The asymmetry calibration based on August -September 2008 data was generated some time ago and tested by reprocessing earth limb data.
SInce then I've made several improvements to asymmetry calibration code to decrease possible systematic errors:
- as asymmetry histograms for heavy ions have significant tails, I implemented fitting function combining gaussian with two exponential tails so that the presence of tails doesn't affect the peak position obtained from the fit.