July 8, 2020
In 2012 the CMS and ATLAS Collaborations announced the discovery of a new particle, that seems mostly consistent with the Higgs boson as predicted by the Standard Model. To understand if that is actually the case, physicists in the CMS collaboration dig deeper and measure the Higgs boson properties.
To understand the Higgs boson and its role in the Standard Model, we need to observe how it behaves. Does it prefer to be produced either with a small or large kinetic energy? Does the Higgs boson appear together with additional hadronic jet activity? This behaviour is intrinsically connected to how much the Higgs boson interacts with the other Standard Model particles or, in more scientific terms, the size of the Higgs boson coupling strength to other particles. Any significant change in behaviour compared to what we know from the Standard Model could imply that something beyond the Standard Model is playing a role. A precise measurement of the Higgs boson production properties is therefore crucial to have a thorough understanding of the Standard Model theory, but also represents a bridge towards the world of new physics and new particles.
The CMS Collaboration has recently exploited the full amount of data collected during the second run of the CERN LHC to probe the deepest secrets of the Higgs boson, measuring the additional energy and the number of extra particles produced together with Higgs bosons. Physicists do this by measuring the so-called differential production cross-section as a function of the Higgs boson transverse momentum, and the associated hadronic activity.
The particle physics group at IFCA is actively involved in both the HL-LHC project and in the improvement of detectors of the CMS experiment, making a more precise study of properties of the Higgs boson. Several members of IFCA are leading some of these initiatives within the CMS experiment.
More information at: http://cms.cern/news/examining-how-higgs-boson-shapes