1. 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

2. C O M E R C I A L

3. 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)

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

5. 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: interference

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

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

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

9. 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

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

11. 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 f ss = 2/ 3 f8 - 2/ 3 f1
f8 = 1/ 6 (uu + dd – 2 ss)
f1 = 1/ 3 (uu + dd + ss)

12. 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

13. 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 ?

14. Singlet
f0(1850)
f0(1540)
f0(1300)

15. 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)

16. Charmed mesons

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

18. The scalar mesons

19. 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