todd k. pedlar the ohio state university for the cleo collaboration recent results in b and d decays...

Todd K. PedlarTodd K. Pedlar

The Ohio State UniversityThe Ohio State Universityfor the CLEO Collaborationfor the CLEO Collaboration

Recent Results in B and D Decays from CLEO

BEACH 2002, Vancouver

June 26, 2002

June 26, 2002

Todd K. Pedlar The Ohio State

University

The Rare Charmless Decays B The Rare Charmless Decays B K KSS00 and and

KK**

OutlineOutline

The Color Suppressed Decay B The Color Suppressed Decay B DD00 and Isospin Analysis of B and Isospin Analysis of B D D

Introduction

New Results from CLEO in D MixingNew Results from CLEO in D Mixing

ConclusionsConclusions

June 26, 2002


University

IntroductionIntroduction• These data were collected These data were collected

with the CLEO detector with the CLEO detector which observed symmetric which observed symmetric ee++ee-- collisions at the collisions at the (4S) (4S) resonance, Eresonance, Ecmcm = 10.56 = 10.56 GeVGeV

• The CLEO detector provides The CLEO detector provides both excellent tracking both excellent tracking resolution and efficiency, resolution and efficiency, as well as superb as well as superb electromagnetic electromagnetic calorimetry.calorimetry.

• The hadronic B analyses The hadronic B analyses presented in this talk are presented in this talk are based on the CLEO II/II.V based on the CLEO II/II.V data sets of 9.67M BB pairsdata sets of 9.67M BB pairs

• The D mixing result is The D mixing result is based on the 9 fbbased on the 9 fb-1-1 CLEO CLEO II.V sampleII.V sample

June 26, 2002


University

The Color Suppressed Decay B The Color Suppressed Decay B DD00 and Isospin Analysis of B and Isospin Analysis of B D D

June 26, 2002


University

Color Suppressed Decays: Color Suppressed Decays: BBDD00•The Internal spectator The Internal spectator

diagram is color-suppressed. diagram is color-suppressed.

•Observation of color-Observation of color-suppressed decays is an suppressed decays is an important input for the important input for the theoretical understanding of theoretical understanding of hadronic B decayshadronic B decays

•Until recently, only color-Until recently, only color-suppressed decays into suppressed decays into charmonium states had been charmonium states had been observed.observed.

First Observations of BFirst Observations of B00 D D0(*)0(*) 00 have have been published by both Belle (PRL 88 been published by both Belle (PRL 88 052002) and 052002) and CLEO (PRL 88 062001)CLEO (PRL 88 062001)

Favored

Suppressed

June 26, 2002


University

• Selection is based on Selection is based on reconstruction of Dreconstruction of D00 in in three decay modes (Kthree decay modes (K-- KK-- and K and K---- combined w/ prompt combined w/ prompt 00’s’s

• Event yields obtained Event yields obtained using an extended using an extended unbinned ML fitunbinned ML fit

Color Suppressed Decays: Color Suppressed Decays: BBDD00

Event shape B helicity angle

22BbeamB pEM

beamB EEE

Free parameters: Nsig, Ncont, Nother

BB

Four input variables at right: PDFs for each obtained from off-res data + signal, generic BB and continuum MC.

June 26, 2002


University

Br(B0D00x

+0.36-0.32

hep-ex/0110055,Phys. Rev. Lett. 88 062001

Color Suppressed Decays: Color Suppressed Decays: BBDD00

(B0D00

June 26, 2002


University

• With the observation of the color suppressed With the observation of the color suppressed decay, all three Ddecay, all three D decays had been decays had been measured, making possible the estimation of measured, making possible the estimation of the strong phase between the contributing the strong phase between the contributing isospin amplitudesisospin amplitudes

• CLEO set out to measure the color-favored CLEO set out to measure the color-favored modes again, in order to improve the precision modes again, in order to improve the precision with which answers about this angle could be with which answers about this angle could be statedstated

Isospin Isospin Analysis of BAnalysis of BDD decaysdecays

June 26, 2002


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Isospin Isospin Analysis of BAnalysis of BDD decaysdecays• In BIn BDD decays, there are two isospin amplitudes decays, there are two isospin amplitudes

