//sigma z2 = in digits - angle estimated supposing vertex constraint
Float_t z = iz*fZWidth+fParam->GetNTBinsL1()*fParam->GetZWidth();
Float_t sd2 = (z*fParam->GetDiffL()*fParam->GetDiffL())/(fZWidth*fZWidth);
//sigma z2 = in digits - angle estimated supposing vertex constraint
Float_t z = iz*fZWidth+fParam->GetNTBinsL1()*fParam->GetZWidth();
Float_t sd2 = (z*fParam->GetDiffL()*fParam->GetDiffL())/(fZWidth*fZWidth);