recent bottomonium results from babar
DESCRIPTION
Recent Bottomonium Results from BaBar. Bryan Fulsom SLAC National Accelerator Laboratory 35 th International Conference on High Energy Physics Paris, France July 22, 2010. Overview. This talk: (1D J ) p + p - (1S) (nS) g (e + e - ) h b (1S) (3S) p + p - h b (1P) - PowerPoint PPT PresentationTRANSCRIPT
Recent Bottomonium Resultsfrom BaBar
Bryan Fulsom
SLAC National Accelerator Laboratory
35th International Conference on High Energy Physics
Paris, France
July 22, 2010
• This talk: (1DJ) (1S)
(nS) (ee) b(1S)
(3S) hb(1P)
(3S) hb(1P) b(1S)
Overview
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 2/22
• BaBar: 1999-2008• 122M (3S) / 100M (2S)
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 2/22
• This talk: (1DJ) (1S)
(nS) (ee) b(1S)
(3S) hb(1P)
(3S) hb(1P) b(1S)
Overview• BaBar: 1999-2008• 122M (3S) / 100M (2S)
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 2/22
• This talk: (1DJ) (1S)
(nS) (ee) b(1S)
(3S) hb(1P)
(3S) hb(1P) b(1S)
Overview• BaBar: 1999-2008• 122M (3S) / 100M (2S)
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 2/22
• This talk: (1DJ) (1S)
(nS) (ee) b(1S)
(3S) hb(1P)
(3S) hb(1P) b(1S)
Overview• BaBar: 1999-2008• 122M (3S) / 100M (2S)
• This talk: (1DJ) (1S)
(nS) (ee) b(1S)
(3S) hb(1P)
(3S) hb(1P) b(1S)
Overview
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 2/22
• BaBar: 1999-2008• 122M (3S) / 100M (2S)
(1DJ)
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 3/22
• Expected (1DJ=1,2,3) properties
– m(1DJ) ~10160 MeV/c2, m(1DJ)
~5-12 MeV/c2, (1DJ) ~30 keV
• Experimental observation (3S) (1D2?) (1S) ll
– B((3S) ll) = (2.5 ± 0.5 ± 0.5) 10-5
– m(1D2?) = 10161.1 ± 0.6 ± 1.6 MeV/c2
• No evidence for (1DJ) (1S)
– Limit: B((1DJ) (1S)) < 4%
– Theory: Kuang & Yan ~40%, Ko ~2%, Moxhay ~0.25%
(1DJ): General Information
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 4/22
• Reconstruct (3S) (1DJ) (1S) ll
– Require exactly 4 tracks
– mll consistent with / constrained to m(1S)
– Minimize E 2 to select best candidate
– m(1DJ) resolution ~ 3 MeV/c2
• Maximum Likelihood fit to mll spectrum
(1DJ) signals: Double Gaussian + Crystal Ball
– Monte Carlo (MC)-determined backgrounds:(3S) bJ(2P) ( or ) (1S)
(3S) (1S) + FSR
(3S) () (1S)(3S) / (2S) ((1S))
(1DJ): BaBar Analysis
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 5/22
m(1D2) = 10164.5 ± 0.8 ± 0.6 MeV/c2
(1DJ): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 6/22
(1DJ): Quantum Numbers
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 7/22
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 8/22
b(1S)
• b(1S) observed in inclusive spectrum for (3S) and (2S)
• Measured properties
– B((3,2S) b(1S)) = (5.1 ± 0.7) 10-4 / (3.9 ± 1.5) 10-4
– mb(1S) = 9390.9 ± 2.8 MeV/c2, b(1S) 10 MeV
– (m(1S) – mb(1S)) = 69.3 ± 2.8 MeV/c2
• Hyperfine splitting theoretical predictions– Lattice: ~50-60 MeV/c2 NRQCD: ~40 MeV/c2
b(1S): General Information
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 9/22
• Converted photons ( ee) improve resolution (25 5 MeV)
– Fit pair of tracks, selected with 2fitter, m,
– Additional cuts: |costhrust|, Ntracks, veto
• Simultaneous fit to E spectrum in (3S) and (2S) datasets
(3,2S) b(1S): Breit-Wigner Crystal Ball
– eeE=m(nS)
ISR (1S): Crystal Ball
bJ(2,1P) (1S): Doppler broadening Crystal Ball
– Background: 4th order polynomial exponential decay
b(1S): Converted Photon Analysis
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 10/22
b(1S): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 11/22
• E and branching fractions as expected
• Mass-constrained fit:
– No evidence for b (2.3stat.)
