| 1. |
- Blennow, Mattias, 1980-, et al.
(författare)
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Neutrinos from WIMP annihilations in the Sun including neutrino oscillations
- 2011
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Ingår i: The Proceedings of the 22nd International Conference on Neutrino Physics and Astrophysics. - : Elsevier. ; , s. 37-38
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Konferensbidrag (refereegranskat)abstract
- The prospects to detect neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.
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| 2. |
- Blennow, Mattias, et al.
(författare)
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Neutrinos from WIMP annihilations in the Sun including neutrino oscillations
- 2006
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Ingår i: Physica Scripta. - : IOP Publishing. - 0031-8949 .- 1402-4896. ; T127, s. 19-21
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Tidskriftsartikel (refereegranskat)abstract
- The prospects for detecting neutrinos from the Sun arising from dark matter annihilations in the core of the Sun are reviewed. Emphasis is placed on new work investigating the effects of neutrino oscillations on the expected neutrino fluxes.
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| 3. |
- Blennow, Mattias, et al.
(författare)
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WIMP neutrinos from the Sun and the Earth
- 2008
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Konferensbidrag (refereegranskat)abstract
- We discuss the propagation treatment of the indirect dark matter detection using WIMP annihilations in the Sun and the Earth. In particular, we focus on treating neutrino interactions and oscillations in a consistent framework, including tau neutrino regeneration and a full three-flavor neutrino oscillation framework. We also discuss the equivalence of using a Monte Carlo approach - suited for inclusion in neutrino telescope Monte Carlos - and the density matrix formalism.
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| 4. |
- Sivertsson, Sofia, 1982-, et al.
(författare)
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Accurate calculations of the WIMP halo around the Sun and prospects for gamma ray detection
- 2008
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Ingår i: Identification of dark matter 2008. - : SISSA. ; , s. 112-
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Konferensbidrag (refereegranskat)abstract
- Weakly interacting massive particles (WIMPs) can be captured by heavenly objects, like the Sun.Under the process of being captured by the Sun, they will build up a population of WIMPs aroundit, that will eventually sink to the core of the Sun. It has been argued with simpler estimatesbefore that this halo of WIMPs around the Sun could be a strong enough gamma ray source to bea detectable signature for WIMP dark matter. We here revisit the problem using detailed MonteCarlo simulations and detailed composition and structure information about the Sun to estimatethe size of the gamma ray flux. Compared to earlier estimates, we find that the gamma ray fluxfrom WIMP annihilations in the Sun halo would be negligible and no current or planned detectorswould even be able to detect this flux.
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| 5. |
- Sivertsson, Sofia, 1982-, et al.
(författare)
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Accurate calculations of the WIMP halo around the Sun and prospects for its gamma-ray detection
- 2010
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Ingår i: Physical Review D. - : The American Physical Society. - 1550-7998 .- 1550-2368. ; 81:6, s. 63502-
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Tidskriftsartikel (refereegranskat)abstract
- Galactic weakly interacting massive particles (WIMPs) may scatter off solar nuclei to orbits gravitationally bound to the Sun. Once bound, the WIMPs continue to lose energy by repeated scatters in the Sun, eventually leading to complete entrapment in the solar interior. While the density of the bound population is highest at the center of the Sun, the only observable signature of WIMP annihilations inside the Sun is neutrinos. It has been previously suggested that although the density of WIMPs just outside the Sun is lower than deep inside, gamma rays from WIMP annihilation just outside the surface of the Sun, in the so-called WIMP halo around the Sun, may be more easily detected. We here revisit this problem using detailed Monte Carlo simulations and detailed composition and structure information about the Sun to estimate the size of the gamma-ray flux. Compared to earlier simpler estimates, we find that the gamma-ray flux from WIMP annihilations in the solar WIMP halo would be negligible; no current or planned detectors would be able to detect this flux.
