%0 Journal Article %T Search for new light gauge bosons in Higgs boson decays to four-lepton final states in pp collisions at root s=8 TeV with the ATLAS detector at the LHC %A ATLAS Collaboration (Aad, G. et al %A Alvarez Piqueras, D. %A Cabrera Urban, S. %A Castillo Gimenez, V. %A Costa, M. J. %A Fernandez Martinez, P. %A Ferrer, A. %A Fiorini, L. %A Fuster, J. %A Garcia, C. %A Garcia Navarro, J. E. %A Gonzalez de la Hoz, S. %A Hernandez Jimenez, Y. %A Higon-Rodriguez, E. %A Irles Quiles, A. %A Jimenez Pena, J. %A Kaci, M. %A King, M. %A Lacasta, C. %A Lacuesta, V. R. %A Marti-Garcia, S. %A Mitsou, V. A. %A Moles-Valls, R. %A Oliver Garcia, E. %A Pedraza Lopez, S. %A Perez Garcia-Estañ, M. T. %A Romero Adam, E. %A Ros, E. %A Salt, J. %A Sanchez Martinez, V. %A Soldevila, U. %A Sanchez, J. %A Torro Pastor, E. %A Valero, A. %A Valladolid Gallego, E. %A Valls Ferrer, J. A. %A Vos, M. %J Physical Review D %D 2015 %V 92 %N 9 %I Amer Physical Soc %@ 1550-7998 %G English %F ATLASCollaborationAad_etal2015 %O WOS:000364019900001 %O exported from refbase (https://references.ific.uv.es/refbase/show.php?record=2443), last updated on Fri, 27 Nov 2015 12:27:57 +0000 %X This paper presents a search for Higgs bosons decaying to four leptons, either electrons or muons, via one or two light exotic gauge bosons Z(d), H -> ZZ(d) -> 4l or H -> Z(d)Z(d) -> 4l. The search was performed using pp collision data corresponding to an integrated luminosity of about 20 fb(-1) at the center-of-mass energy of root s = 8 TeV recorded with the ATLAS detector at the Large Hadron Collider. The observed data are well described by the Standard Model prediction. Upper bounds on the branching ratio of H -> ZZ(d) -> 4l and on the kinetic mixing parameter between the Z(d) and the Standard Model hypercharge gauge boson are set in the range (1-9) x 10(-5) and (4-17) x 10(-2) respectively, at 95% confidence level assuming the Standard Model branching ratio of H -> ZZ* -> 4l, for Z(d) masses between 15 and 55 GeV. Upper bounds on the effective mass mixing parameter between the Z and the Z(d) are also set using the branching ratio limits in the H -> ZZ(d) -> 4l search, and are in the range (1.5-8.7) x 10(-4) for 15 < m(Zd) < 35 GeV. Upper bounds on the branching ratio of H -> Z(d)Z(d) -> 4l and on the Higgs portal coupling parameter, controlling the strength of the coupling of the Higgs boson to dark vector bosons are set in the range (2-3) x 10(-5) and (1-10) x 10(-4) respectively, at 95% confidence level assuming the Standard Model Higgs boson production cross sections, for Z(d) masses between 15 and 60 GeV. %R 10.1103/PhysRevD.92.092001 %U http://arxiv.org/abs/1505.07645 %U https://doi.org/10.1103/PhysRevD.92.092001 %P 092001-30pp