Abstract : A search is presented for exotic decays of a Higgs boson into undetectable particles and one or two isolated photons in pp collisions at a center-of-mass energy of 8 TeV. The data correspond to an integrated luminosity of up to 19.4 inverse femtobarns collected with the CMS detector at the LHC. Higgs bosons produced in gluon-gluon fusion and in association with a Z boson are investigated, using models in which the Higgs boson decays into a gravitino and a neutralino or a pair of neutralinos, followed by the decay of the neutralino to a gravitino and a photon. The selected events are consistent with the background-only hypothesis, and limits are placed on the product of cross sections and branching fractions. Assuming a standard model Higgs boson production cross-section, a 95% confidence level upper limit is set on the branching fraction of a 125 GeV Higgs boson decaying into undetectable particles and one or two isolated photons as a function of the neutralino mass. For neutralino masses from 1 to 120 GeV an upper limit in the range of 7 to 13% is obtained. Further results are given as a function of the neutralino lifetime, and also for a range of Higgs boson masses.
http://hal.in2p3.fr/in2p3-01171155
Contributeur : Sylvie Flores
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Soumis le : vendredi 3 juillet 2015 - 08:17:50
Dernière modification le : jeudi 10 mai 2018 - 02:00:44
V. Khachatryan, M. Besançon, F. Couderc, M. Dejardin, D. Denegri, et al.. Search for exotic decays of a Higgs boson into undetectable particles and photons. Physics Letters B, Elsevier, 2016, 753, pp.363-388. 〈10.1016/j.physletb.2015.12.017〉. 〈in2p3-01171155〉