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| 6. |
- Sivertsson, Sofia, 1982-
(författare)
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Studies of dark matter in and around stars
- 2012
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- There is by now compelling evidence that most of the matter in the Universe is in the form of dark matter, a form of matter quite different from the matter we experience in every day life. The gravitational effects of this dark matter have been observed in many different ways but its true nature is still unknown. In most models, dark matter particles can annihilate with each other into standard model particles; the direct or indirect observation of such annihilation products could give important clues for the dark matter puzzle. For signals from dark matter annihilations to be detectable, typically high dark matter densities are required. Massive objects, such as stars, can increase the local dark matter density both via scattering off nucleons and by pulling in dark matter gravitationally as a star forms. Annihilations within this kind of dark matter population gravitationally bound to a star, like the Sun, give rise to a gamma ray flux. For a star which has a planetary system, dark matter can become gravitationally bound also through gravitational interactions with the planets. The interplay between the different dark matter populations in the solar system is analyzed, shedding new light on dark matter annihilations inside celestial bodies and improving the predicted experimental reach. Dark matter annihilations inside a star would also deposit energy in the star which, if abundant enough, could alter the stellar evolution. This is investigated for the very first stars in the Universe. Finally, there is a possibility for abundant small scale dark matter overdensities to have formed in the early Universe. Prospects of detecting gamma rays from such minihalos, which have survived until the present day, are discussed.
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| 7. |
- Sivertsson, Sofia, et al.
(författare)
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WIMP diffusion in the Solar System including solar WIMP-nucleon scattering
- 2012
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 85:12, s. 123514-
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Tidskriftsartikel (refereegranskat)abstract
- Dark matter in the form of Weakly Interacting Massive Particles (WIMPs) can be captured by the Sun and the Earth, sink to their cores, annihilate and produce neutrinos that can be searched for with neutrino telescopes. The calculation of the capture rates of WIMPs in the Sun and especially the Earth are affected by large uncertainties coming mainly from effects of the planets in the Solar System, reducing the capture rates by up to an order of magnitude (or even more in some cases). We show that the WIMPs captured by weak scatterings in the Sun also constitute an important bound WIMP population in the Solar System. Taking this population and its interplay with the population bound through gravitational diffusion into account cancel the planetary effects on the capture rates, and the capture essentially proceeds as if the Sun and the Earth were free in the galactic halo. The neutrino signals from the Sun and the Earth are thus significantly higher than claimed in the scenarios with reduced capture rates.
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| 8. |
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The 2nd Scandinavian NeutrinO Workshop
- 2006
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Proceedings (redaktörskap) (refereegranskat)abstract
- The first Scandinavian NeutrinO Workshop (SNOW) was held in Uppsala, Sweden, in February 2001. About five years passed until the next SNOW took place—this time in Stockholm, Sweden between 2 May 2006 and 6 May 2006. The aim of the workshop was to cover a variety of topics in neutrino physics with leading researchers in the field as speakers. The Royal Swedish Academy of Sciences (KVA) awarded SNOW 2006 a grant for inviting such speakers. The workshop was mainly directed towards phenomenology and theory with connections to experiments and gave an opportunity for theorists and experimentalists to work together, discuss the latest results, and combine the different branches of neutrino physics. The different topics discussed were: solar and atmospheric neutrinos, reactor and accelerator neutrinos, neutrinos in astrophysics and cosmology, phenomenology of neutrino data, neutrino oscillations, theory and model building, fundamental properties of neutrinos, neutrinoless double beta decay, and flavor physics. Around 70 scientists (spanning from graduate students to world-leading researchers) in the field of neutrino physics participated in SNOW 2006 and 44 talks were presented in plenary sessions. Out of the 44 talks, 37 have been contributed to these proceedings. The talks of SNOW 2006 took place in the Oskar Klein Auditorium at the AlbaNova University Center in Stockholm. The AlbaNova University Center is a joint endeavour between the Royal Institute of Technology (KTH) and Stockholm University. The social program included a welcome reception at KVA, an excursion to the Royal Armoury at the Royal Palace in Stockholm as well as a boat trip in the archipelago of Stockholm, a reception at the City Hall of Stockholm arranged by the city, and finally, a workshop dinner at Häringe Castle south of Stockholm.
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