Please solve both parts

Exercice 8. The significance required for the rejection of a null hypothesis varies enormously according to the applications. The Higgs boson (also called the "God particle") is an elementary particle in the Standard Model of particle physics which explains why some particles have mass. Its existence was first theoretically predicted in the 1960's and experimentally confirmed by an experiment at CERN in 2012, with a statistical significance of 5 sigma (which means 5 standard deviations in a twosided test). (a) What would be the null hypothesis of this experiment? (b) Determine the pvalue associated to this experiment, i.e. the probability that the Higgs boson does not exist according to this experiment