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Some ψ(3686) Physics at BESIII (software performance test)

G.Li, K.L.He and X.H.MO

for Analysis Software Group

BESIII annual meeting

January 10-12, 2006

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Content1. Introduction2.Ψ' -to- J/ transition processesJ/ X, X: 0 0 , + – , 0, , etc. cJ , cJ J/ , multi-track

s .3.Ψ' PP final state. 4.Summary

BESIII simulation based on BOSS 5.0.0

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New discoveries and high precision

PDG04B('00J/)/ B('+–J/)=(59.3±4.3)% [r.e.7%]

CLEOc:PRL94,232002(2005)B('00J/)/ B('+–J/)=(49.24±0.98)% [r.e.2%]

Isospin conservation is confirmed at a 2% level

Theoretical predication:B('00J/)/ B('+–J/)=50%

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CLEOc:PRL94,232002(2005)B('0J/)/ B('J/)=(4.1±0.4 ±0.1)% [r.e.10%]

Isospin violation is observed at a ±0.4% level

Theoretical predication: 1.62% PR194, 1(1990) (1.92–3.45)% PRD24,1210(1988)

BESII:PRD70,012006(2004)B('0J/)/ B('J/)=(4.8±0.5)% [r.e.10.4%]

PDG04B('0J/)/ B('J/)=(3.04±0.70)% [r.e.23%]

230

2/)(16

27

)/(

)/(

uds

ud

mmm

mm

p

p

J

J

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Ψ' -to- J/ transition processesJ/ X, X: 0, 0 0 , + – ,, etc. cJ , cJ J/ , multi-track

s .

BESIII simulation based on BOSS 5.0.0

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'+–J/, J/ All Double Gaussian Fit

inv. mass +–

without 4C fit

inv. mass

without 4C fit

inv. mass +–

with 4C fit

= 17. 4 MeV

= 2. 22 MeV =2. 32 MeV

4C-fit is unnecessary for '+–J/, J/

at BESIII

Sample: 50k

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'00J/ , J/

Crystal Ball Func. Crystal Ball Func.

Gauss Func. Gauss Func.

1st 0 2nd 0

Gauss1 Func.

Gauss2 Func.

inv. mass

= 5. 4 MeV = 5. 5 MeV

= 10.7 MeV

All with 4C fit

m =137.9 MeV m =137.0 MeV

m =3.109 GeV

Sample: 50k

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'0J/ , J/

Crystal Ball Func.+

Gauss Func.

Double Gaussian

= 4. 9 MeV = 14.8 MeV

without 4C fit with 4C fit

inv. mass inv. mass

m =136.1 MeV

m =3.102 GeV

Sample: 50k

cos of in 0 c.m. system

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'J/ , J/

Crystal Ball Func. Double Gaussian

cos of in c.m. system

= 9. 3 MeV = 12.3 MeV

without 4C fit with 4C fit

inv. mass inv. mass

m =550.8 MeV

m =3.101 GeV

Sample: 20k

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Decay mode

Resolution

(MeV)

Without or with 4C-fit' BESIII

(M.C.)

BESII

(Data)

+–J/ + – : 2. 22 ~7.0 no 4C-fit

00J/ 01,0

2 : 5.4, 5.5 — 4C-fit

0J/ 0 : 4.9 12.9 4C-fit

J/ : 9.3 4.1

(5C-fit)

4C-fit

Short Summary

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Ψ' J/ final state

8 M BESIII M.C. Sample

14 M BESIISample

0

c1 c2

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BESIII: (8M , M.C.)m(c1) =3.508GeV,m(c2) =3.553GeV;(c1) =8.1MeV,(c2) =9.4MeV.

BESII: (14M , Data)(c1) =13.3MeV; (c2) =13.2MeV.

Ψ' cJ , cJ J/

c1 c2

0

Ψ' J/(0, ), (0, )c0

m() =549MeV,

m(0) =135MeV.

m(c-) =3.413GeV,(c0) =9.0MeV.

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Inv.mass of chrg.trks. (GeV)

Even

ts

c1

c2

c0c1

c2

c0

c1

c2

c0

Ψ' cJ , cJ Ψ' cJ , cJ KK

c

BESIII: (0.5M , M.C.)Ψ' cJ , cJ multi-tracks

Ψ' cJ , cJ (6)

Ψ' tail

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Ψ' PP final state.

