test of pqcd 12% rule at bes
DESCRIPTION
Test of pQCD 12% Rule at BES. Yongsheng ZHU IHEP, Beijing 100039, China for the BES Collaboration. 32 nd Intern. Conf. on High Energy Physics ( ICHEP’04 ) Aug. 16-22, Beijing, China. OUTLINE Introduction (2S) VP (,,)(,,’),K*K - PowerPoint PPT PresentationTRANSCRIPT
Test of pQCD 12% Rule at BES
Yongsheng ZHU
IHEP, Beijing 100039, ChinaIHEP, Beijing 100039, China
for the BES Collaboration
32nd Intern. Conf. on High Energy Physics ( ICHEP’04 )
Aug. 16-22, Beijing, China
OUTLINE
• Introduction(2S) VP (,,)(,,’),K*K
(2S) VT f2, a2,K*K*2, f2
'
• J/, (2S) PP KSKL
• Summary
0
2
4
6
8
10
12
14
MKI MKII MKIII CBAL BESI BESII CLEOc
3M
14M
INTRODUCTION
J/
0
10
20
30
40
50
60
MarkI I I DM2 BES I BES I I
(2S)
World J/ and (2S) Samples (×106)
14M58M
pQCD 12% rule :
T. Appelquist & H.D. Politzer, PRL 34 (1975) 43 A. De Rujula & S.L. Glashow, PRL 34 (1975) 46
• J/ and ’ hadronic decays proceed via 3 gluons or a virtual photon, omitting the difference of S at J/ and ’ , the ratio of ’ and J/ BRs is
• Assumption : This relation holds for any exclusive hadronic final state.
12%B
B
BB
QeeJ/ψ
eeψ'
XJ/ψ
Xψ'h
INTRODUCTION (Con’t)
puzzle:
• Suppression in VP mode ( & K*K ) revealed by MARK-II { M.E.B. Franklin et al, PRL 51 (1983) 963 }
• Suppression confirmed by BESI with higher sensetivity { Y.S.Zhu, Proc. of ichep ‘96, p.507 }
• Suppression in VT mode found by BESI { J.Z.Bai et al, PRL 81 (1998) 5080 }
Q(f2) < 4.0%, Q(a2)< 2.1%, Q(K*K*2) < 1.8%, Q(f2
’) < 3.7%
%2%,6.0)892*(
KK
%64.0%,23.0)892*(
KK
INTRODUCTION (Con’t)
Theoretical explanations:• Brodsky, Lepage, Tuan: { PRL 59 (1987) 621 }
Intermediate vector glueball• Chaichian & Torngvist : { NP B323 (1989) 75 }
Hadronic form factor • Pinsky : { PL B236 (1990) 479 }
Generalized hindered M1 transition• Li-Bugg-Zou { PR D55 (1997) 1421 }
Final-state interaction• Brodsky-Karliner { PRL 78 (1997) 4682 }
Intrinsic charm |qqcc> Fock components of the light vector mesons• Chen-Braaten { PRL 80 (1998) 5060 }
Fock state with cc pair in a color-octet
INTRODUCTION (Con’t)
Theoretical explanations:• Gerard-Weyers { PL B462 (1999) 324 }
cc annihilation into 5g via 2 steps • Feldmann-Kroll { PR D62 (2000) 074006 }
Decays thru light-quark Fock component by a soft mechanism• Suzuki { PR D63 (2001) 054021 }
(2S) - vector glueball mixing • Rosner { PR D64 (2001) 094002 }
(2S) - (1D) mixing• J. P. Ma { PR D65 (2002) 097506 }
Relativistic Correction
INTRODUCTION (Con’t)
The phase and interference in e+e – experiment
Phase
• For decays via strong and EM amplitudes, the phase and continuum contribution must be considered. • For EM decays, the continuum contribution must be considered.
φ
interference interference
Measure the BRs of (2S) & corresponding Q values
for 10 VP channels,
4 VT channels,
1 PP channel,
to test pQCD 12% rule.
INTRODUCTION (Con’t)
BRs for (2S)(,,)(,,’),K*K
measured
PWA for (2S)+ - 0
Background from continuum considered
using Ecm=3.65 GeV data sample
1. VP Mode
BESII Preliminary
1. VP Mode (Con’t)
1.1 Dalitz plot for J/ Ψand Ψ(2S) 3 are very different
J/ Ψ 3 Ψ(2S) 3
PRD70 (2004) 012005
hep-ex/0408047 submitted to PRL
M in Ψ(2S) 3
(770), (2150) -- dominantBESII Preliminary ( PWA )
1. VP Mode (Con’t)
1.1
Results on BRs____________________________________________________________________________________________________________________________________________
BR BESII (10 – 5 ) PDG04 (10 – 5 )
Ψ(2S) + - 0 18.1 1.8 1.9 8 5
Ψ(2S) 5.1 0.7 0.8 < 8.3
Ψ(2S) (2150) + - 0 19.4 2.5____________________________________________________________________________________________________________________________________________
# 1st measurement or precision much improved
# Interference taken into account
BESII Preliminary ( PWA )
1. VP Mode (Con’t)
1.1 (Con’t)
2.111.2
Dalits plot in (2S) KSK K*(892)K 1.2 K*(892)K
1. VP Mode (Con’t)
K*
K*0
hep-ex/0407037 , submitted to PRL
K*
K*0
Ψ(2S) K + Ψ(2S) K 0
1.2 K*(892)K (Con’t)
1. VP Mode (Con’t) Br±(2.9±1.3±0.4)10 –5
Br0(15.0±2.1±1.9)10 –5
K* K*0
=5.2±2.7
65.6±9.0 Evts.
