Abstract
If R-parity conserving supersymmetry is realised with masses below the TeV scale, sparticles will be produced and decay in cascades at the LHC. In the case of a neutral LSP, which will not be detected, decay chains cannot be fully reconstructed, complicating the mass determination of the new particles. In this paper we extend the method of obtaining masses from kinematical endpoints to include a gluino at the head of a five-sparticle decay chain. This represents a non-trivial extension of the corresponding method for the squark decay chain. We calculate the endpoints of the new distributions and assess their applicability by examining the theoretical distributions for a variety of mass scenarios. The precision with which the gluino mass can be determined by this method is investigated for the mSUGRA point SPS 1a. Finally we estimate the improvement obtained from adding a Linear Collider measurement of the LSP mass.
Highlights
Supersymmetry [1 – 4] provides one of the more popular extensions to the Standard Model at higher energies
For collider experiments this has two important consequences: sparticles will be produced in pairs, and the decay chain of a sparticle will always end with the lightest supersymmetric particle (LSP)
The maximum value of each of these distributions can in principle be calculated for any given decay chain, and this maximum value will be determined by the masses involved in the decay
Summary
Supersymmetry [1 – 4] provides one of the more popular extensions to the Standard Model at higher energies. The maximum value of each of these distributions can in principle be calculated for any given decay chain, and this maximum value will be determined by the masses involved in the decay If these kinematical endpoints are measured, it is possible to obtain the sparticle masses in a numerical fit. To get a sizable sample, events with mll somewhat below mmll ax must be used, which increases the uncertainty of the resulting masses To apply this method to (1.2) the following three effects must be controlled: i) the knowledge of mχ01 — this can be assumed known from the standard endpoint analysis of the squark chain, but the appropriate uncertainties must be included, ii) the systematics from the violation of mll < mmll ax m2lR = mχ A rigorous mχ , and treatment iii) the systematics from the inclusion of all these effects is still wanting. The complicated gluino endpoint mmqqal(xlow) is derived in some detail in appendix B
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
