# The INTEGRAL-SPI 511 keV Signal from Hidden Valleys in Type Ia and Core Collapse Supernova Explosions - High Energy Physics - Phenomenology

The INTEGRAL-SPI 511 keV Signal from Hidden Valleys in Type Ia and Core Collapse Supernova Explosions - High Energy Physics - Phenomenology - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Abstract: We examine under what circumstances the INTEGRAL-SPI 511 keV signal canoriginate from decays of MeV-scale composite states produced by: Athermonuclear type Ia or B core collapse supernovae SNe. The requisitedynamical properties that would account for the observed data are quitedistinct, for cases A and B. We determine these requirements in simplehidden valley models, where the escape fraction problem is naturally addressed,due to the long lifetime of the new composite states. A novel feature ofscenario A is that the dynamics of type Ia SNe, standard candles forcosmological measurements, might be affected by our mechanism. In case A, themass of the state mediating between the hidden sector and the SM $\ee$ could bea few hundred GeV and within the reach of a 500 GeV $\ee$ linear collider. Wealso note that kinetic mixing of the photon with a light vector state mayprovide an interesting alternate mediation mechanism in this case. Scenariosbased on case B are challenged by the need for a mechanism to transport someof the produced positrons toward the Galactic bulge, due to the inferreddistribution of core collapse sources. The mass of the mediator in case B istypically hundreds of TeV, leading to long-lived particles that could, undercertain circumstances, include a viable dark matter candidate. The appearanceof long-lived particles in typical models leads to cosmological constraints andwe address how a consistent cosmic history may be achieved.