First indications of the Higgs boson decaying into two muons
New results from the Large Hadron Collider (LHC) experiments were announced in the press release by CERN on 3rd August followed by the press release by Nagoya University on 11th August. Nagoya University participates in the ATLAS experiment at LHC. M. Tomoto (Designated Professor, Graduate School of Science and KMI), Y. Horii (Lecturer, Graduate School of Science), Y. Kano (Research Fellow, Graduate School of Science), and T. Kawaguchi (Graduate Student, Graduate School of Science) contributed to this research.
The ATLAS and CMS experiments reported the first indications of Higgs boson decaying into two muons. The observed significance was 2σ and 3σ for ATLAS and CMS, respectively. The results are consistent with the standard model of particle physics, and indicate that the muon mass originates from the Higgs mechanism. Previous studies on the origin of particle mass focused on third-generation particles: bottom quark, top quark, and tau lepton. The new result provides the first insight into the origin of particle mass for the second generation. It is expected that the Higgs boson decaying into two muons will be observed with significance greater than 5σ by a further accumulation of data. Learn more at CERN webpage.
Eight years have passed since the discovery of the Higgs boson. In order to understand the properties of this mysterious particle, young physicists at Nagoya University are working hard by competing with the outstanding physicists around the world. (M. Tomoto/Designated Professor)
I am very excited to have seen the first indication of the muon mass originating from the Higgs mechanism. I expect further improvements in sensitivity owing to the high-luminosity upgrade of the LHC experiments. (Y. Horii/Lecturer)
I am glad that we could announce this result, which is an important step towards solving the mystery of the generations of particles. I am hoping to advance this research with more data in the future, with the development of the LHC ATLAS detector for the high-luminosity upgrade. (Y. Kano/ Research Fellow, Graduate School of Science)
I am very glad that I joined the research at this exciting time. We will keep working hard to confirm the results of this research to be a step closer to understanding the nature of the universe. (T. Kawaguchi/Graduate Student, Graduate School of Science)
Paper Title: A search for the dimuon decay of the Standard Model Higgs boson with the ATLAS detector Authors：M. Tomoto, Y. Horii, Y. Kano, T. Kawaguchi et al. (ATLAS Collaboration) Journal: Physics Letters B (submitted)
Preprint: arXiv:2007.07830 [hep-ex]