arXiv subjects

K. Tesima

Publications and source records attributed to K. Tesima.

4 recordsLinked to original sources

arXiv1997

Collimation of the e^+e^- annihilation event

The collimation $C$ of a hadronic event in the e^+e^- annihilation is defined as the average of $\cosθ$, $C=<\cosθ>$, where $θ$ is the angle of each hadron measured from the thrust axis, and the average is over all the hadrons produced in an event. It is an infrared-stable event-shape parameter. $1-\bar C$, the difference between the unity and the average collimation at a given energy, is proportional to the anomalous dimension of the hadron multiplicity at the leading order in MLLA. Its next-to-leading order corrections are calculated.

hep-ph↗

arXiv1995

Multiplicity and Event Shape in the Perturbative QCD

The multiple hadroproduction in the perturbative QCD is briefly reviewed. There are a number of quantities which can be analysed with the use of the high-luminosity TRISTAN data. The analysis will contribute to clarifying some unsolved questions, and to the deeper understanding of the jet physics.

hep-ph↗

arXiv1995

Corrections to Angular Ordering in Multiple Hadroprodroproduction

One of the key ideas in describing the multiparticle production at high energies in the perturbative QCD is the angular ordering in successive soft-gluon emission. We analyse the angular distribution of particles in a jet, and investigate the corrections to the angular ordering. At a small angle from the jet direction, the angular ordering is exact at the next-to-leading order. At a large angle, the angular ordering overestimates the angular particle density by a factor $(1-γ\ln \cos^2(θ/2))$, where $γ$ is the anomalous dimension of the multiplicity. The $O(γ)$ correction restores the boost invariance of the cross section.

hep-ph↗

arXiv1993

Multiplicity with a Thrust Cut

We evaluate the multiplicity of hadrons in the $e^+e^-$-annihilation at a given thrust $T$ in the modified leading-log approximation, including $O(\sqrt{α_s})$ corrections. The calculation is done at a large value of $τ=1-T$ by the use of the factorisation which takes place in the one-particle-inclusive cross section at a given $τ$. At a small $τ$, a different type of factorisation takes place, which also enable us to evaluate the multiplicity. Two approaches are compared numerically. Measuring this quantity near $τ=1/3$, we can determine the multiplicity ratio between a gluon-jet and a quark-jet.

hep-ph↗