Study the W bosons produced in the Large Hadron Collider.   Tiny URL for this page: http://tinyurl.com/lnwmrf8

Introduction

Protons collide with incredible energy in the Large Hadron Collider. Sometimes the result of one of these collisions is a W boson - the particle which mediates the weak nuclear interaction. W bosons can be positive (+) or negative (-) in charge. But...

• How often are W+ bosons made compared to W- bosons in the the LHC?
• Should it be equal because nature has no preference?
• Should we see all W+ because the proton is positive?
• Can we find out?

Let's try.

Procedure

1. Learn a little about LHC, the CMS detector, and finding W candidate events. Look at the introductory slides.
2. Make teams of two and divide the available CMS events among the teams. Each team also gets a report page.
3. Characterize your events and count them:
   • W+ candidates have a single long red muon track which curves clockwise in the magnetic field of CMS.
   • W- candidates have a single long red muon track which curves anti-clockwise in the magnetic field of CMS.
   • W? events are too hard to measure so we cannot tell if they are W+ or W-.
   • Background events have more than one muon or are altogether different.
4. Add them up on the report page. Then collect all the reports from all the teams and add up the number of W+ candidates and the number of W- candidates. Calculate W+/W-. If you like, you can use this spreadsheet.
5. Find what the result was for CMS. How close was your group? Why do you think we get the answer we get? (Hint: it has to do with the structure of the proton,)

Next steps

• Did you notice the mass in GeV on each event? We use these to find the mass of the Z boson in the standard CMS Data Express. Try it with your students!
• Your students can do even more with a CMS or ATLAS masterclass. Talk with a physicist near you about International Masterclasses.
• For a more intense data experience, try the CMS e-Lab.
• Have questions about this activity? Send an e-mail and ask.

A.W. Smith Building, Room 11, Case Western Reserve University (map)

Tuesday, December 10, 2013

Tiny URL for this page:   http://tinyurl.com/ny5gomp

Agenda Time (ET) Activity 13:00 Registration and Greetings 13:15 Introduction to TOTEM Physics (Dr. Corbin Couvalt) 14:00 Introduction to the TOTEM Masterclass (Ken Cecire)  14:45 Student masterclass measurements, assisted by CWRU graduate students 15:30 Discussion of results 15:45 Videoconference with TOTEM Control Room at CERN 16:00 Masterclass ends Learn More The Particle Adventure TOTEM website CERN in 3 min

Questions? Follow-up? More?

Contacts

• Beatrice Bressan
• Ken Cecire
• Jan Kaspar
• Giuseppe Latino

Introduction

The International Linear Collider (ILC) will give physicists a new way to study the Higgs boson with great precision. The ILC will be an electron-positron collider. Electrons and positrons will be produced and then accelerated to high energies before they collide. A result of these collisions can be the Higgs boson. To understand what physicists will look for to find the Higgs signal in ILC, we will examine Z and WW decays from the Large Electron Positron collider (LEP), which operated until 1999 in the tunnel which now houses the Large Hadron Collider.

Objectives

Participants will:

1. Use conservation laws to explain and characterize the decays of Z and W bosons in LEP.
2. Use the hypotheses formed about Z and W decays to predict the patterns of Higgs boson event in ILC.

Workflow

1. LEP Z-decay. Examine the slides of decays of Z-bosons and try to characterize the patterns according to decay products (particles), number of tracks, energy loss, and anything else you observe. This does not all have to be quantitative. Take notes. Discuss and form a consensus on how the Z boson decays. Resources: Slides (original, inverted colors), Information sheet, Notes sheet.
2. LEP WW-decay. Examine the slides of decays of pairs of W-bosons and try to characterize the patterns according to decay products (particles), number of tracks, energy loss, and anything else you observe. This does not all have to be quantitative. Take notes. Discuss and form a consensus on how the W boson pairs decay. Resources: Slides (original, inverted colors), Information sheet, Notes sheet.
3. Higgs in ILC. Examine the ILC/Higgs slides to learn how the Higgs boson will be produced in ILC. Use what you have learned from LEP events to predict what the Higgs events in ILC will look like. Draw diagrams and share these with your colleagues. Resources: Slides, Information sheet, Notes sheet, poster board, markers.

Learn more

• ILC homepage
• Hands-on-CERN
• CMS masterclass in Japanese
• Japan pickes Tohoku site for International Linear Collider (AAAS Science Insider)
• LCWS13

Return to main Workshop page.

Construction

Items needed:

• If constructing detector(s):
  • CRMD kit
  • 6000 series CRMD assembly instructions (included with CRMD kit)
  • tools:
    • multi-meter (digital, accurate to 0.01 v or better)
    • scissors
    • ruler or meter stick 
    • sandpaper
    • "tongue-depressor" stick (in CRMD kit)
    • razor or box cutters
    • tape measure (50ft/20m)
    • protractor
    • extra cotton gloves for handling scintillator
    • optional: oscilloscope
  • supplies:
    • 3/4" (~2 cm) and 3" (~8 cm) electrical tape -- black vinyl
    • ** 1/2" (~1.3 cm) teflon plumbing tape
• power strip(s) for computers and CRMD
• good room to construct and setup the detector with table top space
• access to the outside for placement of the GPS receiver: must have clear view of the sky and within 75 feet of the detector for cable run (antenna can look through a window)
• one computer with USB port for talking to the detector and capturing data
• USB drive for each teacher to upload data and download online files
• verify: data computer will not go into 'sleep' mode; Windows: check 'Control Panel'
• need apps:  'hyperterm' on Win; 'ZTerm' on Mac.  These can be downloaded free.
• USB drivers installed on data computers for “6000” series DAQ, found at:
  • Windows OS
  • Mac OS
  • Linux OS
• User agreement for teacher who will use the detector at school

Venue

Needed for the e-Lab workshop:

• build teacher accounts ahead of time. Need:
  • name:
  • school:
  • city/state/province/prefecture:
  • email: 
  • preferred login name:
  • send to: rspete@fnal.gov
  • You may use this spreadsheet: Tchrdata.xls‎‎
• access for facilitator machine on the local network
  • computer access for each participant with internet (IT staff available: trouble-shooting)
  • root access to each computer for installing apps and rebooting.
  • ability to print e-Lab resources
  • LCD projector: two would be best, but one is OK
  • black/white board & markers
• Print:
  • CRMD quick-start guide (draft for use if not constructing CRMD)
  • CRMD user manuals (print for working groups)
  • Cosmic Extremes, resource for each teacher
  • evaluation forms (and translate?)

Other considerations:

• Set-up and clean-up of room
• Name tags (optional but helpful; romaji kudasai)
• Tables, outlets, lighting, space, etc.
• Computers for detectors and presentation (QuarkNet team may have sufficient for presentation)
• Projector and screen
• Internet Access (important)
• Notebooks/pens/markers (participants bring?)
• Venue and/or Parking Passes if Necessary
• Food related: tea, snack, lunch?

Important Human Elements:

• Physicist to give teachers a talk on cosmic rays
• Presence of local physicist-mentor(s) for teachers
• Continued communication after the workshop
• Translator(s) are helpful for international workshops

Tiny URL for this page: http://tinyurl.com/todaicosmic2013

Agenda

Subject to revision

Resources for teachers

Contact

Ken Cecire

Cheryl Brooks

Bob Peterson

Local organizers: please see the workshop Requirements page.