| 1. |
- Edsjö, Joakim, et al.
(författare)
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High energy neutrinos from cosmic ray interactions in the Sun
- 2017
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- Cosmic rays hitting the outer parts of the Sun result in showers of high energy particles. The shower particles propagate through the solar atmosphere and interact further or decay. Among the shower particles are high energy neutrinos, after production these oscillate between flavours and interact with the solar material while propagating out of the Sun to the Earth. The result is a high energy neutrino flux at the Earth that may be detectable by modern neutrino detectors such as IceCube. Such a neutrino flux will furthermore act as a background in searches for neutrinos coming from annihilations of weakly interacting massive particles, often suggested to be the dark matter in the Universe. We perform an updated calculation of the solar atmospheric neutrino flux using the code MCEq for the cascade evolution in the solar atmosphere and WimpSim for the propagation of the neutrinos from the Sun to the detector on Earth, including full three-flavour treatment of neutrino oscillations and interactions in the Sun.
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| 2. |
- Edsjö, Joakim, et al.
(författare)
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Neutrinos from cosmic ray interactions in the Sun
- 2017
-
Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :06
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Tidskriftsartikel (refereegranskat)abstract
- Cosmic rays hitting the solar atmosphere generate neutrinos that interact and oscillate in the Sun and oscillate on the way to Earth. These neutrinos could potentially be detected with neutrino telescopes and will be a background for searches for neutrinos from dark matter annihilation in the Sun. We calculate the flux of neutrinos from these cosmic ray interactions in the Sun and also investigate the interactions near a detector on Earth that give rise to muons. We compare this background with both regular Earth-atmospheric neutrinos and signals from dark matter annihilation in the Sun. Our calculation is performed with an event-based Monte Carlo approach that should be suitable as a simulation tool for experimental collaborations. Our program package is released publicly along with this paper.
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| 3. |
- Niblaeus, Carl
(författare)
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The Sun as a laboratory for particle physics
- 2017
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- In the paper attached to this thesis, Paper I, we have calculated the flux of neutrinos that emanate from cosmic ray collisions in the solar atmosphere. These neutrinos are created in the cascades that follow the primary collision and can travel from their production point to a detector on Earth, interacting with the solar material and oscillating on the way. The motivation is both a better understanding of the cosmic ray interactions in the solar environment but also the fact that this neutrino flux presents an almost irreducible background for the searches for neutrinos from annihilations between dark matter particles in the Sun’s core.This interesting connection between neutrinos and dark matter make use of the Sun as a laboratory to investigate new models of particle physics. If dark matter consists of weakly interacting massive particles (WIMPs), the Sun will sweep up some of these WIMPs when it moves through the halo of dark matter that our galaxy lies in. These WIMPs will become gravitationally bound to the Sun and over time accumulate in the Sun’s core. In most models WIMPs can annihilate to Standard Model particles when encountering each other. The only particle that can make it out of the Sun without being absorbed is the neutrino. The buildup of WIMPs in the solar interior can therefore lead to a detectable flux of neutrinos.Neutrino telescopes therefore search for an excess of neutrinos from the Sun. To be able to ensure that a detected flux is in fact coming from dark matter annihilations one must properly account for all other sources of neutrinos. At higher energies these are primarily neutrinos created in energetic collisions between cosmic rays and particles in the Earth’s atmosphere, but also the solar atmospheric neutrinos. The latter will be tougher to disentangle from a WIMP signal since they also come from the Sun.We calculate in Paper I the creation of the neutrinos in the solar atmosphere and propagate these neutrinos to a detector on Earth, including oscillations and interactions in the Sun and vacuum oscillations between the Sun and the Earth. We find that the expected flux is small but potentially detectable by current neutrino telescopes, although further studies are needed to fully ascertain the possibility of discovery as well as how to properly disentangle this from a potential WIMP-induced neutrino signal.
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