Quantifying the statistical error in a counting experimentby JoePhysicsNut Tags: binomial, branching fraction, statistics 

#1
Jan2213, 03:54 AM

P: 34

I need to find the statistical error in a counting experiment. Specifically, a decay can proceed via option A or option B and I need to find the branching ratio BR_a=(N_a)/(N_a+N_b). If I were to do this counting experiment multiple times my results for BR_a would follow the binomial distribution since there are two decay channels.
How do I quantify the statistical error in my result given that I conduct the experiment only once? 



#2
Jan2213, 10:25 AM

Mentor
P: 10,864

Do you have a fixed number of decays ("I take data until I have 100 decays in those two channels")?
No => you can treat N_a and N_b as the result of independent Poisson processes. Yes => the denominator is fixed, and N_a comes from a binomial distribution. 



#3
Jan2813, 09:33 PM

Sci Advisor
HW Helper
P: 1,937

The usual statistical error gives N_A+  sqrt{N_A}.



Register to reply 
Related Discussions  
Can we Measure and Quantifying smell? (Dog Experiment)  Medical Sciences  8  
Quantifying the statistical error in a counting experiment  Advanced Physics Homework  0  
Statistical physics: counting states, entropy and temperature  Advanced Physics Homework  2  
Introductory Statistical Mechanics  counting number of microstates  Advanced Physics Homework  3  
Statistical Physics  counting states  Advanced Physics Homework  1 