CMS Wiki Pages

This page is read only. You can view the source, but not change it. Ask your administrator if you think this is wrong.
====== Master & PhD defense exam at UZH CMS ======


===== Exam questions =====

Some typical questions during exams at UZH:
  * Questions about your analysis or thesis (obviously).
    * What is the theoretical or experimental motivation of your model? What motivates your particular chosen set or range of parameter values?
    * What are motivated variations of your signal model? E.g. different mass or coupling parameters.
    * What is the broader context of your model in other experiments? This can be past, current or future experiments like **LEP**, **Tevatron**, or **LH-LHC**. How would your signal show up there? What would the backgrounds be? What exclusions do they give?
    * How would your signal and analysis change with more luminosity (e.g. Run3, LH-LHC data) or higher center of mass energy? (Future colliders.)
    * Questions on the process, like the color flow of Feynman diagram, or parton (like initial b quark) coming from the protons (see PDFs below), ...
    * Is the uncertainty in your result **statistically** or **systematically** driven? (Yuta's favorite.)
    * Specifics about certain **systematics** (nuisance parameters): Which (background) systematics are important? How can they be constrained? ...
  * Detector / accelerations questions:
    * **PDFs** at LHC (quark, b quark, gluon content of proton and anti-proton), see [[https://mstwpdf.hepforge.org/plots/plots.html|bottom plots]].
    * Difference between **LHC**, **LEP**, and **Tevatron**; advantages/disadvantages, production mechanisms, ...
  * Higgs physics
    * In particular the different **Higgs production mechanism** at the LHC or LEP. See e.g. [[https://cds.cern.ch/record/578154/files/0208045.pdf|this article on LEP]], [[https://arxiv.org/abs/2207.00043|this CMS article in Nature]], [[https://arxiv.org/pdf/1703.03952.pdf|this paper on LHC]], or [[https://twiki.cern.ch/twiki/bin/view/LHCPhysics/CrossSections#Latest_plots|the complete set of cross section and branching plots here]].
    * If you are very unlucky the **Higgs mechanism**.
  * Especially for PhD exams:
    * About anything you wrote in your thesis.
    * SM Lagrangians (see [[https://indico.cern.ch/event/775565/contributions/3473286/attachments/1933259/3202727/Woithe_2017_Phys._Educ._52_034001.pdf|page 8]]), or maybe that of your BSM signal model.
    * **Hadronization** (formation of jet).
    * **Neutrinos**: oscillations, seesaw mechanism, ...
    * **Statistics** at the LHC: type of test statistics, how to get **exclusion limits** (upper limits), ... See e.g. [[https://indico.cern.ch/event/173726/|these lectures]], or [[https://indico.cern.ch/event/763661/contributions/3169822/attachments/1733046/2802161/statistical_method_particle_physics.pdf|this talk]].
    * Details about your object reconstruction & identification algorithms (taus, jets, b tagging, ...)
    * How is **luminosity** measured? See e.g. [[https://cms.cern/news/how-does-cms-measure-luminosity|this CMS article]], [[https://cds.cern.ch/record/2676164/files/LUM-18-002-pas.pdf|this PAS]], or [[https://indico.cern.ch/event/1231794/|this ATLAS talk]].
    * For what was the **Nobel Prize** in Physics awarded this/last year? See [[https://en.wikipedia.org/wiki/List_of_Nobel_laureates_in_Physics#Laureates|this Wikipedia page]].
  * ...


===== Exam tips =====

  * You will notice that often the questions are asked awkwardly, and they will repeat them, because the examiner is phishing for a very particular word or phrase.
  * If you do not know what they are looking for, or you do not understand the question, just ask to clarify, and try to have more of an active discussion than an interrogation.
  * As a "cheat" or "hack", you can prepare a lot of material in the back up of your presentation.
Physik-Institut

CMS Wiki Pages

User Tools

Site Tools

Page Tools
