Testing MSW effect in Supernova Explosion with Neutrino event rates. (arXiv:2001.08543v1 [astro-ph.HE])
<a href="http://arxiv.org/find/astro-ph/1/au:+Lai_K/0/1/0/all/0/1">Kwang-Chang Lai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Leung_C/0/1/0/all/0/1">C. S. Jason Leung</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lin_G/0/1/0/all/0/1">Guey-Lin Lin</a>
Flavor transitions in supernova neutrinos are yet to be determined. We
present a method to probe whether or not the Mikheyev-Smirnov-Wolfenstein
effects occur as SN neutrinos propagate outward from the SN core by
investigating time evolutions of neutrino event rates for different flavors in
different kinds of detectors. As the MSW effect occurs, the $nu_e$ flux swaps
with the $nu_x$ flux, which represents any one of $nu_{mu}$, $nu_{tau}$,
$bar{nu}_{mu}$, and $bar{nu}_{tau}$ flux, either fully or partially
depending on the neutrino mass hierarchy. During the neutronization burst, the
$nu_e$ emission evolves in a much different shape from the emissions of
$bar{nu}_e$ and $nu_x$ while the latter two evolve in a similar pattern.
Meanwhile, the luminosity of the the $nu_e$ emission is much larger than those
of the $bar{nu}_e$ and $nu_x$ emissions while the latter two are roughly
equal. As a consequence, the time-evolution pattern of the $nu_e{rm Ar}$
event rates in the absence of the MSW effect will be much different from that
in the occurrence of the MSW effect, in either mass hierarchy. With the
simulated SN neutrino emissions, the $nu_e{rm Ar}$ and inverse beta decay
event rates are evaluated. The ratios of the two cumulative event rates are
calculated for different progenitor masses up to $100~{rm ms}$. We show that
the time evolutions of this cumulative ratios can effectively determine whether
MSW effects really occur for SN neutrinos or not.
Flavor transitions in supernova neutrinos are yet to be determined. We
present a method to probe whether or not the Mikheyev-Smirnov-Wolfenstein
effects occur as SN neutrinos propagate outward from the SN core by
investigating time evolutions of neutrino event rates for different flavors in
different kinds of detectors. As the MSW effect occurs, the $nu_e$ flux swaps
with the $nu_x$ flux, which represents any one of $nu_{mu}$, $nu_{tau}$,
$bar{nu}_{mu}$, and $bar{nu}_{tau}$ flux, either fully or partially
depending on the neutrino mass hierarchy. During the neutronization burst, the
$nu_e$ emission evolves in a much different shape from the emissions of
$bar{nu}_e$ and $nu_x$ while the latter two evolve in a similar pattern.
Meanwhile, the luminosity of the the $nu_e$ emission is much larger than those
of the $bar{nu}_e$ and $nu_x$ emissions while the latter two are roughly
equal. As a consequence, the time-evolution pattern of the $nu_e{rm Ar}$
event rates in the absence of the MSW effect will be much different from that
in the occurrence of the MSW effect, in either mass hierarchy. With the
simulated SN neutrino emissions, the $nu_e{rm Ar}$ and inverse beta decay
event rates are evaluated. The ratios of the two cumulative event rates are
calculated for different progenitor masses up to $100~{rm ms}$. We show that
the time evolutions of this cumulative ratios can effectively determine whether
MSW effects really occur for SN neutrinos or not.
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