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SUMMARY:Exploring Neutrino Mixing angles and Dirac and Majorana CP Violati
 on Phases at GUT Scale
DTSTART;VALUE=DATE-TIME:20020731T100000Z
DTEND;VALUE=DATE-TIME:20020731T110000Z
DTSTAMP;VALUE=DATE-TIME:20261110T063413Z
UID:indico-event-1273@indico.ific.uv.es
DESCRIPTION:The special aspect of the neutrino mixing matrix at $m_Z$ scal
 e is (1) $V_{13}\\sineq 0$ and (2) $\\tan^2 \\theta_{\\rm atm}\\simeq 1$. 
 The recent SNO data implies that the solar mixing angle is far from the ma
 ximal value\, $\\tan^2 \\theta_{\\rm sol}\\simeq 0.37$. From these data\, 
 it may be natural to assume that at GUT scale\, the mixing angles would be
  such that (1) $$V_{13}=0$ and (2) $\\tan^2 \\theta_{\\rm atm}\\simeq 1$. 
 Then\, we explore what kind of solar mixing angle would be at the GUT scal
 e. The model $V_{13}=0$ at GUT scale\, the number of parameters in the neu
 trino mass matrix is three masses\, two mixing angles and two Majorana pha
 ses. At $m_Z$ scale\, $V_{13}$ as well as a Dirac phase is induced by the 
 radiative correction. In particular\, we found that $\\sin^22\\tilde\\thet
 a_{12}\\leq \\sin^22\\theta_{\\rm sol}$\, where $\\theta_{12}$ and $\\thet
 a_{\\rm sol}$ are mixing angles at the GUT scale and at $m_Z$ scale resprc
 tively. This means that if the solar mixing angle at $m_Z$ scale is really
  far from maximal\, $\\tan^2 \\theta_{\\rm sol}\\simeq 0.37$\, then the Bi
 -maximal scheme can not be a realistic model. We also discuss possible siz
 es of $V_{13}$ and a Dirac CP violation phase.We also comment on the relat
 ion between the CP violation phase and phases which appear in leptogenesis
 .\n\nhttps://indico.ific.uv.es/event/1273/
LOCATION:Edf. Institutos de Investigación Sala Seminarios IFIC
URL:https://indico.ific.uv.es/event/1273/
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