A.%20Drutskoy%20%20%20%20%20%20%20%20%20%20%20%20APS%20Topical%20Group%20Meeting%20on%20Hadronic%20Physics%20%20%20%20%20%20%20%20%20October%2024-26,%202004,%20Fermilab

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Properties of the DsJ states
A.Drutskoy, University of Cincinnati
First Meeting of the APS Topical Group on
Hadronic Physics
October 24-26, 2004, Fermilab, Batavia
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
2
Outlook
1. Production of DsJ mesons in continuum
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2. Improved measurement of B -gt DsJ D() decays
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3. First study of B -gt DsJ K and DsJ p decays
4. Conclusions
Last two measurements are Belle preliminary.
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
3
Full statistics at U(4S) 253 fb-1
275 x106 BB pairs
Partial statistics includes 140 fb-1 or 152
x106 BB pairs
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
4
DsJ meson production in continuum


BaBar first observed DsJ(2317) -gt Ds po decay
mode in ee- continuum. No evidence for DsJ(2317)
-gt Dsg, Ds g and Dsgg was found. CLEO confirmed
observed DsJ(2317) signal and established
DsJ(2460) signal. Signal widths were consistent
with detector resolution.



Belle confirmed BaBar and CLEO results. Decay
modes observed are DsJ(2317) -gt Ds p0,
DsJ(2460) -gt Ds p0 and DsJ(2460) -gt
Ds g.






Belle
Belle
Belle
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
5
DsJ meson spectroscopy
In the heavy quark limit, the total angular
momentum of the light quark Jq is a good quantum
number. This leads to spectroscopy with separated
Ds meson spin-doublets (0-, 1-), (0,1),
(1,2).

Ds
DsJ(2460)
Ds
DsJ(2317)
Measured masses of DsJ(2317) and DsJ(2460) are
significantly lower than predictions from
potential models. Widths are consistent with zero
in contrast to expectations.


Large theoretical efforts to explain narrow
DsJ(2317) and DsJ(2460) resonances DK threshold
effect, chiral partners, four-quark states?
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
6
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Improved measurement of B?D DsJ decays
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B -gt D DsJ processes are described by
conventional tree diagram.
D- and D0 decay modes are combined in figures.
275x106 BB pairs.
Masses 2320.01.12.0 and 2459.50.92.0 MeV
Width consistent with resolution
DsJ(2317)?Ds?0
DsJ(2460) ?Ds?0
DsJ(2460) ?Ds?
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
7
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Observation of B?D DsJ decays
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Belle also measured B -gt D DsJ decays (BaBar
recently reported these Bf).
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D and D0 decay modes are combined in figures.
274x106 BB pairs.
DsJ(2317)?Ds?0
DsJ(2460) ?Ds?0
DsJ(2460) ?Ds?
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
8
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Combined (D0 and D-) results for B -gt DsJ D
decays
Decay channel
Bf, 10- 4 Significance
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B ? D DsJ(2317) Dsp0 10.1 ? 1.5 ?
3.0 9.5s B ? D DsJ(2317) Dsg
4.0-1.41.5 (lt8.4) 3.5s B ? D
DsJ(2460) Dsp0 14.8-2.52.8 ? 4.4
8.6s B ? D DsJ(2460) Dsg
6.4 ? 0.8 ? 1.9 11s B ? D
DsJ(2460) Dsg 2.6-1.01.1 (lt5.7)
3.0s B ? D DsJ(2460) Dspp-
1.0-0.40.5 (lt2.3) 2.6s B ? D
DsJ(2460) Dsp0 0.2-0.50.7 (lt1.7)
-- B ? D DsJ(2317) Dsp0
3.1-1.72.1 (lt8.5) 2.0s B ? D
DsJ(2460) Dsp0 28.7-6.47.4 ? 8.6
6.9s B ? D DsJ(2460) Dsg
12.7-2.02.2 ? 3.8 10s
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Belle branching fractions with D meson are about
two times smaller than those obtained by BaBar.
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Measured BF an order of magnitude smaller than in
B-gt DsD decays with pseudoscalar Ds. Theory
similar rates for Ds, Ds, DsJ(2317),DsJ(2460)?
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
9
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Combined (D0 and D-) results for B -gt DsJ D
decays
Bf(DsJ(2460)?Ds ?) / Bf(DsJ(2460) ? Ds ?0)
0.43 ? 0.08 ? 0.04 Bf(DsJ(2460) ? Ds ?0 ) /
Bf(DsJ(2460) ? Ds ?0) lt 0.10
_at_90CL Bf(DsJ(2460) ? Ds ? ?- ) / Bf(DsJ(2460)
? Ds ?0) lt 0.13 _at_90CL Bf(DsJ(2460) ? Ds ?) /
Bf(DsJ(2460) ? Ds ?) lt 0.76
_at_90CL Bf(DsJ(2317) ? Ds ?) / Bf(DsJ(2317) ?
Ds?0) lt 0.70 _at_90CL
J1
J1
J0
J2
DsJ(2460) ? Ds g
DsJ(2317) ? Ds p0

J0 c2/ndf3/8 J1 c2/ndf38/8
J1 c2/ndf4/8 J2 c2/ndf89/8
Data agree with Jp0 for DsJ(2317) and Jp1
for DsJ(2460)

