Limit on the production of a low-mass vector boson ine+e−→Uγ,U→e+e−with the KLOE experiment

• DOI: 10.1016/j.physletb.2015.10.003
• Publication Date: 2015-10-17T16:29:16Z
• Authors: A. Anastasi; D. Babusci; G. Bencivenni; M. Berlowski; C. Bloise; F. Bossi; P. Branchini; A. Budano; L. Caldeira Balke...; B. Cao; F. Ceradini; P. Ciambrone; F. Curciarello; E. Czerwiński; G. D'Agostini; E. Danè; V. De Leo; E. De Lucia; A. De Santis; P. De Simone; A. Di Cicco; A. Di Domenico; R. Di Salvo; D. Domenici; A. D'Uffizi; A. Fantini; G. Felici; S. Fiore; A. Gajos; P. Gauzzi; G. Giardina; S. Giovannella; E. Graziani; F. Happacher; L. Heijkenskjöld; W. Ikegami Andersson; T. Johansson; D. Kamińska; W. Krzemien; A. Kupsc; S. Loffredo; G. Mandaglio; M. Martini; M. Mascolo; R. Messi; S. Miscetti; G. Morello; D. Moricciani; P. Moskal; A. Palladino; M. Papenbrock; A. Passeri; V. Patera; E. Perez del Rio; A. Ranieri; P. Santangelo; I. Sarra; M. Schioppa; M. Silarski; F. Sirghi; L. Tortora; G. Venanzoni; W. Wiślicki; M. Wolke
• Keywords: Dark forces; Nuclear and High Energy Physics; Settore FIS/04; Settore PHYS-01/A - Fisica sperimentale delle interazioni fondamentali e applicazioni; Physics; QC1-999; Dark photon; U boson; 01 natural sciences; Dark matter; Dark forces; Dark photon; U boson; A′; 0103 physical sciences; Dark matter; A′

AbstractThe existence of a new force beyond the Standard Model is compelling because it could explain several striking astrophysical observations which fail standard interpretations. We searched for the light vector mediator of this dark force, the U boson, with the KLOE detector at the DAΦNE e+e− collider. Using an integrated luminosity of 1.54 fb−1, we studied the process e+e−→Uγ, with U→e+e−, using radiative return to search for a resonant peak in the dielectron invariant-mass distribution. We did not find evidence for a signal, and set a 90% CL upper limit on the mixing strength between the Standard Model photon and the dark photon, ε2, at 10−6–10−4 in the 5–520 MeV/c2 mass range.