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  • 1.
    Ahrens, Maryon
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Danninger, Matthias
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Dumm, Jonathan P.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hulth, Per Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Savage, Christopher
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Improved limits on dark matter annihilation in the Sun with the 79-string IceCube detector and implications for supersymmetry2016In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 4, article id 022Article in journal (Refereed)
    Abstract [en]

    We present an improved event-level likelihood formalism for including neutrino telescope data in global fits to new physics. We derive limits on spin-dependent dark matter-proton scattering by employing the new formalism in a re-analysis of data from the 79-string IceCube search for dark matter annihilation in the Sun, including explicit energy information for each event. The new analysis excludes a number of models in the weak-scale minimal supersymmetric standard model (MSSM) for the first time. This work is accompanied by the public release of the 79-string IceCube data, as well as an associated computer code for applying the new likelihood to arbitrary dark matter models.

  • 2.
    Akrami, Yashar
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Savage, Christopher
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Scott, Pat
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    How well will ton-scale dark matter direct detection experiments constrain minimal supersymmetry?2011In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 4, p. 012-Article in journal (Refereed)
    Abstract [en]

    Weakly interacting massive particles (WIMPs) are amongst the most interesting dark matter (DM) candidates. Many DM candidates naturally arise in theories beyond the standard model (SM) of particle physics, like weak-scale supersymmetry (SUSY). Experiments aim to detect WIMPs by scattering, annihilation or direct production, and thereby determine the underlying theory to which they belong, along with its parameters. Here we examine the prospects for further constraining the Constrained Minimal Supersymmetric Standard Model (CMSSM) with future ton-scale direct detection experiments. We consider ton-scale extrapolations of three current experiments: CDMS, XENON and COUPP, with 1000 kg-years of raw exposure each. We assume energy resolutions, energy ranges and efficiencies similar to the current versions of the experiments, and include backgrounds at target levels. Our analysis is based on full likelihood constructions for the experiments. We also take into account present uncertainties on hadronic matrix elements for neutralino-quark couplings, and on halo model parameters. We generate synthetic data based on four benchmark points and scan over the CMSSM parameter space using nested sampling. We construct both Bayesian posterior PDFs and frequentist profile likelihoods for the model parameters, as well as the mass and various cross-sections of the lightest neutralino. Future ton-scale experiments will help substantially in constraining supersymmetry, especially when results of experiments primarily targeting spin-dependent nuclear scattering are combined with those directed more toward spin-independent interactions.

  • 3.
    Akrami, Yashar
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Savage, Christopher
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Scott, Pat
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Statistical coverage for supersymmetric parameter estimation: a case study with direct detection of dark matter2011In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 7, p. 002-Article in journal (Refereed)
    Abstract [en]

    Models of weak-scale supersymmetry offer viable dark matter (DM) candidates. Their parameter spaces are however rather large and complex, such that pinning down the actual parameter values from experimental data can depend strongly on the employed statistical framework and scanning algorithm. In frequentist parameter estimation, a central requirement for properly constructed confidence intervals is that they cover true parameter values, preferably at exactly the stated confidence level when experiments are repeated infinitely many times. Since most widely-used scanning techniques are optimised for Bayesian statistics, one needs to assess their abilities in providing correct confidence intervals in terms of the statistical coverage. Here we investigate this for the Constrained Minimal Supersymmetric Standard Model (CMSSM) when only constrained by data from direct searches for dark matter. We construct confidence intervals from one-dimensional profile likelihoods and study the coverage by generating several pseudo-experiments for two benchmark sets of pseudo-true parameters. We use nested sampling to scan the parameter space and evaluate the coverage for the two benchmarks when either flat or logarithmic priors are imposed on gaugino and scalar mass parameters. We observe both under- and over-coverage, which in some cases vary quite dramatically when benchmarks or priors are modified. We show how most of the variation can be explained as the impact of explicit and implicit priors, where the latter are indirectly imposed by physicality conditions. For comparison, we also evaluate the coverage for Bayesian credible intervals, and (predictably) observe significant under-coverage in those cases.

