55 research outputs found
Introduction to neutrino astronomy
This writeup is an introduction to neutrino astronomy, addressed to
astronomers and written by astroparticle physicists. While the focus is on
achievements and goals in neutrino astronomy, rather than on the aspects
connected to particle physics, we will introduce the particle physics concepts
needed to appreciate those aspects that depend on the peculiarity of the
neutrinos. The detailed layout is as follows: In Sect.~1, we introduce the
neutrinos, examine their interactions, and present neutrino detectors and
telescopes. In Sect.~2, we discuss solar neutrinos, that have been detected and
are matter of intense (theoretical and experimental) studies. In Sect.~3, we
focus on supernova neutrinos, that inform us on a very dramatic astrophysical
event and can tell us a lot on the phenomenon of gravitational collapse. In
Sect.~4, we discuss the highest energy neutrinos, a very recent and lively
research field. In Sect.~5, we review the phenomenon of neutrino oscillations
and assess its relevance for neutrino astronomy. Finally, we offer a brief
overall assessment and a summary in Sect.~6. The material is selected - i.e.,
not all achievements are reviewed - and furthermore it is kept to an
introductory level, but efforts are made to highlight current research issues.
In order to help the beginner, we prefer to limit the list of references,
opting whenever possible for review works and books.Comment: 15 pages, 5 figures. Accepted for publication The European Physical
Journal Plus. Based on the lecture given at the "4th Azarquiel School of
Astronomy", June 2017, Porto Paolo di Capo Passero, Syracuse (Italy)
https://agenda.infn.it/conferenceDisplay.py?confId=1208
Probing new physics with coherent neutrino scattering off nuclei
The possibility off measuring for the first time neutrino-nuclei coherent
scattering has been recently discussed by several experimental collaborations.
It is shown that such a measurement may be very sensitive to non-standard
interactions of neutrinos with quarks and might set better constraints than
those coming from future neutrino factory experiments. We also comment on other
types of new physics tests, such as extra heavy neutral gauge bosons, where the
sensitivity to some models is slightly better than the Tevatron constraint and,
therefore, could give complementary bounds.Comment: 15 pages, 4 figures Discussion about Z prime corrected and extended.
Final version to be published in JHE
Reconciling neutrino flux from heavy dark matter decay and recent events at IceCube
The IceCube detector has recently reported the observation of 28 events at
previously unexplored energies. While the statistics of the observed events are
still low, these events hint at the existence of a neutrino flux over and above
the atmospheric neutrino background. We investigate the possibility that a
significant component of the additional neutrino flux originates due to the
decay of a very heavy dark matter (VHDM) particle via several possible channels
into standard model particles. We show that a combination of a power law
astrophysical neutrino spectrum and the neutrino flux from the decay of a DM
species of mass in the range TeV improves the fit to the observed
neutrino events than that obtained from a best-fit astrophysical flux alone.
Assuming the existence of an astrophysical background described by the IC
best-fit, we also show that, for the decay of even heavier DM particles
( PeV), the same observations impose significant
constraints on the decay lifetimes. Allowing the astrophysical flux
normalization to vary leads to modifications of these limits, however, there is
still a range of dark matter mass and lifetime that is excluded by the IC
results.Comment: v1: 8 pages, 2 figures, 2 tables. v2: Minimization over
three-parameters (DM mass, lifetime and astrophysical power-law flux
normalization); better statistical quantification of fit-goodness;
conclusions unchanged; 15 pg, 3 figs, 2 tables; version to appear in JHE
Determination of the octant in LBNO
According to the recent results of the neutrino oscillation experiment MINOS,
the neutrino mixing angle may not be maximal (). Two
nearly degenerate solutions are possible, one in the lower octant (LO) where
, and one in the higher octant (HO) where
. Long baseline experiments measuring the
are capable of resolving this degeneracy. In this
work we study the potential of the planned European LBNO experiment to
distinguish between the LO and HO solutions.Comment: 12 pages, 8 figures in two set
Status of Dark Matter Searches (Rapporteur Talk)
This article reviews the status of the field of dark matter as of summer
2017, when it was discussed at 35th International Cosmic Ray Conference (ICRC
2017) in Busan, Korea. It is the write-up of a rapporteur talk on the status of
dark matter searches given at the conference.Comment: 24 pages, 18figures, 35th International Cosmic Ray Conference
(ICRC2017
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