Collider Physics at Fermilab•Accelerators•Detectors•MSU’s involvement•W and top quark productionParticle Accelerators•First, radioactive sources, then cosmic rays - both difficult, rare, and uncontrolled as “beams”Rather, rely on electromagnetism to accelerate charged particles and to bend them where they are to go...electric fields acceleratemagnetic fields benda television set is a little particle acceleratorArtificial beams were first produced in the late 1940’s in the form of cyclotronsmagnetic fieldbeamnow, these accelerators are used for nuclear physics researchThe best example in the world is the National Superconducting Cyclotron Laboratory here on campuscont.Higher energies and particle fluxes required a different approach, the synchrotron•much higher energies are possiblea cartoon of a collidingbeam synchtrotron acceleratorelectric fieldcavity accelerates particlesin the beampipemagnets all around the ring keep the beam goingin a circlea detector sits insidethe tunnel where thebeams are forced to collidehead-onprotons orpositronsantiprotons orelectronswhat is Fermilab?•it’s many things to me…•it’s a dedicated scientific community• made up of:1200 physicists, engineers, and staff>1000 faculty, post docs, and students  from > 80 US & ~20 foreign institutions•it’s an amazing scientific instrument•! consisting of:A time machineA particle accelerator for antirotating beams of protons and antiprotonshand-made vehicles to explore the current and the very early universe A source of high energy/intensity beams of kaons and neutrinos•it’s a beautiful single-purpose DOE national lab•! located at:real space: 60 mi west of Chicagoa truly inspiring place to workWilson Halldesigned by the first director, Robert WilsonHEP labs around the world, today.SLAC e+e-Fermilab pp, vCERN e+e-pp ~2008Cornell e+e-KEK e+e-BEPC e+e-DESY epDAΦNE e+e-Fermi National Accelerator LaboratoryNew accelerator(s):Main InjectorCentral labfacilityantiprotonsprotons1 mileCDF experimentDO experiment(Minnesota)fermilab’s back yardbackAccelerator Complex - the time machineantiproton cycleproton cycleeither: coasting protonsor: production of antiprotonshow do we detect particles?•" – by the electromagnetic and strong interaction fingerprints that they leave behind in a sandwich of detector types:precision trackinglow mass, low Z, solenoidal fieldelectron showerelectromagnetic calorimeter, high Zppphoton showerpppphadronic calorimeter, high mass,lower Zhadron jetiron muon spectrometer,precision tracking, toroidal fieldppmuonCharged particle trackingSolenoidal fieldSilicon strips & disksElectromagnetic calorimetryelectrons and photonsHadronic calorimetryProtons, neutrons, pions, etc.Muon trackingToroidal fieldIron shieldGeneric colliding beam detector-the vehiclesThe DØ Collaboration, est. 1984: 75 institutions, from 18 countries, 650 Ph.D.’sThe DØ DetectorPreshowersFiber TrackerForward Muon Tracking+TriggerBeamline Shielding20 mSilicon m-strip Tracker2T SolenoidCentral Muon Scintillators3 liquid Argon “thermos bottles” with plates of depleted Uranium instrumentated electrically on their surfaces…insidethe DØ detectorthe other detector…CDFaccelerator delivers, detector reads, computers analyze:•Every 396 ns…396 x 10-9 sthe proton & anti proton beams are brought close together inside the detectorsthere, the actual interaction rate is 7.5MHz, 7.5x106 interactions per secondeach event record is ~250kB, so this would be a rate of 1.9TB/s - impossibleThe experiment is outfitted with near-real time electronics, designed and produced here in our group• which analyzes what’s happening in each collisionreading the information from ~500,000 electronic channels• picks out those events which appear to match (much debated) physics prioritiesand processes 6kHz of these potentially interesting data to a series of dedicated, home-built processors (again, designed and built at MSU)• Eventually, the information is reduced, combined, filtered to an output stream of 50Hz, at 250kB per eventThese data are then processed on a dedicated computer farm of ~500 linux Pentium processors of the ~2GHz classThe overall data load of the experiment will be in the 5-8 PB (petabyte 1015 B… information• in CD’s: the height of ~100 Sears Towers• processed and analyzed at institutions on 4 continents in a ~2000 processor computational gridmost violent elementary particle collision produced on earthIt required thatthe quarks annihilated within 10-19 m of one another or 1/10,000 the size of a protonThe energetics of this event is consistent with interactions in the early universe ~10–20 s after the big bangqanti qqanti qg, “gluon”“coupling” designatingthe strength of the interaction - STRONGRutherford Scattering of one quark in the proton off of another quark from the antiprotonwith the exchange of a “gluon” a photon-like particle that transmits only the STRONG force.2 events: W boson production & detection•p + antip → W + uninteresting stuff•" " with W → e + νevery few hundred nanoseconds - 1012 or so protons and antiprotons encounter one anotherpanti-pmost go by without interactingoccasionally, a quark from the p and a quark from the anti-p are at particularly large momentum and annihilate, head-on with one another…The other quarks interact, but with much lower initial momentaeνWwhich all happens at nuclear dimensions inside of the few-cm beampipe“coupling” designatingthe strength of the interaction - WEAKqanti qνeWwhat the detector “sees”side viewend viewthe length of this bar is proportional to the amount of energy deposited…it’s a measured quantitynothing counterbalancingmomentum on the other side…suggestthe missing neutrinothe computer’s calculation of the balancing momentum - presumed to be the neutrino’s momentumqanti qνeW“coupling” designatingthe strength of the interaction - WEAKThe next generation is in Europe...~2008•The “Atlas Experiment”Diameter 25 mBarrel toroid length 26 mEnd-cap end-wall chamber span 46 mOverall weight 7000 TonsMSU/UMSLAChow do data move around?unique10Gbps connectivity among the 3 Michigan “research universities”•This’ll keep us busy here at MSU for 20 years.better known as