Determining the spin of supersymmetric particles at the LHC using lepton charge asymmetry

If signals suggesting supersymmetry (SUSY) are discovered at the LHC then it will be vital to measure the spins of the new particles to demonstrate that they are indeed the predicted super-partners. A method is discussed by which the spins of some of the SUSY particles can be determined. Angular distributions in sparticle decays lead to charge asymmetry in lepton-jet invariant mass distributions. The size of the asymmetry is proportional to the primary production asymmetry between squarks and anti-squarks. Monte Carlo simulations are performed for a particular mSUGRA model point at the LHC. The resultant asymmetry distributions are consistent with a spin-0 slepton and a spin-12χ˜20, but are not consistent with both particles being scalars.