Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.
UIUC – HEP: CLEO Task m2(p+p0) (GeV2) m2(p+p-) (GeV2) Mats Selen Aug 5, 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: • DS (BR, double partial recon) : Jeremy (GG - finished) • D0K-en (Mixing Analysis) : Chris (MS - finishing) • D0KS00 (BR & Dalitz Analysis) : Norm, Bob, Topher, Mats • D0K+K-0 (BR & Dalitz Analysis) : Paras, Bob (MS) • D0+-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 Ke (more later)
Mixer/Shaper Crates (24) Drift Chamber Crates Gates CLEO Mixer/Shaper Boards ctrl. DR3 - TQT G / CAL TILE (16) AXTR(16) AXX(16) Flow control & Gating DFC DAQ ASUM Analog TIM TIM Barrel CC Axial tracker QVME DM/CTL DM/CTL TILE(8) STTR(12) L1D ASUM Stereo tracker Endcap CC QVME TIM DM/CTL Level 1 decision AXPR TRCR CCGL TRCR CC Digital TPRO(4) TIM SURF SURF TPRO(2) DM/CTL TCTL TIM DM/CTL The CLEO-c Trigger
DSf (Jeremy Williams, GG) CLEO-II.V • Badly measured at present: World average B(DSf) = (3.6 ± 0.9)% • Calibrates other DS decays: Equivalent of D0K-+for D0decays. Some DS branching fractions Some D0 branching fractions
DS s D0 (1) DS s (K…) BDS* D* Use to find N(D*S) from DS sD0 (2) (…) s D0 Use to find N(D*) from BDS* D* Double Partial Reconstruction Approach: N(DS) Need to evaluate N(DS) Look for B0 DS*+ D*- Using the fact that N(D*S) = N(D*) from B DS* D* to relate (1) and (2) and find B(DS)
Preliminary new CLEO results: B(DSf) = (2.45 ± 0.42 ± 0.19)%
D*+ +D0; D0 K- e+ Right Sign Signal (RS) Wrong Sign Signal (WS) D*+ +D0; D0 D0; D0 K+ e- Some other+;D0 K+ e- Example of Wrong Sign Background D0 Ke (Mixing) Chris Sedlack & MS CLEO-II.V Hard part: Telling WS signal from background Chris’ solution: Neural Net looking at a variety of kinematic vars.
Training & Evaluating the Nets: WS Background WS Signal r r
Fit for mixed & unmixed yields using proper lifetime distribution: Get signal and background shapes from MC. RMIX = 1.1 ± 0.76 % Example fit of partial data sample Studying cuts & systematics beforeopening the box on rest of data
K*(890) + K0(1430) + f0 + NR K*(890) + K0(1430) + f0 + NR + s 0 1 2 0 1 2 m2(p0p0) (GeV2) m2(p0p0) (GeV2) S/(S+B) ~ 70% S ~ 700 D0 Ks00 Dalitz(Norm, BIE & MS) CLEO-II.V+III m2(p0p0) (GeV2) • Complement KSp-p+ analyses • Good place to search for low mass pp • No r00 to get in the way! • Norm re-writing code • Switching to CLEO-c data m2(KSp0)RS (GeV2) Lots more workto do !
a Vtd Vtb* Vud Vub* g b Vcd Vcb* D0K-K+0 Dalitz (Paras Naik, BIE & MS) CLEO-III • New method for measuring CKM phase g by looking at B– → D0 K–, where D0 → K* K. • Phys.Rev. D67 (2003) 071301, Grossman, Ligeti, & Soffer • Needs a measurement of the strong phase difference dD between D0 → K*+ K– and D0 → K*– K+. • D0 → K+K–p0is a great place to measure dD via interference! • Phys.Rev. D68 (2003) 054010, Rosner & Suprun • Dalitz analysis - Resonant substructure • Previous D0 → K+K–p0 branching ratio measurement (CLEO II) can be revisited. B(D0Þ K+K–p0) = (0.14 ± 0.04)% CLEO II result / PDG Value, 151 ± 42 events, 2.7 fb-1 Phys.Rev. D54 (1996) 4211, Asner, et al.