BESIII simulation based on BOSS 5.0.0

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' Pseudoscalar-Pseudoscalar

• Form factors of and can be calculated in framework of Hadronic Helicity Conservation (HHC), which could tell us about quark distribution amplitudes. So measurement of +–, K+K– final states are important and interesting, and also provide test for HHC.

S.J. Brodsky and G.P. Lepage :PRD24, 2848 (1981).

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12%BB

QXJ/ψ

Xψ'h

B ’ Ks KL = (5.24± 0.47 ± 0.48 ) 10 – 5 BES:PRL92,052001(2004)

B J/ Ks KL = (1.82 ± 0.04 ± 0.13 ) 10 – 4 BES:PRD69,012003(2004)

3.7)%(28.8B

B

LKKJ/ψ

LKKψ'

S

S

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J/ , ’ PP

•12% rule problem as we know VP mode is suppressed, eps. ; but for PP channel, the ratio is enhanced:

How about +–, K+K– ?

PDG04:Qh (+–)=(54 ± 35)%Qh (K+K– )=(42 ± 30 )%

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The Relative Phase

J/ψ Decays: 1. AP : 90 ° M. Suzuki, PRD63, 054021 (2001) 2. VP : (106 ±10) ° J. Jousset et al., PRD41, 1389 (1990) D. Coffman et al., PRD38, 2695 (1988) N. N. Achasov, talk at Hadron2001 3. PP : (90 ±10) ° M. Suzuki, PRD60, 051501 (1999) 4. VV : (138 ±37) ° L. Köpke and N. Wermes, Phys. Rep. 74, 67 (1989) 5. NN : (89 ±15) ° R. Baldini et al., PLB444, 111 (1998)

ψ’ Decays:1. VP : φ = 90 °﹣ or 180 ° P. Wang et al. , PRD69, 057502 (2004) 2. PP : φ = ( 82 ±29)° ﹣ or (+121 ±27) ° J. Z. Bai et al. , PRL9, 052001 (2004)

φ

Large phase~ |90º|

Large phase

~ – 90º

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Three channels: π﹢π﹣, K﹢K﹣, and KS KL

could be use to extract the phase (√3/2) M and E.

φ

PP -Parametrization π﹢π ﹣ : E

K﹢K﹣: (√3/2) M +E

KS KL : (√3/2) M

E.Haber and J.Perrier: Phys.Rev.D32, 2961 (1985)

PP -Parameterization π﹢π ﹣ : (E+EC)K﹢K﹣: (√3/2)M +(E+EC) KS KL : (√3/2)M

+Continuum Contribution

’ PP

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BESII

p(π)– p(K)=62 MeV

/p=0.017(1+p2)1/2

(π)= 65 MeV

(K)=62 MeV

Two peaksmerge together,undistinguishable

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’

J/ ’’

p(K) =1.775GeV(K) =0.0110GeV

K

KK

p() =1.837GeV() =0.0117GeV

p() =1.881GeV() =0.0120GeVp(K) =1.820GeV(K) =0.0113GeV

p() =1.542GeV() =0.0085GeVp(K) =1.467GeV(K) =0.0079GeV

All fit error around the level of 10 – 4 GeV

BESIII

momentum (GeV)momentum (GeV)

momentum (GeV)

Even

ts Even

ts

Even

ts

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Bkg MC

signal

14M ψ(2S)J/,’KSKL

PRL 92, 052001 (2004)58M J/ψ

signalMC BkgK*0KS+c.c.

Ks m

ass sid

eban

ds

PRD 69, 012003 (2004)

B ’ Ks KL =

(5.24± 0.47 ± 0.48 ) 10 – 5

B J/ Ks KL =

(1.82 ± 0.04 ± 0.13 ) 10 – 4

PRD 70, 077101 (2004)

B ’’ Ks KL <

2.1 10 – 4 (90% C.L.)

