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1 M. Selen, DOE Visit, 2004 UIUC – HEP: CLEO Task Mats Selen Aug 5, 2004 m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 )

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Presentation on theme: "1 M. Selen, DOE Visit, 2004 UIUC – HEP: CLEO Task Mats Selen Aug 5, 2004 m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 )"— Presentation transcript:

1 1 M. Selen, DOE Visit, 2004 UIUC – HEP: CLEO Task Mats Selen Aug 5, 2004 m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 )

2 2 M. Selen, DOE Visit, 2004 Involvement in CLEO-c: CLEO Spokesman: Mats (with David Cassel) CLEO Run Manager : Topher Trigger Hardware : Topher, Norm, Paras Physics (of course): Everyone Analyses: D S  (BR, double partial recon) : Jeremy (GG - finished) D 0  K  e (Mixing Analysis) : Chris (MS - finishing) D 0  K S  0  0 (BR & Dalitz Analysis): Norm, Bob, Topher, Mats D 0  K + K   0 (BR & Dalitz Analysis) : Paras, Bob (MS) D 0  +    0 (Dalitz Analysis) : 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  K  e  (more later)

3 3 M. Selen, DOE Visit, 2004 The CLEO-c Trigger

4 4 M. Selen, DOE Visit, 2004 What it Looks Like (all more or less alike to untrained eye)

5 5 M. Selen, DOE Visit, 2004 D S  (Jeremy Williams, GG) CLEO-II.V Badly measured at present: World average B(D S  ) = (3.6 ± 0.9)% Calibrates other D S decays: Equivalent of D 0  K   + for D 0 decays. Some D S branching fractions Some D 0 branching fractions

6 6 M. Selen, DOE Visit, 2004 Look for B 0  D S * + D*  Double Partial Reconstruction Approach: N(D S  ) N(DS)N(DS) Need to evaluate Using the fact that N(D * S ) = N(D * ) from B  D S * D * to relate (1) and (2) and find B(D S  ) D S   s D 0 DS DS   s (K  …) Use to find N(D * S ) from B  D S * D* (1) D S   s D 0 Use to find N(D * ) from B  D S * D* (  …)   s D 0 (2)

7 7 M. Selen, DOE Visit, 2004 Signal Background Total

8 8 M. Selen, DOE Visit, 2004 Preliminary new CLEO results: B(D S  ) = (2.45 ± 0.42 ± 0.19)%

9 9 M. Selen, DOE Visit, 2004 D 0  Ke (Mixing) Chris Sedlack & MS CLEO-II.V Right Sign Signal (RS) D *+   + D 0 ; D 0  K  e + ; D *+   + D 0 ; D 0  D 0 ; D 0  K  e  Wrong Sign Signal (WS) Some other  + ; D 0  K  e  Example of Wrong Sign Background Hard part: Telling WS signal from background Chris’ solution: Neural Net looking at a variety of kinematic vars.

10 10 M. Selen, DOE Visit, 2004 Training & Evaluating the Nets: WS Signal WS Background rr

11 11 M. Selen, DOE Visit, 2004 Fit for mixed & unmixed yields using proper lifetime distribution: Get signal and background shapes from MC. Example fit of partial data sample R MIX = 1.1 ± 0.76 % Studying cuts & systematics before opening the box on rest of data

12 12 M. Selen, DOE Visit, 2004 D 0  K s    0 Dalitz (Norm, BIE & MS) CLEO-II.V+III Complement K S     analyses Good place to search for low mass  No   0  0 to get in the way! Norm re-writing code Switching to CLEO-c data S/(S+B) ~ 70% S ~ 700 m 2 (     ) (GeV 2 ) m 2 (  S   ) RS (GeV 2 ) m 2 (     ) (GeV 2 ) K * (890) + K 0 (1430) + f 0 + NR m 2 (     ) (GeV 2 ) K * (890) + K 0 (1430) + f 0 + NR +  Lots more work to do !

13 13 M. Selen, DOE Visit, 2004 D 0  K  K +  0 Dalitz (Paras Naik, BIE & MS) CLEO-III New method for measuring CKM phase  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  D between D 0 → K* + K – and D 0 → K* – K +.  D 0 → K +  –  0 is a great place to measure  D via interference! –Phys.Rev. D68 (2003) , Rosner & Suprun Dalitz analysis - Resonant substructure Previous D 0 → K + K –  0 branching ratio measurement (CLEO II) can be revisited.    V cd V cb * V ud V ub * V td V tb * CLEO II result / PDG Value, 151 ± 42 events, 2.7 fb -1 Phys.Rev. D54 (1996) 4211, Asner, et al. B(D 0  K + K –  0 ) = (0.14  0.04)%

14 14 M. Selen, DOE Visit, 2004 Signal Fraction  77.4% 565 Signal Events  565 (in the signal region) m       (GeV/c 2 ) Both D 0’ s and D 0’ s plotted “K + ” is really K  for a D 0, etc… Data and Dalitz Plot K*  K*   m     2 (GeV/c 2 ) 2 m     2 (GeV/c 2 ) 2 CLEO III : 8.965/fb CLEO III  (4S) Region: 8.965/fb 726 points K     0 signal region (after selection criteria) Dominant resonances: K*  (892 MeV/c 2 )  (1019 MeV/c 2 ) D* + →  + D 0 K + K –  0    → → DATA

