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The STARlight Monte Carlo models 2-photon and photon-Pomeron interactions
in ultra-peripheral heavy ion collisions. The physics approach for the photon-Pomeron 
interactions is described in Klein and Nystrand, Phys. Rev. C60, 014903 (1999),
with the p_t spectrum (including vector meson interference) discussed in Phys. Rev. 
Lett. 84, 2330 (2000). The 2-photon interactions are described in Baltz, Gorbunov, 
Klein, Nystrand, Phys.Rev. C80 (2009) 044902. 

STARlight has several input files, all of which are expected to be in the
same directory as the starlight code.  User-specified input parameters are
read from a file named "slight.in"; these parameters are described
below.

The output of the STARlight Monte Carlo will be written to an ascii file
named "slight.out".

----------------------------------------------------------------------------

The contents of a sample slight.in file are listed below, with 
explanation.  The user should modify this file according to his or her
needs.
BEAM_1_Z = 82	  #Z of projectile
BEAM_1_A = 208    #A of projectile
BEAM_2_Z = 82     #Z of target
BEAM_2_A = 208 	  #A of target
BEAM_GAMMA = 1470 #Gamma of the colliding ions

W_MAX = 12.0   #Max value of w
W_MIN = -1     #Min value of w
W_N_BINS = 40  #Bins i w
      	# maximum and minimum values for w (the gamma-gamma center of mass
	# energy, w = 4(E1)(E2), (Setting W_MIN = -1 tells STARlight to use the default values
	# specified in inputParameters.cpp; otherwise, specify wmin here, and the number
        # of w bins in the lookup tables

RAP_MAX = 8.    # max rapidity
RAP_N_BINS = 80 # Number of y bins used in the cross section calculation

CUT_PT = 0   	 #Cut in pT? 0 = (no, 1 = yes)
PT_MIN = 1.0 	 #Minimum pT in GeV
PT_MAX = 3.0 	 #Maximum pT in GeV
CUT_ETA = 0  	 #Cut in pseudorapidity? (0 = no, 1 = yes)
ETA_MIN = -10 	 #Minimum pseudorapidity
ETA_MAX = 10 	 #Maximum pseudorapidity

PROD_MODE = 2    #gg or gP switch (1 = two-photon, 2 = coherent vector meson, 4 = incoherent vector meson )

N_EVENTS = 10    #Number of events produced

PROD_PID = 443013   #Channel of interest (in PDG notation); currently supported	options listed below
RND_SEED = 34533    #Random number seed

BREAKUP_MODE = 5     #Controls the nuclear breakup
	             # Note that this option only works for lead or gold; it should work at any energy
		     # 1 = hard sphere nuclei (b>2R)
		     # 2 = require that both nuclei break up (Xn,Xn)
		     # 3 = a single neutron from each nucleus (1n,1n)
		     # 4 = require that neither nucleus breaks up (0n,0n) 
		     # 5 = require that there be no hadronic break up 
		     # 	   (This is similar to option 1, but with the actual hadronic interaction
		     # 	   probability)
		     # 6 = require break up of one or both nuclei (Xn)
                     # 7 = require break up of one nucleus (Xn,0n)

INTERFERENCE = 0     #Interference (0 = off, 1 = on)
IF_STRENGTH = 1.     #% of intefernce (0.0 - 0.1)
INT_PT_MAX = 0.24    #Maximum pt considered, when interference is turned on
INT_PT_N_BINS =120   #Number of pt bins when interference is turned on
COHERENT = 1         #Coherent=1,Incoherent=0 production for assym collisions
INCO_FACTOR = 1.     #percentage of incoherence


----------------------------------------------------------------------------

Currently supported 2-photon channel options:
      jetset id		particle
   ---------------------------------
	221		eta			
	331		eta-prime 		
	441		eta-c			
	9010221		f0(975)		
	225		f2(1270)
	115		a2(1320)
	335		f2(1525)
	33		rho0 pair
	11		e+/e- pair
	13 		mu+/mu- pair
	15		tau+/tau- pair

Currently supported vector meson options:
      jetset id		particle
   ---------------------------------

	113		rho0
	223		omega
	333		phi
	443011		J/psi --> e+e-
        443013          J/Psi --> mu+mu- 
	444011		Psi(2S) --> e+e-
	444013		Psi(2S) --> mu+mu- 
	553011 		Upsilon(1S) --> e+e- 
	553013 		Upsilon(1S) --> mu+mu-  
	554011 		Upsilon(2S) --> e+e- 
	554013 		Upsilon(2S) --> mu+mu-  
	555011 		Upsilon(3S) --> e+e- 
	555013 		Upsilon(3S) --> mu+mu-  
	913		rho0 + direct pi+pi- (with interference)
The direct pi+pi- fraction is from the ZEUS results



Logs:

fixed types for class Particle 
- Int -> Double 
- fixed Makefile .. 
   autoconfig will appear in the future .. make sure paths are fixed before compiling 
   this is for includes and libraries in Makefile
- don't forget about link to pythia xml doc 
  This is located in main.cpp

- changed PID of the charged KAON to 321 and neutral kaon to 310 .. it should work now for phi -> kk 

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