1. DsJ* ‘s & charmed strange baryons at Belle
Henryk Palka
INP PAS Krakow
(for Belle)
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

2. cs spectroscopy pre-2003 era:_
cs spectroscopy pre-2003 era:
Ds1(2536) 1+ (?) (Argus 89)
Ds2(2573) 2+ (?) (Cleo 94)
(+ 0- Ds , 1- Ds* )
HQS-motivated potential model (Godfrey,Isgur 85): all L=1 states above DK thr., Γ(jq=1/2) >> Γ(3/2)
D*K
D K
L = 2
….. JP
L = 1
jq = 3/2
jq = 1/2 2+ 1+ 0+
L = 0 1- 0-
mix
jq = sq + L, J = jq + sQ
G-I predicted Ds2(2573) jq = 3/2,
Ds1(2536) fits nicely too (post-diction)
2 missing states not seen for a decade
‘ too wide, difficult to discover ‘
spin-orbit
s-o
s-s
tensor
Theory disputed m(jq=1/2) > m(3/2)
(‘inversion’), mixing level between 3P1
and 1P1 (~ HQS breaking)
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

3. Surprises of 2003: Babar: DsJ.(2317)  Dsπ0
PRL 90, (2003)
Cleo: confirmed DsJ(2317) and
found another one: DsJ(2460)
PRD 68, (2003)
Belle: confirmations + new modes
PRL 92, (2004)
DsJ(2460)  Ds γ
DsJ(2317)  Dsπ0
DsJ(2460)  Ds*π0
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

4. Masses and widths Widths consistent with mass resolutions
New mass measurements from Babar: m(DsJ(2317) )+ ~2 MeV
(hep-ex/ , 211fb-1)
m(2460) - m(2317) ≈
m(1-) - m(0-) = 143 MeV
PDG’04 average mass differences:
m(DsJ(2317)) – m(Ds) = MeV
m(DsJ(2460)) – m(Ds*) = MeV
m(2460) - m(1-) ≈
m(2317)-m(0-) = 348 MeV
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

5. New DSJ* ‘s are produced in B decays
while:
BF(DDs) or DDs*
≈10-2
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

6. DSJ* ‘s spin-parity from BDDsJ*
The initial state state JP=0- restricts v.much possible final state
spin-parities
Angular distributions: DsJ helicity frame, Ds as a spin analyzer
DsJ(2317)  Dsπ0
DsJ(2460)  Ds*π0
J = 1: 2/d.o.f = 4/8
J = 2: 2/d.o.f = 89/8
J = 0: 2/d.o.f = 3/8
J = 1: 2/d.o.f = 38/8
JP = 0+
JP = 1+
PRL 91,
(2003)
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

7. DSJ* ‘s decay modes summary
The only known BR’s :
Ds γ/ Ds*π0 =
( PDG’04 )
Dsπ+ π-/Ds*π0 =
BF’s of the DsJ(2460):
sum of all seen BF is
76±20 %
(Babar hep-ex/ )
All observed decay modes are isospin violating
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

8. Observation of DS1(2536)+  D+ π- K+
hep-ex/
802±86 ev
xP > 0.8
The 2nd 3-body decay of Ds1 observed
( Ds π+ π- : PRL 92, (2004))
2-body invariant mass spectra:
m(D*0) < m(D+) + m(π-), also not enough
energy to produce K*, D**
spectra in reasonable agreement with
2 out of 3-body phase space
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

9. Angular studies of DS1(2536)+  D*+K0s
hep-ex/
3474±64 ev
A clean signal thanks to hard charm f.f.
xP > 0.8
the decay described by 3 angles:
cos α, β not flat Ds1 part. polarized
cos γ: D*+ polarized
1+  Acos2γ L=2: A=3, L=0 : A=0
|S + D|2 = f(R,φ)
A = ± 0.03,
χ2/dof = 1.39
|φ|< 42o
R=ΓS/(ΓS+ΓD)
φ : relative phase
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

10. Summary on DsJ* ‘s DsJ(2317) , DsJ(2460) even better known
than Ds1, Ds2
More precise BF measurements could
discriminate between available models
4 states with right quantum numbers to
form L=1 cs multiplet, do they form it?
Re-examination of the pot. model
(Cahn,Jackson): pot.model rather
inconclusive on which jq multiplet is
heavier
3P1 – 1P1 mixing needs further studies
(also on the DsJ(2460) side):
Ds1D*+K0s shows large S/D
Other pot.model predictions (radial excit.,
higher spins) should be tested
Chiral doublers(Nowak,Zached; Bardeen…):
is m(0+)-m(0-)=m(1+)-m(1-) accidental
(predictions for higer spin exist)
Babar: J=3 ?
(Charm’06,
Meson’06- talk
by Pelizaus)
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

11. Charmed strange baryons
Precision measurement of c0 and c+ masses :
PLB 605, 237 (2005)
c0 ‘s reconstructed in 7 decay modes :
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

12. Charmed strange baryons
c0 and c+ masses :
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

13. Charmed strange baryons
Study of excited states c(2645) :
C(2645)0
C(2645)+
Reflection from
C(2790)0 c’+ -,
c’+  c+ 
(verified with MC)
Reflection from
C(2790)+ c’0 +
(verified with MC)
c’0  c0 
Mass(c+ -)
C+  - ++
Mass(C0 +)
C0  - +
PDG’05:
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

14. Charmed strange baryons
New charmed baryons :
hep-ex/
cx(3077)+
cx(2980)+
wrong-sign c+ K+ -
c+ K0s -
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

15. Charmed strange baryons
hep-ex/
Search for cc (3520)+ c+ K- + (Selex)):
p*(c+)>2.5 GeV , c+ events reconstructed
N=8.3 ± 37.3 < 90% CL
(cc(3520)+)Br(cc(3520)+c+K-+ ) / (c+ ) < @ 90% CL
p*(c+)>2.5 GeV
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle

16. Summary on charmed strange baryons
c0 , c+ and c(2645) mass measurements with
a good precision
Three new charmed stranged barons observed
cx(3077)+  c+ K- +
cx(2980)+  c+ K- +
cx(3077)0  c+ KS0 -
No evidence for cc (3520)+ c+ K- +
QWG’06 BNL, June 2006
Henryk Palka INP PAS / Belle