Abstract:In this series of investigations students analyze real Fermilab data. In the first two investigations students learn how to identify B mesons and W bosons and find the W mass. They can also calculate B lifetime as a "special project." Students use the ideas of conservation of energy and momentum, the effects of magnetic fields on charged particles, relativistic effects and ways to analyze large amounts of data.Introduction to Research:
What the students learn from the first two investigations culminates in the search for the Higgs boson. That investigation uses Monte Carlo (simulated) data mixed with real background data to predict where in the mass range the experimental results may lie. The data is presented in Excel spreadsheets and as event pictures. Students hone their Excel skills creating equations, filling in data and creating and plotting histograms.Physicists at Fermilab are in the midst of a second collider run, Run II. One of the new discoveries they hope to find is evidence of the Higgs boson. The Higgs boson may be thought of as an exchange particle that mediates the property of mass. More properly, particles get mass by interaction with a space full of these Higgs bosons: this is refererred to as the Higgs field.Prior Knowledge: Before doing this project, students should know:
Physicists think Higgs is very heavy and very weakly-interacting. That means that very few will be produced even at the correct mass-energy. It will be difficult to pick them out of all the other particles produced at the same time. It really is the quarks and gluons inside the protons that collide. Many other particles are produced by other quarks and gluons, in addition to the particles that you are hoping to find. Fermilab physicists think that Run II could produce the Higgs in sufficient numbers to be detected. This would be big news!
- Quarks and leptons are fundamental particles in the Standard Model.
- A particle can decay into new particles.
- Accelerators create new particles.
- Detectors record data from particle collisions called events.
- Something about using Excel.We provide background resources and an data analysis page to help students complete the project. You may want to recommend some of these resources to your students.Learner Outcomes: Students will know and be able to:
- Explain how physicists identify particles.
- Explain how physicists look for candiate events.
- Determine a criterion for b quarks critical to identifying candidate events for the Higgs boson.
- Determine B lifetime and W, Z and Higgs masses.
- Hone Excel skills for creating and plotting histograms.
- Explain the effect of analyzing different cuts of the data on the value of W mass.
- Use judgment to interpret plots.Where will physicists look for the Higgs boson? Two huge Physics Task Forces, CDF and DZero, are after the Higgs at Fermilab. They will be looking for events with b quarks and Ws as candidate Higgs events. Students will join the particle hunt by doing a sweep for evidence through CDF data to learn how to identify bs and Ws. They will be looking for minimum or "threshold" values for certain parameters. They will find the W mass by analyzing lots of data.Assessment: