On the Baryometric Status of<sup>3</sup>He

Vangioni‐Flam, Elisabeth; Olive, Keith A.; Fields, Brian D.; Cassé, Michel

doi:10.1086/346232

Cited by 72 publications

(57 citation statements)

References 57 publications

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“…At the same time, it is important to bear in mind that these constraints are on less sure footing than the D constraints. For 3 He, 3 He/H suffers from uncertainties in chemical/stellar evolution [56]. Although 3 He/D has been proposed as an alternative tool to constrain new physics [51,57], present evaluations exist only in the Sun [58], and the determination of primordial 3 He/D requires a rather involved extrapolation of these results.…”

Section: B Cosmic Microwave Backgroundmentioning

confidence: 99%

Supergravity with a gravitino lightest supersymmetric particle

2004

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We investigate supergravity models in which the lightest supersymmetric particle (LSP) is a stable gravitino. We assume that the next-lightest supersymmetric particle (NLSP) freezes out with its thermal relic density before decaying to the gravitino at time t ∼ 10 4 − 10 8 s. In contrast to studies that assume a fixed gravitino relic density, the thermal relic density assumption implies upper, not lower, bounds on superpartner masses, with important implications for particle colliders. We consider slepton, sneutrino, and neutralino NLSPs, and determine what superpartner masses are viable in all of these cases, applying CMB and electromagnetic and hadronic BBN constraints to the leading two-and three-body NLSP decays. Hadronic constraints have been neglected previously, but we find that they provide the most stringent constraints in much of the natural parameter space. We then discuss the collider phenomenology of supergravity with a gravitino LSP. We find that colliders may provide important insights to clarify BBN and the thermal history of the Universe below temperatures around 10 GeV and may even provide precise measurements of the gravitino's mass and couplings.

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Section: B Cosmic Microwave Backgroundmentioning

confidence: 99%

Supergravity with a gravitino lightest supersymmetric particle

2004

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“…Consequently, comparison with 3 He abundance from BBN is subject to caution [17]. at WMAP baryonic density.…”

Section: Abundances Of the Cosmological Elementsmentioning

confidence: 99%

Primordial Nucleosynthesis

Coc¹

2013

Acta Phys. Pol. B

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Abstract. Primordial nucleosynthesis, or Big Bang Nucleosynthesis (BBN), is one of the three evidences for the Big-Bang model, together with the expansion of the Universe and the Cosmic Microwave Background. There is a good global agreement over a range of nine orders of magnitude between abundances of 4 He, D, 3 He and 7 Li deduced from observations, and calculated in primordial nucleosynthesis. This comparison was used to determine the baryonic density of the Universe. For this purpose, it is now superseded by the analysis of the Cosmic Microwave Background (CMB) radiation anisotropies. However, there remain, a yet unexplained, discrepancy of a factor 3-5, between the calculated and observed lithium primordial abundances, that has not been reduced, neither by recent nuclear physics experiments, nor by new observations. We review here the nuclear physics aspects of BBN for the production of 4 He, D, 3 He and 7 Li, but also 6 Li, 9 Be, 11 B and up to CNO isotopes. These are, for instance, important for the initial composition of the matter at the origin of the first stars. Big-Bang nucleosynthesis, that has been used, to first constrain the baryonic density, and the number of neutrino families, remains, a valuable tool to probe the physics of the early Universe, like variation of "constants" or alternative theories of gravity.

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“…It is not yet understood, however, whether 3 He has increased or decreased through the course of stellar and galactic evolution [21,22]. A best estimate [11,5] is 3 He/H = (0.7 ± 0.5) × 10 −5 .…”

Section: Bbn Reaction Rates and Light-element Abundancesmentioning

confidence: 99%

Big Bang nucleosynthesis and the origin and evolution of space-time

Mathews¹

2015

Proceedings of XIII Nuclei in the Cosmos — PoS(NIC XIII)

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Primordial nucleosynthesis remains as one of the pillars of modern cosmology. It is the testing ground upon which all cosmological models must ultimately rest. It is our only probe of the universe during the first few minutes of cosmic expansion and in particular during the important radiation-dominated epoch. There have been significant recent advances in the understanding of the big bang including the recent detection of the inflation-generated gravity-wave background. This talk will review the the current state of observational constraints on primordial abundances along with the key nuclear reactions, their uncertainties and how this knowledge places key constraints on cosmological models. In particular, we will summarize the connections between big bang nucleosynthesis and the birth of the universe, including cosmic gravity waves, inflation, the possible time variation of fundamental constants], the nature and origin of dark matter and dark energy, supersymmetry, and the primordial magnetic field.

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On the Baryometric Status of³He

Cited by 72 publications

References 57 publications

Supergravity with a gravitino lightest supersymmetric particle

Supergravity with a gravitino lightest supersymmetric particle

Primordial Nucleosynthesis

Big Bang nucleosynthesis and the origin and evolution of space-time

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On the Baryometric Status of3He

Cited by 72 publications

References 57 publications

Supergravity with a gravitino lightest supersymmetric particle

Supergravity with a gravitino lightest supersymmetric particle

Primordial Nucleosynthesis

Big Bang nucleosynthesis and the origin and evolution of space-time

Contact Info

Product

Resources

About

On the Baryometric Status of³He