From f41d2cfab0ebe9d8a41333b6a24cf44550ce68d2 Mon Sep 17 00:00:00 2001
From: tlatorre <tlatorre@uchicago.edu>
Date: Mon, 10 Feb 2020 09:37:06 -0600
Subject: fix formula for calculating b for position distribution of light from
 electron showers

Also update the a parameter based on a simple 0 degree polynomial fit to the
shower profiles above 100 MeV.
---
 src/electron.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

(limited to 'src')

diff --git a/src/electron.c b/src/electron.c
index 3f5d4d8..967026c 100644
--- a/src/electron.c
+++ b/src/electron.c
@@ -118,9 +118,9 @@ void electron_get_position_distribution_parameters(double T0, double *a, double
      * See http://pdg.lbl.gov/2014/reviews/rpp2014-rev-passage-particles-matter.pdf. */
     double tmax;
 
-    *b = RADIATION_LENGTH;
+    *b = 43.51;
     tmax = log(T0/ELECTRON_CRITICAL_ENERGY_D2O) - 0.5;
-    *a = fmax(1.1,tmax*(*b)/RADIATION_LENGTH + 1);
+    *a = fmax(1.1,tmax*RADIATION_LENGTH/(*b) + 1);
 }
 
 double electron_get_angular_distribution_alpha(double T0)
-- 
cgit