Search for dark Higgsstrahlung in e+e−→μ+μ− and missing energy events with the KLOE experiment

• Main Authors: A. Anastasi, D. Babusci, G. Bencivenni, M. Berlowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, L. Caldeira Balkeståhl, 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, F. Nguyen, A. Palladino, 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
• Format: Article
• Language: English
• Published: Elsevier 2015-07-01
• Series: Physics Letters B
• Subjects: Dark matter; Dark forces; U boson; Upper limit; Higgsstrahlung
• Online Access: http://www.sciencedirect.com/science/article/pii/S0370269315004372
• ISSN: 0370-2693; 1873-2445

We searched for evidence of a Higgsstrahlung process in a secluded sector, leading to a final state with a dark photon U and a dark Higgs boson h′, with the KLOE detector at DAΦNE. We investigated the case of h′ lighter than U, with U decaying into a muon pair and h′ producing a missing energy signature. We found no evidence of the process and set upper limits to its parameters in the range 2mμ<mU<1000 MeV, mh′<mU.