Abstract
A measurement of production cross sections of the Higgs boson in proton-proton collisions is presented in the π»βπβ’π decay channel. The analysis is performed using 36.1ββfbβ1 of data recorded by the ATLAS experiment at the Large Hadron Collider at a center-of-mass energy of βπ =13ββTeV. All combinations of leptonic (πβββ’π£β’π£
with β=π,π) and hadronic (πβhadronsβπ£) π decays are considered. The π» βπβ’π signal over the expected background from other Standard Model processes is established with an observed (expected) significance of 4.4 (4.1) standard deviations. Combined with results obtained using data taken at 7 and 8 TeV center-of-mass energies, the observed (expected) significance amounts to 6.4 (5.4) standard deviations and constitutes an observation of π» βπβ’π decays. Using the data taken at βπ =13ββTeV, the total cross section in the π» βπβ’π decay channel is measured to be 3.7β’7+0.60β0.59β(stat)β’β+0.87β0.74β(syst)ββpb, for a Higgs boson of mass 125 GeV assuming the relative contributions of its production modes as predicted by the Standard Model. Total cross sections in the π» βπβ’π decay channel are determined separately for vector-boson-fusion production and gluon-gluon-fusion production to be πVBF
π»βπβ’π=0.28Β±0.09β(stat)β’β+0.11β0.09β(syst)ββpb and ππβ‘πβ‘Fπ»βπβ’π=3.1Β±1.0β(stat)β’β+1.6β1.3β(syst)ββpb, respectively. Similarly, results of a fit are reported in the framework of simplified template cross sections. All measurements are in agreement with Standard Model expectations.