uiuc – hep: cleo taskweb.hep.uiuc.edu/home/mats/talks/2004/doe_cleo_04.pdfhep: cleo task mats...

M. Selen, DOE Visit, 2004 1

UIUC UIUC –– HEP: HEP: CLEO TaskCLEO Task

Mats Selen Aug 5, 2004

m2(π+π−) (GeV2)

m2 (

π+ π0 )

(GeV

2 )


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→φπ (BR, double partial recon) : Jeremy (GG - finished)D0→K−eν (Mixing Analysis) : Chris (MS - finishing)D0→KSπ0π0 (BR & Dalitz Analysis) : Norm, Bob, Topher, MatsD0→K+K−π0 (BR & Dalitz Analysis) : Paras, Bob (MS)D0→π+π−π0 (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 → Kπeυ (more later)


TRCR

Mixer/ShaperBoards

TILE(8)

ASUM

QVME

TILE (16)

ASUM

AXTR(16) AXX(16)

DR3 - TQT

STTR(12)

TRCR

L1D

G / CAL

DFC

CLEO

Ana

log

Gates

ctrl.

Mixer/Shaper Crates (24)

QVME

TPRO(2)

TCTL

TIM

DM/CTL

TIM

DM/CTL

TIM

DM/CTL

TPRO(4) TIM

DM/CTL

TIM

DM/CTL

AXPR

CCGL

SURF

SURF

Drift Chamber Crates

Axi

al tr

acke

rSt

ereo

trac

ker

Bar

rel C

CEn

dcap

CC

CC

Dig

ital

Leve

l 1 d

ecis

ion

Flow

con

trol

& G

atin

g

DAQ

The CLEO-c Trigger


What it Looks Like(all more or less alike to untrained eye)


CLEO-II.V

DS→φπ(Jeremy Williams, GG)

• Badly measured at present: World average B(DS→φπ ) = (3.6 ± 0.9)%• Calibrates other DS decays: Equivalent of D0→K−π+ for D0 decays.

Some DSome DSS branching fractionsbranching fractions Some DSome D00 branching fractionsbranching fractions


Double Partial Reconstruction Approach:

N(DS→φπ)Need to evaluateN(DS)

Look for B0 → DS*+ D*−

DS γ πs D0

DS γ πs (Kπ…) Use to find N(D*S) from B →DS* D*

(1)

DS γ πs D0

Use to find N(D*) from B →DS* D*(φπ…) γ πs D0(2)

Using the fact that N(D*S) = N(D*) from B →DS

* D*

to relate (1) and (2) and find B(DS→φπ)


SignalBackgroundTotal


Preliminary new CLEO results:B(DS→φπ ) = (2.45 ± 0.42 ± 0.19)%


D0→ Keν (Mixing)Chris Sedlack & MS

CLEO-II.V

Right Sign Signal (RS)D*+ → π+ D0; D0 → K− e+ν

D*+ → π+ D0; D0 → D0; ; D0 → K+ e−ν Wrong Sign Signal (WS)

Some other π+ ; D0 → K+ e−ν Example of Wrong Sign Background

Hard part: Telling WS signal from backgroundHard part: Telling WS signal from backgroundChris’ solution: Neural Net looking at a variety of kinematic vaChris’ solution: Neural Net looking at a variety of kinematic vars.rs.


Training & Training & Evaluating Evaluating the Nets:the Nets:

WS SignalWS Signal WS BackgroundWS Background

r r


Fit for mixed & unmixed yields Fit for mixed & unmixed yields using proper lifetime distribution:using proper lifetime distribution:

Get signal and background shapes from MC. Get signal and background shapes from MC.

RMIX = 1.1 ± 0.76 %

Example fit of partial data sampleExample fit of partial data sampleStudying cuts & systematics beforeStudying cuts & systematics before

opening the box on rest of dataopening the box on rest of data


D0→ Ksπ0π0 Dalitz(Norm, BIE & MS)

CLEO-II.V+III

S/(S+B) ~ 70%S ~ 700

m2 (

π0 π0 )

(GeV

2 )

m2(ΚSπ0)RS (GeV2)

m2(π0π0) (GeV2)0 1 2

K*(890) + K0(1430) + f0 + NR

m2(π0π0) (GeV2)0 1 2

K*(890) + K0(1430) + f0 + NR + σ

Lots more workto do !

• Complement KSπ−π+ analyses• Good place to search for low mass ππ

• No ρ →π0π0 to get in the way!• Norm re-writing code• Switching to CLEO-c data


D0→K−K+π0 Dalitz(Paras Naik, BIE & MS)

CLEO-IIINew method for measuring CKM phase γ by looking at B–

→ D0 K–, where D0 → K* K. Phys.Rev. D67 (2003) 071301, Grossman, Ligeti, & SofferNeeds a measurement of the strong phase difference δD between D0 → K*+ K– and D0 → K*– K+.D0 → K+ Κ– π0 is a great place to measure δD via interference!

– Phys.Rev. D68 (2003) 054010, Rosner & Suprun

Dalitz analysis - Resonant substructurePrevious D0 → K+ K– π0 branching ratio measurement (CLEO II) can be revisited.

γ

α

β

Vcd Vcb*

Vud Vub* Vtd Vtb

*B(D0 ⇒ K+ K– π0) = (0.14 ± 0.04)%

CLEO II result / PDG Value, 151 ± 42 events, 2.7 fb-1

Phys.Rev. D54 (1996) 4211, Asner, et al.


