Light, long-lived and secluded: can gluinos be driven out from LEP1 data?

Abstract

We briefly report about a possible settlement of the still ongoing dispute concerning the existence of SUSY signals in 4jet events at LEP1. We base our arguments on a simple selection strategy exploiting secondary vertex tagging and kinematical constraints, which could allow one to access or exclude gluino events for a broad range of masses and lifetimes.

Six-quark decays of off-shell $W^+W^-$ pairs via parton-level QCD in electron-positron annihilations

“…Furthermore, to exploit the sort of vertex tagging procedure described in Ref. [22] and recalled in Sect. 2 could be even more fruitful, given the high efficiency and purity foreseen for such a technique by the time the electron-positron linear colliders will have started operation, but provided that τ g ∼ M 4 q αemαsm 5 g > ∼ τ b (e.g., in the SUGRA scenario), with τ b ∼ 1.6 • 10 −12 sec and where M q is the typical squark mass.…”

“…In contrast, it would be intriguing to consider a selection strategy similar to that advocated in Ref. [22], based on the detection of a secondary vertex possibly due to a gluino decay with lifetime between, say, 10 −12 (the typical scale of b and c quarks) and 1 Not quite, it could well be argued, given that in W + W − → 6 quark decays one has to first isolate a subset of four jets which come from the same W ± decay, out of the original six, and since such an operation is in principle affected by the same mis-assignment problems already described. In practise, we will show that is rather easy to select such a subject, the latter preserving the typical angular properties of gauge bosons and fermions exploited in the experimental fits (see discussion later on).…”

“…In contrast, it would be intriguing to consider a selection strategy similar to that advocated in Ref. [22], based on the detection of a secondary vertex possibly due to a gluino decay with lifetime between, say, 10 −12 (the typical scale of b and c quarks) and…”