti🇨🇭 · Roland C. Farrell🇨🇭
A framework for computing the superfluid gap in an effective field theory (EFT) of fermions interacting via momentum-independent contact forces is developed. The leading universal corrections in the EFT are one-loop in-medium effects at the Fermi surface, and reproduce the well-known Gor'kov-Melik-Barkhudarov result. The complete subleading universal corrections are presented here, and include one-loop effects away from the Fermi surface, two-loop in-medium effects, as well as modifications to the fermion propagator. Together, these effects are found to reduce the gap at low densities. Applications to neutron superfluidity in neutron stars are also discussed.
nucl-thcond-mat.quant-gascond-mat.supr-conhep-phPRA(2025)·5 citations

Affiliations

first authorsco-authorsvia INSPIRE