DOE REVIEW AUGUST 2006: CDF GROUP AT HARVARD MELISSA FRANKLIN - PROF JOAO GUIMARAES DA COSTA---PROF 25% SEBASTIAN GRINSTEIN - POST-DOC DANIEL SHERMAN - GRAD STUDENT INGYIN ZAW - GRAD STUDENT JOHN PAUL CHOU - GRAD STUDENT AYANA HOLLOWAY - GRAD STUDENT 2006* SAL RAPPOCCIO - GRAD STUDENT 2005*

agenda Introduction/overview/a little physics -melissa franklin Something about silicon, recent past and future- sebastian grinstein The top quark production cross-section - daniel sherman The soft lepton tagger - john paul chou Flavor changing neutral currents involving top - ingyin zaw Plans for the coming year - joao guimaraes da costa

STATE OF CDF Expect run2 to last through roughly 2009 Silicon will be fine COT will turn off DE/dx Peak luminosity :1.75 * 10 **32 record integrated luminosity: 27 inverse pb per week ( 1 fb per year) Number of interactions per crossing =2 STILL UPGRADES TO DAQ, TRIGGER- good for students Number of working people dwindling - must support running of detector measurements coming in snippets

Steeper and steeper - cdf gets interesting- what can we learn?

Contributions to cdf --central tracker construction, installation, commissioning, online monitoring ( stage0), drift model --central muon detector extension : cmx:design, construction, commissioning, online, upgrades, reconstruction code --silicon detector, silicon daq: positioned and surveyed all ladders, designed and built silicon readout controller src. large role in commissioning, maintaining, three upgrades to src --beamline :code to find cdf beamline automatically for use in almost all analyses --primary vertex algorithm : design, code and implementation --b-tagging: large contributions to present svx b-tagger, wrote run2 code, new loose b-tagger, increased efficiency by 20+20%, soft lepton tagging

Bs mixing limit depended on primevtx written by Harvard

Much work on w+jets+b-tags Over three years 8 people (really everyone in the group in one way or another) Taggers:secvtx tight, loose, soft lepton tag, tag efficiency, mistag matrix, backgrounds, MC, W + heavy flavor Top cross-section major contribution to physics Impacts many analyses: Top mass, top properties,Higgs search, etc

Need cross-section for top mass

Search for new physics in the top sample Top quark lifetime*** FCNC TT-->ttX Higgs

Top lifetime measurement --> d0 of lepton

Cross-check provides first measurement of tau lifetime from CDF:

Top life time First direct limit on the top quark lifetime We select tt-bar events by identifying an electron/muon and a secondary vertex (secvtx) tagged jet in events with >= 3 jets and large missing energy. In such events, the impact parameter (d0) of the lepton should be typically very small. Its distribution can be predicted from (1) the resolution of d0 measurements for high momentum lepton tracks, (2) the characteristics of standard model top quark decays, and (3) the magnitude and d0 distribution of non tt-bar backgrounds. Inconsistency between the predicted distribution and our observation could be indicative of a new, long-lived background to tt-bar, anomalous top production by a long-lived parent particle, or a large t lifetime. Using electron and muon tracks produced in Z0/γ -> e+e- /μ+μ- events to determine the detector resolution, we show that the lepton d0 distribution in top candidate events from 318 pb-1 of CDF data is consistent with expectations, and derive a limit on the top quark lifetime:cτt < % C.L.cτt < % C

blessed analyses 2006 Top lifetime - done. paper in progress Top cross-section with secondary vertices: 395pb-1 paper written + published, 700pb-1 blessed 1fb-1 top cross-section imminent when we get the generation of the MC samples right Limit on the production of TTX this fall Limit on FCNC this fall Measurement of top cross-section using SLTagger: winter

Cdf notes this past year

cdf group in the twilight years Melissa Franklin Joao Guimaraes da Costa 25% Sebastian Grinstein John Paul Chou New student? (taking care of Silicon DAQ and continuing hi-pt W +jet studies and discovering really really new physics)

integrated luminosity Steeper and steeper ; 2-3fb-1 this funding year