15 15 M. Selen, DOE Visit, 2004 Dalitz Fit Projections K*  m     2 (GeV/c 2 ) 2 DATA K*  m     2 (GeV/c 2 ) 2  m     2 (GeV/c 2 ) 2

16 16 M. Selen, DOE Visit, 2004 Dalitz Plot Fit Preliminary!!! Errors only from fit statistics Resonance amplitude a phase  K * (892) + Fixed to 1Fixed to 0 K*(892)    (1020)   nonresonant   7.88 CLEO III Just when things were humming along… - disk crash - still recovering, taking opportunity to rewrite much of analysis code (i.e. make it better etc).

17 17 M. Selen, DOE Visit, 2004 D 0    +  0 (Charles Plager) CLEO-II.V m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 ) S/(S+B) ~ 80% S ~ 1100 No contribution from  (500) at ~1% level m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 ) m 2 (     ) (GeV 2 ) AmplitudePhaseFit Fraction ++ 1 (fixed)0 (fixed)76.5±1.8±4.8 00 0.56±0.02±0.0710±3±323.9±1.8±4.6  0.65±0.03±0.04  4±3±4 32.3±2.1±2.2 NR1.03±0.17±0.3177±8±112.7±0.9±1.7 ** PRD in the works **

18 18 M. Selen, DOE Visit, 2004 The Future of Charm Physics: CLEO-c  (3770) – 3 fb million DD events, 6 million tagged D decays (310 times MARK III) MeV – 3 fb million D s D s events, 0.3 million tagged D s decays (480 times MARK III, 130 times BES)  (3100), 1 fb -1 &  (3686) ~1 Billion J/  decays (170 times MARK III, 20 times BES II) Under way ! CLEO-c

19 19 M. Selen, DOE Visit, 2004 CLEO-c What’s new ?

20 20 M. Selen, DOE Visit, 2004 The Future of Charm Physics: CLEO-c Heavy Flavor Physics: “overcome QCD roadblock” 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: where is it? CLEO-c: D-mixing, charm CPV, charm/tau rare decays. CLEO-c: precision charm absolute Br measurements CLEO-c: precise measurements of quarkonia spectroscopy & decay provide essential data to calibrate theory. Physics beyond SM will have nonperturbative sectors

21 21 M. Selen, DOE Visit, 2004 CLEO-c will soon have 50x more data than this!

22 22 M. Selen, DOE Visit, 2004 Single & Double Tagging: e+e+ ee  ++ K+K+ 

23 23 M. Selen, DOE Visit, 2004 Absolute D branching ratios (S & D tagging)

24 24 M. Selen, DOE Visit, 2004 Absolute D branching ratios (S & D tagging)

25 25 M. Selen, DOE Visit, 2004 D  e  Tagging cleans things SL decays up a lot:

26 26 M. Selen, DOE Visit, 2004 SL branching fractions with CLEO-c now (57.2 pb -1 )

27 27 A first analysis for Doris & Jim 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 +  K  and determine the phase shift near the K* pole but FOCUS did not attempt to measure the variation of s- wave phase with K  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? Studying hadronic physics in charm semileptonic decay

28 28 M. Selen, DOE Visit, 2004 Interference in D +  K*  Data MC K*  interferes with S- wave K  and creates a forward-backward asymmetry in the K* decay angle with a mass variation due to the varying BW phase F-B asymmetry The S-wave amplitude is about 7% of the (H 0 ) K* BW with a 45 o relative phase Focus “ K* ” signal The same relative phase as LASS matches model -15% F-B asymmetry!

29 29 M. Selen, DOE Visit, 2004 Learning more about the s-wave amplitudes const amp LASS amp 25 MeV bins M(K  ) The higher K  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 events  CosV const amp LASS amp   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.

30 30 M. Selen, DOE Visit, 2004 Related SL physics 1.Does s-wave interference occur in decays such as D  e   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  Ke A journey of 1000 miles begins with a single step …. From 60 pb -1 CLEO-c Data MC Even a totally un-cut sample has a beautiful K* signal that is well simulated Doris and Jim are starting to learn the ropes of doing a CLEO-c analysis Doris is spending about half of her time at Cornell

31 31 M. Selen, DOE Visit, 2004 Involvement in CLEO-c: CLEO Spokesman: Mats (with David Cassel) CLEO Run Manager : Topher Trigger Hardware : Topher, Norm, Paras Physics : Everyone Analyses: D S  (BR, double partial recon) : Jeremy (GG - finished) D 0  K  e (Mixing Analysis) : Chris (MS - finishing) D 0  K S  0  0 (BR & Dalitz Analysis): Norm, Bob, Topher, Mats D 0  K + K   0 (BR & Dalitz Analysis) : Paras, Bob (MS) D 0  +    0 (Dalitz Analysis) : Charles (MS – finished*) New UIUC Involvement: Jim Wiss & Doris Kim Summary Future looks great!


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