Positron resonant annihilation into darK mattER

Descripción del proyecto

Información nueva sobre la materia oscura

Los científicos aceptan desde hace tiempo la existencia de la materia oscura invisible para explicar las influencias gravitatorias en nuestro cosmos. La materia oscura parece superar a la materia visible «ordinaria» en una proporción de seis a uno. Sin embargo, como no absorbe, refleja ni emite luz, es difícil de detectar. La denominada materia oscura ligera —materia oscura con una menor masa que la que es objeto de la mayoría de los trabajos de búsqueda— podría ser la clave. En teoría, esta materia, que los detectores no han logrado hallar hasta la fecha, constituye un mundo paralelo distinto a los que conocemos. El equipo del proyecto POKER, financiado con fondos europeos, está intensificando su búsqueda con métodos novedosos que podrían permitir una firma de señal única y un mayor rendimiento de la señal, lo que aumentaría las posibilidades de detectarla.

Objetivo

"The goal of POKER is to establish and demonstrate a new approach to search for light dark matter, based on a missing energy measurement with a positron-beam, active thick-target setup. Light dark matter is the new compelling hypothesis that identifies dark matter with new sub-GeV ""Hidden Sector"" states, neutral under Standard Model interactions and interfacing with our world through a new force. Accelerator-based searches at the intensity frontier are uniquely suited to explore it. However, current and planned efforts are either limited by the low sensitivity or the high backgrounds. This calls for a major breakthrough in the field. The proposed approach overcomes this challenge. The new technique, based on light dark matter production through positron annihilation on atomic electrons, is characterized by a larger signal yield compared to previously explored reactions, and by a unique signal signature resulting from the underlying reaction dynamics: a peak in the missing energy distribution. The re-analysis of “traditional” electron-beam missing energy results, where low-energy secondary positrons are present, has already shown the potential of this technique. POKER will demonstrate its sensitivity by preparing and running a pilot experiment at the CERN H4 beamline with an optimized detector. The test must fulfill strong requirements: the active thick-target must be capable of detecting each impinging particle at very large (MHz) rate, with excellent energy resolution, and to operate in a high radiation dose environment. POKER will set the basis of the first optimized light dark matter search at a positron-beam facility, enabling sensitivity to a large variety of physics cases, from minimal models to more elaborate Hidden Sectors scenarios - such as the ""Strongly Interacting Massive Particles"" conjecture. The pilot run itself will explore a currently unknown territory in the Hidden Sector parameters space, strengthening even more the POKER physics case."