Double spin asymmetry


Double spin asymmetry

I measure a double spin asymmetry defined as follows

Equation 1

where N-(anti)parallel indicates yields measured in one half of the detector when the beam polarisations are aligned (opposite) and P1 and P2 are the polarisations of the beams. Accounting for the relative luminosity, these yields are given by

Equation 2
Equation 2

where the arrows again indicate beam polarisations. Figures one and two show the fill-by-fill measurement of ATT, corrected by the beam polarisation, summed over all pT.

Straight-line fit to fill-by-fill measurement of K0s A_TT
Figure 1: K0S ATT fill-by-fill
Straight-line fit to fill-by-fill measurement of Lambda A_TT
Figure 2: Λ ATT fill-by-fill