arXiv subjects

Y. Kajiyama

Publications and source records attributed to Y. Kajiyama.

3 recordsLinked to original sources

arXiv2008

Flavour physics of leptons and dipole moments

This chapter of the report of the ``Flavour in the era of the LHC'' Workshop discusses the theoretical, phenomenological and experimental issues related to flavour phenomena in the charged lepton sector and in flavour-conserving CP-violating processes. We review the current experimental limits and the main theoretical models for the flavour structure of fundamental particles. We analyze the phenomenological consequences of the available data, setting constraints on explicit models beyond the Standard Model, presenting benchmarks for the discovery potential of forthcoming measurements both at the LHC and at low energy, and exploring options for possible future experiments.

hep-ph↗

arXiv2004

Double Suppression of FCNCs in a Supersymmetric Model

A concrete model which can suppress FCNCs and CP violating phenomena is suggested. It is an $S_3$ symmetric extension of the MSSM in extra dimensions, where only SU(2) and SU(3) gauge multiplets are assumed to propagate in the bulk. They are suppressed due to $S_3$ flavor symmetry at $M_{SUSY}$, and the infrared attractive force of gauge interactions in extra dimensions are used to suppress them at the compactification scale. We find that O(1) disorders of the soft parameters are allowed at the cut-off scale to suppress sufficiently FCNCs and CP violating phenomena.

hep-ph↗

arXiv2001

The 16N Calibration Source for the Sudbury Neutrino Observatory

A calibration source using gamma-rays from 16N (t_1/2 = 7.13 s) beta-decay has been developed for the Sudbury Neutrino Observatory (SNO) for the purpose of energy and other calibrations. The 16N is produced via the (n,p) reaction on 16O in the form of CO2 gas using 14-MeV neutrons from a commercially available Deuterium-Tritium (DT) generator. The 16N is produced in a shielding pit in a utility room near the SNO cavity and transferred to the water volumes (D2O or H2O) in a CO2 gas stream via small diameter capillary tubing. The bulk of the activity decays in a decay/trigger chamber designed to block the energetic beta-particles yet permit the primary branch 6.13 MeV gamma-rays to exit. Detection of the coincident beta-particles with plastic scintillator lining the walls of the decay chamber volume provides a tag for the SNO electronics. This paper gives details of the production, transfer, and triggering systems for this source along with a discussion of the source gamma-ray output and performance.

nucl-ex↗