  • 4.
    Akrami, Yashar
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Scott, Pat
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Bergström, Lars
    Stockholm University, Faculty of Science, Department of Physics.
    A Profile Likelihood Analysis of the Constrained MSSM with Genetic Algorithms2010In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 4, p. 057-Article in journal (Refereed)
    Abstract [en]

    The Constrained Minimal Supersymmetric Standard Model (CMSSM) is one of the simplest and most widely-studied supersymmetric extensions to the standard model of particle physics. Nevertheless, current data do not sufficiently constrain the model parameters in a way completely independent of priors, statistical measures and scanning techniques. We present a new technique for scanning supersymmetric parameter spaces, optimised for frequentist profile likelihood analyses and based on Genetic Algorithms. We apply this technique to the CMSSM, taking into account existing collider and cosmological data in our global fit. We compare our method to the MultiNest algorithm, an efficient Bayesian technique, paying particular attention to the best-fit points and implications for particle masses at the LHC and dark matter searches. Our global best-fit point lies in the focus point region. We find many high-likelihood points in both the stau co-annihilation and focus point regions, including a previously neglected section of the co-annihilation region at large m 0. We show that there are many high-likelihood points in the CMSSM parameter space commonly missed by existing scanning techniques, especially at high masses. This has a significant influence on the derived confidence regions for parameters and observables, and can dramatically change the entire statistical inference of such scans.

  • 5. Athron, Peter
    et al.
    Balazs, Csaba
    Bringmann, Torsten
    Buckley, Andy
    Chrzaszcz, Marcin
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Dickinson, Hugh
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gonzalo, Tomas E.
    Jackson, Paul
    Krislock, Abram
    Kvellestad, Anders
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    McKay, James
    Mahmoudi, Farvah
    Martinez, Gregory D.
    Putze, Antje
    Raklev, Are
    Ripken, Joachim
    Rogan, Christopher
    Saavedra, Aldo
    Savage, Christopher
    Scott, Pat
    Seo, Seon-Hee
    Serra, Nicola
    Weniger, Christoph
    White, Martin
    Wild, Sebastian
    GAMBIT: the global and modular beyond-the-standard-model inference tool2017In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 11, article id 784Article in journal (Refereed)
    Abstract [en]

    We describe the open-source global fitting package GAMBIT: the Global And Modular Beyond-the-Standard-Model Inference Tool. GAMBIT combines extensive calculations of observables and likelihoods in particle and astroparticle physics with a hierarchical model database, advanced tools for automatically building analyses of essentially any model, a flexible and powerful system for interfacing to external codes, a suite of different statistical methods and parameter scanning algorithms, and a host of other utilities designed to make scans faster, safer and more easily-extendible than in the past. Here we give a detailed description of the framework, its design and motivation, and the current models and other specific components presently implemented in GAMBIT. Accompanying papers deal with individual modules and present flrst GAMBIT results. GAMBIT can be downloaded from gambit.hepforge.org.

  • 6. Athron, Peter
    et al.
    Balazs, Csaba
    Bringmann, Torsten
    Buckley, Andy
    Chrzaszcz, Marcin
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Dickinson, Hugh
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gonzalo, Tomas E.
    Jackson, Paul
    Krislock, Abram
    Kvellestad, Anders
    Lundberg, Johan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Mckay, James
    Mahmoudi, Farvah
    Martinez, Gregory D.
    Putze, Antje
    Raklev, Are
    Ripken, Joachim
    Rogan, Christopher
    Saavedra, Aldo
    Savage, Christopher
    Scott, Pat
    Seo, Seon-Hee
    Serra, Nicola
    Weniger, Christoph
    White, Martin
    Wild, Sebastian
    GAMBIT: the global and modular beyond-the-standard-model inference tool2018In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 78, no 2, article id 98Article in journal (Refereed)
    Abstract [en]

    In Ref. (GAMBIT Collaboration: Athron et. al., Eur. Phys. J. C. arXiv: 1705.07908, 2017) we introduced the global-fitting framework GAMBIT. In this addendum, we describe a new minor version increment of this package. GAMBIT 1.1 includes full support for Mathematica backends, which we describe in some detail here. As an example, we backend SUSYHD (Vega and Villadoro, JHEP 07: 159, 2015), which calculates the mass of the Higgs boson in the MSSM from effective field theory. We also describe updated likelihoods in PrecisionBit and DarkBit, and updated decay data included in DecayBit.

  • 7. Athron, Peter
    et al.
    Balazs, Csaba
    Bringmann, Torsten
    Buckley, Andy
    Chrzaszcz, Marcin
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jackson, Paul
    Krislock, Abram
    Kvellestad, Anders
    Mahmoudi, Farvah
    Martinez, Gregory D.
    Putze, Antje
    Raklev, Are
    Rogan, Christopher
    de Austri, Roberto Ruiz
    Saavedra, Aldo
    Savage, Christopher
    Scott, Pat
    Serra, Nicola
    Weniger, Christoph
    White, Martin
    Global fits of GUT-scale SUSY models with GAMBIT2017In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 12, article id 824Article in journal (Refereed)
    Abstract [en]

