The ATLAS collaboration published the results of searching for the associative production of a Higgs boson and a top–antitop quark pair. Investigations were performed using the data collected in the channels of the Higgs boson decay into \(b\bar b\), WW∗, τ+τ−, γγ and ZZ∗over the entire LHC operation period. The production was observed with the statistical significance of 6.3 standard deviations at the expectation of 5.1 within the Standard Model. It is a pleasure to point out that DLNP scientists take an active part in this analysis, dealing with the channel of the Higgs boson decay into τ+τ−.
Yesterday, on 04 June 2018, two experiments, ATLAS and CMS, at the LHC, CERN, reported a discovery that relates two particles: the Higgs boson and the top quark.The scientists measured for the first time direct interaction of the Higgs boson with the top quark during a rare subatomic process.
The Higgs boson was predicted in the 1960s and observed in the CMS and ATLAS experiments in 2012 in collisions of LHC-generated protons by detecting particles into which is decays.The Higgs mechanism, which involves the Higgs boson, gives masses to elementary particles while leaving the photon massless.The Standard Model would be incomplete without the Higgs mechanism at LHC energies.Therefore, the t quark, most massive of quarks, must have the strongest relation to the Higgs boson.Production of a Higgs boson with a top–antitop quark pair (tt̄H) is a rare process, but it allows one to observe how these particles are related to each other.The top quark was observed in the CDF and DZero experiments at Fermilab’s Tevatron in 1995. Despite predictions of scientists about interaction of the top quark with the Higgs boson, all indications were, until now, below the threshold that allowed claiming a discovery. Now everything is quite different after the publications in Physical Review Letters and arXiv.org.
On May 16, 2018, within the framework of the Dubna visit of Prof. K. Jakobs, spokesperson of the ATLAS experiment at the LHC, a meeting of the JINR participants in the ATLAS Collaboration was held.
The results and plans of physics research in the fields of the Standard Model, Higgs boson physics, search for new physics, and heavy quark physics were presented, and the prospects for the JINR participation in the operation of the facility and its upgrading during the upcoming technical shutdown were discussed. Also, readiness of JINR for manufacture of MicroMegas detectors was demonstrated to Prof. K. Jakobs.
ATLAS spokesperson Prof. K. Jakobs speaks about his seminar at DLNP on 16.05.2018, where he presented the results and further plans of research within the ATLAS project at the LHC.
See the full version of the seminar here.
On 27 April 2018, a regular ATLAS weekly working meeting was held at DLNP. O.A. Koval’ (group headed by I.R. Boiko) made a report on the status of the investigations into associative production of the top quark and the Higgs boson. Since this Higgs boson production channel has not been observed yet, the projected research seems to be promising from the point of view of both the investigations of the Standard Model and the search for new physics in the experiments at the LHC.More photos