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’

J/ ’’

p(Ks) =1.762GeV(Ks) =0.0134GeV

KS

KSKS

p(Ks) =1.808GeV(Ks) =0.0137GeV

p(Ks) =1.455GeV(Ks) =0.0119GeV

BESIII

momentum (GeV)momentum (GeV)

momentum (GeV)

Even

ts Even

ts

Even

ts

Gauss fit results

BESII@ ’p(Ks) =1.768GeV(Ks) =0.0342GeV

B.G. need further study

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Based on BESIII detector simulation system, we present some Monte Carlo distributions for transition processes. From fit, we obtain the detector resolutions for +– , 0 , , c1 , c2, etc. Most of indexes are greatly improved comparing with those of BESII detector. Since PP decay mode is concerned with many interesting physics, we check momentum resolutions of +– , K+K– , KSKL channels at BESIII, and see the new detector will provide us with fairly good resolution for particle’s identification. Our limited performance tests based on BESIII detector simulation indicate that there are many important and interesting physics could be studied with the forthcoming new detector.

Summary

Thanks a lot !

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Back-up

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Decay mode

Eff.

(%)

Resolution

(MeV)

Without or with 4C-fit' BESIII

(M.C.)

BESII

(Data)

+–J/ 40.7 + – : 2. 22 ~7.0 no 4C-fit

00J/ 7? 01,0

2 : 5.4, 5.5 — 4C-fit

0J/ 50.3 0 : 4.9 12.9 4C-fit

J/ 39.1 : 9.3 4.1 4C-fit

Summary

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Ψ' J/ final state

1 M BESIII M.C. Sample

14 M BESIISample

0

c1 c2

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Ψ' cJ , cJ J/

c1 c2

0

Ψ' J/(0, ), (0, )BESIII : 1 M Monte Carlo Sample

BESIII: (1M , M.C.)m(c1) =3.508GeV,m(c2) =3.553GeV;(c1) =8.1MeV,(c2) =9.4MeV.

BESII: (14M , Data)(c1) =13.3MeV; (c2) =13.2MeV.

m() =549MeV,

m(0)

=134MeV.

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cJ

μμ

μμ

J/oJ/

μμ

Exclusive Method’ J/

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The phase study in e+e – experiment

Phase

Take the continuum contribution and its interference effect into consideration , we could determine not only the magnitude but

also the sign of the phase. Furthermore, the cont. contr. and its int. effect will exert obvious influence on BR. measurement.

φ

interference interference

–

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DASP:

BES-I:

C.Z.Yuan,P.Wang and X.H.Mo:PLB567, 74 (2003) =(– 8229)°, or (+12127)

°

BES Collaboration:PRL 92, 052001 (2004)

Parameterization and phase study

B ’ Ks K L= (5.24 ± 0.47 ± 0.48) 10 – 5

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/p=0.003(1+p2)1/2

’

J/ ’’

p(K) =1.775GeV(K) =0.0110GeV

K

KK

p() =1.837GeV() =0.0117GeV

p() =1.881GeV() =0.0120GeVp(K) =1.820GeV(K) =0.0113GeV

p() =1.542GeV() =0.0085GeVp(K) =1.467GeV(K) =0.0079GeV

All fit error around the level of 10 – 4 GeV

BESIII

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“12%” rule and mixing model

’ P P enhanced

’ V T suppressed

’ V P some

greatly suppressed

(such as & K*0 K0 )

Some recent studies indicate the S- and D-wave mixing model is a Natural, Simple and

Calculable model ! It probably gives a unified explanation for all 12 % rule deviated

decays

Wang, Yuan and Mo:PLB574,41(2004); &

hep-ph/0402227;

J.L.Rosner : PRD64,094992(2001)

J/ = | 13S1 , ⟩& = | 23S1 & | 1⟩ 3D1 :⟩

⟨f | = f⟩ ⟨ | 23S1 cos⟩ – f⟨ | 13D

1 sin⟩ , ⟨f | ⟩ = f | 2⟨ 3S1 sin⟩ + f⟨ | 13

D1 cos⟩ .(=12º)

“12%” rule:⟨f |J/ / f⟩ ⟨ | 23S1 = ⟩ ee (J/)/ ee (23S1 ) ⟨f | 23S1 ⟩

Mixing :1. f⟨ | = f⟩ ⟨ | 23S1 cos⟩ – f⟨ | 13D

1 sin⟩ ⟨f | & f⟩ ⟨ | 23S1 ⟩ f⟨ | 13D1⟩2. f⟨ | ⟩ = f | 2⟨ 3S1 sin⟩ + f⟨ | 13

D1 cos⟩ ⟨f | ⟩ Br(f) The measurement at can be

used to test the mixing model !