add low level first principle variables
add low level first principle variables:
cos_theta_yy_cm_bbyy phi_yy_cm_bbyy
Photon1_cos_theta_cm_gamgam Photon1_phi_cm_gamgam
HbbCandidate_Jet1_cos_theta_cm_bb HbbCandidate_Jet1_phi_cm_bb
DeltaPhi_bb_yy_cm_bbyy
(and keeping conventions of prefixes/suffixes used in the framework)