Search for Contact Interactions in the Dimuon Final State at ATLAS

TL;DR

This paper searches for new contact interactions in dimuon events at ATLAS, setting limits on the effective scale of potential new physics using early LHC data, thus probing beyond the Standard Model.

Contribution

It introduces a method to set limits on contact interactions at the LHC using a ratio approach with early data, extending previous bounds.

Findings

Lower limit on Lambda at 7.5 TeV with 100 pb^-1 data.

Lower limit on Lambda at 8.7 TeV with 200 pb^-1 data.

Method demonstrates potential to discover or constrain new physics at LHC.

Abstract

The Standard Model has been successful in describing many fundamental aspects of particle physics. However, there are some remaining puzzles that are not explained within the context of its present framework. We discuss the possibility to discover new physics in the ATLAS Detector via a four-fermion contact interaction, much in the same way Fermi first described Weak interactions. Using a simple ratio method on dimuon events, we can set a 95% C.L. lower limit on the effective scale Lambda = 7.5 TeV (8.7 TeV) for the constructive Left-left Isoscalar Model of quark compositeness with 100 pb^-1 (200 pb^-1) of data at sqrt{s} = 10 TeV.