isospin-violation
9.6±4.2 Evts.
) (0S K M
)( KM
1.3 EM Process: 0,,’ at Ecm=3650,3686,3773 MeV1. VP Mode (Con’t)
# For EM processes at continuum e+e- (VP) 0 , , ’
Pvp(S)=q3vp/3; q3
vp – momentum of V or P ;
Fvp(s) – form factor ; =1, 0.672, 0.325 for 0 ,, ’ .
# For EM processes at Ψ(2S) (VP) 0, , ’
=R+cont (INT 0, P.Wang et al, PL B593 (2004) 89 )
# BRs & Fvp(M Ψ(2S)) obtained simultaneously
interference
BESII Preliminary 1.3 EM Process: 0,,’ at Ecm=3650,3686,3773 MeV
e+e- 0 at Ecm=3650 MeV L = 6.42 pb-1
e+e- 0 at Ecm=3773 MeV L = 17.3 pb-1
1. VP Mode
e+e- 0 at Ecm=3686 MeV
N Ψ(2S) = 14M
BESII Preliminary
1.3 EM Process: 0,,’ at Ecm=3650,3686,3773 MeV
FVP(S) and B(Ψ(2S) VP) for 0,,’
BESII Preliminary
1.3 EM Process: 0,,’ at Ecm=3650,3686,3773 MeV
Form factor for
Ψ(2S) 0
Curve A -- J.Gerard, PLB425(1998)365 F(0) ~ 1/S
Curve B –V.Chernyak, hep-ph/9906387 F(0) ~ 1/S2
’ Nevt B(’) (10-5) B(J/) (10-
4)
PDG04
Q (%)
(770) 5.1 0.7 0.8 127 9 0.40 0.08
(2150)
13.2 4.8
1.78 0.65 0.22
1.93 0.23 9.2 3.7
’ 2.5 1.7
1.87 1.27 0.36
1.05 0.18 17.8 12.9
14.0 4.8
1.88 0.64 0.32
4.2 0.6 4.5 1.8
<3.3 < 1.1 15.8 1.6 < 0.7
’ 4.1 2.8 4.3 2.9 1.0 1.67 0.25 26 19
< 3.0 < 0.3 < 0.068
17.8 5.3
3.5 1.0 0.6 6.5 0.7 5.4 1.9
’ 9.1 3.6 3.2 1.3 0.6 3.3 0.4 9.7 4.5
K+K*-+c.c. 9.6 4.2
2.9 1.3 0.4
50 4 0.58 0.27
K0K*0+c.c. 65.6 9.0
15.0 2.1 1.9
42 4 3.6 0.8
* PreliminaryUpper limit @90 ％ C.L.
1.4 Results of VP mode
2.111.25.24.19
Upper limit @90 ％ C.L.
BESII vs. CLEO (’ BRs Results) BESII Preliminary
• Most channels BRs are consistent.
• BES BR() > CLEO by ~ 3, because PWA takes into acount the interference.
• BR(K*0K0) are deviatedCLEO BRs calculated from hep-ex/0407028
VT
Mode
B (2S)X (10 – 4)
(PDG2002 from BES )
B J/X (10 – 3)
(PDG1996)Qh ( % )
f2 < 1.7 (C.L. 90 %)
1.1 ±0.5 ±0.2
4.3±0.6 < 4.0
2.4 ±1.3
a2 < 2.3 (C.L. 90 %) 10.9±2.2 < 2.1
K* K*2 < 1.2 (C.L. 90 %) 6.7±2.6 < 1.8
f2' < 0.45 (C.L. 90 %) 1.23±0.21 † < 3.7
Suppressed!!
