Zc decay width in QCD sum rules F

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, ar. Xiv: 1304. 6433

Introduction Before 2003: After 2003: Cornell potential: Schrödinger equation: “Good” quarkonium spectrum States with “wrong” masses

Isospin violation: Charged states: (2003) (2007)

Ten years of “bad behavior” * * * (2013) BES-III BELLE CLEO c

New questions What is the structure of the new states ? Meson molecule Tetraquark c Hadro-charmonium c 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) !

Maiani, Polosa, Riquer, ar. Xiv: 0708. 3997 2013 Navarra, Nielsen, Richard, ar. Xiv: 1108. 1230

Zc decay width X (3872) < 2. 3 Zc (3900) ~ 50

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 quarks hadrons

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

Problem: it is very difficult to separate a diquark-antidiquark from a meson-meson current ! Fierz transformation diquarks mesons

I just know ! I knew !