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Related papers: Primordial Nucleosynthesis: Accurate Predictions

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We have derived a primordial helium abundance of Yp = 0.2477 +- 0.0029, based on new atomic physics computations of the recombination coefficients of He I and of the collisional excitation of the H I Balmer lines together with observations…

Astrophysics · Physics 2011-02-11 M. Peimbert , V. Luridiana , A. Peimbert

Big-Bang Nucleosynthesis (BBN) predictions of primordial light-element abundances offer a powerful probe of early-Universe physics. However, high-accuracy numerical BBN calculations have become a major computational bottleneck for…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-18 Fan Zhang , Hang Diao , Bohua Li , Joel Meyers , Paul R. Shapiro

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

Nuclear capture of antiprotons from atomic states is studied. Partial widths for single nucleon capture events leading to cold residual nuclei are calculated. Recent CERN experiments that compare the neutron and proton captures are…

Nuclear Theory · Physics 2008-11-26 S. Wycech , J. Skalski , R. Smolanczuk , J. Dobaczewski , J. R. Rook

Big-bang nucleosynthesis (BBN) theory, together with the precise WMAP cosmic baryon density, makes tight predictions for the abundances of the lightest elements. Deuterium and 4He measurements agree well with expectations, but 7Li…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-19 Brian D. Fields

We have measured the nuclear transparency of the fundamental process $\gamma$ n $\to \pi^-$ p in $^4$He. These measurements were performed at Jefferson Lab in the photon energy range of 1.6 to 4.5 GeV and at $\theta^{\pi}_{cm}= 70^\circ$…

Nuclear Experiment · Physics 2016-09-08 D. Dutta

The scattering rate of multi-${\rm TeV}$ and ${\rm PeV}$ energy neutrinos is fast becoming an interesting topic in (astro)particle-physics. This is due to experimental progress at Neutrino Telescopes such as IceCube which have begun to gain…

High Energy Physics - Phenomenology · Physics 2020-04-28 Rhorry Gauld

Using the cosmological constants derived from WMAP, the standard big bang nucleosynthesis (SBBN) predicts the light elements primordial abundances for 4He, 3He, D, 6Li and 7Li. These predictions are in satisfactory agreement with the…

Cosmology and Nongalactic Astrophysics · Physics 2012-08-13 M. Spite , F. Spite , P. Bonifacio

The concordance of standard big bang nucleosynthesis theory and the related observations of the light element isotopes (including some new higher \he4 abundances) will be reviewed. Implications of BBN on chemical evolution, dark matter and…

Astrophysics · Physics 2009-09-15 Keith A. Olive

A method is presented to extract the neutron-skin thickness of atomic nuclei from the second and fourth moments of the electric charge distribution. We show that the value of the proton fourth moment must be independently known in order to…

Nuclear Theory · Physics 2021-08-11 Tomoya Naito , Gianluca Colò , Haozhao Liang , Xavier Roca-Maza

We determine the influence of a variation of the fundamental ``constants'' on the predicted helium abundance in Big Bang Nucleosynthesis. The analytic estimate is performed in two parts: the first step determines the dependence of the…

Astrophysics · Physics 2008-11-26 Christian M. Mueller , Gregor Schaefer , Christof Wetterich

Cosmological measurements of the radiation density in the early universe can be used as a sensitive probe of physics beyond the standard model. Observations of primordial light element abundances have long been used to place non-trivial…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-19 Joel Meyers

The success of primordial nucleosynthesis has been limited by the long-standing Lithium problem. We use a self-consistent perturbative analysis of the effects of relevant theoretical parameters on primordial nucleosynthesis, including…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-08 M. Deal , C. J. A. P. Martins

We investigate the effect of a variation of fundamental constants on primordial element production in Big Bang nucleosynthesis (BBN). We focus on the effect of a possible change in the nucleon-nucleon interaction on nuclear reaction rates…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-09 Alain Coc , Pierre Descouvemont , Jean-Philippe Uzan , Elisabeth Vangioni

In this paper we consider the effects on big bang nucleosynthesis (BBN) of the hadronic decay of a long-lived massive particle. If high-energy hadrons are emitted near the BBN epoch ($t \sim 10^{-2}$ -- $10^2 \sec$), they extraordinarily…

Astrophysics · Physics 2009-11-06 K. Kohri

This paper presents, for the first time, measurements of neutron transparency ratios for nuclei relative to C measured using the (e,e'n) reaction, spanning measured neutron momenta of 1.4 to 2.4 GeV/c. The transparency ratios were extracted…

The re-analysis of the published experimental data on the primary gamma-transition intensities following neutron capture in different groups of neutron resonances in $^{156,158}$Gd has been performed. There are determined the most probable…

Nuclear Experiment · Physics 2009-06-17 A. M. Sukhovoj , V. A. Khitrov

The influence of strongly magnetized electron-positron plasma on the radiative neutrino transition $\nng$ is investigated. The probability and mean losses of the neutrino energy and momentum are calculated taking account of the photon…

High Energy Physics - Phenomenology · Physics 2009-10-31 M. V. Chistyakov , N. V. Mikheev

We have performed for the first time a comprehensive study of the sensitivity of $r$-process nucleosynthesis to individual nuclear masses across the chart of nuclides. Using the latest version (2012) of the Finite-Range Droplet Model, we…

Nuclear Theory · Physics 2015-10-07 M. R. Mumpower , R. Surman , D. -L. Fang , M. Beard , P. Moller , T. Kawano , A. Aprahamian

We discuss the nuclear EMC effect with particular emphasis on recent data for light nuclei including 2H, 3He, 4He, 9Be, 12C and 14N. In order to verify the consistency of available data, we calculate the \chi^2 deviation between different…

High Energy Physics - Phenomenology · Physics 2015-03-14 S. A. Kulagin , R. Petti
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