The higgsino–singlino world at the large hadron collider

Abstract

We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino-singlino mass plane at the large hadron collider at √ s = 14 TeV for an integrated luminosity of 300 fb −1 .

Natural NMSSM after LHC Run I and the Higgsino dominated dark matter scenario

“…So far studies on the NS scenario in the NMSSM are concentrated on the assumption thatχ 0 1 is Singlino-dominated [18][19][20][21][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46]. In this case, the branching ratio of the golden channelt 1 → tχ 0 1 in the LHC search for a moderately light stop is highly suppressed.…”

Searching for singlino-Higgsino dark matter in the NMSSM

“…In this work, we focus on the case where the LSP is a singlino-dominated neutralino (see e.g. [46][47][48][49][50][51]). The mass hierarchy among the bino, winos, higgsinos, and singlino is controlled by the diagonal elements of the neutralino mass matrix: M 1 , M 2 , µ eff , and 2κv s , where κ comes from the singlet self-interaction term 1 3 κŜ 3 .…”

“…Below we will only focus on the singlino-higgsino scenario, where the LSPχ 0 1 is mainly singlino, whileχ 0 2,3 andχ ± 1 are mainly higgsinos. Some recent works on this scenario include studies on LHC searches [46,47] and IceCube indirect searches [50]. In this work, first we will investigate the viable parameter regions and decay patterns of neutralinos and charginos.…”

Sbottoms of natural NMSSM at the LHC

“…As we shall see, this opens up further possibilities of not only having a singlino-like lightest SUSY particle (LSP) but also nontrivial mixings among the singlino and the higgsinos. Impact of the singlino on the NMSSM phenomenology under specific circumstances have been discussed in the literature [34][35][36][37][38][39]. Here, we investigate how the mixed singlino-higgsino LSP would alter the decay pattern of the sbottom in characteristic ways.…”