Gabriella Sciolla

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Beyond CP violation Hadronic Physics at BaBar

• Gabriella Sciolla
• Massachusetts Institute of Technology
• On behalf of the BaBar Collaboration

First Meeting of the APS Topical Group on
Hadronic Physics Fermilab, Oct 24-26, 2004
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Beyond CKM physics Hadronic Studies at
BaBar

• Rich and active field, abundant dataset (250
  fb-1)
• 500 x 106 B mesons produced in very clean
  environment
• B masses, lifetimes, Branching Fractions
• ? Tests of factorization, HQET, HQE, SCET,
• 630 million primary D mesons in ee-?cc
• Charm spectroscopy
• DsJ(2317), DsJ(2460), DsJ(2632), X(3872)
• 500 million continuum events (ee-?qq) with
  qu,d,s
• All kind of light resonance can be produced
• Pentaquarks

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The DsJ(2317) and DsJ (2460) states

• Two narrow states recently discovered by BaBar
  and CLEO
• Extensive studies at BaBar and Belle
• Consistent with P-wave cs states but other
  interpretations not ruled out
• Interesting because
• Unexpectedly low masses
• Narrow states (Glt10 MeV)
• If cs, the observed decays are isospin violating
  narrow
• DsJ(2317) ? Ds p0
• DsJ (2460) ? Ds p0
• More studies needed for a complete understanding
  of their nature

DsJ (2573)
Ds1(2536)
Ds1(2460)
Ds0(2317)
Ds
Ds
Godfrey-Isgur model
S-wave
P-wave
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Reconstruction of DsJ in BaBar

• Inclusive approach (hep-ex/0408067)
• Reconstruct DsJ produced in ee-?cc decays
• Advantage
• High statistics ? mass and widths
• Disadvantage
• Higher background ? angular analysis is hard
• Exclusive approach (hep-ex/0408041)
• DsJ produced in fully reconstructed B decays
• Example B? DsJD0 with DsJ?Dsp0
• Advantage very low background
• Angular analysis, exclusive BF
• Disadvantage statistics is lower

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Mass of DsJ(2317) ?Dsp0
hep-ex/0408067 125 fb-1

• DsJ(2317) ? Dsp0
• DS?K0K- or fp
• p(DsJ) gt 3.2 GeV/c2 (cc events)
• p(p0) gt 400 MeV/c2
• Reflections

m(Dsp0) GeV/c2
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Mass of DsJ(2460) ? Dsg
hep-ex/0408067 125 fb-1

• Reconstruct DsJ(2460) ? Dsg
• DS?K0K_ or fp
• p(DsJ)gt3.2 GeV/c2 (cc events)
• p(g) gt 500 MeV/c2
• Reflections

m(Dsg) GeV/c2
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Mass of DsJ(2460) ? Dsp0g
hep-ex/0408067 125 fb-1
Ds(2112) low side band

• Reconstruct DsJ(2460) ? Dsp0g
• Two possible intermediate resonances
• Ds(2112)p0 or DsJ(2317)g
• 2D fit to distinguish each contribution
• To enhance S/B
• m(Dsg) (2112 2) MeV/c2
• Reflections

Ds(2112) high side band
m(Dsp0g) GeV/c2
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Mass of DsJ(2460) and Ds1(2536) in Dspp-
hep-ex/0408067 125 fb-1
Ds1(2536)
DsJ(2460)
m(Dsp p-) GeV/c2
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Combined results of DsJ inclusive analysis
hep-ex/0408067 125 fb-1

• For channels with significant signal measured
  relative B.F.
• For channels with no significant signal, measure
  95 CL upper limit
• For DsJ(2460), combined mass measurement

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DsJ() from B ? DsJ() D()
hep-ex/0408041 122 million BB pairs
DsJ(2317)?Dsp0

• Channels studied
• B?DsJ() D()0
• B0?DsJ() D()-

DsJ(2460)?Dsp0
DsJ(2460)?Dsg
mB
m(DsJ)
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DsJ () from B ? DsJ () D()
hep-ex/0408041 122 million BB pairs
B0?DsJD-
B0?DsJD-
B?DsJD0
B?DsJD0
m(Dsg)
m(DsJ(2460)? Dsp0)
m(DsJ(2460)? Dsg)
m(DsJ(2317)? Dsp0)
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B ? DsJ ()D( ) Results
hep-ex/0408041 122 million BB pairs

• ? Results for B?DsJ()D are first measurements
• Results for B?DsJ()D in good agreement
  with Belle

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Helicity analysis of DsJ (2460)
hep-ex/0408041 122 million BB pairs

• Channels
• B? DsJ(2460) D
• DsJ(2460) ? Dsg
• Helicity angle qh between p(DsJ) in B frame and
  p(DS) in DsJ frame
• Fit cos(qh) with distribution expected for J1
  and J2
• J1 is preferred (c24/4)
• J2 is disfavored (c236/4)

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Search for DsJ(2632) ? Dsh
hep-ex/0408087 (124 fb-1)

• DsJ (2632) ? Dsh and D0K was recently
  reported by SELEX
• BaBar should be able to access both modes

