implement flat pT generation for pi0 and eta

Author: rashigupt

MC/config/PWGHF/pythia8/generator/pythia8_NonHfe.cfg

@@ -8,11 +8,13 @@ Beams:idB 2212 			# proton
 Beams:eCM 13600. 		# GeV
 
 ### processes
-SoftQCD:inelastic on		# all inelastic processes
+
+ProcessLevel:all = off       # <--- MUST ADD
 
 ### decays
 ParticleDecays:limitTau0 on	
 ParticleDecays:tau0Max 10.
+### processes
 
 ### switch off all decay channels
 111:onMode = off