    We present the most comprehensive global fits to date of three supersymmetric models motivated by grand unification: the Constrained Minimal Supersymmetric Standard Model (CMSSM), and its Non-Universal Higgs Mass generalisations NUHM1 and NUHM2. We include likelihoods from a number of direct and indirect dark matter searches, a large collection of electroweak precision and flavour observables, direct searches for supersymmetry at LEP and Runs I and II of the LHC, and constraints from Higgs observables. Our analysis improves on existing results not only in terms of the number of included observables, but also in the level of detail with which we treat them, our sampling techniques for scanning the parameter space, and our treatment of nuisance parameters. We show that stau co-annihilation is now ruled out in the CMSSM at more than 95% confidence. Stop co-annihilation turns out to be one of the most promising mechanisms for achieving an appropriate relic density of darkmatter in all threemodels, whilst avoiding all other constraints. We find high-likelihood regions of parameter space featuring light stops and charginos, making them potentially detectable in the near future at the LHC. We also show that tonne-scale direct detection will play a largely complementary role, probing large parts of the remaining viable parameter space, including essentially all models with multi-TeV neutralinos.

  • 8. Athron, Peter
    et al.
    Balazs, Csaba
    Bringmann, Torsten
    Buckley, Andy
    Chrzaszcz, Marcin
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jackson, Paul
    Krislock, Abram
    Kvellestad, Anders
    Mahmoudi, Farvah
    Martinez, Gregory D.
    Putze, Antje
    Raklev, Are
    Rogan, Christopher
    Saavedra, Aldo
    Savage, Christopher
    Scott, Pat
    Serra, Nicola
    Weniger, Christoph
    White, Martin
    A global fit of the MSSM with GAMBIT2017In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 12, article id 879Article in journal (Refereed)
    Abstract [en]

    We study the seven-dimensional Minimal Super-symmetric Standard Model (MSSM7) with the new GAMBIT software framework, with all parameters defined at the weak scale. Our analysis significantly extends previous weak-scale, phenomenological MSSM fits, by adding more and newer experimental analyses, improving the accuracy and detail of theoretical predictions, including dominant uncertainties from the Standard Model, the Galactic dark matter halo and the quark content of the nucleon, and employing novel and highly-efficient statistical sampling methods to scan the parameter space. We find regions of the MSSM7 that exhibit co-annihilation of neutralinos with charginos, stops and sbottoms, as well as models that undergo resonant annihilation via both light and heavy Higgs funnels. We find high-likelihood models with light charginos, stops and sbottoms that have the potential to be within the future reach of the LHC. Large parts of our preferred parameter regions will also be accessible to the next generation of direct and indirect dark matter searches, making prospects for discovery in the near future rather good.

  • 9. Athron, Peter
    et al.
    Balazs, Csaba
    Dal, Lars A.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gonzalo, Tomas E.
    Kvellestad, Anders
    Stockholm University, Nordic Institute for Theoretical Physics (Nordita).
    McKay, James
    Putze, Antje
    Rogan, Chris
    Scott, Pat
    Weniger, Christoph
    White, Martin
    SpecBit, DecayBit and PrecisionBit: GAMBIT modules for computing mass spectra, particle decay rates and precision observables2018In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 78, no 1, article id 22Article in journal (Refereed)
    Abstract [en]

    We present the GAMBIT modules SpecBit, DecayBit and PrecisionBit. Together they provide a new framework for linking publicly available spectrum generators, decay codes and other precision observable calculations in a physically and statistically consistent manner. This allows users to automatically run various combinations of existing codes as if they are a single package. The modular design allows software packages fulfilling the same role to be exchanged freely at runtime, with the results presented in a common format that can easily be passed to downstream dark matter, collider and flavour codes. These modules constitute an essential part of the broader GAMBIT framework, a major new software package for performing global fits. In this paper we present the observable calculations, data, and likelihood functions implemented in the three modules, as well as the conventions and assumptions used in interfacing them with external codes. We also present 3-BIT-HIT, a command-line utility for computing mass spectra, couplings, decays and precision observables in the MSSM, which shows how the three modules can easily be used independently of GAMBIT.

