Scalar%20mesons%20from%20from%20s%20to%20?b0

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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
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C O M E R C I A L
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The low-lying scalars

• See next talk by Ning WU

pp elastische Streuung f0(470)
f0(980)
und a0(980) K0(700)
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Nc 3
Nc 5

• Reminder, Pelaez
• s, k are
• non-qq
• objects

Nc 10
Nc 3
Nc 5
Nc 10
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From 1300 to 1500 MeV and Babar
B -gt K (KK)
B -gt K(pp)
f0(1370)
glueball
f0(1500)
no f0(1500)
no f0(1370)
BaBar 2 states at 1500 MeV? Ochs
Minkowski 1 8 interference
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• f0(1500) is flavour octet state
• Remark there is no narrow
• Not in pp
• scattering

f0(1370)
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• Not in B decays (see above),
• nor in central production
• nor in pp annihilation
• into 5 pions

PP -gt rr
4p invariant mass (GeV)
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Nor in radiative J/y decays to pp
No f0(980)
f0(1760)
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From 1710 to 1810 MeV and BES

• Three observations
• f0(1710), f0(1790), f0(1810)
• KK pp fw
• J/y -gt wKK fpp gfw
• 
  Flavour 8

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

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• 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

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• The three observations
• f0(1710), f0(1790), f0(1810)
• KK pp fw
• J/y -gt wKK fpp gfw
• can be one scalar state, f0(1760), in a
• flavour octet qqqq configuartion

WHERE ARE THE SINGLET STATES ?
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Singlet
f0(1850)
f0(1540)
f0(1300)
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The Y(3940)

• ee- -gt J/y X
• Belle X(3940)
• M3943 /-6 /-6 MeV
• G lt 52 MeV
• hc(3S)

• 2g -gt DD
• Belle Z(3930)
• M3931 /-4 /-2 MeV
• G 20 /-8 /-3 MeV
• cc2(2P)

• B -gt K J/y w
• Belle X(3940)
• M3943 /-11 /-13 MeV
• G 87 /-22 /-26 MeV
• cc0(2P)

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Charmed mesons
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D0(2400) and Ds0(2317) -gt D0(1980) needed
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The scalar mesons
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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 -gt pp via p exchange
• Thank you for your
  patience