--- /dev/null
+The STARlight Monte Carlo models 2-photon and photon-Pomeron interactions\r
+in ultra-peripheral heavy ion collisions. The physics approach for the photon-Pomeron \r
+interactions is described in Klein and Nystrand, Phys. Rev. C60, 014903 (1999),\r
+with the p_t spectrum (including vector meson interference) discussed in Phys. Rev. \r
+Lett. 84, 2330 (2000). The 2-photon interactions are described in Baltz, Gorbunov, \r
+Klein, Nystrand, Phys.Rev. C80 (2009) 044902. \r
+\r
+STARlight has several input files, all of which are expected to be in the\r
+same directory as the starlight code. User-specified input parameters are\r
+read from a file named "slight.in"; these parameters are described\r
+below.\r
+\r
+The output of the STARlight Monte Carlo will be written to an ascii file\r
+named "slight.out".\r
+\r
+----------------------------------------------------------------------------\r
+\r
+The contents of a sample slight.in file are listed below, with \r
+explanation. The user should modify this file according to his or her\r
+needs.\r
+BEAM_1_Z = 82 #Z of projectile\r
+BEAM_1_A = 208 #A of projectile\r
+BEAM_2_Z = 82 #Z of target\r
+BEAM_2_A = 208 #A of target\r
+BEAM_GAMMA = 1470 #Gamma of the colliding ions\r
+\r
+W_MAX = 12.0 #Max value of w\r
+W_MIN = -1 #Min value of w\r
+W_N_BINS = 40 #Bins i w\r
+ # maximum and minimum values for w (the gamma-gamma center of mass\r
+ # energy, w = 4(E1)(E2), (Setting W_MIN = -1 tells STARlight to use the default values\r
+ # specified in inputParameters.cpp; otherwise, specify wmin here, and the number\r
+ # of w bins in the lookup tables\r
+\r
+RAP_MAX = 8. # max rapidity\r
+RAP_N_BINS = 80 # Number of y bins used in the cross section calculation\r
+\r
+CUT_PT = 0 #Cut in pT? 0 = (no, 1 = yes)\r
+PT_MIN = 1.0 #Minimum pT in GeV\r
+PT_MAX = 3.0 #Maximum pT in GeV\r
+CUT_ETA = 0 #Cut in pseudorapidity? (0 = no, 1 = yes)\r
+ETA_MIN = -10 #Minimum pseudorapidity\r
+ETA_MAX = 10 #Maximum pseudorapidity\r
+\r
+PROD_MODE = 2 #gg or gP switch (1 = two-photon, 2 = coherent vector meson, 4 = incoherent vector meson )\r
+\r
+N_EVENTS = 10 #Number of events produced\r
+\r
+PROD_PID = 443013 #Channel of interest (in PDG notation); currently supported options listed below\r
+RND_SEED = 34533 #Random number seed\r
+\r
+OUTPUT_FORMAT = 2 #Form of the output (not considered at this state)\r
+\r
+BREAKUP_MODE = 5 #Controls the nuclear breakup\r
+ # Note that this option only works for lead or gold; it should work at any energy\r
+ # 1 = hard sphere nuclei (b>2R)\r
+ # 2 = require that both nuclei break up (Xn,Xn)\r
+ # 3 = a single neutron from each nucleus (1n,1n)\r
+ # 4 = require that neither nucleus breaks up (0n,0n) \r
+ # 5 = require that there be no hadronic break up \r
+ # (This is similar to option 1, but with the actual hadronic interaction\r
+ # probability)\r
+ # 6 = require break up of one or both nuclei (Xn)\r
+ # 7 = require break up of one nucleus (Xn,0n)\r
+\r
+INTERFERENCE = 0 #Interference (0 = off, 1 = on)\r
+IF_STRENGTH = 1. #% of intefernce (0.0 - 0.1)\r
+COHERENT = 1 #Coherent=1,Incoherent=0 production for assym collisions\r
+INCO_FACTOR = 1. #percentage of incoherence\r
+BFORD = 9.5 #Deuteron slope parameter (dsig/dt = exp(BFORD*t))\r
+INT_PT_MAX = 0.24 #Maximum pt considered, when interference is turned on\r
+INT_PT_N_BINS =120 #Number of pt bins when interference is turned on\r
+\r
+\r
+----------------------------------------------------------------------------\r
+\r
+Currently supported 2-photon channel options:\r
+ jetset id particle\r
+ ---------------------------------\r
+ 221 eta \r
+ 331 eta-prime \r
+ 441 eta-c \r
+ 9010221 f0(975) \r
+ 225 f2(1270)\r
+ 115 a2(1320)\r
+ 335 f2(1525)\r
+ 33 rho0 pair\r
+ 11 e+/e- pair\r
+ 13 mu+/mu- pair\r
+ 15 tau+/tau- pair\r
+\r
+Currently supported vector meson options:\r
+ jetset id particle\r
+ ---------------------------------\r
+\r
+ 113 rho0\r
+ 223 omega\r
+ 333 phi\r
+ 443011 J/psi --> e+e-\r
+ 443013 J/Psi --> mu+mu- \r
+ 444011 Psi(2S) --> e+e-\r
+ 444013 Psi(2S) --> mu+mu- \r
+ 553011 Upsilon(1S) --> e+e- \r
+ 553013 Upsilon(1S) --> mu+mu- \r
+ 554011 Upsilon(2S) --> e+e- \r
+ 554013 Upsilon(2S) --> mu+mu- \r
+ 555011 Upsilon(3S) --> e+e- \r
+ 555013 Upsilon(3S) --> mu+mu- \r
+ 913 rho0 + direct pi+pi- (with interference)\r
+The direct pi+pi- fraction is from the ZEUS results\r
+\r
+\r
+\r
+Logs:\r
+\r
+fixed types for class Particle \r
+- Int -> Double \r
+- fixed Makefile .. \r
+ autoconfig will appear in the future .. make sure paths are fixed before compiling \r
+ this is for includes and libraries in Makefile\r
+- don't forget about link to pythia xml doc \r
+ This is located in main.cpp\r
+\r
+- changed PID of the charged KAON to 321 and neutral kaon to 310 .. it should work now for phi -> kk \r
+\r
+- incoherent formfactor was hardcoded for dAu events, it should now accept coherent too.\r
+- Had hardcoded narrow and wide resonances for VMs. The user can again select gg_or_gp (2 or 3)\r
+except for the psi family. This is still always narrow.\r
+- Changed the spin dependence for VMs going to ee/mumu(gammaavectormeson::gettheta). It was only for psi and now upsilon will follow too\r
+inretrospect, i should probably have done this first and merge psifamily back into gammaavm.cpp\r