Detection of leptonic dark matter

Abstract

Weakly interacting massive particles (WIMPs) are among the favored candidates for cold dark matter in the universe. The phenomenology of supersymmetric WIMPs has been quite developed during recent years. However, there are other possibilities which have not been discussed as much. One example is a right-handed massive neutrino, which has recently been proposed in the context of a version of the Zee model for massive neutrinos. This TeV-scale, leptonic WIMP (or LIMP, for short) may at first sight appear to be essentially undetectable. However, we point out that the radiatively induced annihilation rate into leptons and photons is bound to be substantial, and provides a conspicuous gamma-ray signature for annihilations in the galactic halo. This gives a window of opportunity for AirČerenkov Telescopes with ability to observe the galactic center, such as the HESS and CANGAROO arrays, and also for the GLAST space telescope. In addition, the contribution to the positron cosmic ray flux is in principle detectable, but this would require very strong local density enhancements in the dark matter halo distribution.PACS numbers: 95.35.+d, 14.60.St, 95.85.Pw, 95.85.Ry, 98.70.Rz

A model of radiative neutrino mass: with or without dark matter

“…[7][8][9][10]). In this paper we investigate a three-loop model of neutrino mass that is related to the KNT model.…”

The Search for Dark Matter via Gamma Rays from Astronomical Sources Using EGRET and GLAST

“…An energy resolution of 5% has been assumed for the line signal. Other examples are discussed in [11].…”

“…This is a version of the Zee model [20], which has been quite successful in reproducing the observed mass and mixing pattern of solar and atmospheric neutrinos (see, e.g., [21]). The authors of [11] point out that the radiatively induced annihilation rate of these LIMPs into leptons and photons is bound to be substantial, and provides a conspicuous gamma-ray signature for annihilations in the galactic halo.…”

“…Can such a heavy right handed neutrino be an acceptable dark matter candidate or LIMP? Reference [11] explores the ramifications such a model [19] where a righthanded neutrino of mass on the order of a few TeV plays a crucial role in giving mass to the otherwise massless standard model neutrinos through a highorder loop mechanism. This is a version of the Zee model [20], which has been quite successful in reproducing the observed mass and mixing pattern of solar and atmospheric neutrinos (see, e.g., [21]).…”

“…Leptonic dark matter is not totally hopeless from the viewpoint of detection via the annihilation channels L R L R → l + l -γ, γγ. [11] a) In general, the γ ray flux from WIMP annihilation is given by, EGRET GLAST GC source in LAT ~ 10 arc sec location.…”