I offer three questions below, and you are welcome to think any or all of them over today and tomorrow. In two days I will give my answer, explain the underlying physics a bit, and comment your own answers, if you have been capable of typing them despite your skyrocketing glycemic index.
1. An experiment selects events of signal with a frequency f=0.1 Hz and events of background with a frequency b = 100 Hz. Compute the time of data taking it takes to observe the signal with a statistical significance of N=5 standard deviations, if the expected background rate is perfectly well known.
2. How much longer do you need to run the experiment to get to 5 sigma if there is a 0.02% systematic uncertainty on the b rate in the setup of exercise 1?
3. Why was the top quark sought in association with a bottom quark during the eighties, and later during the nineties only looked for in the pair production process?
Tommaso Dorigo is an experimental particle physicist, who works for the INFN at the University of Padova, and collaborates with the CMS experiment at the CERN LHC. He coordinates the European network AMVA4NewPhysics as well as research in accelerator-based physics for INFN-Padova, and is an editor of the journal Reviews in Physics. In 2016 Dorigo published the book “Anomaly! Collider physics and the quest for new phenomena at Fermilab”. You can get a copy of the book on Amazon.