03/25/22 Ping Wang (IHEP, Beijing) 1 Ping Wang (for the collaboration of BESIII) Institute of High Energy Physics, Beijing, China PHIPSI11, Novosibirsk, Sept, 2011 Charmonium Decays at BESIII
Dec 31, 2015
04/19/23 Ping Wang (IHEP, Beijing) 1
Ping Wang
(for the collaboration of BESIII)
Institute of High Energy Physics, Beijing, China
PHIPSI11, Novosibirsk, Sept, 2011
Charmonium Decays at BESIII
04/19/23 Ping Wang (IHEP, Beijing) 2
Outline
Brief introduction of BEPCII & BESIIICharmonium decays: 'P , cJV, cJVVSummary
04/19/23 Ping Wang (IHEP, Beijing) 3
BEPCII & BESIIIBEPCII & BESIII
Charm energy region
Updated detectors
Large luminosity
BESIII is special!
Abundant potential physics with BESIII.
04/19/23 Ping Wang (IHEP, Beijing) 4
Charmonium spectrum below open charm threshold
106M 106M (2S) at BESIII(2S) at BESIII
0
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' P( P(00,,,,'), arise surprises), arise surprises
CLEO-c: J/ψ, ψ', ψ'' PRJ/ = (21.1± 0.9)%
No Evidence for ' 0 or Br(′′)=(1.19 ± 0.09)%
R' < 1.8% at 90% CL
R' << RJ/
PRD 79, 111101 (2009)
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”.
theorytheory experimentexperiment
04/19/23 Ping Wang (IHEP, Beijing) 6
’’ P P at BESIIIat BESIIIψ'→ γη'ψ'→ γη
(First observation)ψ'→γ0
(First observation)
PRL 105, 261801 (2010)
Possible interpretation: Q. Zhao, Phys. Lett. B697, 52 (2011)
R′= 1.10±0.38±0.07% << RJ/
+-0
000
’+-
’+-
Mode B(’) [x10-6] B(J/) [x10-4] Q (%)0 1.580.42 0.350.03 4.5 1.3 1.380.49 11.040.34 0.13 0.04
’ 1269 52.81.5 2.4 0.2
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cJcJ V( V(,,,,) , prediction by pQCD ) , prediction by pQCD
much lower than experimentmuch 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.
04/19/23 Ping Wang (IHEP, Beijing) 8
cJcJ V( V(,,,,)) results at BESIII results at BESIII)(M )(M )(M
KK0
Phys. Rev. D 83, 112005 (2011)
An non-pQCD explanation “hadronic loop correction”, D.Y Chen et al. arXiv:1005.0066v2[hep-ph] EPJC70, 177-182 (2010)
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 First
observationobservation
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Polarization ofPolarization of c1c1 V( V(,,,,) ) L: Longitudinal polarization, T: Transverse polarization, θ: Helicity angle
015.0014.0034.0158.0
Tf044.0
026.0090.0087.0247.0
Tf
10.0
09.013.012.029.0
Tf
1c 1c 1c
22 sin2
1cos)1(
cos TT ffd
d
Longitudinal polarization dominates
D.V. Amelin et al. (VES Collaboration), Z. Phys. C 66, 71 (1995)C.N. Yang, Phys. Rev. 77, 242 (1950)
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ccVV(V=VV(V=, , , suppressed decays, 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 yetBESII on c0,2 / PLB 642,197(2006), PLB 630,7 (2005)
Reconstruct and via K+K- or +-0
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First observation Evidence
Accepted by PRLAccepted by PRLccVV VV at BESIIIat BESIII
Large distance effect: X. H. Liu, et al, PRD 81, 014017 (2010) D.Y. Chen, et al, PRD 81, 074006 (2010)
04/19/23 Ping Wang (IHEP, Beijing) 12
summarysummary With very high luminosity, BEPCII/BESIII is the b
est 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.