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Trigger Upgrades, Hardware and Heavy Flavor Physics at CDF http://www.physics.purdue.edu/~mjones/talks/mjones_cdf_Aug19_2008.ppt • Level 1 track trigger • Level 2 calorimter trigger • Time-of-Flight • D+sK-/D+K- correlations • Bs J/ψη • B D*s0(2317)±X • WZ/ZZ with Zbb Trigger Upgrades Matthew Jones (Assistant Professor) Gene Flanagan (Postdoc) Niharika Ranjan (Graduate student, M. Jones) Robert Gustafson (Undergarduate, M. Jones) Hardware responsibilities Heavy Flavor Physics High pT Physics 2008 DOE review
Trigger Upgrades • Almost all events recorded by CDF require tracks or jets in the Level 1 trigger. • Trigger bandwidth has remained approximately constant. • At high luminosity, trigger rate is dominated by fakes and grows rapidly with increasing instantaneous luminosity. • Without upgrades, high bandwidth triggers (B-physics) are pre-scaled (ie, dropped) at high luminosity. • Purdue played an important role in the selection and implementation of the trigger upgrade path. c. 2004 today 2008 DOE review
Trigger Rates at High Luminosity • Confirm tracks using hits on stereo wires 2008 DOE review
TDC+XTC TDC+XTC TDC+XTC TDC+XTC TDC+XTC TDC+XTC TDC+XTC TDC+XTC Finder Finder Finders Stereo Finders Stereo Finders Stereo Finders The XFT Track Trigger Stereo XFT Upgrade Existing axial XFT system Fiber 16 bits @ 45 MHz LVDS 18 bits @ 45 MHz Fiber 16 bits @ 45 MHz 30.3 MHz channel link Stereo Finders Linker Level 2 SLAM Linkers Baylor, UC Davis, FNAL, UIUC, OSU, INFN,Purdue XTRP Purdue commissioning effort 2008 DOE review
Trigger Upgrade Contributions • Efficiency analysis carried out by Purdue demonstrated operational readiness in October 2006. • Very good performance for high pT tracks. • Efficiency for low momentum tracks disfavored pursuing multi-track B-trigger proposals. • Summary presented at Real-Time 2007 conference • Published as IEEE Trans. Nucl. Sci. vol. 55, pp. 126-132, 2008. • Purdue responsibility expanded to oversee the commissioning of Level 2 interfaces (UC Davis). • Level 2 calorimeter (ie, Jet/MET) trigger upgrade: • Purdue involvement with analysis. • Existing experience with Level 2 trigger operations • Flanagan Trigger representative to QCD group 2008 DOE review
Level 2 Calorimeter Trigger • Remaining trigger bottle-neck for high luminosity operation is the calorimeter • Level 2 clustering algorithm from Run I: • Starts at lowest (η,φ) • Cluster location taken as seed tower position • Biases energy and cluster position at high luminosity η “Pac-Man” φ 2008 DOE review
Level 2 Calorimeter Upgrade • Studied jet trigger rates due to clustering algorithms for L2 upgrade proposal. • Wrote and commissioned L2 calorimeter and track trigger algorithms. 2008 DOE review
Provides particle ID when pT<1.5 GeV/c Same Side Kaon Tag (Δms) Fragmentation studies Past institutional involvement: Penn, MIT, FNAL, Berkeley Japan, Italy, Korea, Spain Current institutes providing pager coverage: Purdue (electronics) Spain (calibration) Main operational issues: On-line hardware/software maintenance Calibration at high luminosities PMT aging issues Time-of-Flight Operations 2008 DOE review
Physics Analysis • Historically motivated by interest in B0s decays and oscillations: • Same-side kaon tag • D+K± and D+sK± correlations • Observation of CP-even decay B0sJ/ψη • Search for BD*s0(2317)+X (undergraduate research) • High pT physics: • WZ/ZZ production using (with FNAL + Chicago) 2008 DOE review
Same-side kaon tag works very well. Why? Reconstruct D+s/D+φK+ High statistics Statistically isolate prompt component Measure K,π,p fractions in cone around D Compare with Pythia fragmentation models: no previous direct comparisons with data. D+K± and D+sK± correlations 2008 DOE review
D+K± and D+sK± correlations Observe significantly more D+sK- than D+sK+ or D+K±: Next: increased statistics, quantify systematics, direct comparison with Pythia string fragmentation model. 2008 DOE review
CP-Even decays B0sJ/ψη, J/ψη’ • Important physics: • Lifetime compared with impure CP final state • Other results: • No significant observations (at Belle, CLEO) • Branching ratios relative to J/ψφ • Pseudoscalar mixing angle, θP: • CP violation (via B0sJ/ψφ analysis) 2008 DOE review
CP-Even decays B0sJ/ψη, J/ψη’ • Challenging at CDF: • Low ET photons • Calorimeter alignment • Strip chamber response • Still, it can be done! • Blind search approach: • Expected yields in 1.3 fb-1 with cτ > 100 μm: • N(B0sJ/ψη, ηγγ) = 122-185 • N(N(B0sJ/ψη’, η’π+π-γ) = 55-41 • Expect a 3.5σ signal with 1.3 fb-1, plan to publish based on 2.7 fb-1 5σ significance. 2008 DOE review
Electroweak physics, but similar to Higgs Challenges: low b-tag efficiency Investigating ANN based on jet shapes and impact parameters Di-jet mass resolution Understand fundamental contributions QCD background Using MET significance Combine with WZ/ZZ with Zbb 2008 DOE review
Summary • Purdue has made important contributions to Level 1 and Level 2 trigger upgrades • Essential for efficient operation at high luminosity. • Responsible for Time-of-Flight hardware • On call experts, hardware maintenance, long term operational issues. • Heavy Flavor and high pT Physics Analysis • B0s physics and di-boson analysis • Many opportunities remain, but resources are being redirected for work on CMS. 2008 DOE review