• Best fit result in mb(1S) region:
– Differs by +12.4+3.8-4.0 MeV/c2 (3.3stat., 2.6 w. syst.)
ee: Results Summary
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 12/22
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 13/22
hb(1P)
• Expect mhb(1P) = (mb0(1P)+3mb1(1P)+5mb2(1P)) / 9 9900 MeV/c2
• Production mechanisms
– B((3S) hb(1P)) ~ 10-3 – 10-2
– B((3S) hb(1P)) ~ 10-3
– R(hb (1P) / hb (1P)) = 0.05 – 20
• Expected decays
– hb(1P) ggg (57%), b(1S) (41%), gg (2%)
• Previous searches
– B((3S) hb(1P)) < 1.8 10-3
– B((3S) hb(1P)) < 2.8 10-3
hb(1P): General Information
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 14/22
• Reconstruct pair of oppositely charged tracks
– Cuts on Etotal, R2, Ntracks, KS
veto (flight length, cos )
• Define recoil mass: mR2 = (m(3S) – E
)2 – P
2
2 fit to mR with 7 components
– hb signal: Symmetric two-sided Crystal Ball (TCB)
(3S) (2S): Asymmetric TCB + Bifurcated Gaussian (2S) (1S): same, with fixed feed-down components b1,2(2P) b1,2(1P): TCB, with fixed peak position
– KS
: MC-determined phase space
– Non-peaking background: 6th order Chebychev polynomial
hb(1P): Analysis Strategy
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 15/22
hb(1P): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 16/22
hb(1P): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 17/22
• No evidence for hb signal at mhb = 9900 MeV/c2
– B((3S) hb(1P)) = (0.0 ± 0.5 ± 0.3)10-4 (<110-4 UL)
• Most significant scan point <2 significance
• Exclude B((3S)hb(1P)) > 2.510-4 (90% CL) over range
hb(1P): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 18/22
• Reconstruct () +
– Require E consistent with hb(1P) b(1S)
– Cuts on Ntracks, R2, veto (all candidates), cosh
• Define missing mass: m.m.()2 = (m(3S) – E)2 – P
2
– Constrain m to improve resolution
– N from m fit in each m.m.() bin
2 fit of m.m.() distribution
– hb(1P) signal: Double Crystal Ball
– Background: 6th order polynomial, from reweighted MC
hb(1P): Analysis Strategy
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 19/22
hb(1P): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 20/22
• Fixed mass fit:
– B((3S)hb(1P)b(1S)) = (3.1±1.1±0.4)10-4 (2.7)
– 1.510-4 < B((3S)hb(1P)b(1S)) < 4.910-4
• Best fit mhb = 9903 ± 4 ± 1 MeV/c2 consistent with predictions
• Combined results:
– R(hb(1P) / hb(1P)) > 3.2 (>1.5 for mhb = 9903 MeV/c2)
hb(1P): Fit Results
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 21/22
(1DJ) (1S)
– First observation of (1DJ) hadronic decays
– Quantum numbers and precise m(1D2) measurement
(2,3S) converted photon spectrum
– Most significant (2.6) “b” signal at 9403.3±2.4+0.9-1.5 MeV/c2
– Improved and first direct bJ(1,2P) (1S) measurement
• hb(1P) Search
– No evidence for (3S) hb(1P)
– Marginal evidence (2.7) for (3S) hb(1P) b(1S)
– B((3S)hb(1P)) / B((3S)hb(1P)) > 1 at 90% C.L.
Summary
Recent Bottomonium Results from BaBar / Bryan Fulsom / ICHEP / 2010.07.22 / Page 22/22
FIN