CMS closes major chapter of Higgs measurements

Dear Physics Colleagues:

The CMS Collaboration posted the following public release about an important milestone in studying properties of the recently discovered Higgs boson.

The Brown group played a major role in the discovery of the Higgs boson and in the final stretch leading to these new “legacy” results from CMS. Gerald Guralnik, our dear friend and colleague, who – alas – didn’t live to see this major result, has done pioneering work predicting the existence of this new particle in 1964. The quest for the Higgs boson, its discovery, and the final steps of the analysis made public today were led by Prof. Greg Landsberg, the CMS Physics Coordinator in 2012-2013; he also oversaw the preparation of the new CMS publication, which summarizes the new result, in his current role as a CMS Deputy Publication Committee Chair [arXiv:1407.0558]. Prof. Meenakshi Narain and Michael Segala (Ph.D. ‘13) contributed to one of the five types of analyses that led to the discovery, while research associate Joshua Swanson spearheaded another of these five types; together, these two analyses allowed CMS to claim strong evidence for the Higgs boson couplings to fermions, with the strength consistent with the standard model predictions. This result just appeared in Nature Physics last month [doi:10.1038/nphys3005]. Prof. Heintz led an internal review of one of the three of most important Higgs boson discovery analyses. Other members of our group laid a solid foundation of the new results by commissioning, operating, and optimizing major parts of the CMS detector: silicon tracker, hadron calorimeter, and trigger.

For the next Run of the LHC that will start in 2015, we are looking forward to measuring the properties of the Higgs boson with high precision and to look for possible other members of an extended Higgs-boson family that is predicted by many models, most notably by supersymmetry. Brown graduate student Zeynep Demiragli is writing her thesis on exotic decay modes of the Higgs boson under the guidance of Prof. Landsberg. Graduate students Alex Garabedian and Sinan Sagir are probing anomalous couplings of the Higgs boson and are searching for a charged Higgs boson under the guidance of Prof. Narain and research associate Edward Laird and graduate student Zaixing Mao are searching for a more massive Higgs boson with Prof. Heintz.

The new CMS results are a big triumph for science and for our Brown University High-Energy Physics group.

Profs. Cutts, Heintz, Landsberg, and Narain