BaBar%202007

1
BaBar 2007

• EM clusters and tau pairs
• Roger Barlow

2
Photons and splitoffs

• Photon showers spread over several crystals
  compact
• Splitoffs spread over several crystals spread
  out
• Shape Variables Combine using Neural Net (D J
  Bard)
• Segment Energies
• Form Photon
• Consistency quantity

400-500 MeV
3
Cut on Photon Consistency

Harder cut gives purer signal (evidence from ?0
peak) at price of lower statistics
4
Rival LAT cut
LAT is a shape used by ARGUS and others. Clearly
hopeless
5
Results
Loss of signal in real data is a good match to
parabola.

6
Tau Analysis

• Take Tau11 skim at SLAC
• Adapt JongTimGrahams CompositionTools work
• Write ntuples for all runs 1-5 data and MC
  (28,000 files)
• Copy to Manchester /afs space

7
Things to do with it(1)

• Count ??? -?? ? - , ? e -, e e pairs and
  check run luminosities and consistencies
• Now M Phys project

8
Things to do with it(2)

• Look for 2 prongs 2 photons

9
2nd class current?

• With Kaon
• With pion

10
Things to do with it(3)

• Look for 4 photons 2 ?0s
• Meson states a1(1260), f0(980)
• Keep me busy in 2008.