Synopsis:
I compiled efficiency plots for the above reaction by comparing the three body calculation to three different scenarios of 2 body calculations (pXk-, pk+X, Xk+k-).
Cuts were made on the data using plots of proton acceptance, k+ acceptance, k- acceptance, and expected missing mass. The values I used for these cuts are recorded here.
The following are the plots of efficiency that I obtained for the three different calculations.
1) gamma p -> p X k-
The efficiency for this reaction was in the mid-nineties. Overall, as can be seen, there is no theta dependence on the efficiency, which is exactly what was wanted in the experiment. I cut the angle at 40 degrees because after this point the size of the bins were extremely small and hence large errors in efficiency were produced due to the small bin size.
2) gamma p -> p k+ X
The results for the efficiency in this case were terrible. However, there is a clear explanation for why this is the case, and how the graph above is not indeed a true representation of the efficiency. Due to time constraints and the fact that the results of the Efficiency Analysis are not important, I did not pursue this matter further.
The important graph to note in determining why the plot for K- efficiency turned out so badly is the plots of the three missing masses, shown below.
The first plot is for K+, the second for K-, and the third for P. What is very obvious is that the number of background events is far larger for the plot of K- than it is for the plot of K+ or for P. This means that when the missing mass cut is made on the data, there remains a very large number of events in the K- calculation which should not be included. Since this background number of events is far higher for K-, when the results of the three body calculation are compared to the two body calculation for K-, the three body calculation appears far smaller, resulting in a lower, and less consistent efficiency.
3) gamma p -> X k+ k-
Here, as well, the efficiency is in the mid-nineties and once again I cut the angle at 40 degrees due to the lack of data beyond this point. Once again, there is no theta dependence in the efficiency.
Conclusion:
Overall, despite the lack of hard numbers and results, a definite trend can be observed from the results and a reasonable conclusion can be made on the efficiency. Obviously there are many other factors to consider when calculating the efficiency of the detectors, but this gives some form of overview to the process. As well as this, since the objective of this exercise was to familiarize myself with the system, the goal has definitely been met, indeed further than expectations.