  • 10. Athron, Peter
    et al.
    Balázs, Csaba
    Bringmann, Torsten
    Buckley, Andy
    Chrzaszcz, Marcin
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Jackson, Paul
    Kahlhoefer, Felix
    Krislock, Abram
    Kvellestad, Anders
    McKay, James
    Mahmoudi, Farvah
    Martinez, Gregory D.
    Putze, Antje
    Raklev, Are
    Rogan, Christopher
    Saavedra, Aldo
    Savage, Christopher
    Scott, Pat
    Serra, Nicola
    Weniger, Christoph
    White, Martin
    Status of the scalar singlet dark matter model2017In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 8, article id 568Article in journal (Refereed)
    Abstract [en]

    One of the simplest viable models for dark matter is an additional neutral scalar, stabilised by a symmetry. Using the GAMBIT package and combining results from four independent samplers, we present Bayesian and frequentist global fits of this model. We vary the singlet mass and coupling along with 13 nuisance parameters, including nuclear uncertainties relevant for direct detection, the local dark matter density, and selected quark masses and couplings. We include the dark matter relic density measured by Planck, direct searches with LUX, PandaX, SuperCDMS and XENON100, limits on invisible Higgs decays from the Large Hadron Collider, searches for high-energy neutrinos from dark matter annihilation in the Sun with IceCube, and searches for gamma rays from annihilation in dwarf galaxies with the Fermi-LAT. Viable solutions remain at couplings of order unity, for singlet masses between the Higgs mass and about 300 GeV, and at masses above 1 TeV. Only in the latter case can the scalar singlet constitute all of dark matter. Frequentist analysis shows that the low-mass resonance region, where the singlet is about half the mass of the Higgs, can also account for all of dark matter, and remains viable. However, Bayesian considerations show this region to be rather fine-tuned.

  • 11.
    Baltz, Edward A.
    et al.
    Stanford, USA.
    Bergström, Lars
    Stockholm University, Faculty of Science, Department of Physics.
    Bringmann, Torsten
    Stockholm University, Faculty of Science, Department of Physics.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Sellerholm, Alexander
    Stockholm University, Faculty of Science, Department of Physics.
    Pre-launch estimates for GLAST sensitivity to Dark Matter annihilation signals2008In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, Vol. 0807, no 013Article in journal (Refereed)
    Abstract [en]

    We investigate the sensitivity of the Gamma-ray Large Area Space Telescope (GLAST) for indirectly detecting weakly interacting massive particles (WIMPs) through the γ-ray signal that their pair annihilation produces. WIMPs are among the favorite candidates for explaining the compelling evidence that about 80% of the mass in the Universe is non-baryonic dark matter (DM). They are serendipitously motivated by various extensions of the standard model of particle physics such as supersymmetry and universal extra dimensions (UED). With its unprecedented sensitivity and its very large energy range (20 MeV to more than 300 GeV) the main instrument on board the GLAST satellite, the Large Area Telescope (LAT), will open a new window of discovery. As our estimates show, the LAT will be able to detect an indirect DM signature for a large class of WIMP models given a cuspy profile for the DM distribution. Using the current state of the art Monte Carlo and event reconstruction software developed within the LAT collaboration, we present preliminary sensitivity studies for several possible sources inside and outside the Galaxy. We also discuss the potential of the LAT to detect UED via the electron/positron channel. Diffuse background modeling and other background issues that will be important in setting limits or seeing a signal are presented

  • 12.
    Berg, Marcus
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Gondolo, Paolo
    University of Utah.
    Lundström, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Sjörs, Stefan
    Stockholm University, Faculty of Science, Department of Physics.
    Neutralino Dark Matter in BMSSM Effective Theory2009In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 08Article in journal (Refereed)
    Abstract [en]

    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.

  • 13.
    Bergström, Lars
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bringmann, Torsten
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Complementarity of direct dark matter detection and indirect detection through gamma rays2011In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 83, no 4, p. 045024-Article in journal (Refereed)
    Abstract [en]

    We show, by using an extensive sample of viable supersymmetric models as templates, that indirect detection of dark matter through gamma rays may have a large potential for identifying the nature of dark matter. This is, in particular, true also for models that give too weak dark matter-nucleon scattering cross sections to be probed by present and planned direct detection experiments. Also models with a mass scale too high to be accessible at CERN's LHC accelerator may show up in next-generation imaging Cherenkov telescope arrays. Based on our findings, we therefore suggest to view indirect searches as genuine particle physics experiments, complementing other strategies to probe so far unknown regions in the parameter space of e.g. supersymmetric models, and propose a new approach that would make use of telescopes dedicated for dark matter searches. As a concrete example for the potential of such an approach, we consider an array of imaging air Cherenkov telescopes, the Dark Matter Array (DMA), and show that such an experiment could extend present-day limits by several orders of magnitude, reaching a large class of models that would remain undetected in both direct detection experiments and searches at the LHC. In addition, in a sizable part of the parameter space, signals from more than one type of dark matter detection experiment would be possible, something that may eventually be necessary in order to identify the dark matter candidate.

