UIUC HEP: CLEO Task. Mats Selen Aug 5, m 2 (π + π ) (GeV 2 ) m 2 (π + π 0 ) (GeV 2 ) M. Selen, DOE Visit,

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1 UIUC HEP: CLEO Task m 2 (π + π 0 ) (GeV 2 ) m 2 (π + π ) (GeV 2 ) Mats Selen Aug 5, 2004 M. Selen, DOE Visit,

2 Involvement in CLEO-c: CLEO Spokesman CLEO Run Manager Trigger Hardware Physics (of course) Analyses: D S φπ (BR, double partial recon) D 0 K eν (Mixing Analysis) D 0 K S π 0 π 0 (BR & Dalitz Analysis) D 0 K + K π 0 (BR & Dalitz Analysis) D 0 π + π π 0 (Dalitz Analysis) : Mats (with David Cassel) : Topher : Topher, Norm, Paras : Everyone : Jeremy (GG - finished) : Chris (MS - finishing) : Norm, Bob, Topher, Mats : Paras, Bob (MS) : Charles (MS finished*) New UIUC Involvement: Jim Wiss & Doris Kim Expertise in Dalitz analyses and SL decays Already involved with several analysis Very interested in D Kπeυ (more later) M. Selen, DOE Visit,

3 The CLEO-c Trigger Mixer/Shaper Crates (24) Analog ctrl. Mixer/Shaper Boards TILE (16) ASUM QVME TILE(8) ASUM QVME TCTL Barrel CC Endcap CC Drift Chamber Crates DR3 - TQT AXTR(16) AXX(16) TIM DM/CTL STTR(12) TIM DM/CTL Stereo tracker Axial tracker Gates G / CAL DFC TIM DM/CTL L1D TRCR TRCR AXPR CCGL Level 1 decision Flow control & Gating CLEO DAQ TPRO(4) SURF TPRO(2) SURF CC Digital TIM DM/CTL TIM DM/CTL M. Selen, DOE Visit,

4 What it Looks Like (all more or less alike to untrained eye) M. Selen, DOE Visit,

5 D S φπ (Jeremy Williams, GG) CLEO-II.V Badly measured at present: World average B(D S φπ ) = (3.6 ± 0.9)% Calibrates other D S decays: Equivalent of D 0 K π + for D 0 decays. Some D S branching fractions Some D 0 branching fractions M. Selen, DOE Visit,

6 Double Partial Reconstruction Approach: Need to evaluate N(D S φπ) N(D S ) Look for B 0 D S * + D* (1) D S γ π s D 0 D S γ π s (Kπ ) Use to find N(D * S) from B D S * D* (2) (φπ ) γ π s D0 Use to find N(D * ) from B DS* D* D S γ π s D 0 Using the fact that N(D * S) = N(D * ) from B D S * D * to relate (1) and (2) and find B(D S φπ) M. Selen, DOE Visit,

7 Signal Background Total M. Selen, DOE Visit,

8 Preliminary new CLEO results: B(D S φπ ) = (2.45 ± 0.42 ± 0.19)% M. Selen, DOE Visit,

9 D 0 Keν (Mixing) Chris Sedlack & MS CLEO-II.V D *+ π + D 0 ; D 0 K e + ν Right Sign Signal (RS) D *+ π + D 0 ; D 0 D 0 ; D 0 K + e ν Wrong Sign Signal (WS) Some other π + ;D 0 K + e ν Example of Wrong Sign Background Hard part: Telling WS signal from background Chris solution: Neural Net looking at a variety of kinematic vars. M. Selen, DOE Visit,

10 Training & Evaluating the Nets: WS Signal WS Background r M. Selen, DOE Visit, r

11 Fit for mixed & unmixed yields using proper lifetime distribution: Get signal and background shapes from MC. R MIX = 1.1 ± 0.76 % Example fit of partial data sample Studying cuts & systematics before opening the box on rest of data M. Selen, DOE Visit,

