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

/ Authors

A. Anastasi, D. Babusci, G. Bencivenni, M. Berłowski, C. Bloise, F. Bossi, P. Branchini, A. Budano, L. Balkest̊ahl, L. Balkest̊ahl

and 69 more authors

B. Cao, B. Cao, F. Ceradini, P. Ciambrone, F. Curciarello, F. Curciarello, E. Czerwiński, E. Czerwiński, G. D'Agostini, E. Dané, V. Leo, E. Lucia, A. Santis, P. Simone, A. Cicco, A. Domenico, R. Salvo, D. Domenici, A. D’uffizi, A. Fantini, G. Felici, S. Fiore, S. Fiore, A. Gajos, A. Gajos, P. Gauzzi, G. Giardina, G. Giardina, S. Giovannella, E. Graziani, F. Happacher, L. Heijkenskjöld, L. Heijkenskjöld, W. Andersson, W. Andersson, T. Johansson, T. Johansson, D. Kamińska, D. Kamińska, W. Krzemień, A. Kupść, A. Kupść, S. Loffredo, G. Mandaglio, G. Mandaglio, M. Martini, M. Mascolo, R. Messi, S. Miscetti, G. Morello, D. Moricciani, P. Moskal, P. Moskal, F. Nguyen, A. Palladino, A. Passeri, V. Patera, E. Rio, A. Ranieri, P. Santangelo, I. Sarra, M. Schioppa, M. Silarski, F. Sirghi, L. Tortora, G. Venanzoni, W. Wiślicki, M. Wolke, M. Wolke

/ Abstract

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 DA Phi NE. 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 2m(mu) < m(U) < 1000 MeV, m(h') < m(U). (C) 2015 The Authors. Published by Elsevier B.V.

Journal: Physics Letters B

DOI: 10.1016/j.physletb.2015.06.015