| 1. |
- Berg, Marcus, et al.
(författare)
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Neutralino Dark Matter in BMSSM Effective Theory
- 2009
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :08
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Tidskriftsartikel (refereegranskat)abstract
- We study thermal neutralino dark matter in an effective field theory extension of the MSSM, called ``Beyond the MSSM'' (BMSSM) in Dine, Seiberg and Thomas (2007). In this class of effective field theories, the field content of the MSSM is unchanged, but the little hierarchy problem is alleviated by allowing small corrections to the Higgs/higgsino part of the Lagrangian. We perform parameter scans and compute the dark matter relic density. The light higgsino LSP scenario is modified the most; we find new regions of parameter space compared to the standard MSSM. This involves interesting interplay between the WMAP dark matter bounds and the LEP chargino bound. We also find some changes for gaugino LSPs, partly due to annihilation through a Higgs resonance, and partly due to coannihilation with light top squarks in models that are ruled in by the new effective terms.
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| 2. |
- Bozorgnia, Nassim, et al.
(författare)
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Ring-like features in directional dark matter detection
- 2012
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :6
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Tidskriftsartikel (refereegranskat)abstract
- We discuss a novel dark matter signature relevant for directional detection of Weakly Interacting Massive Particles (WIMPs). For heavy enough WIMPs and low enough recoil energies, the maximum of the recoil rate is not in the direction of the average WIMP arrival direction but in a ring around it at an angular radius that increases with the WIMP mass and can approach 90 degrees at very low energies. The ring is easier to detect for smaller WIMP velocity dispersion and larger average WIMP velocities relative to the detector. In principle the ring could be used as an additional indication of the WIMP mass range.
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| 3. |
- Bringmann, Torsten, et al.
(författare)
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DarkSUSY 6 : an advanced tool to compute dark matter properties numerically
- 2018
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : IOP Publishing. - 1475-7516. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- The nature of dark matter remains one of the key science questions. Weakly Interacting Massive Particles (WIMPs) are among the best motivated particle physics candidates, allowing to explain the measured dark matter density by employing standard big-bang thermodynamics. Examples include the lightest supersymmetric particle, though many alternative particles have been suggested as a solution to the dark matter puzzle. We introduce here a radically new version of the widely used DarkSUSY package, which allows to compute the properties of such dark matter particles numerically. With DarkSUSY 6 one can accurately predict a large variety of astrophysical signals from dark matter, such as direct detection rates in low-background counting experiments and indirect detection signals through antiprotons, antideuterons, gamma rays and positrons from the Galactic halo, or high-energy neutrinos from the center of the Earth or of the Sun. For thermally produced dark matter like WIMPs, high-precision tools are provided for the computation of the relic density in the Universe today, as well as for the size of the smallest dark matter protohalos. Furthermore, the code allows to calculate dark matter self-interaction rates, which may affect the distribution of dark matter at small cosmological scales. Compared to earlier versions, DarkSUSY 6 introduces many significant physics improvements and extensions. The most fundamental new feature of this release, however, is that the code has been completely reorganized and brought into a highly modular and flexible shape. Switching between different pre-implemented dark matter candidates has thus become straight-forward, just as adding new - WIMP or non-WIMP - particle models or replacing any given functionality in a fully user-specified way. In this article, we describe the physics behind the computer package, along with the main structure and philosophy of this major revision of DarkSUSY. A detailed manual is provided together with the public release at www.darksusy.org.
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| 4. |
- Edsjö, Joakim, et al.
(författare)
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Accurate relic densities with neutralino, chargino and sfermion coannihilations in mSUGRA
- 2003
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Ingår i: Journal of Cosmology and Astroparticle Physics. - : Institute of Physics Pub. ; 04, s. 001-029
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Tidskriftsartikel (refereegranskat)abstract
- Neutralinos arise as natural dark matter candidates in many supersymmetric extensions of the Standard Model. We present a novel calculation of the neutralino relic abundance in which we include all so-called coannihilation processes between neutralinos, charginos and sfermions, and, at the same time, we apply the state of the art technique to trace the freeze-out of a species in the early Universe. As a first application, we discuss here results valid in the mSUGRA framework; we describe general trends as well as performing a detailed study of the neutralino relic densities in the mSUGRA parameter space. The emerging picture is fair agreement with previous analyses in the same framework, however we have the power to discuss it in much more detail than previously done. For example, we find that the cosmological bound on the neutralino mass is pushed up to ~565 GeV in the stau coannihilation region and to ~1500 GeV in the chargino coannihilation region.
