Finding the asymmetry in the number of polarised Z0 bosons.

1
Finding the asymmetry in the number of polarised
Z0 bosons.
For signal-gtlarge energy(ET ETot) PT
difference between e1e2 of ee-
by 280GeV !!!
(Unexpected unknown?)
Agreement between truth MC data (before Atlfast
smears) and Atlfast data.
-gtlook at the angular distributions spins in Z0
rest frame using Spcl MC data.
2
Results-finally!

• Employed a Lorentz boost function (from BaBar C
  course/P.F. Kunz).

• Plotted cos? and ? (boosted/Z0 rest frame).
  Also cos? and ? (laboratory
• 
  frame- as a
  check).

• Boosted frame (Z0 rest frame)

3

• Laboratory frame

4
Conclusions

• No.Z0L gt No.Z0T -gt explains this large E/PT
  difference -gt good. But

• Next question Why is this so?

• Important notes

• Production ss s(ZL ZL) gt s(ZT ZT) -gt spin
  nature of radion and gravition
• 
  (spin-0)
  (spin-2)
• compare -gt SM production of ZLZL is
  suppressed.
• 
  

Reference hep-ph/0103308
2. Also noticed Massive particles -gtdecaying-gt
VLVL (where V is a W or Z0).
e.g. Higgs case H-gtZZ gt s(ZLZL) is pronounced
at the Higgs peak.
So,
Low E (SM) gg-gtZTZT
qqbar-gtZTZT High E(BSM) gg-gtG or ?-gtZLZL
qqbar-gtG or ?-gtZLZL
Reference CERN-TH 5248/88 EWN Glover JJ van
der Bij
5
Origin of EWSB?

• Still largely unknown (using SM).

• Theories for mechanism of EWSB include
  strong-self interactions

-gtResponsible for removing symmetry between
photon (massless) and
W, W-,
Z0 (massive).

• New physics (new resonances) supply-gt 3x degrees
  of freedom (Goldstone
• 
  
  bosons)
• -gtswallowed by the gauge bosons (WL and ZL ).

-gtNew physics MUST appear at 1TeV scale (so not
to violate unitarity).
-gtTeV scale Graviton resonances?
Work in progress

• Started using the KTjet clustering algorithm for
  a more detailed jet analysis.