250 likes | 340 Views
Z c decay width in QCD sum rules. F.S. Navarra. University of São Paulo. New states in the charmonium spectrum. Z c decay width. Peñiscola 27/05/2013. Dias, Navarra, Nielsen, Zanetti, arXiv:1304.6433. Introduction. Before 2003:. After 2003:. Cornell potential:.
E N D
Zc decay width in QCD sum rules F.S. Navarra University of São Paulo New states in the charmonium spectrum Zc decay width Peñiscola 27/05/2013 Dias, Navarra, Nielsen, Zanetti, arXiv:1304.6433
Introduction Before 2003: After 2003: Cornell potential: Schrödinger equation: “Good” quarkonium spectrum States with “wrong” masses
Isospin violation: (2003) Charged states: (2007)
Ten years of “bad behavior” * * BES-III * (2013) BELLE CLEO c
New questions What is the structure of the new states ? Meson molecule Tetraquark c c Hadro-charmonium Hybrid
What is the relation between them ? X(3872) must have a charged partner Maiani (2005) Z+(4430) is its first radial excitation ! Maiani (2007)
Navarra,Nielsen,Richard, arXiv:1108.1230 Maiani,Polosa,Riquer, arXiv:0708.3997 2013
Zc decay width < 2.3 X (3872) ~ 50 Zc (3900)
Two body decay Phase Space
Amplitude A comes from the Lagrangian Example: How do we know the coupling constant ?
Coupling constants in QCD sum rules QCD sum rules hadrons quarks
The OPE side Zc = diquark – antidiquark …
Problem: it is very difficult to separate a diquark-antidiquark from a meson-meson current ! Fierz transformation diquarks mesons
Tetraquark has color entanglement. How to enforce it ? Require color exchange during the decay ! Color-connected diagrams
The phenomenological side Insert complete sets of states into Define ?
Choose the structure: Input numbers: Coupling constant:
Results Maiani (2013) 29 19 4 4 Total width
Summary Zc is the charged partner of X(3872) Tetraquark approach reproduces the mass and the decay width
Ten years of “bad behavior” 2003: X(3872) 2013: Z+(3900)
How to group the new states ? fifties, sixties… Gell-Mann 150 150 150
Problem: it is very difficult to separate a diquark-antidiquark from a meson-meson current ! Fierz transformation diquarks mesons
I just know ! I knew !