Search for the standard model Higgs boson decaying to tau pairs produced in association with a W or Z boson

A search for the standard model Higgs boson produced in association with a W or Z boson is presented using data collected in 2011 and 2012 with the CMS detector at the LHC. The topologies studied here have three- or four-leptons final states. The Higgs boson decay channel analysed is the ditau channel where the tau can decay via an electron, a muon or hadronically. The W and Z boson decays used to enhance the signal events are into electron or muon and the dielectrons or dimuons, respectivelly. The analysis uses $pp$ collision data samples corresponding to integrated luminosities of 5.0 fb$^{-1}$ collected at \mbox{$\sqrt{s}=7$ TeV} and 19.5 fb$^{-1}$ of 8 TeV. Upper limits at 95\% C.L. between 2.9 and 4.6 times the standard model prediction are established on the product of Higgs boson cross section and tau pair decay branching fraction for Higgs masses between 110 and 145 GeV/$c^2$