A Method to Estimate the Boson Mass and to Optimise Sensitivity to Helicity Correlations of tau+tau- Final States

Abstract

In proton-proton collisions at LHC energies, Z and low mass Higgs bosons would be produced with high and predominantly longitudinal boost with respect to the beam axis. This note describes a new analysis tool devised to handle this situation in cases when such bosons decay to a pair of tau-leptons. The tool reconstructs the rest frame of the tau+tau- pair by finding the boost that minimises the acollinearity between the visible tau decay products. In most cases this gives a reasonable approximation to the rest frame of the decaying boson. It is shown how the reconstructed rest frame allows for a new method of mass estimation. Also a considerable gain in sensitivity to helicity correlations is obtained by analysing the tau-jets in the reconstructed frame instead of using the laboratory momenta and energies, particularly when both tau-leptons decay hadronically.

13 pages, method extended with 3D boost finder

References in corpus (5)

• Search for neutral Higgs bosons decaying to tau pairs in pp collisions at sqrt(s) = 7 TeV
• Search for Neutral MSSM Higgs Bosons Decaying to Tau Pairs in pp Collisions at sqrt(s)=7 TeV
• Search for neutral MSSM Higgs bosons decaying to tau^+ tau^- pairs in proton-proton collisions at sqrt(s) = 7 TeV with the ATLAS detector
• Search for the standard model Higgs boson in tau final states
• Implications of the ATLAS and CMS searches in the channel $pp \to Higgs \to τ^+τ^$ for the MSSM and SM Higgs bosons