Naslov
Updated results on the new boson discovered in the search for the standard model Higgs boson in the H → ZZ → 4l channel in pp collisions at √s = 7 and 8 TeV

Autori
Amapane, N. ; ... ; Kovac, M. ; Plestina, R. ; Puljak, I. ; ...

Izvornik
CMS Analysis Note 2012/367

Vrsta, podvrsta
Ostale vrste radova, ostalo

Godina
2012

Ključne riječi
CMS; Higgs boson

Sažetak
Measurements of the properties of the new boson recently observed at a mass near 125 GeV in the CMS experiment are reported. The results are obtained from a comprehensive search for the standard model Higgs boson in the H $\rightarrow$ ZZ decay channel, where both Z's decay to electron, muon, or tau lepton pairs. The search covers Higgs boson mass hypotheses in the range $110 < m_H < 1000$ GeV. The analysis uses pp collision data recorded by the CMS detector at the LHC, corresponding to integrated luminosities of 5.1 ${; ; \rm fb}; ; ^{; ; -1}; ; $ at $\sqrt{; ; s}; ; = 7$ TeV and 12.2 ${; ; \rm fb}; ; ^{; ; -1}; ; $ at $\sqrt{; ; s}; ; = 8$ TeV. The new boson is observed with a local significance above the expected background of 4.5 standard deviations. The signal strength $\mu$, relative to the expectation for the standard model Higgs boson, is measured to be $\mu = 0.80^{; ; + 0.35}; ; _{; ; -0.28}; ; $ at 126 GeV. A measurement of its mass gives $126.2 \pm 0.6$ (stat) $\pm 0.2$ (syst)~GeV. The hypothesis $0^+$ of the standard model for the spin $J=0$ and parity $P=+1$ quantum numbers is found to be consistent with the observation. The data disfavor the pseudoscalar hypothesis $0^-$ with a $\mathrm{; ; CL_s}; ; $ value of 2.4\%. No other significant excess is found, and upper limits at 95\% confidence level exclude the ranges 113- -116 GeV and 129- -720 GeV while the expected exclusion range for the standard model Higgs boson is 118--670 GeV.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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