Search for exotic decays of a Higgs boson into undetectable particles and one or more photons

CMS [UCL] Basegmez, Suzan [UCL] Beluffi, Camille [UCL] Bondu, Olivier [UCL] Brochet, Sébastien [UCL] Bruno, Giacomo [UCL] Castello, Roberto [UCL] Caudron, Adrien [UCL] Ceard, Ludivine [UCL] Da Silveira, Gustavo Gil [UCL] Delaere, Christophe [UCL] Favart, Denis [UCL] Forthomme, Laurent [UCL] Giammanco, Andrea [UCL] Hollar, Jonathan [UCL] Jafari, Abideh [UCL] Jez, Pavel [UCL] Komm, Matthias [UCL] Lemaitre, Vincent [UCL] Mertens, Alexandre [UCL] Nuttens, Claude [UCL] Perrini, Lucia [UCL] Pin, Arnaud [UCL] Piotrzkowski, Krzysztof [UCL] Popov, Andrey [UCL] Quertenmont, Loic [UCL] Selvaggi, Michele [UCL] Vidal Maroño, Miguel [UCL]

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 this class of models and 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.