Charmonium Dynamics at Thresholds H. Lenske Institut für Theoretische Physik, JLU Giessen and GSI Darmstadt
Dec 14, 2015
Charmonium Dynamicsat
Thresholds
H. Lenske
Institut für Theoretische Physik, JLU Giessen
and
GSI Darmstadt
2
Agenda:
• Charmonium Spectroscopy
• Charmonium Production
• Physics Content of Line Shapes
3
Charmonium at the DD-Threshold
• Closed quarkonic channels: confined cc states• Closed hadronic channels : sub-threshold DD-states• Open hadronic channels : DD-channels
4
Charmonium Spectroscopy in the Quark Model
5
Quarkonium: Confined Systems of Heavy (cc,bb) Quarks
cc
e- e+
6
Charmomium Spectrum in the Quark Model
0
4( ) ( , )
3Breit s
hyperfineV r V r V rr
J. Lopez, H.L., 2014
• Unified description of D-mesons and Charmonium• Spectra, wave functions, form factors…
7
Charmonium Production and Spectroscopy at the Threshold
8
The „BIC“-view of Continuum Spectra
• Closed channel E* is embedded into a continuum of open channels• E* decays only via interaction V(r) with open channels
BIC - Bound State Embedded into the Continuum Scale-independent, universal phenomenon
BIC{
9
• Quark model description of charmonium and D-mesons• „3P0“ Lagrangian for pair creation in ccD(cq)D(qc) coupling
gm h.c. 30
q q qPL
Charmonium Wave Function at the DD Threshold
3 1c b b k DD
b DD
3 3 31 1 1
0 0 *0 0
~ z (cc) d k z k
e.g. b= '(3686)2 S , ''(3770)1 D , '''(4040)3 S ...
DD=D D ,D D ,D D ...
10
Channel Coupling and the 13D1 cc Component of y(3770)
2 1( ) Im ( )
JS G
1
( ) 1 ( )P
Spectral Distribution Spectral Factor
11
DD elastic scattering: total p-wave cross sectionIsoscalar 2p and vector meson exchange plus channel coupling
12
Charmonium Production Scenario:Coherent cc and DD production
Quarkonic HadronicProduction Form Factor
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Spectral Properties of cc-States(Cornell-Breit Potential)
Quark Model predictions for e+e- width and 3D1 suppression:
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3 1c b b k DD ~ z (cc) d k z k
Wave Function at the Charmonium Threshold
Single confined channel b=y(13D1) and single open channnel s=DD:
} }
Quarkonic„hard“ component
Hadronic„soft“ component
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Production Cross Sections at the Charmonium Threshold
2
rDD 2
r
q cote e DD ~
1 cot
c sr1
cDD
| T | e e x ( ) q= ; cot
x ( )k | T | e e
Single confined channel c=y(13D1) and single open channnel s=DD:
2
( )1
c s
qM T
16
2
rDD 2
r
2 3 21F DD
DD DD5/2
20R
r R R RR R
q cote e DD ~
1 cot
8 kk T e e
3s
m scot ; m m m (s)
m (s)
Charmonium Production@BES III and PANDA:BIC and Fano-Resonances
The line shape parameter:
b
1DD
(cc) | T | e e q=
k | T | e e
• Controlling the line shape asymmetry • Indicator of the reaction scenario: quarkonic vs.
hadronic
Xu Cao, H. L., arXiv:1408.5600 [nucl-th]
DD-Dynamics at Threshold Channel Coupling and the Line Shape of y‘‘(3770)
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0 0D D threshold
3729.7 MeV
D D threshold
3739.2 MeV
3.65
(2s / 3686)
X(3900) ??
q=-2.1±0.3
18
Line Shape of Reaction Form Factor and Physics Content
cc
DD
| T | Quarkonic q= ~ e e , pp ,...
k | T | Hadronic
q=-0.2 q=-1 q=-10
Dominance of hadronic
production
balanced quarkonic and
hadronic production
Dominance of quarkonic production
• Line shape controlled by quarkonic content • Line shape depends on production reaction• Spectral distribution of the SAME final state depend on initial state
cc
cc
cc
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Production of y‘‘(3770) and the DD Spectral Distributions
(Data: BES Collaboration)
Derived Parameters:
Xu Cao, H.L., 2015
20Science 340,716 (2013)
Laser-Modelling of Fano-Line Shapes
Defining features of Fano-Resonances:
Asymmetric line shapes and GR<<mR
21
Summary and Outlook
• Charmonium Spectroscopy
• Dynamics of charmonium production in (e+,e-), (p,p)…
• Resonances, closed and open channels
• Charmonium cross sections and spectral distributions
• Physics content of charmonium line shapes
• Charmonium production and spectroscopy at PANDA
• Production of charmed baryons at PANDA
Credits to Xu Cao, Juan Lopez, and Radhey Shyam