(I=1/2 and 3/2) which contribute to the decay process(I=1/2 and 3/2) which contribute to the decay process

• We can write the amplitudes for the three BWe can write the amplitudes for the three BDD decays as follows:decays as follows:

2/32/1000

2/32/10

2/3

0

3

2

3

2)(

3

1

3

2)(

)(

AADBA

AADBA

ADBA

)(2)(

)(

00

0

DADA

DA

June 26, 2002


University

Isospin Isospin Analysis of BAnalysis of BDD decaysdecays• We may express the two amplitudes in the following We may express the two amplitudes in the following

manner:manner:

• And the phase difference between these amplitudes And the phase difference between these amplitudes thus:thus:

)(2

1)()(

2

3||

)(||

00022/1

022/3

DDDA

DA

||4

)(6)()(3)cos(

2/32/1

000

AA

DDDI

cos cos II 1 1 final final state interactions.state interactions. Current PDG values, cos Current PDG values, cos

II 1 by just over 11 by just over 1

June 26, 2002


University

• CLEO has re-measured the two color-CLEO has re-measured the two color-favored Bfavored BDD decays, B decays, B--DD00- - and Band B00DD++--

• In these measurements DIn these measurements D00 is reconstructed is reconstructed as before in 3 modes, (Kas before in 3 modes, (K-- K K-- and K and K----

and D and D++ in one (K in one (K--

• Yields are obtained by simple ML fits to the Yields are obtained by simple ML fits to the data, which are subject to a very few cuts in data, which are subject to a very few cuts in E, event shape variables, etc, to attack BB E, event shape variables, etc, to attack BB and continuum backgrounds, respectivelyand continuum backgrounds, respectively


June 26, 2002


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• The results of these measurements The results of these measurements reflect improved precision with reflect improved precision with respect to the current PDG respect to the current PDG averagesaverages

• These measurements are These measurements are systematics, not statistics systematics, not statistics dominated. The two most dominated. The two most significant syst. errors are external significant syst. errors are external in nature:in nature:

– Individual D branching fractions Individual D branching fractions (CLEO-c ?)(CLEO-c ?)

– ff0000 and f and f+- +- errors (help from BaBar errors (help from BaBar / Belle ? )/ Belle ? )


Br(Br(BB--DD00--xxxx (PDG) (PDG)

Br(Br(BB00DD++--

xxxx (PDG) (PDG)

June 26, 2002


University

• In addition, we have determined the strong phase In addition, we have determined the strong phase difference cos difference cos II. .

• Using the combined measurements of Using the combined measurements of Br(BBr(B00DD0000by by CLEO and Belle, CLEO and Belle, 2.92 2.92 0.45 x 10 0.45 x 10-4-4, we have obtained, we have obtained

hep-ex/0206030,Submitted to PRD-RC


)%90(1.385.16

863.0cos

oo

030.0

038.0

035.0

036.0

023.0

024.0

CLI

I

from unity

June 26, 2002


University

The Rare Charmless Decays BThe Rare Charmless Decays B00 K KSS00and Kand K**

June 26, 2002


University

BB00 K KSS00 and K and K**

• Recently there have been several Recently there have been several observations of charmless two-body decays B observations of charmless two-body decays B K K at CLEO and at the B factories at CLEO and at the B factories

• The pseudoscalar-vector companions to this The pseudoscalar-vector companions to this decay, B decay, B K K** and B and B K K, provide useful , provide useful additional information (including, ultimately, additional information (including, ultimately, additional avenues for observing CP) additional avenues for observing CP)

• Here we present the observation of BHere we present the observation of B00 KKSS

00, and of B, and of B00 K K*+*+, based on the full , based on the full CLEO II/II.V data set of 9.67 M BB pairs. CLEO II/II.V data set of 9.67 M BB pairs.

June 26, 2002


University

• In the analysis of KIn the analysis of KSS00 , K, KSS are selected by requiring are selected by requiring

2.52.5 mass consistency and well-measured displaced mass consistency and well-measured displaced secondary verticessecondary vertices

• In analyzing both the KIn analyzing both the KSS00 and K and K++ final states, very final states, very

loose cuts are first applied on loose cuts are first applied on E, ME, MBCBC, cos , cos sphsph, cos , cos BB and a Fisher discriminant formed from a combination of and a Fisher discriminant formed from a combination of event shape variables.event shape variables.

