0000000000085950
AUTHOR
Zobernig G.
Three-prong τ decays with charged kaons
Final states with charged kaons in three-prong τ decays are studied by exploiting the particle identification from the dE/dx measurement. The results are based on a sample of about 1.6 × 105 detected τ pairs collected with the ALEPH detector between 1991 and 1995 around the Z peak. The following branching ratios have been measured: B(τ- → K−K+π−ντ) = (1.63 ± 0.21 ± 0.17) × 10−3, B(τ− → K−π+π−ντ) = (2.14 ± 0.37 ± 0.29) × 10−3, B(τ− → K−K+π−π0ντ) = (0.75 ± 0.29 ± 0.15) × 10−3, and B(τ− → K−π+π−π0ντ) = (0.61 ± 0.39 ± 0.18) × 10−3. The first two measurements are more precise than the current world averages, while the last two channels are investigated for the first time. The 95% C.L. upper limi…
Improved measurements of electroweak parameters from Z decays into fermion pairs
The properties of the Z resonance are measured on the basis of 190000 Z decays into fermion pairs collected with the ALEPH detector at LEP. Assuming lepton universality, M(Z) = (91.182 +/- 0.009exp +/- 0.020L;P) GeV, GAMMA(Z) = (2484 +/- 17) MeV, sigma(had)0 = (41.44 +/- 0.36) nb, and GAMMA(had)/GAMMA(ll) = 21.00 +/- 0.20. The corresponding number of light neutrino species is 2.97 +/- 0.07. The forward-backward asymmetry in leptonic decays is used to determine the ratio of vector to axial-vector coupling constants of leptons: g(V)2(M(Z)2)/g(A)2(M(Z)2) = 0.0072 +/- 0.0027. Combining these results with ALEPH results on quark charge and bbBAR asymmetries, and tau-polarization, sin2 theta(W)(M(…
Production ofK 0 and Λ in hadronic Z decays
Measurements of the inclusive cross-sections forK 0 and Λ production in hadronic decays of the Z are presented together with measurements of two-particle correlations within pairs of Λ andK 0. The results are compared with predictions from the hadronization models Jetset, based on string fragmentation, and Herwig, based on cluster decays. TheK 0 spectrum is found to be harder than predicted by both models, while the Λ spectrum is softer than predicted. The correlation measurements are all reproduced well by Jetset, while Herwig misses some of the qualitative features and overestimates the size of the $$\Lambda \bar \Lambda $$ correlation. Finally, the possibility of Bose-Einstein correlatio…
A study of tau decays involving eta and omega mesons
The 132 pb(-1) of data collected by ALEPH from 1991 to 1994 have been used to analyze eta and omega production in 7 decays. The following branching fractions have been measured: B(tau(-) --> nu(tau)omega h(-)) = (1.91 +/- 0.07 +/- 0.06) x 10(-2), B(tau(-) --> nu(tau)omega h(-)pi(0)) = (4.3 +/- 0.6 +/- 0.5) x 10(-3), B(tau(-) --> nu(tau)eta K-) = (2.9(-1.2)(+1.3) +/- 0.7) x 10(-4), B(tau(-) --> nu(tau)eta(h)(-)pi(0)) = (1.8 +/- 0.4 +/- 0.2) x 10(-3) and the 95% C.L. limit B(tau(-) --> nu(tau)eta pi(-)) < 6.2 x 10(-4) has been obtained. The omega pi(-) and eta pi(-)pi(0) rates and dynamics are found in agreement with the predictions made from e(+)e(-) annihilation data with the help of isospi…
Search for CP violation in ZmF ττ
Abstract Using the 18.8 pb−1 of data accumulated at LEP in 1990 and 1991 with the ALEPH detector, a direct test of neutral current CP-invariance is performed by a search for CP-odd correlations in Z decays to τ pairs where both τ decay modes are identified. No evidence for CP-violation is observed. The weak dipole moment of the τ has been measured to be dτ(mZ) = (1.3 ± 1.4 ± 0.1) × 10−17 e·cm which results in an upper limit on the weak dipole moment of |dτ(mZ)| ⩽ 3.7 × 10−17 e·cm with 95% confidence level.
Search for Magnetic Monopoles and Stable High-Electric-Charge Objects in 13 Tev Proton-Proton Collisions with the ATLAS Detector
We thank CERN for the very successful operation of the LHC, aswell as the support staff fromour institutionswithout whom ATLAS could not be operated efficiently. We acknowledge the support of ANPCyT, Argentina; YerPhI, Armenia; ARC, Australia; FWF, BMWFW, Austria; ANAS, Azerbaijan; SSTC, Belarus; CNPq, FAPESP, Brazil; NSERC, CFI, NRC, Canada; CERN; CONICYT, Chile; CAS, NSFC, MOST, China; COLCIENCIAS, Colombia; VSC CR, MSMT CR, MPO CR, Czech Republic; DNSRC, DNRF, Denmark; IN2P3-CNRS, CEA-DRF/IRFU, France; SRNSFG, Georgia; MPG, HGF, BMBF, Germany; GSRT, Greece; RGC, Hong Kong SAR, Hong Kong China; Benoziyo Center, ISF, Israel; INFN, Italy; JSPS, MEXT, Japan; JINR; CNRST, Morocco; NWO, Nether…
AN INVESTIGATION INTO INTERMITTENCY
The results of an investigation based on ALEPH data, e+ e- --> hadrons at square-root s = 91 GeV, into fluctuations in rapidity space are presented. It is found that the behaviour of the factorial moments is well represented by the Lund parton shower model. An estimate is made of the scale of fluctuations needed to describe the data. Differential moments are introduced and are used to demonstrate that within the average represented by the traditional factorial moments the pattern of fluctu10.1007/BF01483869ations is itself a strong function of rapidity. This pattern is shown to be primarily associated with the emission of hard gluons. The implied structure between the hadron clusters and pa…