Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed

Steven Blusk, Syracuse University 1

Hadronic Charm Decays in CLEO

Steven Blusk, Syracuse University(on behalf of the CLEO Collaboration)

XXXIII International Conference on High Energy Physics

July 26 – August 2, 2006, Moscow, Russia Introduction Ds Scan D0, D± Branching Fractions

Cabibbo favored Cabibbo-suppressed

Ds Branching Fractions Inclusive , and Exclusive CF

Amplitude Analyses D0 ++

D0 K+K-0

Summary

Other CLEO Charm TalksLeptonic Charm decays Sheldon Stone (this session) Semileptonic Charm decays Yongsheng Gao Session 10-3DCSD, DK S. Blusk, Session 8-2Y(4260) at CLEO Ian Shipsey, Session 9-3Charmonium decays at CLEO Tomasz Skwarnicki, Session 9-4


The Charm Landscape Near Threshold

DD

S SD D* *D D

*S SD D * *

S SD D

*D D

(3770) (4160)

(3770)DD Pure C=-1 No addn’l particles Low multiplicity Clean recon.

CLEO

Lep & SL decays isolate the strong interaction effectscritical checks on LQCD, modelsHadronic BF’s needed for normalization of B BF’s, strong phases, strong int. effects+…

E>3940 MeV for Ds

production

Ds Scan – next 2 slides

e+ e-DD

(3770)DD


No need to reconstruct D*, as Mbc differentiates event types.

For DD and DsDs cut on E and use Mbc to extract yields.

For other event types cut on Mbc and use invariant mass to extract yield.

DD

DsDs*

DD DsDs

DD*

D*D*

E > = 0

Ecm=4160 MeV Simulations

The Ds Scan

12 scan points~60 pb-1 (total)

Scan the region 3970-4260 MeV Optimize Ds physics Study D(s) XS in this region Confirm Y(4260)

Ecm=4160 MeV selected Additional 180 pb-1 collected at 4160 MeV

DD

*

SSD D

S SD D

* *S SD D

*DD * *D D


Inclusive DInclusive Hadrons

Exclusive DD

Total Charm & Multibody

D*+

D0

X

e+

e-

D0 Momentum (GeV/c)

DD

*DD

* *D D

D*D

No DD observed (using similar MM

technique)

Three ways to determine hadronic cross-section: Inclusive hadronic event counting Inclusive D meson Exclusive D(*) D(*) final states

Are there multi-body events?Look for D*+Dwith p(D*)<400 MeV (below kinematic limit for D*D* events)

Clear that exclusive final states do not saturate the total charm XS.


D Hadronic BF (Cabibbo-Favored)

2i j ij

DDij i j

ij ji

j ij

N NN

N

NB

N

Since ij i j, correlated systematics cancel in NDD

To first order, Bi is independent of tag modes’ efficiencies, ,L.

Use 3 D0 and 6 D+ modes - Count #Single Tags (ST): Ni

obs (9 modes) - Count # Double tags (DT): Nij

obs (45 pairs of modes)

Expected #ST:Expected #DT:

expij i j ijDDN N B B

exp 2i i iDDN N B

Double Tagged, 281 pb-1

Update from 57 pb-1 to 281 pb-1 underway

Some systematics still being studied.

O(1%) stat & syst errors on golden modes in sight…

Preliminary


D Hadronic BF (Cabibbo-Suppressed)B (10-3) CLEO-c PDG (10-3)

1.39 ± 0.04 ± 0.03 1.38 ± 0.05

0.79 ± 0.05 ± 0.04 0.84 ± 0.22

13.2 ± 0.2 ± 0.5 11 ± 4

7.3 ± 0.1 ± 0.3 7.3 ± 0.5

9.9 ± 0.6 ± 0.7 ---

4.1 ± 0.5 ± 0.2 ---

1.25 ± 0.06 ± 0.08 1.33 ± 0.22

3.35 ± 0.10 ± 0.20 3.1 ± 0.4

4.8 ± 0.3 ± 0.4 ---

11.6 ± 0.4 ± 0.7 ---

1.60 ± 0.18 ± 0.17 1.82 ± 0.25

+0 ++- +00

++-0 +++-- ++

+- 00

+- +-0+- +-

+-0

+- 00 Isospin Analysisof final stateA(I=2)/A(I=0) = 0.420±0.014 ±0.010Strong phase shift: = (86.4±2.8±3.3)0

Large FSI in D decays..Other first/improved BF’sD00, +-, D++


Inclusive D(s) Hadronic Decays Inclusive ss rates expected to be higher for Ds

+ than D0/D+.

Ds(,+X ingredient in one method of measuring Bs fraction in Y(5S) decays.

CLEO-c measurements with 281 pb-1 D0/D+ (3770 MeV) and 71 pb-1 Ds

+ (4170 MeV).

Fully reconstruct one D(s), search for , on other side, subtract sideband.

includes feed-down from ´.

