Flavor physics of leptons and dipole moments Raidal, M.; van der Schaaf, A.; Bigi, I. ...
European physical journal. C, Particles and fields,
09/2008, Letnik:
57, Številka:
1-2
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
This chapter of the report of the “Flavor in the era of the LHC” Workshop discusses the theoretical, phenomenological and experimental issues related to flavor phenomena in the charged lepton sector ...and in flavor conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavor structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the standard model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
The aim of this Letter is to discuss phenomenological consequences of a particular unification model (Z3 model) inspired by F-theory. The most distinctive feature of this model is a variety of ...(cosmologically feasible) options for the NLSP and NNLSP, beyond the usually considered benchmark scenarios.
We present predictions for flavour-violating charged-lepton decays induced by the seesaw mechanism implemented within the constrained minimal supersymmetric standard model (CMSSM) with universal ...input soft supersymmetry breaking terms. We assume that one heavy singlet neutrino almost decouples from the seesaw mechanism, as suggested by the pattern of light neutrino masses and mixing angles. This is suggested independently by sneutrino inflation with a low reheating temperature,
T
RH
≲10
7
GeV
, so as to avoid overproducing gravitinos. This requirement further fixes the mass of the weakly-coupled sneutrino, whose decays may lead to leptogenesis. We find that
BR(
μ→
eγ)≳10
−13 but
BR(
τ→
μγ)≲10
−9 in the bulk of the acceptable parameter space, apart from a few isolated points. The ratio
BR(
μ→
eγ)/
BR(
τ→
eγ) depends on only one complex parameter, and is particularly interesting to compare with experiment.
Rearrangements of the EWS gene with ETS transcription factor genes as a result of chromosomal translocation and high expression levels of CD99MIC2 characterize the Ewing family of tumors (EFT). This ...group of rather undifferentiated neoplasms affects bone and soft tissue in children and young adults mostly between 5 and 30 years of age (median, 15 years). This study reports a case of a CD99MIC2 positive small round cell tumor in the breast of a 60-year-old woman in whom a t(11;22)(q24;q12) chromosomal aberration was identified by cytogenetic analysis. Reverse transcriptase (RT)-polymerase chain reaction (PCR) followed by sequence analysis revealed expression of a chimera transcript in which EWS exon 10 was fused to FLI1 exon 6. Previously, this gene fusion has been reported to occur in approximately 3% of EFT. The specific gene rearrangement of EWS intron 10 was confirmed on Southern blot of genomic DNA. This study further contributes to the growing list of unusual neoplasms in adults that carry genotypic and phenotypic traits of the EFT.
Phys.Rev.D76:053008,2007 We provide a framework for quasi-degenerate neutrinos consistent with a
successful leptogenesis, based on the L_mu-L_tau flavor symmetry and its
breaking pattern. In this ...scheme, a fine-tuning is needed to arrange the small
solar neutrino mass splitting. Once it is ensured, the atmospheric neutrino
mass splitting and the deviation from the maximal atmospheric mixing angle are
driven by the same symmetry breaking parameter lambda~0.1, and the reactor
angle is predicted to be slightly smaller than lambda, while the Dirac CP phase
is generically of order one. Given that the pseudo-Dirac nature of right-handed
neutrinos is protected from the flavor symmetry breaking, a small mass
splitting can be generated radiatively. For moderate values of tan(beta)~10,
this allows for low-scale supersymmetric leptogenesis, overcoming a strong
wash-out effect of the quasi-degenerate light neutrinos and evading the
gravitino overproduction.
This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton ...sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.
We provide a framework for quasi-degenerate neutrinos consistent with a successful leptogenesis, based on the L_mu-L_tau flavor symmetry and its breaking pattern. In this scheme, a fine-tuning is ...needed to arrange the small solar neutrino mass splitting. Once it is ensured, the atmospheric neutrino mass splitting and the deviation from the maximal atmospheric mixing angle are driven by the same symmetry breaking parameter lambda~0.1, and the reactor angle is predicted to be slightly smaller than lambda, while the Dirac CP phase is generically of order one. Given that the pseudo-Dirac nature of right-handed neutrinos is protected from the flavor symmetry breaking, a small mass splitting can be generated radiatively. For moderate values of tan(beta)~10, this allows for low-scale supersymmetric leptogenesis, overcoming a strong wash-out effect of the quasi-degenerate light neutrinos and evading the gravitino overproduction.
JCAP 0610:005,2006 The three-year data from WMAP are in stunning agreement with the simplest
possible quadratic potential for chaotic inflation, as well as with new or
symmetry-breaking inflation. We ...investigate the possibilities for incorporating
these potentials within supergravity, particularly of the no-scale type that is
motivated by string theory. Models with inflation driven by the matter sector
may be constructed in no-scale supergravity, if the moduli are assumed to be
stabilised by some higher-scale dynamics and at the expense of some
fine-tuning. We discuss specific scenarios for stabilising the moduli via
either D- or F-terms in the effective potential, and survey possible
inflationary models in the presence of D-term stabilisation.
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