UIUC – HEP: CLEO Task

M. Selen, DOE Visit, 2004 1

UIUC – HEP: UIUC – HEP: CLEO TaskCLEO Task

Mats Selen Aug 5, 2004

m2() (GeV2)

m2 (

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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) D0Ke (Mixing Analysis) : Chris (MS - finishing) D0KS00 (BR & Dalitz Analysis) : Norm, Bob, Topher, Mats D0K+K0 (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)


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)


DS (Jeremy Williams, GG)

CLEO-II.V

• Badly measured at present: World average B(DS ) = (3.6 ± 0.9)%• Calibrates other DS decays: Equivalent of D0K+ for D0 decays.

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


Look for B0 DS*+ D*

Double Partial Reconstruction Approach:

N(DS)N(DS)

Need to evaluate

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

* D* to relate (1) and (2) and find B(DS)

DS s D0

DS s (K…) Use to find N(D*S) from B DS* D*

(1)

DS s D0

Use to find N(D*) from B DS* D*(…) s D0(2)


SignalBackgroundTotal


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


D0 Ke (Mixing)Chris Sedlack & MS

CLEO-II.V

Right Sign Signal (RS)D*+ + D0; D0 Ke+

D*+ + D0; D0 D0; ; D0 Ke Wrong Sign Signal (WS)

Some other + ; D0 Ke 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 vars.Chris’ solution: Neural Net looking at a variety of kinematic vars.


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.

Example fit of partial data sampleExample fit of partial data sample

RMIX = 1.1 ± 0.76 %

Studying cuts & systematics beforeStudying cuts & systematics beforeopening the box on rest of dataopening the box on rest of data


D0 Ks0 Dalitz(Norm, BIE & MS)

CLEO-II.V+III

• Complement KSanalyses• Good place to search for low mass

• No 00 to get in the way!• Norm re-writing code• Switching to CLEO-c data

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

m2 (

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(GeV

2 )

m2(S)RS (GeV2)

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0 1 2

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

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0 1 2

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

Lots more workto do !


D0KK+0 Dalitz(Paras Naik, BIE & MS)

CLEO-III New method for measuring CKM phase 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 D between D0 →

K*+ K– and D0 → K*– K+. D0 → K+ – 0 is a great place to measure D via interference!

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

Dalitz analysis - Resonant substructure Previous D0 → K+ K– 0 branching ratio measurement

(CLEO II) can be revisited.

Vcd Vcb*

Vud Vub* Vtd Vtb

*

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

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

B(D0 K+ K– 0) = (0.14 0.04)%


Signal Fraction 77.4%

Signal Events 565565(in the signal region)

m (GeV/c2)

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

Data and Dalitz PlotData and Dalitz Plot

K*

K*

m

2

(GeV

/c2 )2

m2 (GeV/c2)2

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

726 points

K 0

signal region(after selection criteria)

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

D*+ → + D0

K+ K– 0

→→

DATA

DATA


Dal

itz F

it Pr

ojec

tions

Dal

itz F

it Pr

ojec

tions

K*m2 (GeV/c2)2

DATA

K*

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m2 (GeV/c2)2


Dalitz Plot FitDalitz Plot FitPreliminary!!!

Errors only from fit statistics

ResonanceResonance amplitude amplitude aa phase phase

KK**(892)(892)++ Fixed to 1 Fixed to 0K*(892)K*(892)-- 0.5220 0.0541 331.28 10.10(1020)(1020) 0.6157 0.0573 102.80 13.27

nonresonantnonresonant 5.8390 0.4506 223.10 7.88

CLEO IIICLEO 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).


D0+0

(Charles Plager)

CLEO-II.V

m2() (GeV2)

m2 (

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(GeV

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

S ~ 1100

No contribution from (500) at ~1% level

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0 1 2 3m2() (GeV2)

0 1 2 3m2() (GeV2)

0 1 2 3

Amplitude Phase Fit Fraction

+ 1 (fixed) 0 (fixed) 76.5±1.8±4.8

0 0.56±0.02±0.07 10±3±3 23.9±1.8±4.6

0.65±0.03±0.04 4±3±4 32.3±2.1±2.2

NR 1.03±0.17±0.31 77±8±11 2.7±0.9±1.7

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


The Future of Charm Physics: CLEO-c

(3770) – 3 fb-1

30 million DD events, 6 million tagged D decays(310 times MARK III)

MeV – 3 fb-1

1.5 million DsDs events, 0.3 million tagged Ds 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)

4140~S

Underway !

CLEO-c


CLEO-c What’s new ?


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


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


Single & Double Tagging:e+ e

0D

0D

+

K+


Absolute D branching ratios (S & D tagging)


De

Tagging cleans things SL decays up a lot:


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

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


Interference in D+ K* DataMC

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

asy

mm

etry

(m K

The S-wave amplitude is about 7% of the (H0) K* BW with a 45o relative phase

Focus “K*” signal

The same relative phase as LASS

matches model

-15% F-B asymmetry!


Learning more about the s-wave amplitudes

const ampLASS amp

25 MeV bins

M(K)

Re

ImBW

The higher K 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

Cos

V

const ampLASS 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.


Related SL physics1. Does s-wave interference occur in decays such as De

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 amplitudes All experimentalists have been assuming the spectroscopic pole forms But we know the spectroscopic poles are wrong for DKe

A journey of 1000 miles begins with a single step….

Km

From 60 pb-1 CLEO-c

DataMC

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


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) D0Ke (Mixing Analysis) : Chris (MS - finishing) D0KS00 (BR & Dalitz Analysis) : Norm, Bob, Topher, Mats D0K+K0 (BR & Dalitz Analysis) : Paras, Bob (MS) D0+0 (Dalitz Analysis) : Charles (MS – finished*)

New UIUC Involvement: Jim Wiss & Doris Kim

Summary

Future looks great!

UIUC – HEP: CLEO Task

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