Mattione DCdEdx Study

//during reconstruction:
	//compute dE/dx separately for fdc & cdc (reject 1 of the materials if significantly fewer hits than the other) (reject largest hits of each (separately))
	//compute the means & sigmas for each separately
	//combine the dE/dx's using bragg additivity (calculate the weights!)
	//calculate the uncertainty on the combined dE/dx (transformation of errors)
	//calculate the average combined dE/dx (use bragg additivity, with the individual means)
	//calculate the chisq
	//weight = L1*rho1/A1 OVER sum(Ln*rhon/An): # scattering sites (with Na's canceled)
//to find means & chisq's (for fdc & cdc separately):
	//tree: beta, x, and dE/dx