12 CLEO-II.V+III D 0 K s π 0 π 0 Dalitz (Norm, BIE & MS) Complement K S π π + analyses Good place to search for low mass ππ No ρ π 0 π 0 to get in the way! Norm re-writing code Switching to CLEO-c data m 2 (π 0 π 0 ) (GeV 2 ) S/(S+B) ~ 70% S ~ 700 K * (890) + K 0 (1430) + f 0 + NR K * (890) + K 0 (1430) + f 0 + NR + σ m 2 (Κ S π 0 ) RS (GeV 2 ) Lots more work to do! 0 m 2 (π 0 π 0 1 ) (GeV 2 2 ) 0 m 2 (π 0 π 0 1 ) (GeV 2 2 ) M. Selen, DOE Visit,

13 CLEO-III D 0 K K + π 0 Dalitz (Paras Naik, BIE & MS) New method for measuring CKM phase γ by looking at B D 0 K, where D 0 K* K. Phys.Rev. D67 (2003) , Grossman, Ligeti, & Soffer Needs a measurement of the strong phase difference δ D between D 0 K* + K and D 0 K* K +. D 0 K + Κ π 0 is a great place to measure δ D via interference! Phys.Rev. D68 (2003) , Rosner & Suprun Dalitz analysis - Resonant substructure Previous D 0 K + K π 0 branching ratio measurement (CLEO II) can be revisited. γ α V ud V ub * V td V tb * V cd V cb * β B(D 0 K + K π 0 ) = (0.14 ± 0.04)% CLEO II result / PDG Value, 151 ± 42 events, 2.7 fb -1 Phys.Rev. D54 (1996) 4211, Asner, et al. M. Selen, DOE Visit,

14 Data and Dalitz Plot CLEO III ϒ(4S) Region: 8.965/fb D* + π + D 0 K + K π 0 DATA K ± Κ m π 0 signal region (after selection criteria) Signal Fraction 77.4% Signal Events 565 (in the signal region) γγ m Κ +π 02 (GeV/c 2 ) 2 Both D 0 s and D 0 s plotted K + is really K for a D 0,etc Dominant resonances: K* ± (892 MeV/c 2 ) φ (1019 MeV/c 2 ) DATA 726 points φ K*+ m Κ +Κ π 0 (GeV/c2 ) K* m Κ π 02 (GeV/c 2 ) 2 M. Selen, DOE Visit,

15 φ m Κ + Κ 2 (GeV/c 2 ) 2 K* + m Κ + π 0 2 (GeV/c 2 ) 2 Dalitz Fit Projections Dalitz Fit Projections DATA K* m Κ π 0 2 (GeV/c 2 ) 2 M. Selen, DOE Visit,

16 Dalitz Plot Fit Resonance K * (892) + K*(892) - φ (1020) nonresonant Preliminary!!! Errors only from fit statistics amplitude a Fixed to ± ± ± phase θ Fixed to 0 CLEO III ± ± ± 7.88 Just when things were humming along - disk crash - still recovering, taking opportunity to rewrite much of analysis code (i.e. make it better etc). M. Selen, DOE Visit,

17 CLEO-II.V NR 1.03±0.17±0.31 D 0 π π + π 0 (Charles Plager) ** PRD in the works ** Amplitude Phase ρ + π 1 (fixed) 0 (fixed) 76.5±1.8±4.8 ρ 0 π ±0.02± ±3±3 23.9±1.8±4.6 ρ π ±0.03±0.04 4±3±4 32.3±2.1±2.2 77±8±11 Fit Fraction 2.7±0.9±1.7 No contribution from σ(500) at ~1% level m 2 (π + π 0 ) (GeV 2 ) S/(S+B) ~ 80% S ~ 1100 m 2 (π + π ) (GeV 2 ) m 2 (π + π ) (GeV 2 ) m 2 (π + π 0 ) (GeV 2 ) m 2 (π π 0 ) (GeV 2 ) M. Selen, DOE Visit,

18 The Future of Charm Physics: CLEO-c CLEO-c Under way! ψ(3770) 3 fb million DD events, 6 million tagged D decays (310 times MARK III) S ~ 4140 MeV 3 fb million D s D s events, 0.3 million tagged D s decays (480 times MARK III, 130 times BES) ψ(3100), 1 fb -1 & ψ(3686) ~1 Billion J/ψ decays (170 times MARK III, 20 times BES II) M. Selen, DOE Visit,