  • 14. Blennow, Mattias
    et al.
    Edsjoe, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Ohlsson, Tommy
    Neutrinos from WIMP annihilations obtained using a full three-flavor Monte Carlo approach2008In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 1, p. 21-Article in journal (Refereed)
    Abstract [en]

    Weakly interacting massive particles (WIMPs) are one of the main candidates for making up the dark matter in the Universe. If these particles make up the dark matter, then they can be captured by the Sun or the Earth, sink to the respective cores, annihilate, and produce neutrinos. Thus, these neutrinos can be a striking dark matter signature at neutrino telescopes looking towards the Sun and/or the Earth. Here, we improve previous analyses on computing the neutrino yields from WIMP annihilations in several respects. We include neutrino oscillations in a full three-flavor framework as well as all effects from neutrino interactions on the way through the Sun (absorption, energy loss, and regeneration from tau decays). In addition, we study the effects of non-zero values of the mixing angle theta(13) as well as the normal and inverted neutrino mass hierarchies. Our study is performed in an event-based setting which makes these results very useful both for theoretical analyses and for building a neutrino telescope Monte Carlo code. All our results for the neutrino yields, as well as our Monte Carlo code, are publicly available. We find that the yield of muontype neutrinos from WIMP annihilations in the Sun is enhanced or suppressed, depending on the dominant WIMP annihilation channel. This effect is due to an effective favor mixing caused by neutrino oscillations. For WIMP annihilations inside the Earth, the distance from source to detector is too small to allow for any significant amount of oscillations at the neutrino energies relevant for neutrino telescopes.

  • 15. Bringmann, Torsten
    et al.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Cornell, Jonathan M.
    Dal, Lars A.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Farmer, Ben
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Kahlhoefer, Felix
    Kvellestad, Anders
    Putze, Antje
    Savage, Christopher
    Scott, Pat
    Weniger, Christoph
    White, Martin
    Wild, Sebastian
    DarkBit: a GAMBIT module for computing dark matter observables and likelihoods2017In: European Physical Journal C, ISSN 1434-6044, E-ISSN 1434-6052, Vol. 77, no 12, article id 831Article in journal (Refereed)
    Abstract [en]

    We introduce DarkBit, an advanced software code for computing dark matter constraints on various extensions to the Standard Model of particle physics, comprising both new native code and interfaces to external packages. This release includes a dedicated signal yield calculator for gamma-ray observations, which significantly extends current tools by implementing a cascade decay Monte Carlo, as well as a dedicated likelihood calculator for current and future experiments (gamLike). This provides a general solution for studying complex particle physics models that predict dark matter annihilation to a multitude of final states. We also supply a direct detection package that models a large range of direct detection experiments (DDCalc), and provides the corresponding likelihoods for arbitrary combinations of spin-independent and spin-dependent scattering processes. Finally, we provide custom relic density routines along with interfaces to DarkSUSY, micrOMEGAs, and the neutrino telescope likelihood package nulike. DarkBit is written in the framework of the Global And Modular Beyond the StandardModel Inference Tool (GAMBIT), providing seamless integration into a comprehensive statistical fitting framework that allows users to explore new models with both particle and astrophysics constraints, and a con-sistent treatment of systematic uncertainties. In this paper we describe its main functionality, provide a guide to getting started quickly, and show illustrative examples for results obtained with DarkBit (both as a standalone tool and as a GAMBIT module). This includes a quantitative comparison between two of the main dark matter codes (DarkSUSY and micrOMEGAs), and application of DarkBit's advanced direct and indirect detection routines to a simple effective dark matter model.

  • 16. Bringmann, Torsten
    et al.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Gondolo, Paolo
    Ullio, Piero
    Bergström, Lars
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    DarkSUSY 6: an advanced tool to compute dark matter properties numerically2018In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 7, article id 033Article in journal (Refereed)
    Abstract [en]

    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.

  • 17.
    Edsjö, Joakim
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Elevant, Jessica
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Enberg, R.
    Niblaeus, Carl
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Neutrinos from cosmic ray interactions in the Sun2017In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 6, article id 033Article in journal (Refereed)
    Abstract [en]

    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.

  • 18.
    Edsjö, Joakim
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Schelke, Mia
    Stockholm University, Faculty of Science, Department of Physics.
    Ullio, Piero
    SISSA, via Beirut 4, I-34014 Trieste.
    Gondolo, Paolo
    Department of Physics, Case Western Reserve University, 10900 Euclid Ave, Cleveland.
    Accurate relic densities with neutralino, chargino and sfermion coannihilations in mSUGRA2003In: Journal of Cosmology and Astroparticle Physics, Vol. 04, p. 001-029Article in journal (Refereed)
    Abstract [en]

    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.

