English
Related papers

Related papers: Nucleosynthesis in Hot and Dense Media

200 papers

We consider the effects on big bang nucleosynthesis (BBN) of the radiative decay of a long-lived massive particle. If high-energy photons are emitted after the BBN epoch ($t \sim 1 - 10^3$ sec), they may change the abundances of the light…

High Energy Physics - Phenomenology · Physics 2011-05-05 M. Kawasaki , K. Kohri , Takeo Moroi

Neutrino-matter interactions play a key role in binary neutron star mergers. Thermodynamics conditions at the surfaces where neutrinos decouple from matter influence neutrino spectra, ultimately affecting the evolution of the remnant and…

The spectrum of the Cosmic Microwave Background follows Planck's black body radiation formula and shows a remarkable constant temperature of T = 2.7. About 380 000 years after the Big Bang at a temperature of T = 3000 Kelvin in the matter…

Nuclear Theory · Physics 2013-12-13 Amand Faessler , Rastislav Hodak , Sergey Kovalenko , Fedor Simkovic

We present $\beta$-delayed neutron emission and $\beta$-delayed fission calculations for heavy, neutron-rich nuclei using the coupled Quasi-Particle Random Phase Approximation plus Hauser-Feshbach (QRPA+HF) approach. From the initial…

Nuclear Theory · Physics 2018-12-12 M. R. Mumpower , T. Kawano , T. M. Sprouse , N. Vassh , E. M. Holmbeck , R. Surman , P. Moller

If the energy density of the Universe before nucleosynthesis is dominated by a scalar field phi that decays and reheats the plasma to a temperature T_{RH} smaller than the standard neutralino freeze out temperature, the neutralino relic…

High Energy Physics - Phenomenology · Physics 2009-11-11 Graciela Gelmini , Paolo Gondolo , Adrian Soldatenko , Carlos E. Yaguna

We re-investigate the evolution of the strongly degenerate neutrinos in the early universe. With the larger degeneracy, the neutrino number freezes at higher temperatures because the neutrino annihilation rate decreases. We consider very…

Astrophysics · Physics 2009-11-07 Kazuhide Ichikawa , M. Kawasaki

Experimental measurements in terrestrial laboratory, space and astrophysical observations of variation and fluctuation of nuclear decay constants, measurements of large enhancements in fusion reaction rate of deuterons implanted in metals…

Solar and Stellar Astrophysics · Physics 2009-11-19 M. Coraddu , M. Lissia , P. Quarati , A. M. Scarfone

We reexamine big bang nucleosynthesis with large-scale baryon density inhomogeneities when the length scale of the density fluctuations exceeds the neutron diffusion length ($\sim 10^7-10^8$ cm at BBN), and the amplitude of the fluctuations…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-12 John D. Barrow , Robert J. Scherrer

We consider relatively heavy neutrinos $\nu_H$, mostly contributing to a sterile state $\nu_s$, with mass in the range 10 MeV $\lesssim m_s \lesssim m_{\pi} \sim 135$ MeV, which are thermally produced in the early universe in collisional…

High Energy Physics - Phenomenology · Physics 2021-08-03 Leonardo Mastrototaro , Pasquale Dario Serpico , Alessandro Mirizzi , Ninetta Saviano

Nuclear quantum effects (NQEs) on the structures and transport properties of dense liquid hydrogen at densities of 10-100 g/cm3 and temperatures of 0.1-1 eV are fully assessed using \textit{ab initio} path-integral molecular dynamics…

Materials Science · Physics 2019-12-10 Dongdong Kang , Huayang Sun , Jiayu Dai , Zengxiu Zhao , Yong Hou , Jiaolong Zeng , Jianmin Yuan

It is known that the finite temperature and density (FTD) corrections increase the electron mass, charge and modify the properties of the emitted radiation. All the signals, travelling through the astronomical bodies, carry over the…

High Energy Physics - Phenomenology · Physics 2021-10-22 Samina Masood

To constrain the universe before recombination (380000 years after the Big Bang), we mostly rely on the measurements of the primordial abundances that indicate the first insight into the thermal history of the universe. The first production…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-30 Tahani Makki , Mounib El Eid , Grant Mathews

In this study we present a comprehensive sensitivity atlas for Big Bang Nucleosynthesis (BBN) in which we quantify the dependence of the primordial abundances of helium-4, deuterium, and lithium-7 as well as $N_{\rm{eff}}$ on variations in…

High Energy Physics - Phenomenology · Physics 2026-03-25 Anne-Katherine Burns

We study effects of long-lived massive particles, which decay during the big-bang nucleosynthesis (BBN) epoch, on the primordial abundances of light elements. Compared to the previous studies, (i) the reaction rates of the standard BBN…

High Energy Physics - Phenomenology · Physics 2018-12-04 Masahiro Kawasaki , Kazunori Kohri , Takeo Moroi , Yoshitaro Takaesu

Big bang nucleosynthesis (BBN) and the cosmic baryon density from cosmic microwave background anisotropies together predict a primordial Li7 abundance a factor of 2--3 higher than that observed in galactic halo dwarf stars. A recent…

Astrophysics · Physics 2008-12-18 Brian D. Fields , Keith A. Olive , Elisabeth Vangioni-Flam

Some thermonuclear (type I) X-ray bursts at the neutron star surfaces in low-mass X-ray binaries take place during hard persistent states of the systems. Spectral evolution of these bursts is well described by the atmosphere model of a…

High Energy Astrophysical Phenomena · Physics 2018-12-17 V. F. Suleimanov , J. Poutanen , K. Werner

Standard thermal freeze-out scenarios with QCD-scale interaction rates predict a $uuddss$ sexaquark relic abundance many orders of magnitude below the observed dark matter density, representing a key challenge for sexaquark dark matter…

High Energy Physics - Phenomenology · Physics 2026-05-05 Marianne Moore , Stefano Profumo

We explore heavy-element nucleosynthesis by rapid neutron capture (r-process) in the decompressing ejecta from the surface of a neutron star. The decompression is triggered by a violent phase transition to strange quark matter (quark-nova…

Nuclear Theory · Physics 2009-03-19 Prashanth Jaikumar , Bradley S. Meyer , Kaori Otsuki , Rachid Ouyed

The thermal evolution of the shell correction energy is investigated for deformed nuclei using Strutinsky prescription in a self-consistent relativistic mean-field framework. For temperature independent single-particle states corresponding…

Nuclear Theory · Physics 2009-11-07 B. K. Agrawal , Tapas Sil , S. K. Samaddar , J. N. De

We investigate the non-radiative decay during nucleosynthesis of a massive tau neutrino with mass 0.1 - 1 MeV into an electron neutrino and a scalar or pseudoscalar particle, $\phi$. The full Boltzmann equation is used and shown to give…

High Energy Physics - Phenomenology · Physics 2009-10-30 S. Hannestad