Can experiment distinguish between a four quark scalar

Can experiment distinguish between a four quark scalar, a molecule, a glueball or a qq meson ? n s n qq g s g qq

QCD = q(i QCD q=u, d, s, c, b 1971 D - mq ) q 1 -4 G G

vacuum Chiral symmetry breaking vacuum

Scalar mesons

Scalar mesons s = E 2 complex s-plane CERN-Munich I=J=0

I=J=0 f 0(980) 1 T 2 0 0. 4 0. 8 1. 2 1. 6 M ( ) (Ge. V) KK

Scalar mesons complex s-plane CERN-Munich f 0 I=J=0

Into the complex plane E Im E Re E ER = 441 - i 272 Me. V Caprini, Colangelo, & Leutwyler

I=J=0 Zou

Scalar mesons

Scalar mesons 1 Ge. V 1

Scalar mesons

Scalar multiplet 1 Ge. V { , , KK

J/ Scalar multiplet BES f 0 1 Ge. V { , ,

diquarks: colour tetraquark Jaffe & Wilczek Scalar diquarks [ud] [us] [ds] [cd] [cu] [cs]

Scalar meson multiplets qq qqqq

Scalar meson multiplets qq qqqq Jaffe Maiani, Piccinini, Polosa, Riquer Black, Schechter et al

Scalar meson multiplets qq qqqq Nc large stable Nc large meson continuum

quark model = hadron world? 1 M 2 – s – i. M

quark model = hadron world? 1 Nc

f 0 40% Tornqvist van Beveren

Lattice QCD q q

0++ mesons Amsler & Close 1710 Amsler et al 1500 1430 1370 g g 980 qq qq

0++ mesons SLAC 1710 Weingarten et al 1500 1430 1370 g g 980 qq qq

0++ J/ mesons BES 1810 1710 f 0 1500 1430 1370 Bicudo et al 980 g g qq qq

Scalar mesons complex s-plane CERN-Munich f 0 I=J=0

Isospin-mixing E K 0 K 0 K+ K- Achasov et al Hanhart et al

u d p n d u u u d Weinberg : range of forces d d

qq K K s n qq n s

Quark state v Molecule KK Im E Re E f 0 Weinberg Morgan E

Quark state v Molecule KK Im E Re E f 0 Weinberg Morgan E

Jost function: 1 pole v 2 pole II I K+ K 0 K 0 k 2 plane (KK c. m. momentum) IV III

Jost function: 1 pole v 2 pole K II I IV III K n s s n k 2 plane (KK c. m. momentum) Weinberg Morgan

Jost function: 1 pole v 2 pole II I IV III qq qq k 2 plane (KK c. m. momentum) Weinberg Morgan

Jost function: 1 pole v 2 pole phase-shift II I IV III 2 1 E (Ge. V) k 2 plane (KK c. m. momentum) Morgan & P

Jost function: 1 pole v 2 pole phase-shift II I IV III CM E (Ge. V) k 2 plane (KK c. m. momentum) Morgan & P

Heavy flavour decays Mark III KK

Heavy flavour decays BES KK

Ds (MM) decay FOCUS Ba. Bar pwa preliminary

Jost function: 1 pole v 2 pole preliminary II I IV III n s s n qq qq Wilson & P

Jost function: 1 pole v 2 pole K K preliminary II I IV III n s s n qq qq Wilson & P

J/ g j

Dalitz plot: D+ K - + + K*(892) K*0(800) Malvezzi, P m 2 (K- +) Ge. V 2 K*0(1430) m 2 (K- +) Ge. V 2

K scattering into the complex plane ER = 658 - i 289 Me. V Descotes-Genon, Mousallam E Im E Re E

heavy flavour decays can teach us about light meson physics LAL, Orsay November 2007