OK, this is just getting ridiculous
August 16, 2007
Belle claims to see a “Z(4430)” as a π±ψ’ structure in B → Kπ±ψ’ decays. This joins the X(3872), Y(3940), Y(4260), Y(4350), and Y(4660) in the zoo of incomprehensible things above DD threshold that decay to charmonia. Unlike the other objects, this one is charged, which means it can’t be a hybrid or conventional charmonium state.
August 16, 2007 at 11:06 am
so, any conjecture about what it is?
August 16, 2007 at 3:06 pm
I think the standard answer would be a four-quark state, which can have charge, isospin, strangeness, and so on. I don’t know if anyone who’s advocated multiquark explanations for the previous states wanted a state at this mass though.
August 24, 2007 at 7:36 pm
If the Belle state, Z(4430)-> psiprime pi+,
is correct, then this is the smoking gun
evidence of an exotic (a charged charmonium
resonance) state that cannot come from a
conventional qqbar meson. This could be the most
important discovery since the J/psi which led to the discovery of charmonium and charmed states.
A possible explanation for the Z(4430) is a four quark state. New families of four quark states might be discovered in the near future. If this is wrong it might turn into another Pentaquark saga.
August 31, 2007 at 7:58 am
[...] 31st, 2007 Three theoretical discussions of the Z(4430) state have shown up on hep-ph in the last couple of [...]