منابع مشابه
Leptonic Photons and Nucleosynthesis
Should U(1) long-range forces be associated to electron, muon and/or tau quantum number then their ”fine structure constants” are seen to be bound by nucleosynthesis data to be less than about 1.7× 10. For τ and μ this is the best upper limit up to date. ∗Laboratoire associé au C.N.R.S. — URA D0063. While the rôle of electric charge, weak isospin, and color is completely clarified in the modern...
متن کاملBig-Bang Nucleosynthesis Reactions Catalyzed by a Long-Lived Negatively-Charged Leptonic Particle
Accurate quantum three-body calculation is performed for the new rank of big-bang nucleosynthesis (BBN) reactions that are catalyzed by a hypothetical long-lived negativelycharged, massive leptonic particle (called X−) such as a supersymmetric (SUSY) particle stau, the scalar partner of the tau lepton. It is known that if the X− particle has a lifetime of τX >∼ 10 3 s, it would capture a light ...
متن کاملLeptonic and semi - leptonic B decays
We present results for the semi-leptonic and leptonic decays of B mesons. These non-perturbative matrix elements are important for constraining the CKM matrix. Results are presented for the pseudoscalar and vector decay constants, as well as flavour breaking ratios and heavy quark symmetry relations. We consider the chiral and momentum dependence of the semi-leptonic form factors of the decay B...
متن کاملHypernovae and their Nucleosynthesis
We review the characteristics of nucleosynthesis in ’Hypernovae’, i.e., corecollapse supernovae with very large explosion energies ( ∼ > 10 ergs). The hypernova yields show the following characteristics: 1) The mass ratio between the complete and incomplete Si burning regions is larger in hypernovae than normal supernovae. As a result, higher energy explosions tend to produce larger [(Zn, Co, V...
متن کاملNeutrinos and Primordial Nucleosynthesis
The importance of the Big Bang Nucleosynthesis (BBN) as a unique tool for studying neutrino properties is discussed, and the recent steps towards a self-consistent and robust handling of the weak reaction decoupling from the thermal bath as well as of the neutrino reheating following the e − e− annihilation are summarized. We also emphasize the important role of the Cosmic Microwave Background ...
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ژورنال
عنوان ژورنال: Physics Letters B
سال: 1997
ISSN: 0370-2693
DOI: 10.1016/s0370-2693(97)00119-6