Transcript 幻灯片 1 - Novosibirsk

Charmonium Decays
at BESIII
Ping Wang
(for the collaboration of BESIII)
Institute of High Energy Physics, Beijing, China
PHIPSI11, Ping
Novosibirsk,
Sept, 2011
7/17/2015
Wang (IHEP, Beijing)
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Outline
Brief introduction of BEPCII & BESIII
Charmonium decays:
'P , cJV, cJVV
Summary
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Ping Wang (IHEP, Beijing)
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BEPCII & BESIII
Large luminosity
Updated detectors
Charm energy region
BESIII is special!
Abundant potential physics with BESIII.
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Ping Wang (IHEP, Beijing)
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Charmonium spectrum below open charm threshold
0
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Ping Wang (IHEP, Beijing)
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' P(0,,'), arise surprises
V P are important tests for various mechanisms:
Vector meson Dominance Model (VDM); Couplings &
form factor; Mixing of -′(-c); FSR by light quarks;
12% rule and “  puzzle”.
theory
experiment
CLEO-c: J/ψ, ψ', ψ''  P
RJ/ = (21.1± 0.9)%
No Evidence for '  0 or  
Br(′′)=(1.19 ± 0.09)%
R' < 1.8% at 90% CL
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R' << RJ/
PRD 79, 111101 (2009)
Ping Wang (IHEP, Beijing)
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’ P at BESIII
ψ'→ γη
(First observation)
ψ'→ γη'
+-0
’+-
000
’+-
PRL 105, 261801 (2010)
ψ'→γ0
(First observation)
R′= 1.10±0.38±0.07% << RJ/
Mode
0

’
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B(’) [x10-6]
1.580.42
1.380.49
1269
B(J/) [x10-4]
0.350.03
11.040.34
52.81.5
Q (%)
4.5  1.3
0.13  0.04
2.4  0.2
Possible interpretation:
Q. Zhao, Phys. Lett. B697, 52 (2011)
Ping Wang (IHEP, Beijing)
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cJ V(,,) , prediction by pQCD
much lower than experiment
• Information of C-even state
• Two gluon coupling
• Possible glue-ball or hybrid states
• Hadronization
Br. are in unit of 10-6.
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Ping Wang (IHEP, Beijing)
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cJ V(,,) results at BESIII
Phys. Rev. D 83, 112005 (2011)
M ( )
    
M ()
M ()
     0
  K K 
BESIII
<10.5
228±13±16
<20.8
<12.9
69.7±7.2±5.6
<6.1
<16.2
25.8±5.2±2.0
<8.1
First
observation
An non-pQCD explanation “hadronic
loop correction”,
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Ping Wang (IHEP, Beijing)
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D.Y Chen et al. arXiv:1005.0066v2[hep-ph]
EPJC70, 177-182 (2010)
Polarization of c1 V(,,)
L: Longitudinal polarization, T: Transverse polarization,
θ: Helicity angle
d
1
2
 (1  fT ) cos   fT sin 2 
d cos 
2
c1  
c1  
fT  0.158 0.03400..015
014
fT  0.247 00..090
087  0.026
0.044
c1  
0.10
fT  0.29 00..13
12  0.09
Longitudinal polarization dominates
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D.V. Amelin et al. (VES Collaboration), Z. Phys. C 66, 71 (1995)
Wang
(IHEP,
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C.N. Yang, Ping
Phys.
Rev.
77,Beijing)
242 (1950)
cVV(V=, ), suppressed decays
 cJ    and cJ    are Singly OZI suppressed
 c1  and c1 is suppressed by helicity
selection rule.
 cJ  is doubly OZI suppressed, not measured yet
BESII on c0,2    /  
PLB 642,197(2006), PLB 630,7 (2005)
Reconstruct  and 
via K+K or +-0
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Ping Wang (IHEP, Beijing)
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cVV at BESIII
Accepted by PRL
First observation
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Evidence
Large distance
effect: X. H. Liu, et al, PRD 81, 014017 (2010)
Ping Wang (IHEP, Beijing)
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D.Y. Chen, et al, PRD 81, 074006 (2010)
summary
 With very high luminosity, BEPCII/BESIII is the
best instrument to study the physics at -charm
region.
 BESIII has obtained good measurements on
decays of ′ P, cJ V and cJ VV.
 With the accumulated 106M ′ sample, these
results are precision measurements or first
observation.
 More exciting/interesting results are coming.
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Ping Wang (IHEP, Beijing)
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