Signal Fraction ≈ 77.4%Signal Events ≈ 565565

(in the signal region)

mΚ+Κ−π0 (GeV/c2)

Both D0’s and D0’s plotted“K+” is really K− for a D0, etc…

K*−

K*+

φ

mΚ

+ π02

(GeV

/c2 )

2

mΚ−π02 (GeV/c2)2

CLEO III CLEO III ϒ(4S) Region: : 8.965/fb8.965/fb

726 points

K± Κm π0

signal region(after selection criteria)

Dominant resonances:K*± (892 MeV/c2) φ (1019 MeV/c2)

D*+ → π+ D0

K+ K– π0

γ γ

→→

DATA

DATA

Data and Dalitz PlotData and Dalitz Plot


K*+

mΚ+π02 (GeV/c2)2

φmΚ+Κ−2 (GeV/c2)2

Dal

itz F

it Pr

ojec

tions

Dal

itz F

it Pr

ojec

tions

K*− mΚ−π02 (GeV/c2)2DATA


Dalitz Plot FitDalitz Plot FitPreliminary!!!

Errors only from fit statistics

223.10 ± 7.885.8390 ± 0.4506nonresonantnonresonant102.80 ± 13.270.6157 ± 0.0573φ φ (1020)(1020)331.28 ± 10.100.5220 ± 0.0541K*(892)K*(892)--Fixed to 0Fixed to 1KK**(892)(892)++phase phase θθamplitude amplitude aaResonanceResonance

CLEO IIICLEO III

Just when things were humming along…- disk crash- still recovering, taking opportunity to rewrite muchof analysis code (i.e. make it better etc).


D0→π−π+π0

(Charles Plager)

CLEO-II.V

m2(π+π−) (GeV2)

m2 (

π+ π0 )

(GeV

2 ) S/(S+B) ~ 80%

S ~ 1100

No contribution from σ(500) at ~1% level2.7±0.9±1.777±8±111.03±0.17±0.31NR

32.3±2.1±2.2−4±3±40.65±0.03±0.04ρ−π+

23.9±1.8±4.610±3±30.56±0.02±0.07ρ0π0

76.5±1.8±4.80 (fixed)1 (fixed)ρ+π−

Fit FractionPhaseAmplitude

** PRD in the works **** PRD in the works **

m2(π+π0) (GeV2) 0 1 2 3

m2(π−π0) (GeV2) 0 1 2 3

m2(π+π−) (GeV2) 0 1 2 3


CLEO-c

The Future of Charm Physics: CLEO-c

ψ(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)

4140~S

ψ(3100), 1 fb-1 & ψ(3686) ~1 Billion J/ψ decays(170 times MARK III, 20 times BES II)


CLEO-c What’s new ?


The Future of Charm Physics: CLEO-c

Heavy Flavor Physics: “overcome QCD roadblock”

Leptonic decays → decay constants• CLEO-c: precision charm absolute Br measurements

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.


CLEO-c will soon have 50x more data than this!


Single & Double Tagging:e+ e−

0D

0D

π−

π+

K+

Κ−


Absolute D branching ratios (S & D tagging)


Tagging cleans things SL decays up a lot:

D→πeυ


SL branching fractions with CLEO-c now (57.2 pb-1)

27

A first analysis for Doris & Jim

Studying hadronic physics in charm semileptonic decay0. The lack of final state interactions makes semileptonic decay a

particularly clean environment for studying hadronic physics. Anexample 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?


Interference in D+→ K* µνDataMC

F-B

asy

mm

etry

(m Kπ )

Focus “K*” signal

matches model

-15% F-B asymmetry!

K* µν interferes with S- wave Kπand 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 (H0) K* BW with a 45o relative phase

The same relative phase as LASS


Learning more about the s-wave amplitudes

const ampLASS amp

25 MeV bins

M(Kπ)

Re

ImBW

α

The higher Kπ 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

even

ts×C

osV

const ampLASS amp

ΓΓ

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.


Related SL physics1. 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 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

3. For that matter-- what is the q2 dependence of the K* helicity amplitudesAll experimentalists have been assuming the spectroscopic pole formsBut 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

Doris is spending about half of her time at Cornell

Km π

From 60 pb-1

CLEO-cDataMC

Even a totallyun-cut sample has a beautiful K* signal that is well simulated


SummaryInvolvement in CLEO-c:• CLEO Spokesman : Mats (with David Cassel)• CLEO Run Manager : Topher• Trigger Hardware : Topher, Norm, Paras• Physics : Everyone

Analyses:DS→φπ (BR, double partial recon) : Jeremy (GG - finished)D0→K−eν (Mixing Analysis) : Chris (MS - finishing)D0→KSπ0π0 (BR & Dalitz Analysis) : Norm, Bob, Topher, MatsD0→K+K−π0 (BR & Dalitz Analysis) : Paras, Bob (MS)D0→π+π−π0 (Dalitz Analysis) : Charles (MS – finished*)

New UIUC Involvement: Jim Wiss & Doris Kim

Future looks great!

uiuc – hep: cleo taskweb.hep.uiuc.edu/home/mats/talks/2004/doe_cleo_04.pdfhep: cleo task mats...

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