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There is a high demand for nuclear data in multidisciplinary subject like nuclear astrophysics. The two areas of nuclear physics which are most clearly related to one another are stellar evolution and nucleosynthesis. The necessity for…

Nuclear Theory · Physics 2025-03-27 Vinay Singh , Debasis Bhowmick , D. N. Basu

We demonstrate that a nonthermal distribution of particles described by a kappa distribution can be accurately approximated by a weighted sum of Maxwell-Boltzmann distributions. We apply this method to modeling collision processes in…

Solar and Stellar Astrophysics · Physics 2015-09-09 Michael Hahn , Daniel Wolf Savin

Numerical values of charged-particle thermonuclear reaction rates for nuclei in the A=14 to 40 region are tabulated. The results are obtained using a method, based on Monte Carlo techniques, that has been described in the preceding paper of…

Solar and Stellar Astrophysics · Physics 2015-05-18 Christian Iliadis , Richard Longland , Art Champagne , Alain Coc , Ryan Fitzgerald

In solar interior, it is the equilibrium velocity distribution of few high-energy protons and nuclei that participates in determining nuclear fusion reaction rates. So, it is inappropriate to use the Maxwellian velocity distribution to…

Astrophysics · Physics 2007-05-23 Jian-Miin Liu

A connection between fractional calculus and statistical distribution theory has been established by the authors recently. Some extensions of the results to matrix-variate functions were also considered. In the present article, more results…

Statistical Mechanics · Physics 2011-03-01 A. M. Mathai , H. J. Haubold

An analytic study of the reaction probability integrals corresponding to the various forms of the slowly varying cross-section factor $S(E)$ is attempted. Exact expressions for reaction probability integrals are expressed in terms of the…

Astrophysics · Physics 2007-05-23 M. A. Chaudhry , H. J. Haubold , A. M. Mathai

Indirect methods using nucleus-nucleus reactions at high energies (here, high energies mean $\sim$ 50 MeV/nucleon and higher) are now routinely used to extract information of interest for nuclear astrophysics. This is of extreme relevance…

Nuclear Theory · Physics 2015-10-05 C. A. Bertulani

Cosmic ray nuclei fluxes are expected to be measured with high precision in the near future. For instance, high quality data on the antiproton component could give important clues about the nature of the astronomical dark matter. A very…

Astrophysics · Physics 2008-11-26 D. Maurin , F. Donato , R. Taillet , P. Salati

The S\'ersic model is the de facto standard to describe the surface brightness distribution of hot stellar systems. An important inconvenience of this analytical model is that the corresponding luminosity density and associated properties…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 M. Baes , E. Van Hese

We argue that the Maxwellian approximation can essentially underestimate the rates of some nuclear reactions in hot plasma under conditions very close to thermal equilibrium. This phenomenon is demonstrated explicitly on the example of…

Plasma Physics · Physics 2009-11-13 Makoto Nakamura , Victor T. Voronchev , Yasuyuki Nakao

The density profiles and other quantities of physical interest for spherically symmetric systems are computed by assuming that a collisionless stellar gas may relax to the non-Gaussian power law distribution suggested by the nonextensive…

Astrophysics · Physics 2011-07-19 J. A. S. Lima , R. E. de Souza

A stochastic model is proposed for the acceleration of non-relativistic particles yielding to energy spectra with a shape of a Weibull\textquoteright s function. Such particle distribution is found as the stationary solution of a…

Space Physics · Physics 2016-02-23 G. Pallocchia , M. Laurenza , G. Consolini

The Balmer line profiles of nonradiative supernova remnant shocks provide the means to measure the post-shock proton velocity distribution. While most analyses assume a Maxwellian velocity distribution, this is unlikely to be correct. In…

Astrophysics · Physics 2009-11-13 J. C. Raymond , Philip A. Isenberg , J. M. Laming

A new integral formula, which has not been compiled in any integral tables or mathematical softwares, is proposed to obtain the analytical energy-angular spectra of the particles that are sequentially emitted from the discrete energy levels…

Nuclear Theory · Physics 2015-12-16 Xiaojun Sun , Jingshang Zhang

The interpretation of the available and forthcoming data obtained from multimessenger astrophysical observations -- potentially providing unprecedented access to neutron star properties -- will require the development of novel, accurate…

Nuclear Theory · Physics 2022-11-09 Omar Benhar , Alessandro Lovato , Giovanni Camelio

On contrary to the customary thought, the well-known ``lemma'' that the distribution function of a collisionless Boltzmann gas keeps invariant along a molecule's path represents not the strength but the weakness of the standard theory. One…

Data Analysis, Statistics and Probability · Physics 2007-05-23 C. Y. Chen

The neutron emission rates in thermal excited nuclei are conventionally described by statistical models with a phenomenological level density parameter that depends on excitation energies, deformations and mass regions. In the microscopic…

Nuclear Theory · Physics 2015-06-22 Yi Zhu , Junchen Pei

We calculated the Maxwellian-averaged cross sections (MACS) and astrophysical reaction rates of the stellar nucleosynthesis reactions (n,$\gamma$), (n,fission), (n,p), (n,$\alpha$) and (n,2n) using the ENDF/B-VII.0-, JEFF-3.1-, JENDL-3.3-,…

Solar and Stellar Astrophysics · Physics 2014-11-18 B. Pritychenko , S. F. Mughaghab , A. A. Sonzogni

In our calculation of neutron star crust heating we include several key new model features. In earlier work electron capture (EC) only allowed neutron emission from the daughter ground-state; here we calculate, in a deformed QRPA model, EC…

Astrophysics · Physics 2008-12-18 Sanjib S. Gupta , Toshihiko Kawano , Peter Möller

The well-known astrophysical resonant reaction rate equations for an isolated narrow resonance have been reexamined. The validity of those `look reliable' assumptions used in deriving the analytic reaction rate equations has been checked,…

Solar and Stellar Astrophysics · Physics 2009-12-11 J. J. He