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Related papers: Weak interaction rates of $sd$-shell Urca pairs in…

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Charge-exchange reactions are an important tool for determining weak-interaction rates. They provide stringent tests for nuclear structure models necessary for modeling astrophysical environments such as neutron stars and core-collapse…

In this work, Na isotopes with mass varying from $A=$ 20 to 31 have been studied using DJ16A, JISP16 and N3LO microscopic effective interactions in the $sd$-shell. These effective interactions are derived for $sd$-shell using no-core shell…

Nuclear Theory · Physics 2023-02-13 Subhrajit Sahoo , Praveen C. Srivastava , Toshio Suzuki

We perform a systematic study of Gamow-Teller (GT) transitions in the 2p1f shell, using the nuclear shell model with two schematic Hamiltonians. The use of the shell model provides flexibility to analyze the role of different proton-neutron…

Nuclear Theory · Physics 2019-09-12 A. Carranza M. , S. Pittel , Jorge G. Hirsch

In the late stages of stellar core-collapse, prior to core bounce, electron captures on medium-heavy nuclei drive deleptonization and simulations require the use of accurate reaction rates. Nuclei with neutron number near $N=50$, just above…

Accurate estimate of neutrino energy loss rates are needed for the study of the late stages of the stellar evolution, in particular for cooling of neutron stars and white dwarfs. Proton-neutron quasi-particle random phase approximation…

Nuclear Theory · Physics 2012-03-21 Jameel-Un Nabi

We examine several ``landmarks'' for the effects of the tensor interaction on the properties of light nuclei. These were usually discussed in the context of small-space shell-model calculations. We show, using $G$ matrices derived from a…

Nuclear Theory · Physics 2009-09-25 L. Zamick , D. C. Zheng , M. Fayache

Electron captures on nuclei play an essential role for the dynamics of several astrophysical objects. The capture rate can be derived in perturbation theory where allowed nuclear transitions (Gamow-Teller transitions) dominate, except at…

Nuclear Theory · Physics 2021-07-07 Karlheinz Langanke , Gabriel Martínez-Pinedo , Remco Zegers

Extrapolation of perturbative nucleon spin fluctuation rates seems to suggest a strong suppression of weak interactions in supernova cores. We derive a new sum rule for the dynamical spin-density structure function which relates the spin…

Astrophysics · Physics 2008-11-26 Guenter Sigl

Recent observations in galaxies and clusters indicate dark matter density profiles exhibit core-like structures which contradict to the numerical simulation results of collisionless cold dark matter. On the other hand, it has been shown…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Man Ho Chan

Applying TQRPA calculations of Gamow--Teller strength functions in hot nuclei, we compute the (anti)neutrino spectra and energy loss rates arising from weak processes on hot $^{56}$Fe under pre-supernova conditions. We use a realistic…

Nuclear Theory · Physics 2023-06-29 Alan A. Dzhioev , A. V. Yudin , N. V. Dunina-Barkovskaya , A. I. Vdovin

Nuclei close to the neutron drip line are described employing an interaction model which is based on the low-momentum interaction $V_{lowk}$. This effective two-body interaction which is determined to reproduce the nucleon-nucleon (NN)…

Nuclear Theory · Physics 2009-10-29 E. N. E. van Dalen , P. Gögelein , H. Müther

Isospin-equilibrating weak processes, called ``Urca" processes, are of fundamental importance in astrophysical environments like (proto-)neutron stars, neutron star mergers, and supernovae. In these environments, matter can reach high…

Nuclear Theory · Physics 2025-04-18 Pranjal Tambe , Debarati Chatterjee , Mark Alford , Alexander Haber

We study the heat capacity and neutrino emission reactions (direct and modified Urca processes, nucleon-nucleon bremsstrahlung, Cooper pairing of nucleons) in matter of supranuclear density of the neutron star cores with superfluid neutrons…

Astrophysics · Physics 2011-02-16 D. G. Yakovlev , K. P. Levenfish , Yu. A. Shibanov

Understanding the thermal structure of the outer crust of accreting neutron stars is important to interpret astronomical X-ray observations. Ground-state to ground-state $\beta$-decay transitions of neutron-rich nuclei comprising the crust…

We have systematically investigated the excitation spectra of $p$-shell hypernuclei within the shell model based on the nucleon-nucleon and hyperon-nucleon interactions. For the effective nucleon-nucleon interaction, we adopt the Gogny…

Nuclear Theory · Physics 2020-01-08 X. Y. Chen , Z. Zhou , W. G. Jiang , B. S. Hu , F. R. Xu

Gamow-Teller (GT) strength transitions are an ideal probe for testing nuclear structure models. In addition to nuclear structure, GT transitions in nuclei directly affect the early phases of Type Ia and Type-II supernovae core collapse…

Nuclear Theory · Physics 2011-08-04 Jameel-Un Nabi , Muhammad Sajjad

The shell model within the $2s1d0g_{7/2}0h_{11/2}$ shell is applied to calculate nuclear structure properties of the even Z=52 - 62, N=82 isotones. The results are compared with experimental data and with the results of a quasiparticle…

Nuclear Theory · Physics 2009-10-30 A. Holt , T. Engeland , E. Osnes , M. Hjorth-Jensen , J. Suhonen

We have collected continuum data of a sample of D-type symbiotic stars. By modelling their spectral energy distribution in a colliding-wind theoretical scenario we have found the common characteristics to all the systems: 1) at least two…

Solar and Stellar Astrophysics · Physics 2015-05-14 R. Angeloni , M. Contini , S. Ciroi , P. Rafanelli

We present results from large-scale shell-model calculations of even and odd tin isotopes from 134Sn to 142}Sn with a shell-model space defined by the 1f7/2,2p3/2,0h9/2,2p1/2,1f5/2,0i13/2 single-particle orbits. An effective two-body…

Nuclear Theory · Physics 2008-11-26 M. P. Kartamyshev , T. Engeland , M. Hjorth-Jensen , E. Osnes

Starting from a Skyrme interaction with tensor terms, the $\beta$-decay rates of $^{52}$Ca have been studied within a microscopic model including the $2p-2h$ configuration effects. We observe a redistribution of the strength of Gamow-Teller…

Nuclear Theory · Physics 2017-12-06 A. P. Severyukhin