RHS Gamma catcher wrongly corrected during 1997

It appears that the right hand (side 1) gamma catcher is incorrectly connected. A plot of PhiLeft vs PhiRight for events with clusters at both ends shows that PhiLeft = PhiRight, rather than PhiLeft = PhiRight+pi, as would be expected for Bhabha scattering.

A comparison of PhiFE vs PhiFK for the RH detectors confirms that the Right detector is wrong. ( Second plot, same file )

A fix was introduced in FD428/03 to correct this, and so the 1997 pass 3 data is OK. Plots 3 and 4 show the corrected distributions.

Many thanks to Graham Wilson for discovering this interesting feature.