152K tags228K tagsD0 X D+ X Ds

+ X3K tags

B (%) PDG

D0 9.4 ± 0.4 ± 0.6 <13%

D 5.7 ± 0.5 ± 0.5 <13%

Ds 23.7 ± 3.1 ± 1.9 -

B ´ (%) PDG

D0 2.6 ± 0.2 ± 0.2 -

D 1.0 ± 0.2 ± 0.1 -

Ds 8.7 ± 1.9 ± 0.6 -

B (%) PDG

D0 1.0 ± 0.1 ± 0.1 1.7 ± 0.8

D 1.1 ± 0.1 ± 0.2 <1.8

Ds 16.1 ± 1.2 ±0.6 18 +15 -10

Much larger rates for Ds as anticipated.


Exclusive Ds Hadronic Decays

Mode DS+ DS-

KsK+ 1055±39 928±37

K+K-+ 4316±89 4350±89

K+K-+ 1160±85 1251±84

+-+ 970±80 947±78

+ 547±50 570±50

+ 362±23 372±24

Double Tag Yields

Ds hadronic BF’s, particular , critical. BF~20% Follows very similar procedure as for (3770)DD

inv vs Mbc driven by DsDs* kinematics.

Look at 6 modes: KsK+, K+K-+, K+K-+, +-+,+,+

Double Tag yieldsdetermined via sidebandsubtraction

Signal region

Sideband regions


Ds Hadronic BF’sLikelihood fit used to extract BF’s

Errors already << PDG

Preliminary

Ds+ partial BF:CLEO-c (±10 MeV around ) 1.98±0.12±0.09 (~x2+O(10%)) (Preliminary !!)

DsK+Kyield vsK+K- mass

Ds is a critical measurement, but must be careful Interference & cross-feed with nearby f0(980) is an issue Define a partial BF within some window around the . This is actually what experimentalists need

For reference: Ds+

PDG06: 4.4±0.6BaBar: 4.8±0.5±0.4 (1.008<M(K+K-)<1.035 GeV)


D+ +-+ Dalitz Analysis - Motivation

Projections/Fits Isobar Model

σ required, implemented as a BW resonance

FOCUS: K-matrix approach - No need for a , employed a () S-wave to describe data

Although not entirely clear this is correct:“… the K-matix approach employed in Ref [5] does not meet the chiral requirementsof a soft expansion for low energies…” [J. Oller, PRD71 054030]

Can CLEO-c confirm, refute, add more confusion to the saga?

No

With

But BW does not account for phase variation across the Dalitz plot [D. Bugg hep-ph/0510021]

E791

BESII- J/

Described viaa complex pole


• L=281 pb-1 @ (3770)• Untagged analysis• Signal box for DP

– |ΔE|<2– |mBC-mD|< 2

• Backgd boxes for DP– |ΔE|<2– 5<|mbc-mD|<9

DP Statistics: N(π−π+π+) ~2600 ev. N(Ksπ+) ~2240 ev. Nback ~ 2150 ev.

D+ +-+ Dalitz Analysis

6991 on DP

Signal~2600

ev.

D+→π−π+π+

D+→K0Sπ+


D+ +-+ Dalitz Results (Preliminary)Mode Fit Values

Relative

Amplitude

Phase(degrees)

Fit Fraction (%)

(770)+ 1.0 0 20.0±2.3±0.9

f0(980)+ 1.4±0.2±0.2 12±10±5 4.1±0.9±0.3

f2(1270)+ 2.1±0.2±0.1 237±6±3 18.2±2.6±0.7

f0(1370)+ 1.3±0.4±0.2 -21±15±14 2.6±1.8±0.6

f0(1500)+ 1.1±0.3±0.2 -44±13±16 3.4±1.0±0.8

pole 3.7±0.3±0.2 -3±4±2 41.8±1.4±2.5

Limits on Other Contributing Modes

(1450)+

0.9±0.5 51±22 <2.4

f0(1710)+ 1.0±1.5 -17±90 <3.5

f0(1790)+ 1.0±1.1 23±58 <2.0

Non-resonant

0.17±0.14 -17±90 <3.5

I=2 ++

S-wave0.17±0.14 23±58 <3.7 Consistency with E791

- E791 BW Fit Fraction = (46.3±9.0±2.1)% pole provides a good description of the DP

2 21( ) , where, (0.47 0.22) GeVA

A

Pole s s is s

Likelihood Fit including: Amplitude, phase, spin-dependent PW (ie. BW), angular distribution, Blatt Weiskopf angular momentum penetration factor.


D0K+K-0 Dalitz Analysis (1) Motivation:

CKM angle can be measured using interference betweenB+ D0K+ and B+D0K+ and the CC modes. [GLS, PRD 67 071301 (2003)] Two of the key inputs are rD and D, defined through:

rD and D can be independently determined by analyzing the D0K+K-0 DP.