BES-I results PRL81(1998)5080
PRD67(2003)052002
† This value from DM2 only
12 % rule ( pQCD rule ) Test
2. VT Mode
† This value from DM2 only
Suppressed!! PR D69 (2004) 072001
MCYXψ'
obsYXψ'
Xψ' εBNn
B
VT mode
B’ X (10 – 4)
(BES-II)
B J/X (10 – 3)
(PDG2004)Qh(%)
f2 2.05± 0.41 ± 0.38 4.3±0.6 4.8±1.5
a2 2.55± 0.73± 0.47 10.9±2.2 2.3±1.1
K* K*2 1.86± 0.32 ± 0.43 6.7±2.6 2.8±1.3
f2' 0.44 ± 0.12 ± 0.11 1.23±0.21 † 3.6±1.5
BES-II
2. VT Mode (Con’t)
PRL92 (2004) 052001 PRD69 (2004) 012003
Ψ(2S) KS KL J/Ψ KS KL
Ks mass sidebands
Bkg MC
signal
14M ψ(2S)
Ks mass sidebands
MC BkgK*0KS+c.c.
signal
58M J/ψ
3. PP Mode
%12/
)2(
XJ
XS
h
B
BQ
B (2S) Ks K L = (5.24± 0.47 ± 0.48 ) 10 – 5
B J/ Ks K L = (1.82 ± 0.04 ± 0.13 ) 10 – 4
)%3.48.28(B
B
/
)2(
LKKJ
LKKS
S
S
4B(Ψ(2S)) enhanced!
1st measurement
Improved Accuracy
3. PP Mode (Con’t)
–(8229)° (12127) °
B( (2S) K
S
KL )
= 5.24
10 – 5
PLB567 (2003)73
K+K– & +
inputs ;Input 1:DASP;Input 2:BESI ;Input 3: K+K–
from BESI & + by form factor.
Ψ(2S) KS KL Phase between strong
and EM amplitude
3. PP Mode (Con’t)
# Measurements for BRs or upper limits of VP channels:
’ (,,)(,,’), K*K
# In ’ 3, (770) & (2150) dominant.
# Large isospin-violation in ’ KK* channel.
# F(0,,’) at Ecm=3650, 3686, 3773 MeV measured.
# Improved BRs of VT channel ’ f2, a2, K* K*2, f2’
# First measurement for BR of Ψ(2S) KS KL ;
Phase between EM and strong amplitudes is -82o or 121o.
# 12% rule tested for all these decay modes.
some suppressed, some enhanced, some consistent.
SUMMARY
SUMMARY
BESII Preliminary
Test of pQCD 12% Rule
SUMMARY
BESII preliminary
Test of pQCD 12% Rule
# 12% rule seems to be too simplistic.
# A theory which can quantitatively
describing these data is desired.
# More and accurate data on J/ and (2S)
are helpful
to elucidate the J/ and (2S) properties,
as well as properties of strong interaction.
Comments
Thanks a lot !
谢谢 !
BESII Detector
VC: xy = 100 m TOF: T = 180 ps counter: r= 3 cm MDC: xy = 220 m BSC: E/E= 22 % z = 5.5 cm dE/dx= 8.5 % = 7.9 mr B field: 0.4 T p/p=1.7(1+p2) z = 2.3 cm
INTRODUCTION
1. ψ(2S) 2. Other quarkonia3. Hadron spectroscopy
INTRODUCTION (Con’t)
EXP B(’ )
(10-5)
Q ( )
(%)
B(’ K+K*-
+cc)
(10-5)
Q (K+K*-)
(%)
MK II < 8.3 < 0.65 < 5.4 < 1.1
BES I * < 2.9 < 0.23 < 3.2 < 0.64
BES II 5.1 0.6 0.7**
0.40 0.08** 2.9 1.4 0.4 0.58 0.29
BRs of & K+K* -- +cc Comparison with previous results
* Y.S.Zhu, Proc. Ichep 96, p.507** BES II . PWA takes into account (770), excited states & their interferencies.
(Upper limit @90 ％ C.L.)
1.2 K*(892)K (Con’t)
1. VP Mode (Con’t)
BESII Preliminary ( PWA )
1. VP Mode (Con’t)
1.1 (Con’t)
BESII Preliminary 1.3 EM Process: 0,,’ at Ecm=3650,3686,3773 MeV
e+e- at Ecm=3650MeV
e+e- ’ at Ecm=3773 MeV
Ψ(2S)
Ψ(2S) ’
e+e- at Ecm=3773 MeV
e+e- ’ at Ecm=3650MeV
Ψ(2S)
{ Ψ(2S) 0 not seen }
BESII Preliminary
Ψ(2S) ’
( ’ +-, +- )
1.4 Other VP Channels
• Most channels BRs are consistent.
• BES BR() > CLEO by ~ 3, because PWA takes into acount the interference.
• BR(K*0K0) are deviated.
Upper limit @90 ％ C.L.
BESII vs. CLEO (’ BRs Results)
CLEO BRs calculated from hep-ex/0407028
BESII Preliminary
)1270(2f
f2
(1270)
B.G.(M.C.)
B.G.( )
B.G.
a2 (1320)
)1320(2a
02
0 )1430()892(
B.G.K*
2 (1430)
K*(892)
)1525(2f
B.G.
f2' (1525)
f0(980)
2. VT Mode BES-II