A New Boson with a Mass of 125 GeV Observed with the CMS Experiment at the Large Hadron Collider

• Published in: Science (American Association for the Advancement of Science) Vol. 338; no. 6114; pp. 1569 - 1575
• Main Authors: Abbaneo, D, Abbiendi, G, Abbrescia, M, Abdullin, S, Abdulsalam, A, Acharya, B S, Acosta, D, Acosta, J G, Adair, A, Adam, W, Adam, N, Adamczyk, D, Adams, T, Adams, M R, Adiguzel, A, Adler, V, Adolphi, R, Adzic, P, Afanasiev, S, Agostino, L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 21.12.2012; The American Association for the Advancement of Science
• Subjects: Atoms & subatomic particles; Average linear density; Bosons; Electrons; Exact sciences and technology; Experiments; Higgs boson; Higgs bosons; Large Hadron Collider; Leptons; Muons; Other particles (including hypothetical); Particle accelerators; Particle collisions; Particle physics; Photons; Physics; Properties of specific particles; Quarks; Searching; Standard deviation; Standard model (particle physics); Standard-model higgs bosons; statistical analysis; Statistical Significance; The Higgs Boson; The physics of elementary particles and fields; uncertainty; Z boson; Protons; CERN; LHC collider; Fluctuations; Uncertainty; Leptons; Higgs bosons; Probability; Particle models; Quarks; W bosons; Hadrons; Standard model; Standard deviation; Scalar fields; Muons
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1230816

The Higgs boson was postulated nearly five decades ago within the framework of the standard model of particle physics and has been the subject of numerous searches at accelerators around the world. Its discovery would verify the existence of a complex scalar field thought to give mass to three of the carriers of the electroweak force—the W + , W - , and Z 0 bosons—as well as to the fundamental quarks and leptons. The CMS Collaboration has observed, with a statistical significance of five standard deviations, a new particle produced in proton-proton collisions at the Large Hadron Collider at CERN. The evidence is strongest in the diphoton and four-lepton (electrons and/or muons) final states, which provide the best mass resolution in the CMS detector. The probability of the observed signal being due to a random fluctuation of the background is about 1 in 3 × 10 6 . The new particle is a boson with spin not equal to 1 and has a mass of about 1.25 giga—electron volts. Although its measured properties are, within the uncertainties of the present data, consistent with those expected of the Higgs boson, more data are needed to elucidate the precise nature of the new particle.