add photons from delta rays to likelihood calculation

This commit updates the likelihood function to take into account Cerenkov light
produced from delta rays produced by muons. The angular distribution of this
light is currently assumed to be constant along the track and parameterized in
the same way as the Cerenkov light from an electromagnetic shower. Currently I
assume the light is produced uniformly along the track which isn't exactly
correct, but should be good enough.

1 files changed, 14 insertions, 0 deletions

diff --git a/src/muon.h b/src/muon.h
index 586d67d..456c11e 100644
--- a/src/muon.h
+++ b/src/muon.h
@@ -5,6 +5,20 @@
 
 #define EULER_CONSTANT 0.57721
 
+/* Number of photons in the range 200 nm - 800 nm generated per MeV of energy
+ * lost to radiation for electrons.
+ *
+ * FIXME: This is just a rough estimate, should use an energy dependent
+ * quantity from simulation.
+ *
+ * FIXME: Actually determine what this is. */
+#define MUON_PHOTONS_PER_MEV 7368.0
+
+void muon_get_position_distribution_parameters(double T0, double *a, double *b);
+double muon_get_angular_distribution_alpha(double T0);
+double muon_get_angular_distribution_beta(double T0);
+void muon_get_delta_ray_distribution_parameters(double T0, double *a, double *b);
+double muon_get_delta_ray_photons(double T0);
 double muon_get_range(double T, double rho);
 double muon_get_dEdx_rad(double T, double rho);
 double muon_get_dEdx(double T, double rho);