6,519 research outputs found
Beyond the Standard Model with leptogenesis and neutrino data
In this short review I discuss how high energy (type I) seesaw models can be
nicely embedded within grand-unified models and reproduce the observed
matter-antimatter asymmetry with leptogenesis. In particular, after discussing
general features and results in leptogenesis,
I focus on -inspired leptogenesis and on a particular solution, the
strong thermal -inspired solution, that provides an interesting way to
understand neutrino mixing parameters: the non-vanishing reactor mixing angle,
the emerging negative sign of and the slight hints favouring
normally ordered neutrino masses and an atmospheric mixing angle in the first
octant. I also briefly discuss leptogenesis within two right-handed seesaw
neutrino models. In this case a a third decoupled right-handed neutrino can
provide a candidate for very heavy cold decaying dark matter produced from
right-handed neutrino mixing with a mass in the TeV-EeV range and its decays
would give a contribution to the IceCube high energy neutrino events in
addition to an astrophysical component.Comment: 12 pages, 2 Figures; compendium of plenary talks given at Neutrino
2016, NuFact 2016 and IPA 2016; v2: Ref.'s adde
News on Leptogenesis
The possibility to explain the CMB measurement of the baryon asymmetry with
leptogenesis results in a stringent bound on the neutrino masses such that
[(m_1)^2+(m_2)^2+(m_3)^2]^(1/2) < 0.30 eV. We discuss the implications of such
a bound for future experiments on the absolute neutrino mass scale.Comment: 12 pages, 4 figures included. Talk given at the Third Tropical
Workshop: Neutrinos, Branes and Cosmology, 19-23 August 2002, San Juan,
Puerto Rico. v2 references adde
The cosmological information on neutrino mixing
Cosmology provides interesting information on neutrino mixing models with
sterile neutrinos. In this case non standard BBN effects can be relevant. We
show how the recent measurement of the baryon content from the observations of
CMB anisotropies together with the primordial nuclear abundances measurements
can be used to constrain them. In particular four neutrino mixing models are
potentially at variance with the cosmological observations. We also discuss the
possible scenarios from future experiments.Comment: 5 pages, LaTeX, JHEP style, talk given at EPS HEP 2001, Budapest,
Hungary, 12 - 18 July 200
Measurement results of transmit delay diversity for DVB-T networks
This paper describes work carried out by Brunel University and Broadreach systems (UK) to quantify the advantages that can be achieved if transmit diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial performed during the winter of 2007/2008 in Uxbridge (UK) is described. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4 dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive- non line of sight situations
Flavor effects in thermal leptogenesis
We review recent developments in leptogenesis on flavor effects. Their
account discloses an important connection between the matter-antimatter
asymmetry of the Universe and CP violation at low energies. Besides, they
modify the upper bound on the neutrino masses holding in the unflavored case.
In this respect, it is important to identify the exact condition for flavor
effects to be relevant and for the `fully flavored' Boltzmann equations to be
valid.Comment: 3 pages, no figure ; contribution to the proceedings of NOW 2006,
Conca Specchiulla, Sep. 9-16, 200
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