• Signal yields are obtained from a ML fit using PDFs for Signal yields are obtained from a ML fit using PDFs for the above variables as in the color suppressed analysis.the above variables as in the color suppressed analysis.

• The KThe K** contribution to each final state sample above is contribution to each final state sample above is obtained through simultaneous analyses of the Dalitz obtained through simultaneous analyses of the Dalitz plotsplots


June 26, 2002


University

• We observe the rare B We observe the rare B decay Bdecay B00 K KSS

00 (without regard to (without regard to resonant resonant substructure)substructure)with a with a signal significance of signal significance of 8.18.1hep-ex/0206024

Submitted to Phys. Rev. Lett.


Br(Br(BB00KKSS00--

(stat.)(stat.)(syst.)(syst.)xx

June 26, 2002


University

• Simultaneous analysis of the Simultaneous analysis of the Dalitz plots for both KDalitz plots for both KSS

00 and and KK++ topologies reveals the topologies reveals the process process BB00 K K*+*+ (892) (892)with with a signal significance of 4.6a signal significance of 4.6

• Most predictions for this BR are in Most predictions for this BR are in the range 2-14 x 10 the range 2-14 x 10-6-6. Flavor . Flavor SU(3) predictions (Chiang & SU(3) predictions (Chiang & Rosner) obtain 17.3 x 10Rosner) obtain 17.3 x 10-6 -6

(assuming maximal P-T (assuming maximal P-T interference)interference)


Br(B0K*+-(stat.)(syst.)x

K*/KS 20%

June 26, 2002


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New Results from CLEO in D MixingNew Results from CLEO in D Mixing

June 26, 2002


University

Updated D mixing results from Updated D mixing results from CLEOCLEO

• It’s not It’s not completelycompletely different – after all, we’re different – after all, we’re looking at the same final state of Klooking at the same final state of Kss

• This analysis is based on 9 fbThis analysis is based on 9 fb-1-1 of data collected of data collected with the CLEO II.V configuration (with SVX)with the CLEO II.V configuration (with SVX)

• DD** with p > 2 GeV are selected (favoring with p > 2 GeV are selected (favoring continuum-produced D* pairs), and the resulting continuum-produced D* pairs), and the resulting DD00 are flavor tagged using the are flavor tagged using the ss from D from D**DD00ss

• Reconstruction of the D* takes advantage of the Reconstruction of the D* takes advantage of the very small vertical extent of the beam spotvery small vertical extent of the beam spot

June 26, 2002


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D mixing - motivationD mixing - motivation

xx mixing: mixing: Channel for new Channel for new physics…physics…

yy mixing: mixing: SM background…SM background…

2

yM

x

* New physics will enhance x but not y* New physics will enhance x but not y* CP violation in mixing would be a * CP violation in mixing would be a smoking smoking gungun for new physics for new physics

Two types of mixing:Two types of mixing:

June 26, 2002


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D mixing - methodsD mixing - methods

Ultimately, need to fit Ultimately, need to fit proper decay timeproper decay time in order to distinguish mixing (both in order to distinguish mixing (both xx and and yy) from doubly Cabibbo-suppressed (DCS) decays…) from doubly Cabibbo-suppressed (DCS) decays…

Complication: phase difference, K, between CF and DCS amplitudes can lead to observable quantities x’ and y’, related to x and y by a rotation

0D

0DdoublydoublyCabibboCabibbosuppressedsuppressed((RRDD))

mixingmixing((xx22+y+y22))

CabibboCabibboFavoredFavored (CF)(CF)

““Wrong sign”Wrong sign”

K

Notation:Notation: ““right-signed” (RS)right-signed” (RS) => Cabibbo- => Cabibbo-favored decaysfavored decays

““wrong-signed” (WS)wrong-signed” (WS) => Mixing or => Mixing or doubly Cabibbo-suppressed decaysdoubly Cabibbo-suppressed decays

Look for mixing in “wrong signed” (WS) Look for mixing in “wrong signed” (WS) decays of decays of DD00……

