diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/likelihood.c | 2 | ||||
| -rw-r--r-- | src/pdg.c | 5 | ||||
| -rw-r--r-- | src/pdg.h | 9 |
3 files changed, 11 insertions, 5 deletions
diff --git a/src/likelihood.c b/src/likelihood.c index 7da81bb..7c3d10f 100644 --- a/src/likelihood.c +++ b/src/likelihood.c @@ -530,7 +530,7 @@ double nll_muon(event *ev, int id, double T0, double *pos, double *dir, double t beta0 = p0/E0; /* FIXME: is this formula valid for muons? */ - theta0 = get_scattering_rms(range/2,p0,beta0,1.0,HEAVY_WATER_DENSITY)/sqrt(range/2); + theta0 = get_scattering_rms(range/2,p0,beta0,1.0)/sqrt(range/2); params.p = path_init(pos, dir, T0, range, theta0, getKineticEnergy, p, z1, z2, n, p->mass); @@ -1,7 +1,8 @@ #include "pdg.h" #include "math.h" +#include "sno.h" -double get_scattering_rms(double x, double p, double beta, double z, double rho) +double get_scattering_rms(double x, double p, double beta, double z) { /* Returns the RMS width of the scattering angle for a particle deflected * by many small-angle scatters after a distance `x`. `p` is the momentum @@ -22,5 +23,5 @@ double get_scattering_rms(double x, double p, double beta, double z, double rho) * See Equation 33.15 in * http://pdg.lbl.gov/2018/reviews/rpp2018-rev-passage-particles-matter.pdf. */ if (x == 0.0) return 0.0; - return (13.6/(beta*p))*z*sqrt(x*rho/RADIATION_LENGTH)*(1+0.038*log((x*z*z)/(RADIATION_LENGTH*beta*beta/rho))); + return (13.6/(beta*p))*z*sqrt(x*WATER_DENSITY/RADIATION_LENGTH)*(1+0.038*log((x*z*z)/(RADIATION_LENGTH*beta*beta/WATER_DENSITY))); } @@ -2,13 +2,18 @@ #define PDG_H #define SPEED_OF_LIGHT 29.9792458 /* cm/ns */ -/* From http://pdg.lbl.gov/2017/AtomicNuclearProperties/HTML/water_liquid.html */ +/* From http://pdg.lbl.gov/2017/AtomicNuclearProperties/HTML/water_liquid.html. + * + * Technically there is a different radiation length for D2O and H2O, and each + * should be divided by the density of the water. However, the results for + * water and heavy water are very close so instead of having to keep track of + * which medium we are in we just use the radiation length in light water. */ #define RADIATION_LENGTH 36.08 /* g/cm^2 */ #define ELECTRON_MASS 0.5109989461 /* MeV */ #define MUON_MASS 105.6583745 /* MeV */ #define PROTON_MASS 938.272081 /* MeV */ #define FINE_STRUCTURE_CONSTANT 7.297352566417e-3 -double get_scattering_rms(double x, double p, double beta, double z, double rho); +double get_scattering_rms(double x, double p, double beta, double z); #endif |