Search

We continue our examination of prospects for the discovery of heavy Higgs bosons of natural SUSY (natSUSY) models at the high luminosity LHC (HL-LHC), this time focusing on charged Higgs bosons. In natSUSY, higgsinos are expected at the few hundred GeV scale whilst electroweak gauginos inhabit the TeV scale and the heavy Higgs bosons, H, A and H ± could range up tens of TeV without jeopardizing naturalness. For TeV-scale heavy SUSY Higgs bosons H, A and H ± , as currently required by LHC searches, SUSY decays into gaugino plus higgsino can dominate H ± decays provided these decays are kinematically accessible. The visible decay products of higgsinos are soft making them largely invisible, whilst the gauginos decay to W, Z or h plus missing transverse energy ( E T ). Charged Higgs bosons are dominantly produced at LHC14 via the parton subprocess, g b → H ± t . In this paper, we examine the viability of observing signatures from H ± → τ ν , H ± → t b and H ± → W , Z , h + E T events produced in association with a top quark at the HL-LHC over large Standard Model (SM) backgrounds from (mainly) t t ¯ , t t ¯ V and t t ¯ h production (where V = W , Z ). We find that the greatest reach is found via the SM H ± (→ τ ν) + t channel with a subdominant contribution from the H ± (→ t b) + t channel. Unlike for neutral Higgs searches, the SUSY decay modes appear to be unimportant for H ± searches at the HL-LHC. We delineate regions of the m A vs. tan β plane, mostly around m A ∼ 1–2 TeV, where signals from charged Higgs bosons would serve to confirm signals of a heavy, neutral Higgs boson at the 5 σ level or, alternatively, to exclude heavy Higgs bosons at the 95% confidence level at the high luminosity LHC. [ABSTRACT FROM AUTHOR]

In supersymmetry (SUSY) models with low electroweak naturalness (natSUSY), which have been suggested to be the most likely version of SUSY to emerge from the string landscape, higgsinos are expected at the few hundred GeV scale, whilst electroweak gauginos inhabit the TeV scale. For TeV-scale heavy neutral SUSY Higgs bosons H and A, as currently required by LHC searches, the dominant decay modes of H , A are gaugino plus higgsino provided these decays are kinematically open. The light higgsinos decay to soft particles, so are largely invisible, whilst the gauginos decay to W, Z or h plus missing transverse energy ( E T ). Thus, we examine the viability of H , A → W + E T , Z + E T and h + E T signatures at the high luminosity LHC (HL-LHC) in light of large standard model (SM) backgrounds from (mainly) t t ¯ , V V and V h production (where V = W , Z ). We also examine whether these signal channels can be enhanced over backgrounds by requiring the presence of an additional soft lepton from the decays of the light higgsinos. We find significant regions in the vicinity of m A ∼ 1 – 2 TeV of the m A vs. tan β plane, which can be probed at the high luminosity LHC, using these dominant signatures by HL-LHC at 5 σ and at the 95% confidence level (CL). [ABSTRACT FROM AUTHOR]

We examine production and decay of heavy neutral SUSY Higgs bosons p p → H , A → τ τ ¯ within the hMSSM and compare against a perhaps more plausible natural supersymmetry scenario dubbed m h 125 (nat) which allows for a natural explanation for m w e a k ≃ m W , Z , h ∼ 100 GeV while maintaining m h ≃ 125 GeV. We evaluate signal against various Standard Model backgrounds from γ , Z → τ τ ¯ , t t ¯ and vector boson pair production V V . We combine the transverse mass method for back-to-back (BtB) taus along with the ditau mass peak m τ τ method for acollinear taus as our signal channels. This technique ultimately gives a boost to the signal significance over the standard technique of using just the BtB signal channel. We evaluate both the 95% CL exclusion and 5 σ discovery reach in the m A vs. tan β plane for present LHC with 139 fb−1, Run 3 with 300 fb−1 and high luminosity LHC (HL-LHC) with 3000 fb−1 of integrated luminosity. For tan β = 10 , the exclusion limits range up to m A ∼ 1 , 1.1 and 1.4 TeV, respectively. These may be compared to the range of m A values gleaned from a statistical analysis of the string landscape wherein m A can range up to ∼ 8 TeV. [ABSTRACT FROM AUTHOR]