3,900 h?gg in Ds sample
196,000 Ds
events/5 MeV/c2
events/1.3 MeV/c2
m(gg) GeV/c2
m(KK-p) GeV/c2
p(DsJ) gt 4.0 GeV/c
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Search for DsJ (2632) ? Dsh
hep-ex/0408087 (124 fb-1)

• To study correlated production of Ds and h
  subtract side bands from intersection region no
  signal observed

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Search for DsJ (2632) ? D0K
hep-ex/0408087 (124 fb-1)

• In BaBar, very clean Ds2(2573) in D0K invariant
  mass, but no DsJ(2632)

Ds2(2573)
SELEX
BaBar
DsJ(2632)
p(DsJ) gt 4.0 GeV/c
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Search for DsJ (2632) ? DKs
hep-ex/0408087 (124 fb-1)
Very clean Ds1(2536) in DKS invariant mass, but
no DsJ(2632)
Events/2.5 MeV/c2
Ds1 (2536)
DsJ (2632)
M(DKs) m(D) GeV/c2
p gt 4.0 GeV/c
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X(3872) in B-?(J/ypp-)K-
hep-ex/0406022 117 million BB pairs

• Discovered by Belle, confirmed by CDF
• Interpretation uncertain
• Charmonium? DD molecule? ccg hybrid?
• Experimental method
• B-?K- J/y pp- to suppress background
• X(3872) reconstructed in J/ypp-
• Reconstructed events 30.5 5.8
• No evidence for 1P1 charmonium hc(3526)

m(J/ypp-)
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Search for X(3872)- in B0?(J/yr-)K
hep-ex/0408083 213 million BB pairs

• If X(3872)?J/Yr0 ? J/y (pp-)?
• ? IX(3872) 1 ? Expect X(3872)-?J/Yr-
• If X(3872) belongs to I triplet and I is
  conserved in B decays
• ? BF(B?X-K) 2 BF(B?X0K)
• Searched for B0? X-K and B-? X-KS with X- ?
  J/Yr-

No signal observed isospin triplet hypothesis
excluded Problt1/600
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A new state of matter? Pentaquarks

• Evidence for several narrow exotic states has
  been published recently

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Pentaquark production at ee-

• Can pentaquarks be produced in ee-?
• ee- produce all hadrons
• Production rates depend on mass and spin, not on
  quark content
• If pentaquark are produced as
• the other baryons, we expect
• q5 8 x 10-4 / event
• X--5 4 x 10-5 / event

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Search for Pentaquarks at BaBar

• Dedicated searches
• q5, X 5- -, X 50
• Inclusive searches for other states of the
  10585
• N5, S5
• Dedicated searched for some states from other
  multiplets
• E.g. Q in B decays

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Search for Q5(1540)?pKs
hep-ex/0408064 (123 fb-1)
mass(pKS) GeV/c2
mass(pKS) GeV/c2

• Tight selection for p and KS
• Clean Lc(2285) signal 52,000 events
• No structure observed 1540 MeV/c2
• Overall or in bins of momentum

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Search for X5- - ? X-p- / X50 ? X-p
hep-ex/0408064 (123 fb-1)
X0(1532)
Xc 0(2470)
mass(X-p-) GeV/c2
mass(X-p0) GeV/c2

• Decay chain
• Two displaced vertices (X and L)
• Control samples X0(1530) and Xc(2470) ? X-p
• No narrow resonances observed in the region
  1.862 GeV/c2

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Inclusive search to LK, S0K, pKS
hep-ex/0408064 (123 fb-1)

• Inclusive search in LK, S0K, pKS
• LK, S0K from X5-, X50, N5, N50
• pKS from S5
• No pentaquark signal observed

mass(pKS) GeV/c2
mass(LKS) GeV/c2
mass(LK) GeV/c2
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Interpretation of results
hep-ex/0408064 (123 fb-1)

• 95 C.L. limits on differential production
  x-section extracted for previously observed modes
• Branching fraction assumptions
• BF(q5 ? pKS)25
• BF(X 5- - ? X- p-)50
• Limits on total production x-section
• Rates well below baryons
• q5 suppressed by factor 8
• X 5- - suppressed by factor 2

q5
p (GeV/c)
-- G 1 MeV/c2 __ G18 MeV/c2
X5- -
p (GeV/c)
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Search for Q ?pK in B decays
89 fb-1 hep-ex/0408037

• Recent observation of B?ppK
• 212 events (68 with pp from cc)
• Could part of the signal be
• B?pQ with Q ?pK?
• Q characteristics
• member of the 27-plet (uuuds)
• I1, I31
• Mass 1.43-1.70 GeV/c2
• Width 37-80 MeV/c2
• No signal observed set limits on product of BF

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Summary

• In addition to many CKM measurements, BaBar has
  produced many interesting results in hadronic
  physics
• Selected examples
• DsJ states
• DsJ(2317) and DsJ(2460) masses and BF angular
  analysis starting
• Search for DsJ (2632) negative results
  puzzling
• X(3872) state
• Confirmed existance, study of properties just
  starting
• Pentaquark searches
• Many final states searched, none seen
• Limits below expectation for baryons (factor 2-8)
• More statistics will help solving open questions
• Expect 500 fb-1 by 2006

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The future of BaBar