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<h3>TÜBİTAK - FEZA GÜRSEY INSTITUTE</h3>
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<h1>Seminars</h1>
May 20 (Thursday), 2010 - 14:00 <br>
<b>Yamaç Pehlivan</b> (Mimar Sinan Fine Arts University) <br>
<b>Neutrino Self Refraction and Nonlinear Flavor Oscillations</b> <br>
<br>
<b>Abstract :</b> In a dense neutrino gas, neutrino-neutrino scattering
creates a refractive
effect on the flavor oscillations of neutrinos in a way which is
similar to
the refraction of light waves in ordinary matter. However, the neutrino
self
refraction is different from ordinary refraction as in the former the
refracting and the refracted particles are indistinguishable. This
turns a
dense neutrino gas into a highly nonlinear many-body system. Clearly
one
needs very high neutrino densities for the tiny neutrino-neutrino
scattering
cross section to play an important part but such high neutrino
densities are
believed to be reached in the Early Universe, in core collapse
supernovae
and possibly in gamma ray bursts.
<br>
<br>
In this talk, I will summarize the neutrino self refraction problem
with an
emphasis on its many body character. I will then point to the
similarities
between a self interacting dense neutrino gas and another many body
system
that we are familiar with, namely a system with pairing interactions
which
is used to describe Cooper pairs in the BCS theory of superconductivity
and
nucleon pairs in nuclear shell model. An interesting property that a
self
interacting dense neutrino gas has in common with the later models is
that
it possesses dynamical symmetries. I will talk about the possible
implications of these dynamical symmetries on the resulting neutrino
flavor
oscillations. <br>
<br>
<a href="http://www.gursey.gov.tr/autoposter/posters/48.pdf"
target="_blank">Poster</a><br>
<br>
<br>
<font size="-1">For requests, apply to <b>seminar[et]gursey_gov_tr</b>.</font>
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