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Related papers: The (ir)Relevance of Initial Conditions in Soft Le…

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We show that soft supersymmetry breaking terms involving the heavy sneutrinos can lead to sneutrino-antisneutrino mixing and to new sources of CP violation, which are present even if a single generation is considered. These terms are…

High Energy Physics - Phenomenology · Physics 2008-11-26 Yuval Grossman , Tamar Kashti , Yosef Nir , Esteban Roulet

A large lepton asymmetry could be generated in the Early Universe by oscillations of active to sterile neutrinos with a small mixing angle sin 2 \theta < 10^-2. The final order of magnitude of the lepton asymmetry \eta is mainly determined…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. Buras , D. V. Semikoz

Soft supersymmetry breaking terms involving heavy singlet sneutrinos can be the dominant source of leptogenesis. The relevant range of parameters is different from standard leptogenesis: a lighter Majorana mass, M < 10^9 GeV (allowing a…

High Energy Physics - Phenomenology · Physics 2009-11-10 Tamar Kashti

Soft leptogenesis is a scenario in which the cosmic baryon asymmetry is produced from a lepton asymmetry generated in the decays of heavy sneutrinos (the partners of the singlet neutrinos of the seesaw) and where the relevant sources of CP…

High Energy Physics - Phenomenology · Physics 2011-09-07 Chee Sheng Fong , M. C. Gonzalez-Garcia , Enrico Nardi

By including all leading quantum-statistical effects at finite temperature, we show that no net asymmetry of leptons and sleptons is generated from soft leptogenesis, save the possible contribution from the resonant mixing of sneutrinos.…

High Energy Physics - Phenomenology · Physics 2015-06-16 Bjorn Garbrecht , Michael J. Ramsey-Musolf

We consider the full Boltzmann equations for standard and soft leptogenesis, instead of the usual integrated Boltzmann equations which assume kinetic equilibrium for all species. Decays and inverse decays may be inefficient for thermalising…

High Energy Physics - Phenomenology · Physics 2009-10-02 J. Garayoa , S. Pastor , T. Pinto , N. Rius , O. Vives

We study ``soft leptogenesis'', a new mechanism of leptogenesis which does not require flavour mixing among the right-handed neutrinos. Supersymmetry soft-breaking terms give a small mass splitting between the CP-even and CP-odd…

High Energy Physics - Phenomenology · Physics 2010-04-05 Giancarlo D'Ambrosio , Gian F. Giudice , Martti Raidal

Leptogenesis is studied within the seesaw neutrino mass model in a regime where all sterile neutrinos have prompt rather than delayed decays. It is shown that during neutrino thermal production lepton asymmetries are generated in both…

High Energy Physics - Phenomenology · Physics 2007-05-23 Luis Bento

We consider leptogenesis induced by soft supersymmetry breaking terms ("soft leptogenesis"), in the context of the inverse seesaw mechanism. In this model there are lepton number (L) conserving and L-violating soft supersymmetry-breaking…

High Energy Physics - Phenomenology · Physics 2010-10-27 J. Garayoa , M. C. Gonzalez-Garcia , N. Rius

We analyze the effects of lepton asymmetry on neutrino oscillations and on cosmological nucleosynthesis with active-sterile oscillating neutrinos. It is shown that small lepton asymmetries, L < 0.01, whose direct kinetic effect on…

Astrophysics · Physics 2009-11-06 Daniela Kirilova , Mihail Chizhov

We explore in some detail the hypothesis that the generation of a primordial lepton-antilepton asymmetry (Leptogenesis) early on in the history of the Universe is the root cause for the origin of matter. After explaining the theoretical…

High Energy Physics - Phenomenology · Physics 2009-11-11 W. Buchmuller , R. D. Peccei , T. Yanagida

We revisit flavour effects in soft leptogenesis relaxing the assumption of universality for the soft supersymmetry breaking terms. We find that with respect to the case in which the heavy sneutrinos decay with equal rates and equal CP…

High Energy Physics - Phenomenology · Physics 2010-12-20 Chee Sheng Fong , M. C. Gonzalez-Garcia , Enrico Nardi , J. Racker

Soft leptogenesis is a mechanism which generates the matter-antimatter asymmetry of the Universe via the out-of-equilibrium decays of heavy sneutrinos in which soft supersymmetry breaking terms play two important roles: they provide the…

High Energy Physics - Phenomenology · Physics 2015-05-05 Rathin Adhikari , Arnab Dasgupta , Chee Sheng Fong , Raghavan Rangarajan

Leptogenesis is an attractive scenario in which neutrino masses and baryon asymmetry of the Universe are explained together under a minimal set of assumptions. After formulating the problem of initial conditions and introducing the strong…

High Energy Physics - Phenomenology · Physics 2014-10-22 Luca Marzola

We propose a minimal and motivated extension of the Standard Model characterised by an approximate lepton number conservation, which is able to simultaneously generate neutrino masses and to account for a successful baryogenesis via…

High Energy Physics - Phenomenology · Physics 2016-08-24 Michele Lucente , Asmaa Abada , Giorgio Arcadi , Valerie Domcke

We study leptogenesis in the supersymmetric standard model plus the seesaw. We identify important qualitative differences that characterize supersymmetric leptogenesis with respect to the non-supersymmetric case. The lepton number…

High Energy Physics - Phenomenology · Physics 2010-12-17 Chee Sheng Fong , M. C. Gonzalez-Garcia , Enrico Nardi , J. Racker

We investigate quantitatively the extent to which having a primordial leptonic asymmetry (n_nu \neq n_nubar) relaxes the bounds on light sterile neutrinos imposed by BBN and LSS. We adopt a few assumptions that allow us to solve the…

Astrophysics · Physics 2008-11-26 Yi-Zen Chu , Marco Cirelli

I review the origin of the lepton asymmetry which is converted to a baryon excess at the electroweak scale. This scenario becomes more attractive if we can relate it to other physical phenomena. For this reason I elaborate on the conditions…

High Energy Physics - Phenomenology · Physics 2009-11-07 E. A. Paschos

In this article we discuss lepton asymmetry effect on BBN with neutrino oscillations. We argue that asymmetry much smaller than 0.01, although not big enough to influence directly the nucleosynthesis kinetics, can effect considerably BBN…

High Energy Physics - Phenomenology · Physics 2007-05-23 M. V. Chizhov , D. P. Kirilova

Oscillations of active to sterile neutrinos with a small mixing angle sin 2 \theta < 10^{-2} could generate a large lepton asymmetry in the Early Universe. The final order of magnitude of the lepton asymmetry \eta is mainly determined by…

High Energy Physics - Phenomenology · Physics 2011-05-23 R. Buras , D. V. Semikoz
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