Research Education for Teachers Summer 2013 Caroline Fletcher Advisor: Dan Karmgard
Projects • Astrophysics • Compact Muon Solenoid
Astrophysics • Observational Astronomy • Telescope alignment • Celestron 8-inch. • Image taking • SBIG ST-8XECCD camera and attached it to the Celestron CPC800 11-inch Schmidt-Cassegrain telescope.
Cartoon Muon Solenoid Program: • Components: • Image • This is a three dimensional image of the Compact Muon Solenoid (CMS) detector. • Can rotate and view every inch of the detector while studying the variety of events. CMS
Graphic Controls • Controls the transparency of each detector part. • Detectable Path • This is the actual physics. (The vector sum of Transverse momentum in the x-y plane) CMS
Event type • EM: Electrons/Positrons/Photons • These stop in the Ecal • HD: Charged pions/neutral kaons • These stop in the Hcal • Mu: Muons/Neutrions • These travel through the entire detector. • Charge • Determines the shape of the track. • 0 = straight line • -1/+1 bend in the opposite direction. • Px/Py/Pz • The charge determines the direction and the momentum determines the amount of curvature. • This will only occur in the x-y plane due to the solenoid being oriented along the z-axis. • Vertex • Where the collision occurred (0 cm) CMS
Underlying Event • This allows you to see EVERYTHING!! (HELP ME) • AvgBkg • The average background value is used as the average of a flat distribution. • Lower number = less realistic • PtCut • This filter allows you to concentrate on the transverse momentum. • Higher momentum = less tracks • Track • Number assigned to each track. • Color • This enables you to “pin-point” the exact track you wish to study when concentrating on momentum. • Help and Home • Self explanatory! CMS
Particle Identification • Color Code • Since tracks are generated without your interaction, colors have been assigned to particle type • Electrons = Green • Photons = Light Blue • Hadrons = Yellow • Muons = Red • Neutrinos = Dark Blue CMS
Track information • Hold shift and left mouse together, and a box will appear. • pz = Momentum on the z-axis • pT = Transverse Momentum • φ = Angular displacement • ɳ = Efficiency • VTX = Vertex • M = Mass • E = Energy • ID = Particle CMS
pT Cut (MeV) = 0 • Hard Quantum Chromodynamics (QCD) • Hadron-Hadron collisions and predicted by the perturbation theory. • Fragment into jets. pT Cut (GeV) = 5
pT Cut (MeV) = 0 • Top Quark • The heaviest of all six which makes it very short lived. • The been has to be at least 7 TeV. • Decay into W-boson and a bottom quark. pT Cut (GeV) = 5
LeptoQuark • Hypothetical Particle (Do I need to say more?) • pp collisions with energies around 7 TeV. Being heavy, these particles decay very quickly into one of three generations. pT Cut (MeV) = 0 pT Cut (GeV) = 5
Standard Model (SM) Higgs • This particle has no spin, electric charge, or color change with mass around 125 GeV/c2. • Unstable = Quick Decay • Many believe that this particle explains why some particles are massive and others mass-less. • Most probable decays: • b-quark-b-antiquark, charmed quark-charmed antiquark, or tau-anti-tau. • Other possibilities: • WW and ZZ, although these particles will also undergo another stage of decay (lepton-anti-lepton, neutron-anti-neutron, quark-anti-quark)
pT Cut (MeV) = 0 pT Cut (GeV) = 5
Prompt Photons • pp collisions and are detected in the eCal. • Because they do not fragment into jets, we can achieve a more accurate picture of these photons. • Two processes • Low pT • The quark gluon Compton Scattering process dominates. • High pT • Quark anti-quark annihilation dominates. • As the curves steepness decreases, the pTwill increases.
pT Cut (GeV) = 5 pT Cut (MeV) = 0
Weak Boson Exchange • W and Z particles that are the carrier of the electromagnetic force. • We only see the decay particles! • There are 24 possibilities with only 21 that are visible. • Most common: quark-antiquark pair which you can see as jets.
pT Cut (MeV) = 0 pT Cut (GeV) = 5
pT Cut (GeV) = 5 Single pT Cut (MeV) = 0
pT Cut (MeV) = 0 Boson Pair pT Cut (GeV) = 5
pT Cut (MeV) = 0 Boson + Jet pT Cut (GeV) = 5
CMS public data (The REAL thing!!!!) • How to choose your data set • Select data file: Choose which type of event you would like to research. • Event: Public released data usually in sequential order. • Muon Filters: • Tracker is the inner most part of the detector, and the muons that are detected in this section produce ambiguous results in all other parts of the detector. • Stand Alone: This type of muon is detected in the spectrometer and has no detection in the tracker. These muons are more than likely produced from a decay and are also accompanied with a jet. • Global: This type of muon is measured in all sections of the detector.
Jet cones: The cones indicate that there are many particles traveling together in the same direction away from the same source. This is also a sign that a quark collision may have just occurred. You may check this box for on/off view. • Jet Hadrons: • Quarks or Gluons have been knocked out of the proton.