Joint analysis of Higgs decays and electroweak precision observables in the Standard Model with a sequential fourth generation

Abstract

We analyse the impact of LHC and Tevatron Higgs data on the viability of the Standard Model with a sequential fourth generation (SM4), assuming Dirac neutrinos and a Higgs mass of 125 GeV. To this end we perform a combined fit to the signal cross sections of pp -> H -> gamma gamma,ZZ*,WW* at the LHC, to p pbar -> VH -> V b bbar (V = W, Z) at the Tevatron and to the electroweak precision observables. Fixing the mass of the fourth generation down-type quark b' to 600 GeV we find best-fit values of m_t' = 632 GeV, m_l4 = 113.6 GeV and m_nu4 = 58.0 GeV for the other fourth-generation fermion masses. We compare the chi-square values and pulls of the different observables in the three and four-generation case and show that the data is better described by the three-generation Standard Model. We also investigate the effects of mixing between the third and fourth-generation quarks and of a future increased lower bound on the fourth-generation charged lepton mass of 250 GeV.

References in corpus (9)

• Search for the Standard Model Higgs boson in the diphoton decay channel with 4.9 fb-1 of pp collisions at sqrt(s) = 7 TeV with ATLAS
• Anatomy of New Physics in B-Bbar mixing
• Search for the Standard Model Higgs boson in the decay channel H->ZZ(*)->4l with 4.8 fb-1 of pp collision data at sqrt(s) = 7 TeV with ATLAS
• Less space for a new family of fermions
• Precision Constraints on Extra Fermion Generations
• Possible evidence for the breakdown of the CKM-paradigm of CP-violation
• Addendum to: Predictions for Higgs production at the Tevatron and the associated uncertainties
• Search for heavy bottom-like quarks in 4.9 inverse femtobarns of pp collisions at sqrt(s) = 7 TeV
• Long Lived Fourth Generation and the Higgs

Cited by in corpus (11)

• Search for pair produced fourth-generation up-type quarks in pp collisions at sqrt(s) = 7 TeV with a lepton in the final state
• Search for vector-like T quarks decaying to top quarks and Higgs bosons in the all-hadronic channel using jet substructure
• Review of searches for vector-like quarks, vector-like leptons, and heavy neutral leptons in proton-proton collisions at $\sqrt{s}$ = 13 TeV at the CMS experiment
• Status of the fourth fermion generation before ICHEP2012: Higgs data and electroweak precision observables
• Search for single production of a vector-like T quark decaying to a top quark and a Z boson in the final state with jets and missing transverse momentum at $\sqrt{s}=$ 13 TeV
• Search for the Anomalous Interactions of Up-Type Heavy Quarks in $\gamma \gamma$ Collision at the LHC
• Search for vector-like bottom quark via $Zb$ production at the LHC
• Search for pair production of the heavy vectorlike top partner in same-sign dilepton signature at the HL-LHC
• Chiral heavy fermions in a two Higgs doublet model: 750 GeV resonance or not
• Indian Contributions to LHC Theory
• Boosting Invisible Higgs Searches by Tagging a Gluon Jet for Gluon Fusion Process