Aspects of the same-sign diboson signature from wino pair production with light higgsinos at the high luminosity LHC

Abstract

Naturalness arguments applied to simple supersymmetric (SUSY) theories require a set of light higgsinos with mass ∼jμj not too far from m h . These models have an inverted electroweakino spectrum with jμj ≪ M 2 which leads to a rather clean, hadronically quiet, same-sign diboson (SSdB) signature at hadron colliders arising from neutral-plus-charged wino pair production. We improve and expand our earlier studies of this signature for discovering SUSY in natural SUSY models by (i) including backgrounds which were not previously considered and which turn out to be significant, (ii) devising more efficient cuts to successfully contend with these larger backgrounds and determining the discovery reach and exclusion ranges for winos with these cuts, emphasizing projections for the updated integrated luminosity target for HL-LHC of 3 ab −1 , and (iii) emphasizing the utility of this channel for natural models without gaugino mass unification. We display the kinematic characteristics of the relatively jet-free same sign dilepton þ E T events (from leptonic decays of both Ws) and find that these are only weakly sensitive to the parent wino mass. We also examine the charge asymmetry in these events and show that its measurement can be used to check the consistency of the wino origin of the signal. Finally, we show that-because the wino branching fractions in natural SUSY are essentially independent of details of the underlying model-a determination of the rate for clean, same-sign dilepton events yields a better than 10% determination of the wino mass over the entire mass range where experiments at the HL-LHC can discover the wino signal.

Mirage mediation from the landscape

“…It is expected that M 2 ∼ 0.8 − 2.2 TeV. The LHC can access wino pair productionχ ± 2χ 0 4 via the samesign diboson signature [60,61] (SSdB) which is unique to SUSY models with light higgsinos: pp →χ ± 2χ 0 4 → W ± W ± + E T . The clean signature and signal production rate may allow one to extract a measurement of M 2 at HL-or HE-LHC via the total SSdB production rate.…”

Investigating New Physics Models with Signature of Same-Sign Diboson + ${E\!\!/}_{T}$

“…Earlier analyses have been done in this regard in Ref. [17,18]. Our current SUSY analysis differs from these earlier analyses in several aspects to be discussed in detail in Sec.…”

“…[16], we choose the two extra parameter non-universal Higgs (NUHM2) model [3,4] with µ M 1 < M 2 < M 3 which can give rise to a clean SSdB + / E T signature via wino-pair production, as pointed out in Ref. [17,18]. The corresponding Feynman diagram is shown in Fig.…”

“…Motivated by the earlier analyses [17,18], we put a set of basic cuts, dubbed the S1-cuts, to reduce the SM backgrounds. Explicitly, the S1-cuts include:…”

Mini-review: Expectations for supersymmetry from the string landscape

“…This gives a unique SS dilepton plus MET signature with minimal jet activity (just that from ISR) in distinction to SS dileptons from gluino and squark production where substantial jet activity is expected. Signal and background and LHC reach have been plotted out in Ref's [63][64][65] Since light higgsinos are expeted in landscape SUSY with radiatively-driven naturalness, then it makes sense to build something like the International Linear e + e − Collider (ILC). The ILC is touted as a Higgs factory, but if √ s > 2m(higgsino) ∼ 250 − 700 GeV, then it may turn out to be a higgsino factory as well [66].…”