S.D. Rindani

Electron-positron annihilation into three jets in the integer-charge quark model

Abstract We discuss e + e − → 3 jets in the integer-charge qaurk model. In the lowest non-trivial order, ignoring coloured Higgs scalars, we find that three-gluon jets would be observable at present PETRA energies if the gluon mass m g ⪅ 2 GeV. As an experimental test, the angular distribution is presented.

Contribution of coloured Higgs bosons to e+e− annihilation into two jets

Abstract We examine the effect of the coloured Higgs bosons (of the integer-charge quark model) on electron-positron annihilation into two jets. The overall angular distribution of the quark + gluon + Higgs jets in the scaling limit is found to be 1+0.57 cos 2 θ .

Do the PETRA two-photon jet experiments rule out integrally charged quarks?

Abstract The data on two-jet production in the PETRA single-tag two-photon experiments have been analyzed in the integer-charge quark model based on a spontaneously broken SU(3) colour gauge theory. The results show that the model is consistent with experiment for m g ⪅200 MeV, where m g refers to the gluon mass parameter in the model (and not to the physical gluon mass).

Contribution of gluons and coloured Higgs bosons to e+-e− annihilation into three jets

Abstract Three-jet thrust and angular distributions in e + e − annihilation are calculated in the integer-charge quark model. The complete contributions of gluons and Higgs scalars are presented. Deviations from QCD results are in general less than or comparable to the experimental errors, except for m g ≲ 2 GeV and m H ⪢ 30 GeV.

Validity of the equivalent-photon approximation for the production of massive spin-1 particles

We point out that the equivalent-photon approximation (EPA) for processes with massive spin-1 particles in the final state would have validity in a more restricted kinematic domain than for processes where it is commonly applied, viz., those with spin-1/2 or spin-0 particles in the final state. We obtain the criterion for the validity ofEPA for the two-photon production of a pair of charged, massive, point-like spin-1 particlesV±, each of massM and with a standard magnetic moment (κ=1). In a process in which one of the photons is real and the other virtual with four-momentumq, the condition for the validity ofEPA is |q2|≪M2, in addition to the usual condition |q2|≪W2,W being theV+V− invariant mass. In a process in which both photons are virtual (with four-momentaq andq′), our condition is |q2||q′2|W4 ≪ 16M8, in addition to |q2| ≪M2, |q′2| ≪M2 and |q2| ≪W2, |q′2| ≪W2. Even when these extra conditions permitting the use ofEPA are not fulfilled, convenient approximate expressions may still be obtained assuming merely |q2| ≪W2 and |q′2| ≪W2.We also discuss how the extra conditions are altered when the vector bosons are incorporated in a spontaneously broken gauge theory. Examples ofW boson production in Weinberg-Salam model are considered for which the condition |q2||q′2|W4 ≪ 16M8 is shown to be removed.

A note on the annihilation of polarised e+e− beams into jets in the broken colour gauge theory

Abstract The dependence of angular distribution on polarisation for the processes of transverse or longitudinally polarised e + e - beams annihilating into two or three jets has been got from very general considerations. It is seen that when weak interaction effects are negligible polarisation calculations yield no new information on the model used other than what has been obtained with unpolarised beams.

Spin dependence of the charged-gluon contribution in deep-inelastic scattering

Abstract In the integer-charge quark model, it is found that because of the photon-gluon mixing, only the zero-helicity gluons couple to deep-inelastic probes. As a particular consequences, gluons do not contribute to the (longitudinal) polarization asymmetry σ (↑↓) − σ (↑↑) in polarized electroproduction in the scaling limit.

Decays ofW andZ in the broken-colour model

The two-gluonic decay modes ofW andZ in the broken colour model with integrally charged quarks are considered. The gluonic branching ratios are found to be 3% and 2·7% forW andZ respectively. The angular distributions of the decays ofW andZ to two jets of hadrons are also worked out.