Both D0’s and D0’s plotted “K+” is really K- for a D0,etc… Data and Dalitz Plot CLEO III ¡(4S) Region: 8.965/fb Dominant resonances: K*± (892 MeV/c2) f(1019 MeV/c2) D*+ → p+ D0 → K+ K–p0 → gg DATA 726 points DATA K±Kmp0 signal region (after selection criteria) mK+p02 (GeV/c2)2 Signal Fraction » 77.4% Signal Events »565 (in the signal region) f K*+ K*- mK-p02 (GeV/c2)2 mK+K-p0 (GeV/c2)
mK+K-2 (GeV/c2)2 f K*+ Dalitz Fit Projections mK+p02 (GeV/c2)2 DATA K*- mK-p02 (GeV/c2)2
CLEO III Dalitz Plot Fit Preliminary!!! Errors only from fit statistics Just when things were humming along… - disk crash- still recovering, taking opportunity to rewrite much of analysis code (i.e. make it better etc).
0 1 2 3 m2(p+p0) (GeV2) D0-+0(Charles Plager) S/(S+B) ~ 80% S ~ 1100 ** PRD in the works ** CLEO-II.V m2(p+p0) (GeV2) No contribution from s(500) at ~1% level m2(p+p-) (GeV2) 0 1 2 3 0 1 2 3 m2(p+p-) (GeV2) m2(p-p0) (GeV2)
The Future of Charm Physics: CLEO-c CLEO-c y(3770) – 3 fb-1 30 million DD events, 6 million tagged D decays (310 times MARK III) Underway ! MeV – 3 fb-1 1.5 million DsDs events, 0.3 million tagged Ds decays (480 times MARK III, 130 times BES) y(3100), 1 fb-1 & y(3686) ~1 Billion J/y decays (170 times MARK III, 20 times BES II)
What’s new ? CLEO-c
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.
K+ K- e- e+ p- p+ Single & Double Tagging:
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+Kpmn and determine the phase shift near the K* pole but FOCUS did not attempt to measure the variation of s-wave phase with Kp mass because of backgrounds. • How well can Cleo-c follow the s-wave phase and amplitude variation given a yield comparable to FOCUS but with greatly reduced backgrounds? • What can we learn about interference in other 4 body semileptonic decay?
Interference in D+ K* mn F-B asymmetry -15% F-B asymmetry! matches model Focus “K*” signal DataMC K* mn interferes with S- wave Kp and creates a forward-backward asymmetry in the K* decay angle with a mass variationdue to the varying BW phase The S-wave amplitude is about 7% of the (H0) K* BW with a 45o relative phase The same relative phase as LASS
Learning more about the s-wave amplitudes 25 MeV bins const ampLASS amp const ampLASS amp eventsCosV G G Kpi mass M(Kp) 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. The higher Kp mass is where the amplitude variation is most interesting. As the s-wave phase shift passes 900 , the cosV asymmetry should reverse. We need the background free environment of CLEO-c to see this
Related SL physics DataMC From 60 pb-1 CLEO-c • Does s-wave interference occur in decays such as Dren?The FOCUS environment has far too much background to see this • What is the q2 dependence of form factors that describe the coupling to the s-wave piece? This might provide additional LQCD tests.The FOCUS q2 resolution is too poor to resolve this • For that matter-- what is the q2 dependence of the K* helicity amplitudesAll experimentalists have been assuming the spectroscopic pole forms But we know the spectroscopic poles are wrong for DKen A journey of 1000 miles begins with a single step…. Doris and Jim are starting to learn the ropes of doing a CLEO-c analysisDoris is spending about half of her time at Cornell Even a totallyun-cut sample has a beautiful K* signal that is well simulated
Summary • Involvement in CLEO-c: • CLEO Spokesman : Mats (with David Cassel) • CLEO Run Manager : Topher • Trigger Hardware : Topher, Norm, Paras • Physics : Everyone • Analyses: • DS (BR, double partial recon) : Jeremy (GG - finished) • D0K-en (Mixing Analysis) : Chris (MS - finishing) • D0KS00 (BR & Dalitz Analysis) : Norm, Bob, Topher, Mats • D0K+K-0 (BR & Dalitz Analysis) : Paras, Bob (MS) • D0+-0 (Dalitz Analysis) : Charles (MS – finished*) • New UIUC Involvement: Jim Wiss & Doris Kim Future looks great!