Scalar mesons from from s to b0 Eberhard Klempt Helmholtz-Institut für Strahlen- und Kernphysik, Universität Bonn, FRG The low-lying scalars From 1300 to 1700 MeV and Babar From 1700 to 1850 MeV and BES The Y(3940) Charmed scalars The scalar mesons Why in PWA workshop Workshop on Partial Wave Analysis and Dalitz Plot Analysis January 25-26, 2007, Beijing, China

C O M E R C I A L

The low-lying scalars pp elastische Streuung und See next talk by Ning WU pp elastische Streuung f0(470) f0(980) und a0(980) K*0(700)

Reminder, Pelaez: s, k are non-qq objects Nc =3 Nc =5 Nc =10 Nc =3

From 1300 to 1500 MeV and Babar B+ -> K+(pp) B+ -> K+ (KK) glueball f0(1500) no f0(1500) no f0(1370) BaBar: 2 states at 1500 MeV? Ochs + Minkowski: 1 + 8 interference

f0(1500) is flavour octet state Remark: there is no narrow Not in pp scattering f0(1370)

Not in B decays (see above), nor in central production: nor in pp annihilation into 5 pions: PP -> rr 4p invariant mass (GeV)

Nor in radiative J/y decays to pp BES No f0(980) f0(1760)

From 1710 to 1810 MeV and BES Three observations: f0(1710), f0(1790), f0(1810) KK pp fw J/y -> wKK fpp gfw Flavour 8

J/y decays to wX no 1710 f0(980) 1710 1790 no 1790

1 f0(1810) must be flavour octet 2 fw signals four - quark state 3 assume f0(1710), f0(1790), f0(1810) are one fourquark - state f0(1760) 4 produced is nn or ss. These dress to become a fourquark – state 5 nn = 1/ 3 f8 + 2/ 3 f1 ss = 2/ 3 f8 - 2/ 3 f1 f8 = 1/ 6 (uu + dd – 2 ss) f1 = 1/ 3 (uu + dd + ss)

f8 = 1/ 6 (uu + dd – 2 ss) f1 = 1/ 3 (uu + dd + ss) expand: f8 = 1/ 6 (uu + dd – 2 ss) f1 = 1/ 3 (uu + dd + ss) dd + ss uu + ss uu + dd collect: f8 = 1/ 6 (uuss + ddss – 2 uudd) f1 = 1/ 3 (uudd + ddss+ uuss) convert: nn = 1/ 2 (uuss + ddss) decaying into KK ss = (uudd) decaying into pp

SINGLET STATES ? WHERE ARE THE The three observations: f0(1710), f0(1790), f0(1810) KK pp fw J/y -> wKK fpp gfw can be one scalar state, f0(1760), in a flavour octet qqqq configuartion WHERE ARE THE SINGLET STATES ?

Singlet f0(1850) f0(1540) f0(1300)

The Y(3940) hc(3S) cc0(2P) cc2(2P) e+e- -> J/y + X Belle: X(3940) M=3943 +/-6 +/-6 MeV G < 52 MeV hc(3S) B -> K + J/y w Belle: X(3940) M=3943 +/-11 +/-13 MeV G = 87 +/-22 +/-26 MeV cc0(2P) 2g -> DD Belle: Z(3930) M=3931 +/-4 +/-2 MeV G = 20 +/-8 +/-3 MeV cc2(2P)

Charmed mesons

D*0(2400) and D*s0(2317) -> D*0(1980) needed

The scalar mesons

Why in PWA workshop? Location of poles can be where dips are observed in mass spectra. PWA has to allow for a backgound, e.g from rr -> pp via p exchange Thank you for your patience