0 *

0 *

( )

( )Di

D

A D K Kr e

A D K K

Uses ~9 fb-1 of data collected on/just below (4S) Reconstruct D*+D0+, D*-D0-

Charge of bachelor tags the D0 flavor at production Signal/sideband regions as shown 735 Signal candidates

Analysis Overview


D0K+K-0 Dalitz Analysis (2)Similar fitting technique to D +-+ analysis

Mode Fit Values

Relative

Amplitude

Phase(degrees)

Fit Fraction (%)

1.0 0 46.1±3.1

0.52±0.05±0.04 332±8±11 12.3±2.2

+ 0.64 ±0.04 326±9 14.9±1.6

NR 5.62±0.45 220±5 36.0±3.7

Read off the values from the DP fit

rD= 0.52±0.05±0.04D = (332±8±11)o

First measurement of D. Significant improvement on rD over previous value using K*K BF’s

K*+

K*-

K*+


Next-to final remarks

Some more details, recent talks, pubs on these topics Ds Scan:

R. Poling, CHARM2006, “New results of the CLEO-c scan from 3970-4260” S. Blusk, CIPANP2006, “Ds Scan and Confirmation of the Y(4260)”

D Hadronic Analysis: Q. He et al., Phys. Rev. Lett, 95, 121801 (2005) (57 pb-1) P. Onyisi, CHARM2006, “Hadronic Charm decay at CLEO-c” (281 pb-1)

Cabibbo-suppressed Decays: P. Rubin et al., Phys. Rev. Lett.96, 081802 (2005). Ds Inclusive & Exclusive: S. Stone, FPCP06, “Hadronic Charm Decays and D Mixing “ D+-+ Dalitz Analysis:

D. Cinabro, FPCP06 “Interference Effects in D Meson Decays” M. Dubrovin, CHARM2006, “Charm Dalitz Analyses from CLEO-c”

DK+K-0 Dalitz: C. Cawfield, et al, hep-ex/0606045, submitted to Phys. Rev. D D. Cinabro, FPCP06 “Interference Effects in D Meson Decays”

Many thanks to my CLEO collaborators, especially: P. Onyisi, A. Ryd, B. Lang, M. Dubrovin, H. Mahlke-Krueger


Summary CLEO-c is hitting it stride already many measurements have surpassed world averages

Ds scan Ecm = 4160 MeV optimal for Ds physics Expect ~4-5X more DD and Ds

+Ds- data by mid-

2008.

Significant improvements on knowledge of D hadronic BF’s and many new modes being uncovered.

Critical improvements on golden modes Should have error on Beff(Ds) ~ 5%

Hadronic analyses have just begun… many more to come.

More (open charm) hadronic, semileptonic and leptonic results in this session and CKM/Rare decays session


BACKUPS


D Hadronic Overview

e+ e-

DD

D Reconstruction Techniques in CLEO-c Untagged analysis – reconstruct only one D meson in signal mode, use Bref

Tagged analysis Reconstruct 1 D meson in “clean” hadronic modes with “large” *B Use remaining charged particles & showers to reconstruct second D meson.

Hadronic (this talk) Semileptonic (see talk by Yongshen Gao in Session 10) Leptonic (see talk by Sheldon Stone in Session 10)

Use kinematic variables: E=Ebeam-ED

2 2bc beam DM E p


Substructure in CS modes

Mbc-MD3

E Signal RegionE Sideband Region

+- 00

D++-0 Signal D++-0

Sideband

D++00

SignalD++00

Sideband

D++--0

SignalD++--0

Sideband

3.61 ± 0.25 ± 0.26 3.0 ± 0.6

< 0.34 (90% CL) ---

0.62 ± 0.14 ± 0.05 ---

< 0.26 (90% CL) ---

< 1.9 (90% CL) ---

1.7 ± 0.5 ± 0.2 ---

Mode CLEO-c PDG


• Minimize Log likelihood

• PDF

• Matrix element

• Partial waves (PWR):

– Spin-dependent BW for conventional resonances

– I=2 π+π+ S-wave

– π+π− S-waves:

–Oller

–Flatte

Dalitz Fit Details1

2 log ( , )N

n nn

L PDF x y

2( , ) | ( , ) | ( , ) (1 ) ( , )s BPDF x y f N M x y x y f N B x y

RiR R R R

reson

M a e PW F aR= amplitude, R = relative phasePWR = Mass & spin dependent partial wave functionR = Angular distributionFR = Blatt-Weiskopf angular momentum penetration factor

20 ( )2

2 00

( ) 1( )

2

i mIJ

m ea m

i

2 21( ) , where, (0.47 0.22) GeVA

A

Pole s s is s

For S-wave(s=m

2)

0

0

(890) 2 2 2 2

1( )

( )ff KK KK

Flatte mm m i g g

gab == coupling of f0 to abab=2pa/m (phase space factor)

Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed

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Transcript of Introduction D s Scan D 0 , D ± Branching Fractions Cabibbo favored Cabibbo-suppressed