A Search for the Top and $b^\prime$ Quarks in Hadronic $\Z^0$ Decays

The OPAL collaboration Akrawy, M.Z. ; Alexander, G. ; Allison, J. ; et al.
Phys.Lett.B 236 (1990) 364-374, 1990.
Inspire Record 283784 DOI 10.17182/hepdata.29702

We report on a search for new quarks in hadronic Z° decays. From the event shape analysis of a data sample containing 2185 multihadronic annihilation events, we observe no evidence for the top or b' quarks. We derive limits for the top and b' quark masses under the assumption of various possible standard model and non-standard model decay schemes. Our search is sensitive to quark masses larger than 23 GeV/ c 2 ; it yields the following lower limits at a 95% confidence level: 44.5 GeV/ c 2 for the top quark mass and 45.2 GeV/ c 2 for the b′ quark mass.

1 data table

Measured event shape distributions - uncorrected.


Search for Top Quark and a Test of Models Without Top Quark at the Highest {PETRA} Energies

Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.
Phys.Rev.Lett. 50 (1983) 799, 1983.
Inspire Record 182337 DOI 10.17182/hepdata.20549

With a PETRA energy scan in ≤30-MeV steps, the continuum production of open top quark up to 38.54 GeV is excluded. Over regions of energy scan from 29.90 to 38.63 GeV limits are set on the product of hadronic branching ratio and electronic width BhΓee for toponium to be less than 2.0 keV at the 95% confidence level. By a search for flavor-changing neutral currents in b decay, models without a top quark are excluded.

4 data tables

MEASUREMENT OF R IN ENERGY SCAN FROM SQRT(S) = 29.9 TO 3.146 AND 33.0 TO 36.72.

MEASUREMENT OF R IN THE RANGE SQRT(S) 37 TO 38.63 GEV.

THRUST DISTRIBUTION FOR EVENTS IN THE RANGE SQRT(S) 37.94 TO 38.63 AND 38.54 TO 38.63.

More…