19 CLEO-c What s new? M. Selen, DOE Visit,

20 The Future of Charm Physics: CLEO-c Heavy Flavor Physics: overcome QCD roadblock CLEO-c: precision charm absolute Br measurements Leptonic decays decay constants Semileptonic decays Vcd, Vcs, V_CKM unitarity check, form factors Absolute D Br s normalize B physics Test QCD techniques in c sector, apply to b sector improved Vub, Vcb, Vtd, Vts Physics beyond SM will have nonperturbative sectors CLEO-c: precise measurements of quarkonia spectroscopy & decay provide essential data to calibrate theory. Physics beyond SM: where is it? CLEO-c: D-mixing, charm CPV, charm/tau rare decays. M. Selen, DOE Visit,

21 CLEO-c will soon have 50x more data than this! M. Selen, DOE Visit,

22 K + Single & Double Tagging: Κ 0 D e + 0 D e π + π M. Selen, DOE Visit,

23 Absolute D branching ratios (S & D tagging) M. Selen, DOE Visit,

24 Absolute D branching ratios (S & D tagging) M. Selen, DOE Visit,

25 Tagging cleans things SL decays up a lot: D πeυ M. Selen, DOE Visit,

26 SL branching fractions with CLEO-c now (57.2 pb -1 ) M. Selen, DOE Visit,

27 A first analysis for Doris & Jim Studying hadronic physics in charm semileptonic decay 0. The lack of final state interactions makes semileptonic decay a particularly clean environment for studying hadronic physics. An example is the complicated physics of broad s-wave resonances. 1. FOCUS was able to observe s-wave interference with the dominant K*(896) channel in D + Kπµν and determine the phase shift near the K* pole but FOCUS did not attempt to measure the variation of s- wave phase with Kπ mass because of backgrounds. 2. How well can Cleo-c follow the s-wave phase and amplitude variation given a yield comparable to FOCUS but with greatly reduced backgrounds? 3. What can we learn about interference in other 4 body semileptonic decay? 27

28 Focus K* signal Interference in D + K* µν Data MC F-B asymmetry mkπ ( ) -15% F-B asymmetry! matches model K* µν interferes with S- wave Kπ and creates a forward-backward asymmetry in the K* decay angle with a mass variation due to the varying BW phase The S-wave amplitude is about 7% of the (H 0 ) K* BW with a 45 o relative phase The same relative phase as LASS M. Selen, DOE Visit,

29 Learning more about the s-wave amplitudes 25 MeV bins Γ Γ const amp LASS amp events CosV const amp LASS amp Im BW α Re Focus was limited to the K* peak region because serious non-charm backgrounds dominate out of this region. There is almost no discrimination between a constant and the expected s-wave amplitude from scattering experiments in the narrow region probed by Focus. M(Kπ) The higher Kπ mass is where the amplitude variation is most interesting. As the s-wave phase shift passes 90 0, the cosv asymmetry should reverse. We need the background free environment of CLEO-c to see this M. Selen, DOE Visit,

30 Related SL physics 1. Does s-wave interference occur in decays such as D ρeν? The FOCUS environment has far too much background to see this 2. What is the q 2 dependence of form factors that describe the coupling to the s-wave piece? This might provide additional LQCD tests. The FOCUS q 2 resolution is too poor to resolve this 3. For that matter-- what is the q 2 dependence of the K* helicity amplitudes All experimentalists have been assuming the spectroscopic pole forms But we know the spectroscopic poles are wrong for D Keν A journey of 1000 miles begins with a single step. Doris and Jim are starting to learn the ropes of doing a CLEO-c analysis Data MC From 60 pb -1 CLEO-c Even a totally un-cut sample has a beautiful K* signal that is well simulated Doris is spending about half of her time at Cornell mk π M. Selen, DOE Visit,

31 Summary Involvement in CLEO-c: CLEO Spokesman CLEO Run Manager Trigger Hardware Physics Analyses: D S φπ (BR, double partial recon) D 0 K eν (Mixing Analysis) D 0 K S π 0 π 0 (BR & Dalitz Analysis) D 0 K + K π 0 (BR & Dalitz Analysis) D 0 π + π π 0 (Dalitz Analysis) : Mats (with David Cassel) : Topher : Topher, Norm, Paras : Everyone : Jeremy (GG - finished) : Chris (MS - finishing) : Norm, Bob, Topher, Mats : Paras, Bob (MS) : Charles (MS finished*) New UIUC Involvement: Jim Wiss & Doris Kim Future looks great! M. Selen, DOE Visit,