Exploring the unknown with the Higgs boson - new ATLAS results released

Exactly five years after the Higgs boson discovery at the Large Hadron Collider (LHC) at CERN, new studies of this particle, involving significant MPP contributions, are presented at the EPS-HEP conference in Venice. The results are based on Run-2 proton-proton collision data collected by the ATLAS detector during 2015 and 2016 and containing three times more Higgs bosons than before.

A candidate for a Higgs boson decay into two electrons (blue) and two muons (red), recorded in September 2015 with the ATLAS detector at the LHC.

A candidate for a Higgs boson decay into two electrons (blue) and two muons (red), recorded in September 2015 with the ATLAS detector at the LHC. (Image: CERN)

Until recently, the Higgs boson had been observed decaying to photons, tau-leptons, and W and Z bosons. For the first time now, there is an evidence for the Higgs boson's favoured decay to a pair  of b-quarks. The new data additionally allows for a more precise measurement of the Higgs boson mass and its production and decay processes, providing stronger limits on possible interactions in theories beyond the Standard Model.

The Higgs boson also plays a crucial role in searches for new particles. With the Run-2 data, the upper limits on the production of heavy Higgs boson partners are in many cases reduced by almost a factor of two. The limits on the dark matter particle production in association with the Higgs boson are improved to the same extent. Other searches outside of the Higgs sector, such as searches for supersymmetric particles have improved their limits by a similar amount. The quest for the unknown still continues with more data being taken since May 2017.

Contact:

Dr. Sandra Kortner
Max Planck Institute for Physics
+49 89 32354-288

References with MPP contributions:

ATLAS-CONF-2017-020, ATLAS-CONF-2017-026, ATLAS-CONF-2017-032,
ATLAS-CONF-2017-043
, ATLAS-CONF-2017-046, ATLAS-CONF-2017-050,
ATLAS-CONF-2017-055
, ATLAS-CONF-2017-058, arXiv:1707.01302.