  • 19. Fairbairn, M.
    et al.
    Scott, P.
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, J.
    Stockholm University, Faculty of Science, Department of Physics.
    The zero age main sequence of WIMP burners2008In: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 77, p. 047301-Article in journal (Refereed)
    Abstract [en]

    We modify a stellar structure code to estimate the effect upon the main sequence of the accretion of weakly-interacting dark matter onto stars and its subsequent annihilation. The effect upon the stars depends upon whether the energy generation rate from dark matter annihilation is large enough to shut off the nuclear burning in the star. Main sequence weakly-interacting massive particles (WIMP) burners look much like proto-stars moving on the Hayashi track, although they are in principle completely stable. We make some brief comments about where such stars could be found, how they might be observed and more detailed simulations which are currently in progress. Finally we comment on whether or not it is possible to link the paradoxically hot, young stars found at the galactic center with WIMP burners.

  • 20.
    Gustafsson, Michael
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Lundström, Erik
    Stockholm University, Faculty of Science, Department of Physics.
    Bergström, Lars
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Significant Gamma Lines from Inert Higgs Dark Matter2007In: Physical Review Letters, Vol. 99, no 041301Article in journal (Refereed)
    Abstract [en]

    One way to unambiguously confirm the existence of particle dark matter and determine its mass would be to detect its annihilation into monochromatic gamma-rays in upcoming telescopes. One of the most minimal models for dark matter is the inert doublet model, obtained by adding another Higgs doublet with no direct coupling to fermions. For a mass between 40 and 80 GeV, the lightest of the new inert Higgs particles can give the correct cosmic abundance of cold dark matter in agreement with current observations. We show that for this scalar dark matter candidate, the annihilation signal of monochromatic γγ and Zγ final states would be exceptionally strong. The energy range and rates for these gamma-ray line signals make them ideal to search for with the soon upcoming GLAST satellite.

  • 21.
    Johansen, Marianne
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Jokaim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hellman, Sten
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Milstead, David
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Long-lived Stops in MSSM Scenarios with a Neutralino LSP2010In: Journal of High Energy Physics (JHEP), ISSN 1126-6708, E-ISSN 1029-8479, no 8, article id 005Article in journal (Refereed)
    Abstract [en]

    This work investigates the possibility of a long-lived stop squark in supersymmetric models with the neutralino as the lightest supersymmetric particle (LSP). We study the implications of meta-stable stops on the sparticle mass spectra and the dark matter density. We find that in order to obtain a sufficiently long stop lifetime so as to be observable as a stable R-hadron at an LHC experiment, we need to fine tune the mass degeneracy between the stop and the LSP considerably. This increases the stop-neutralino co-anihilation cross section, leaving the neutralino relic density lower than what is expected from the WMAP results for stop masses ≲1.5 TeV/c 2. However, if such scenarios are realised in nature we demonstrate that the long-lived stops will be produced at the LHC and that stop-based R-hadrons with masses up to 1 TeV/c2 can be detected after one year of running at design luminosity.

  • 22.
    Lundström, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Gustafsson, Michael
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Inert Doublet Model and LEP II Limits2009In: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 79, p. 035013-1-035013-13Article in journal (Refereed)
    Abstract [en]

    The inert doublet model is a minimal extension of the standard model introducing an additional SU(2) doublet with new scalar particles that could be produced at accelerators. While there exists no LEP II analysis dedicated for these inert scalars, the absence of a signal within searches for supersymmetric neutralinos can be used to constrain the inert doublet model. This translation however requires some care because of the different properties of the inert scalars and the neutralinos. We investigate what restrictions an existing DELPHI Collaboration study of neutralino pair production can put on the inert scalars and discuss the result in connection with dark matter. We find that although an important part of the inert doublet model parameter space can be excluded by the LEP II data, the lightest inert particle still constitutes a valid dark matter candidate

  • 23.
    Savage, Christopher
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Bohm, Christian
    Stockholm University, Faculty of Science, Department of Physics.
    Danninger, Matthias
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Finley, Chad
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Flis, Samuel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hulth, Per-Olof
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Johansson, Henrik
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Seo, Seon Hee
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Walck, Christian
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Wolf, Martin
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Zoll, Marcel
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Use of event level neutrino telescope data in global fits for theories of new physics2012In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 11, article id 057Article in journal (Refereed)
    Abstract [en]

    We present a fast likelihood method for including event-level neutrino telescope data in parameter explorations of theories for new physics, and announce its public release as part of DarkSUSY 5.0.6. Our construction includes both angular and spectral information about neutrino events, as well as their total number. We also present a corresponding measure for simple model exclusion, which can be used for single models without reference to the rest of a parameter space. We perform a number of supersymmetric parameter scans with IceCube data to illustrate the utility of the method: example global fits and a signal recovery in the constrained minimal supersymmetric standard model (CMSSM), and a model exclusion exercise in a 7-parameter phenomenological version of the MSSM. The final IceCube detector con figuration will probe almost the entire focus-point region of the CMSSM, as well as a number of MSSM-7 models that will not otherwise be accessible to e. g. direct detection. Our method accurately recovers the mock signal, and provides tight constraints on model parameters and derived quantities. We show that the inclusion of spectral information significantly improves the accuracy of the recovery, providing motivation for its use in future IceCube analyses.