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| 5. |
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| 6. |
- Gondolo Paolo, Ingelman Gunnar, Thunman Mats
(författare)
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Atmospheric muons and neutrinos from charm
- 1996
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Ingår i: NUCLEAR PHYSICS B PROCEEDINGS SUPPLEMENT. - : ELSEVIER SCIENCE BV. ; , s. 472-474
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Konferensbidrag (refereegranskat)abstract
- We have updated our previous investigation of the production of muons and neutrinos in cosmic ray interactions with the atmosphere, taking account of recent results from the ep collider HERA in our QCD-based model for hadronic interactions. Qualitatively,
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| 7. |
- Savage, Christopher, et al.
(författare)
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XENON10/100 dark matter constraints in comparison with CoGeNT and DAMA : Examining the L(eff) dependence
- 2011
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Ingår i: Physical Review D. - 1550-7998 .- 1550-2368. ; 83:5, s. 055002-
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Tidskriftsartikel (refereegranskat)abstract
- We consider the compatibility of DAMA/LIBRA, CoGeNT, XENON10 and XENON100 results for spin-independent (SI) dark matter weakly interacting massive particles, particularly at low masses (similar to 10 GeV), assuming a standard dark matter halo. The XENON bounds depend on the scintillation efficiency factor L(eff) for which there is considerable uncertainty. Thus we consider various extrapolations for L(eff) at low energy. With the L(eff) measurements we consider, XENON100 results are found to be insensitive to the low-energy extrapolation. We find the strongest bounds are from XENON10, rather than XENON100, due to the lower energy threshold. For reasonable choices of L(eff) and for the case of SI elastic scattering, XENON10 is incompatible with the DAMA/LIBRA 3 sigma region and severely constrains the 7-12 GeV WIMP mass region of interest published by the CoGeNT Collaboration.
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| 8. |
- Thunman Mats, Ingelman Gunnar, Gondolo Paolo
(författare)
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A Monte-Carlo Calculation of Atmospheric Muon and Neutrino Fluxes
- 1995
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Ingår i: NUCLEAR PHYSICS B Proc Suppl. ; , s. 274-277
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Konferensbidrag (refereegranskat)abstract
- Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with a cascade simulation program based on Lund Monte Carlo programs. The resulting `conventional' muon and neutrino fluxes (from $\pi ,K$ decays) agree
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| 9. |
- Thunman Mats, Ingelman Gunnar, Gondolo Paolo
(författare)
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Charm production and high energy atmospheric muon and neutrino fluxes
- 1996
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Ingår i: ASTROPARTICLE PHYSICS. - : ELSEVIER SCIENCE BV. - 0927-6505. ; 5:3-4, s. 309-332
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Tidskriftsartikel (refereegranskat)abstract
- Production of muons and neutrinos in cosmic ray interactions with the atmosphere has been investigated with Monte Carlo models for hadronic interactions. The resulting conventional muon and neutrino fluxes (from pi and K decays) agree well with earlier ca
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| 10. |
- Zackrisson, Erik, et al.
(författare)
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Finding high-redshift dark stars with the James Webb Space Telescope
- 2010
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Ingår i: Astrophysical Journal. - : The American Astronomical Society. - 0004-637X .- 1538-4357. ; 717:1, s. 257-267
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Tidskriftsartikel (refereegranskat)abstract
- The first stars in the history of the universe are likely to form in the dense central regions of similar to 10(5)-10(6) M-circle dot cold dark matter halos at z approximate to 10-50. The annihilation of dark matter particles in these environments may lead to the formation of so-called dark stars, which are predicted to be cooler, larger, more massive, and potentially more long-lived than conventional population III stars. Here, we investigate the prospects of detecting high-redshift dark stars with the upcoming James Webb Space Telescope (JWST). We find that all dark stars with masses up to 10(3) M-circle dot are intrinsically too faint to be detected by JWST at z > 6. However, by exploiting foreground galaxy clusters as gravitational telescopes do, certain varieties of cool (T-eff <= 30,000 K) dark stars should be within reach at redshifts up to z approximate to 10. If the lifetimes of dark stars are sufficiently long, many such objects may also congregate inside the first galaxies. We demonstrate that this could give rise to peculiar features in the integrated spectra of galaxies at high redshifts, provided that dark stars make up at least similar to 1% of the total stellar mass in such objects.
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