ROOT Analysis Project 1 - Analysis of the 13 TeV Diphoton mass spectrum

In this project, you will examine the distribution of invariant mass of pair of high energy photons from ATLAS and CMS collected at sqrt(s)=13 TeV. A set of histograms will be provided to you. You should do the following tasks by adapting the code used in the class.

• • Implement the background distributions (functional forms are available in the CMS note and ATLAS note) and fit to the spectra

  • Assume a gaussian function for signal with a width between 10 and 40 GeV

  • Calculate p0-value at various mass points

  • Calculate 95% CL upper limits on hypothetical signal events

Here are some questions you want to consider during this project

• • What is the best fit mass, width and number of excess events. (Be sure to quote uncertainties on the numbers)

  • When scanning p0 value as function of mass try widths of 10, 20, 30, 40 GeV.

  • Is the "excess" around 750 GeV consistent between CMS and ATLAS in terms of width of the peak?