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Because understanding the nature of the signal is critical defining both the search strategy and the required background samples, the top priority has been the development of a robust simulation of quirk dynamics that is as complete as possible. Towards this end, we have developed a standalone Monte Carlo simulation of quirk dynamics to better define the ATLAS-specific signature for and sensitivity to mesoscopic quirks. Initial results of this work indicate that we will double to mass reach of a previous search at the Tevatron with 1 fb-1 of collected data.
However, a full Geant-based simulation is required to develop specific cuts for signal selection and allow the development of an unbiased background sample.
Although our current simulation In Our simulations of quirks have become sufficiently detailed to reveal their own shortcomings: important details of quirk dynamics and their signature in the detector depend upon the interactions of quirks with the material in the detector. Therefore, in order to understand the signal adequately, a full Geant4 simulation of quirks will be required, both to assess the signal sensitivity as a function of quirk masses and confinement scales and to develop unbiased samples of data that are needed to model the expected backgrounds.
Plans
The task of implementing the simulation of quirk dynamics in Geant is just beginning and Work on implementing quirks in Geant4 has begun, but is far from trivial because it involves fundamental changes to the way the Geant propagates particles through the detector volume.This is now moving towards implementation of quirks in Geant4, which will be required in order to fully understand both our signal and the issues that limit our rejection of backgrounds from random tracks: pairwise rather than individually. In parallel, we are beginning to develop background samples given our current level of understanding for the signature.