A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
10
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B0-gt DsJ K- and B0-gt DsJ p decays
DsJ(2317) and DsJ(2460) mesons are selected to
search for B-gtDsJ K and BgtDsJp decays.
W exchange diagram
Final state interactions
Tree, 4-quark DsJ content

The DsJ K final state has a completely different
quark content than original B meson.
Within factorization approach, Cabbibo-Kobayashi-M
askawa matrix element Vub can be obtained from
ratio Bf(B-gt Dsp) / Bf(B-gt Ds D)
(0.4240.041) x Vub/Vcb2
Measured branching fractions (Belle) Bf(B0-gt Ds
K-) (2.930.550.79)x10-5 Bf(B0-gt Ds
p)(1.940.470.52)x10-5
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Studies of B-gtDsJD, B-gtDsJK and B-gt DsJp
decays are important to understand the nature of
DsJ mesons (2- quark or 4- quark DsJ content ?).
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
11
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First study of B0-gtDsJ K- and B0-gt DsJ p decays


DsJ(2317) -gt Ds p0 , DsJ(2460) -gt Ds g
152 x106 BB pairs, L 140fb-1

Ds-gt fp, K0K, KSK
6.8 s
DsJ(2317) K-
DsJ(2317) K-
DsJ(2317) p
DsJ(2317) p
DsJ(2460) K-
DsJ(2460) K-
DsJ(2460) p
DsJ(2460) p
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
12
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Study of B0-gtDsJ K- and DsJ p decays
Fit to mass difference DM M(DsJ)-M(Ds) (mass
and width are allowed to float) Data
DM(DsJ(2317))(351.2 1.6) MeV/c2 MC
DM(DsJ(2317))(348.5 0.3) MeV/c2
(2317.5) Resolution s Data s(6.0 1.2)MeV/c2
MC s(6.1 0.2)MeV/c2
Flat -gt Jp0
Obtained branching fraction and upper limits
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Bf(B0-gtDsJ(2317) K-) x Bf(DsJ(2317)-gtDs p0)
(5.31.5 0.7 1.4)x10-5
-1.3
DsJ(2317)- p (DsJ(2317)-gtDsp0) DsJ(2460) K- (DsJ(2460)-gtDsg) DsJ(2460)- p (DsJ(2460)-gtDsg)
lt2.5x10-5 (90CL) lt0.94x10-5 (90CL) lt0.40x10-5 (90CL)
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Measured B0-gt DsJ(2317) K- branching fraction is
of the same order as B0-gtDs K- branching
fraction and at least 2 times larger than
that for B0-gtDsJ(2460)K- decay
(Bf(DsJ(2460)-gtDsg)30) -gt unexpected !!!
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A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
13
Why is that?
Bf(B0-gtDsJ(2317) D-) x Bf(DsJ(2317)-gtDs p0)
(10.32.3 3.1)x10-4
-2.0
Bf(B0-gtDs D-) (8.0 3.0)x10-3
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Bf(B0-gtDsJ(2317) K-) x Bf(DsJ(2317)-gtDs p0)
(5.31.5 0.7 1.4)x10-5
-1.3
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Bf(B0-gtDs K-) (2.93 0.55 0.79)x10-5
Theoretical expectations (naïve)
Bf(B0-gtDs M)
1, if DsJ is two-quark state.
for M D, K, p

Bf(B0-gtDsJ(2317) M)
10, if DsJ is four-quark state.
Four-quark tree diagram (for DsJ K- decay) can
change this ratio.
Probably too naïve Ask theorists to explain
this.
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
14
Conclusions
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Decays B -gt DsJ D() were measured with improved
accuracy. Obtained branching fractions are of
order of magnitude smaller than those with a
pseudoscalar Ds . Angular distributions indicate
that the DsJ(2317) is 0 and the DsJ(2460) is
1.
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B0 -gt DsJ K- and DsJ p were studied for the
first time. The branching fraction for B0-gt
DsJ(2317) K- is of the same order as B0-gtDs K-
branching fraction and more than two times
larger than that for B0-gtDsJ(2460)K- decay
(assuming Bf(DsJ(2460)-gtDsg)30).
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More experimental measurements are required to
understand the nature of DsJ mesons.
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
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Background slides
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Procedures to extract B signal yield
Two almost independent variables MB and DE can be
used to select B meson signal

MB (Ebeam)2 (S Pi)2
DE SEi - Ebeam

Methods to extract B signal yield 1) Cut on MB
and fit to DE 2) Cut on DE and fit to MB 3)
Double dimensional fit to MB and DE
distribution 4) If B-gtP1P2P3 cut DE and MB box
and look at resonant structures in M(P1P2) mass
distribution.
A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
17
Continuum Suppression

• To separate spherical BB events from jet-like
  continuum events, topological variables are
  used
• Second Fox-Wolfram moment
• Super Fox-Wolfram
• (six modified Fox-Wolfram moments, Fisher
  discriminant)
• 3) Angle between B meson and
• beam axis direction
• 4) Angle between thrusts of
• selected B meson particles and all other
  particles in event
• Likelihood ratio includes all info.

A. Drutskoy APS
Topical Group Meeting on Hadronic Physics
October 24-26, 2004, Fermilab
18
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