Higgs boson properties
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Higgs Boson Properties: Mass, Width, and Quantum Numbers
The Higgs boson, discovered in 2012 by the ATLAS and CMS collaborations at CERN, has a measured mass of about 125 GeV. This value has been confirmed by multiple experiments and is consistent with the predictions of the Standard Model of particle physics 1245+1 MORE. The width of the Higgs boson, which relates to its lifetime, is measured to be very small—around 3.2 MeV, in agreement with the Standard Model expectation of 4.1 MeV . The spin-parity quantum numbers of the Higgs boson have been established as 0⁺, confirming it as a scalar particle as predicted 910.
Higgs Boson Couplings and Decay Channels
The Higgs boson interacts with other particles through couplings that are proportional to their masses, as described by the Higgs mechanism. Measurements have confirmed its couplings to both bosons (like W and Z bosons) and fermions (such as top and bottom quarks, and tau leptons), with observed rates matching Standard Model predictions within current experimental uncertainties 1245+3 MORE. The Higgs boson decays into various channels, including bosonic (WW, ZZ, γγ) and fermionic (bb, ττ) final states, and these decay patterns have been observed and measured in detail 1245+1 MORE.
Production Cross-Sections and Signal Strength
The production cross-sections of the Higgs boson in different modes (such as gluon-gluon fusion, vector boson fusion, and associated production with top quarks or vector bosons) have been measured at the LHC. These measurements are in good agreement with Standard Model predictions. For example, the cross-section for Higgs decaying to four leptons (via ZZ*) is measured to be about 2.92 fb, closely matching the predicted value of 2.76 fb . The signal strength modifier, which compares observed rates to Standard Model expectations, is found to be very close to 1, indicating no significant deviations 259.
CP Properties and Beyond the Standard Model Searches
The charge conjugation and parity (CP) properties of the Higgs boson have been probed, confirming it as a CP-even scalar. Future colliders and more precise measurements aim to further test for possible CP-odd or mixed CP states, which would indicate new physics beyond the Standard Model 510. So far, no significant deviations from the Standard Model have been observed, and invisible or exotic decays of the Higgs boson are strongly constrained by current data 4579.
Future Prospects for Higgs Boson Studies
The proposed Future Circular Collider (FCC) aims to achieve even higher precision in measuring Higgs boson properties, including its mass, width, self-coupling, and rare decay modes. Techniques like the "recoil mass" method will allow for direct and model-independent measurements of key parameters, potentially revealing subtle effects of new physics .
Conclusion
In summary, the Higgs boson has a mass of about 125 GeV, a very narrow width, and scalar quantum numbers, with its couplings and decay patterns matching Standard Model predictions. Ongoing and future experiments will continue to refine these measurements and search for any signs of new physics in the Higgs sector 1245+5 MORE.
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Measurements of properties of the Higgs boson decaying into the four-lepton final state in pp collisions at s=13$$ \sqrt{s}=13 $$ TeV
The Higgs boson mass is measured to be 125.26 0.21 GeV and its width is constrained to H 1.10 GeV, with a 95% confidence level.
Reconstructing Higgs boson properties from the LHC and Tevatron data
The standard model Higgs boson with a mass 125 GeV provides an acceptable global fit to data, but better fits can be achieved by non-standard scenarios that reproduce anomalies in the data.
Measurement of the Higgs boson width and evidence of its off-shell contributions to ZZ production
The Higgs boson's off-shell contributions to Z boson production can be measured using data from the CERN Large Hadron Collider, supporting its off-shell production and lifetime parameters.
Higgs physics opportunities at FCC
The Future Circular Collider (FCC) could advance our understanding of Higgs boson properties by using the "recoil mass" technique to measure key parameters like mass, self-coupling, and couplings.
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