Positron Fraction in the Cmssm ∗
نویسندگان
چکیده
A fit to the present cosmic ray positron fraction can be considerably improved, if in addition to the positron production by nuclear interactions in the universe the possible contribution from supersymmetric dark matter annihilation is taken into account. We scan over the complete SUSY parameter space of the Constrained Minimal Supersymmetric Model (CMSSM) and find that in the acceptable regions the neutralino annihilation into bb quark pairs is the dominant channel with hard positrons emerging from the semileptonic decays of the B-mesons.
منابع مشابه
Positron Fraction from Dark Matter Annihilation in the CMSSM
We investigate, if the cosmic ray positron fraction, as reported by the HEAT and AMS collaborations, is compatible with the annihilation of neutralinos in the supergravity inspired Constrained Minimal Supersymmetric Model (CMSSM), thus complementing previous investigations, which did not consider constraints from unification, electroweak symmetry breaking and the present Higgs limits at LEP. We...
متن کاملPositron Fraction from Dark Matter Annihilation in the CMSSM
We investigate, if the cosmic ray positron fraction, as reported by the HEAT and AMS collaborations, is compatible with the annihilation of neutralinos in the supergravity inspired Constrained Minimal Supersymmetric Model (CMSSM), thus complementing previous investigations, which did not consider constraints from unification, electroweak symmetry breaking and the present Higgs limits at LEP. We...
متن کاملSensitivities to the SUSY Scale from Electroweak Precision Observables
Precision measurements, now and at a future linear electron-positron collider (ILC), can provide indirect information about the possible scale of supersymmetry. Performing a χ analysis, we illustrate the present-day and possible future ILC sensitivities within the constrained minimal supersymmetric extension of the Standard Model (CMSSM), varying the parameters so as to obtain the cold dark mat...
متن کاملCalculation of Positron Distribution in the Presence of a Uniform Magnetic Field for the Improvement of Positron Emission Tomography (PET) Imaging Using GEANT4 Toolkit
Introduction Range and diffusion of positron-emitting radiopharmaceuticals are important parameters for image resolution in positron emission tomography (PET). In this study, GEANT4 toolkit was applied to study positron diffusion in soft tissues with and without a magnetic field for six commonly used isotopes in PET imaging including 11C, 13N, 15O, 18F, 68Ga, and 82Rb. Materials and Methods GEA...
متن کاملPositron annihilation lifetime spectroscopy in nickel ferrite and iron oxide nanopowders
In this study, a positron annihilation lifetime spectrometer was set up and its resolution was optimized. The spectrometer is a fast-slow arrangement with time resolution of 250 ps. To obtain lifetime components and their intensities from analyzing positron annihilation lifetime spectrum, the Pascual software is used. Positrons are from a source of radioactive 22NaCl with 20 μCi activity enclos...
متن کامل