Search for a pseudoscalar boson decaying into a Z boson and the 125 GeV Higgs boson in ℓ+ℓ−bb‾<

Abstract

Results are reported on a search for decays of a pseudoscalar A boson into a Z boson and a light scalar h boson, where the Z boson decays into a pair of oppositely-charged electrons or muons, and the h boson decays into bb. The search is based on data from proton-proton collisions at a center-of-mass energy √ s = 8 TeV collected with the CMS detector, corresponding to an integrated luminosity of 19.7 fb −1 . The h boson is assumed to be the standard model-like Higgs boson with a mass of 125 GeV. With no evidence for signal, upper limits are obtained on the product of the production cross section and the branching fraction of the A boson in the Zh channel. Results are also interpreted in the context of two Higgs doublet models.

Phenomenological signatures of additional scalar bosons at the LHC

“…B.7, we note that in the limit where cos(β − α) → 0 (and therefore sin(β − α) → 1), the cou- [47][48][49].…”

Flavor from the electroweak scale

“…For M = 500 GeV, substantial regions of the model parameter space are ruled out, however for M = 600 GeV the model is considerably less constrained. The right panel of figure 15 also shows the ATLAS bounds [65] In the left panel we show current exclusion bounds for σ(gg → A)×Br(A → hZ → bb) based on the CMS data [66]. In the right panel we show exclusion bounds for [65].…”

“…There are several experimental studies constraining σ(gg → A) × Br(A → hZ), with the light Higgs further decaying into bottom quarks [65,66], tau leptons [65], as well as multi-leptons [49].…”

“…We consider the measurement of σ(gg → A)×Br(A → hZ)×Br(h → bb) by ATLAS [65] and the measurement of σ(gg → A) × Br(A → hZ → + − bb) by CMS [66] with − = e − , µ − . Both experiments give their bounds assuming narrow width approximation for the heavy scalar.…”

Hierarchical versus degenerate 2HDM: The LHC run 1 legacy at the onset of run 2

“…We discuss now the limits on the 2HDM parameter space from ATLAS and CMS searches of A 0 decaying via A 0 → Zh (h →bb, h → ττ) [66,67], via A 0 → γγ [68,69] and A 0 → ττ [70,71]. For the A 0 → ττ searches, the production of A 0 in association with abb pair is taken into account by the ATLAS/CMS experimental analyses in addition to production through gluon fusion, the former being important for type II at large values of t β .…”