A search for invisible Higgs bosons produced in e+e− interactions at LEP 2 energies

Graviscalars from higher-dimensional metrics and curvature-Higgs mixing

“…At LEP2, the invisible decaying Higgs boson has been searched for by all four collaborations [21]. No evidence has been found for this state, and the lower limit on the mass of At the Tevatron with 30 fb −1 of integrated luminosity, an invisibly decaying Higgs boson could be discovered at greater than 5σ significance if its mass is below 110 GeV, and it could be excluded at the 95% C.L.…”

A tale of two portals: testing light, hidden new physics at future e + e − colliders

“…When m χ = 0.495m K , the dark matter resonantly annihilates, improving the reach for indirect searches and dramatically lowering We also show comparisons to the current fit, sin α < 0.33 [68], future LHC projections of 0.28 (0.20) using 300 fb −1 (3 ab −1 ) luminosity [1], and precision δσ(Zh) measurements constraining 0.084 (0.055) using 5 ab −1 (10 ab −1 ) [3,4,94]. We plot the excluded region from LEP searches for invisible low mass Higgs in ZS channel in cyan [18][19][20][21]. .…”

“…The ZH Higgsstrahlung process is also used to push the mass exclusion to 114.4 GeV [19][20][21], although the intermediate mass range between these two limits are not comprehensively covered. In our model, S →KK is the dominant decay when g D sin α, and the decay branching fractionZ → SZ and the production cross section σ(ZS) are hence sin 2 α suppressed compared to the SM rate.…”

“…Both of these marginal operators have been studied autonomously at electron colliders in the hidden photon context [5][6][7][8][9][10][11][12][13][14][15][16][17] and the hidden scalar context [18][19][20][21][22][23]. Some works study both operators in tandem [24][25][26] or adopt an effective operator approach [27].…”

Exposing the dark sector with future Z factories

“…At LEP-II, a low mass Higgs has been searched in the e þ e − → Z → Z Ã h channel, where Z decays visibly and h decays invisibly, with an integrated luminosity of ∼114 pb −1 [61]. The Higgs bremsstrahlung process Zh is also used at higher ffiffi ffi s p to set a limit on heavier Higgs up to 114.4 GeV [94][95][96]. The searches can put constraints on sin α for the similar process Zs, which we give in Fig.…”