
Evidence for the associated production of the Higgs boson and a top quark pair with the ATLAS detector
Babar Ali
IEAP CTU in Prague (CR)
Abstrakt: A search for the associated production of the Higgs boson with a top quark pair (tˉtH) in multilepton final states using a dataset corresponding to an integrated luminosity of 36.1 fb−1 of proton--proton collision data recorded by the ATLAS experiment at a centre-of-mass energy √s=13 TeV at the Large Hadron Collider is reported. Higgs boson decays to WW∗, ττ, and ZZ∗ are targeted. Seven final states, categorised by the number and flavour of charged-lepton candidates, are examined for the presence of the Standard Model Higgs boson with a mass of 125 GeV and a pair of top quarks. An excess of events over the expected background from other Standard Model processes is found with an observed significance of 4.1 standard deviations, compared to an expectation of 2.8 standard deviations. The best fit for the tˉtH production cross section is σ(tˉtH)=790+230−210 fb, in agreement with the Standard Model prediction of 507+35−50~fb. The combination of this result with other tˉtH searches from the ATLAS experiment using the Higgs boson decay modes to bˉb, γγ and ZZ∗→4ℓ, has an observed significance of 4.2 standard deviations, compared to an expectation of 3.8 standard deviations. This provides evidence for the tˉtH production mode.
Seminář se koná v úterý 7. listopadu ve 14:00
v zasedací místnosti ÚTEF ČVUT, Praha 2 ‐ Albertov, Horská 3a/22.
doc. Dr. André Sopczak tajemník semináře |
doc. Ing. Ivan Štekl, CSc. ředitel |
doc. Dr. André Sopczak předseda NPS, ČS IEEE |
NUCLEAR & PLASMA SCIENCES SOCIETY CHAPTER
IEEE Czechoslovakia section
http://www.ieee.cz/en/nps