Measurement of the transverse spin correlations in the decay Z ---> tau+ tau-

Collaboration
Apr, 1997
14 pages
Published in:
  • Phys.Lett.B 405 (1997) 191-201
Report number:
  • CERN-PPE-97-047,
  • CERN-PPE-97-47
Experiments:

Citations per year

199720012005200920133012
Abstract: (Elsevier)
For τ leptons produced in e + e − → τ + τ − interactions there are, in addition to the longitudinal spin correlations, two independent transverse spin correlations associated with the transverse (within the production plane) and normal (to the production plane) polarization components. A measurement of the transverse-transverse and transverse-normal τ spin correlations in the decay Z → τ + τ − , C TT and C TN , is presented based on the aplanarity angle of the decay products of both τ leptons. Using 80 pb −1 of data collected by ALEPH on the peak of the Z resonance, the results are C TT = 1.06±0.13 (stat) ±0.05(syst), and C TN = 0.08±0.13(stat)±0.04(syst). These values are in agreement with the Standard Model predictions, C TT = 0.99 and C TN = −0.01.
  • electron positron: colliding beams
  • electron positron: annihilation
  • Z0: electroproduction
  • Z0: leptonic decay
  • tau: pair production
  • tau: polarization
  • spin: correlation
  • spin: transverse
  • tau: leptonic decay
  • tau: semileptonic decay