  • 24.
    Scott, P.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Conrad, Jan
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Bergström, Lars
    Stockholm University, Faculty of Science, Department of Physics.
    Farnier, C.
    Akrami, Yashar
    Stockholm University, Faculty of Science, Department of Physics.
    Direct constraints on minimal supersymmetry from Fermi-LAT observations of the dwarf galaxy Segue 12010In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, no 1, p. 31-50Article in journal (Refereed)
    Abstract [en]

    The dwarf galaxy Segue 1 is one of the most promising targets for the indirect detection of dark matter. Here we examine what constraints 9 months of Fermi-LAT gamma-ray observations of Segue 1 place upon the Constrained Minimal Supersymmetric Standard Model (CMSSM), with the lightest neutralino as the dark matter particle. We use nested sampling to explore the CMSSM parameter space, simultaneously fitting other relevant constraints from accelerator bounds, the relic density, electroweak precision observables, the anomalous magnetic moment of the muon and B-physics. We include spectral and spatial fits to the Fermi observations, a full treatment of the instrumental response and its related uncertainty, and detailed background models. We also perform an extrapolation to 5 years of observations, assuming no signal is observed from Segue 1 in that time. Results marginally disfavour models with low neutralino masses and high annihilation cross-sections. Virtually all of these models are however already disfavoured by existing experimental or relic density constraints.

  • 25.
    Scott, P.
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Fairbairn, M.
    Edsjö, J.
    Stockholm University, Faculty of Science, Department of Physics.
    Dark stars at the Galactic Centre: the main sequence2009In: Monthly notices of the Royal Astronomical Society, ISSN 0035-8711, E-ISSN 1365-2966, Vol. 394, no 1, p. 82-104Article in journal (Refereed)
    Abstract [en]

    In regions of very high dark matter density such as the Galactic Centre, the capture and annihilation of WIMP dark matter by stars has the potential to significantly alter their evolution. We describe the dark stellar evolution code DarkStars, and present a series of detailed grids of WIMP-influenced stellar models for main-sequence stars. We describe the changes in stellar structure and main-sequence evolution which occur as a function of the rate of energy injection by WIMPs, for masses of 0.3–2.0 M⊙ and metallicities Z= 0.0003–0.02 . We show what rates of energy injection can be obtained using realistic orbital parameters for stars at the Galactic Centre, including detailed consideration of the velocity and density profiles of dark matter. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits. If there is a spike of dark matter induced by the supermassive black hole at the Galactic Centre, single solar mass stars following orbits with periods as long as 50 yr and eccentricities as low as 0.9 could be significantly affected. Binary systems with similar periods about the Galactic Centre could be affected on even less eccentric orbits. The most striking observational effect of this scenario would be the existence of a binary consisting of a low-mass protostar and a higher mass evolved star. The observation of low-mass stars and/or binaries on such orbits would either provide a detection of WIMP dark matter, or place stringent limits on the combination of the WIMP mass, spin-dependent nuclear-scattering cross-section, halo density and velocity distribution near the Galactic Centre. In some cases, the derived limits on the WIMP mass and spin-dependent nuclear-scattering cross-section would be of comparable sensitivity to current direct-detection experiments.

  • 26.
    Scott, Pat
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Fairbairn, M
    Low mass stellar evolution with WIMP capture and annihilation2008In: Dark Matter in Astroparticle and Particle Physics: Dark 2007, proceedings of the 6th International Heidelberg Conference, University of Sydney, Australia, 24-28 September 2007 / [ed] editors, Hans Volker Klapdor-Kleingrothaus, Geraint F. Lewis, Singapore: World Scientific , 2008, p. 387-392Conference paper (Refereed)
  • 27.
    Scott, Pat
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Fairbairn, M
    The DarkStars code: a publicly available dark stellar evolution package2009In: Dark Matter in Astroparticle and Particle Physics: Dark 2009, 2009, p. 320-327Conference paper (Refereed)
  • 28.
    Scott, Pat
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Fairbairn, M
    Edsjö, Joakim
    Impacts of WIMP dark matter upon stellar evolution: main-sequence stars2008In: Identification of dark matter 2008: August 18-22, 2008 Stockholm, Sweden, 2008, p. 73-Conference paper (Refereed)
    Abstract [en]

