T->SetAlias("pcalc","(B.tr.p[0]+0.1+.14*B.tr.x[0]-0.1*(B.tr.x[0]*B.tr.x[0])+0.1*B.tr.y[0])")
Most of the correction seems to come from the focal plane x and a
constant 100MeV shift (see figure 1 from the referenced HALOG entry).
Until I get the time to do a calibration as we did for the last
kinematic, this is the most reliable momentum we have for the spectrometer.