Diphoton and diboson probes of fermiophobic Higgs bosons at the LHC

• Published in: The journal of high energy physics Vol. 2016; no. 6; pp. 1 - 22
• Main Authors: Delgado, Antonio, Garcia-Pepin, Mateo, Quirós, Mariano, Santiago, José, Vega-Morales, Roberto
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.06.2016; Springer Nature B.V
• Subjects: Bosons; Classical and Quantum Gravitation; Couplings; Elementary Particles; Higgs bosons; High energy physics; Large Hadron Collider; Mathematical analysis; Physics; Physics and Astronomy; Quantum Field Theories; Quantum Field Theory; Quantum Physics; Regular Article - Theoretical Physics; Relativity Theory; Scalars; Searching; String Theory; Vectors (mathematics); Beyond Standard Model; Higgs Physics
• ISSN: 1029-8479; 1029-8479
• DOI: 10.1007/JHEP06(2016)042

A bstract Extensions of the Standard Model Higgs sector with electroweak charged scalars can possess exotic ‘Higgs’ bosons with vanishing or suppressed couplings to Standard Model fermions. These ‘fermiophobic’ scalars, which cannot be produced via gluon fusion, are constrained by LHC measurements of the 125 GeV Higgs boson to have a small vacuum expectation value. This implies that vector boson fusion and associated vector boson production are in general suppressed rendering conventional Higgs searches insensitive. However, Drell-Yan Higgs pair production, which is not present in the SM, can be sizeable even in the limit of vanishing exotic Higgs vacuum expectation value. We utilize this to show that diphoton searches at 8 TeV LHC already rule out a large class of neutral fermiophobic Higgs bosons below ∼ 110 GeV. This includes fermiophobic scalars found in two Higgs doublet as well as Higgs triplet and Georgi-Machacek type models. Our results extend the only relevant limit on fermiophobic Higgs bosons obtained by a recent CDF analysis of 4 γ + X Tevatron data. Furthermore, diphoton limits are independent of the decay of the second Higgs boson and thus apply even for degenerate masses in contrast to the CDF search. We also find that if the fermiophobic Higgs has very enhanced couplings to photons, masses as large as ∼ 150 GeV can be ruled out while if these couplings are somehow highly suppressed, masses below ∼ 90 GeV can still be ruled out. Finally, we show that WW and ZZ diboson searches may serve as complementary probes for masses above the diphoton limit up to ∼ 250 GeV and discuss prospects at 13 TeV LHC.