    The presence of large amounts of WIMP dark matter in stellar cores has been shown to have significant effects upon models of stellar evolution. We present a series of detailed grids of WIMPinfluenced

    stellar models for main sequence stars, computed using the

    DarkStars code. We describe the changes in stellar structure and main sequence evolution which occur for masses ranging from 0.3 to 2.0 M and metallicities from Z = 0:0003–0: 02, as a function of the rate

    of energy injection by WIMPs. We then go on to show what rates of energy injection can beobtained using realistic orbital parameters for stars near supermassive black holes, including detailed considerations of dark matter halo velocity and density profiles. Capture and annihilation rates are strongly boosted when stars follow elliptical rather than circular orbits, causing WIMP annihilation to provide up to 100 times the energy of hydrogen fusion in stars at the Galactic centre

  • 29.
    Silverwood, Hamish
    et al.
    Univ Canterbury, Dept Phys & Astron, Christchurch 8140, New Zealand.
    Scott, Pat
    McGill Univ, Dept Phys, Montreal, PQ H2W 2L8, Canada Organization-Enhanced Name(s) McGill University .
    Danninger, Matthias
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Savage, Chris
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC). Department of Physics & Astronomy, University of Utah, Salt Lake City.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Adams, Jenni
    Univ Canterbury, Dept Phys & Astron, Christchurch 8140, New Zealand.
    Brown, Anthony M.
    Univ Canterbury, Dept Phys & Astron, Christchurch 8140, New Zealand.
    Hultqvist, Klas
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Sensitivity of IceCube-DeepCore to Neutralino Dark Matter in the MSSM-252013In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, Vol. 03, p. 023-Article in journal (Refereed)
    Abstract [en]

    We analyse the sensitivity of IceCube-DeepCore to annihilation of neutralino dark matter in the solar core, generated within a 25 parameter version of the minimally supersymmetric standard model (MSSM-25). We explore the 25-dimensional parameter space using scanning methods based on importance sampling and using DarkSUSY 5.0.6 to calculate observables. Our scans produced a database of 6.02 million parameter space points with neutralino dark matter consistent with the relic density implied by WMAP 7-year data, as well as with accelerator searches. We performed a model exclusion analysis upon these points using the expected capabilities of the IceCube-DeepCore Neutrino Telescope. We show that IceCube-DeepCore will be sensitive to a number of models that are not accessible to direct detection experiments such as SIMPLE, COUPP and XENON100, indirect detection using Fermi-LAT observations of dwarf spheroidal galaxies, nor to current LHC searches.

  • 30.
    Sivertsson, Sofia
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Accurate calculations of the WIMP halo around the Sun and prospects for its gamma-ray detection2010In: Physical Review D. Particles and fields, ISSN 0556-2821, E-ISSN 1089-4918, Vol. 81, no 6, p. 63502-Article in journal (Refereed)
    Abstract [en]

    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.

  • 31.
    Sivertsson, Sofia
    et al.
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics. Stockholm University, Faculty of Science, The Oskar Klein Centre for Cosmo Particle Physics (OKC).
    WIMP diffusion in the Solar System including solar WIMP-nucleon scattering2012In: Physical Review D, ISSN 1550-7998, E-ISSN 1550-2368, Vol. 85, no 12, p. 123514-Article in journal (Refereed)
    Abstract [en]

    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.

  • 32.
    Wikström, Gustav
    et al.
    Stockholm University, Faculty of Science, Department of Physics.
    Edsjö, Joakim
    Stockholm University, Faculty of Science, Department of Physics.
    Limits on the WIMP-Nucleon Scattering Cross-Section from Neutrino Telescopes2009In: Journal of Cosmology and Astroparticle Physics, ISSN 1475-7516, E-ISSN 1475-7516, Vol. 04, no 009, p. 1-13Article in journal (Refereed)
    Abstract [en]

    Neutrino-telescopes like Super-Kamiokande and IceCube have started to explore the neutrino fluxes from WIMP annihilations in the Sun. The non-observation of a signal can put constraints on the WIMP properties. We here focus on the neutrino signal from WIMP annihilation in the Sun and show that under reasonable assumptions, the non-observation of a signal from IceCube puts a much tighter constraint on the spin-dependent WIMP-proton scattering cross-section than current direct detection experiments like COUPP and KIMS. For the spin-independent scattering cross-section, the limits from IceCube and current direct detection experiments like XENON10 and CDMS place similar constraints. We here go through the assumptions being made and the uncertainties that arise in converting from limits on the muon flux from the Sun to limits on the WIMP-proton cross-section, and present our results as easy to use conversion factors.

1 - 32 of 32
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