June 26, 2002


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Current D Mixing LimitsCurrent D Mixing Limits

“Typical” non-SM predictions (many higher and lower, however)

“Typical” upper SM predictions

If If KK unknown, WS unknown, WS hadronic limits must hadronic limits must be weakened to be weakened to accommodate any accommodate any possible rotationpossible rotation

SU(3) flavor SU(3) flavor symmetry badly symmetry badly broken=> Final broken=> Final state interactions state interactions expected to be expected to be importantimportant

- KK measurements are starting to cut measurements are starting to cut into range of some non-SM predictions into range of some non-SM predictions - LONG wayLONG way to go before we hit SM to go before we hit SM levelslevels

June 26, 2002


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DD0 0 KKss00 Motivation Motivation

• Measure x and y (not x’2 and y’)

• RS and WS occupy the SAME Dalitz plot: Thus making possible a measurement of relative strong phase between CF and DCS

• Only mode with sensitivity to sign of x!

• y sensitivity comparable to CP eigenstate (eg., D0->K+K-) analyses •Complicated Dalitz plot

and proper time fit required

June 26, 2002


University

preliminary preliminary

DD0 0 KKss00 PreliminaryPreliminary results results

June 26, 2002


University

73529900 SKDN


June 26, 2002


University


The significance of the overall fit drops by 5 when WS K* is forced to zero.

June 26, 2002


University

o4

1158

*

054.0030.0

050.0016.0

*

) 11152(

029.0131.0Α

K

K

o3

532

*

05.007.0

*

) 2149(

0.04 05.068.1Α

K

K

1680,1430,1430

,1370 ,1270 ,980

, , , , resonant,-non

*20

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*0*

KKK

fff

KK

0

0.1Α00

00

S

S

K

KPhase convention:Phase convention:

Final fit with 10 contributing Final fit with 10 contributing intermediate states:intermediate states:

Right signRight sign

First measurement of strong First measurement of strong phase difference between CF phase difference between CF and DCS!and DCS!

o 143* K

% 2.03.06.0

||

||2

2*0

RS

WSWS A

AKDR

Wrong signWrong sign


Needed for extraction of in BDK

Submitted to PRL

June 26, 2002


University

Summary: D Mixing via Summary: D Mixing via DD00KKss

00

• We have observed several contributions to the We have observed several contributions to the substructure in Dsubstructure in D00KKss

00including a wrong sign including a wrong sign DD00KK*+*+contribution at the 5contribution at the 5 level, which must level, which must arise from either D mixing or DCSDarise from either D mixing or DCSD• Separate fits for DSeparate fits for D00 and D and D00 tags have been tags have been performed, with no statistically significant difference performed, with no statistically significant difference observed (no CPV evident)observed (no CPV evident)

• In addition, CLEO will have RIn addition, CLEO will have RDD(I.e. the DCSD part of (I.e. the DCSD part of the WS/RS ratio), x, y, and Athe WS/RS ratio), x, y, and ACPCP measurements from measurements from the time dependent version of this analysis very the time dependent version of this analysis very soonsoon

June 26, 2002


University

ConclusionsConclusions• CLEO has observed the color suppressed decay CLEO has observed the color suppressed decay BB00

DD00and made new measurements of color-allowed and made new measurements of color-allowed decays decays BB00 D D++ and and BB-- D D00.. We have also presented a We have also presented a measurement of cos measurement of cos II which represents a strong which represents a strong suggestion of final state interactions in suggestion of final state interactions in B B D Ddecays.decays.

• We have presented new results for We have presented new results for BB00 K KSS00 and and

through an analysis of the Dalitz plot, a result for through an analysis of the Dalitz plot, a result for BB00 KK*+*+

• We have presented a We have presented a preliminarypreliminary update of our update of our measurements of D mixing, this time using measurements of D mixing, this time using DD00KKss

00a a promising channel for sensitive measurements of the promising channel for sensitive measurements of the mixing parameters x and y. Time dependent analysis of mixing parameters x and y. Time dependent analysis of this mode is forthcoming.this mode is forthcoming.

todd k. pedlar the ohio state university for the cleo collaboration recent results in b and d decays...

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