The activity of Nara Women's University High Energy Physics Laboratory began in 1968.
In the first 10 years, when the activity of this laboratory started, we had worked on the bubble chamber experiment. In 1978, we introduced an automatic bubble chamber photo measuring device to our laboratory to improve our research and education base.Also, we dispatched female students to KEK (Former: Institute of High Energy Physics, Present: High Energy Accelerator Research Organization) many times and contributed significantly to the advancement of female researchers in the field of high energy physics in Japan.
In the 1980s, we started to work on the TRISTAN experiment (KEK, Japan), which was the world's highest-energy electron-positron collision experiment at the time. We participated in the TOPAZ detector (*1) group and was in charge of the development and verification of the Forward Calorimeter installed closest to the beamline. Especially we succeeded in improving the energy resolution of the second-generation calorimeter. This detector is designed using BGO (bismuth germanate) scintillator and has enabled high-precision measurement. This result made significant progress in revealing of physics phenomena. For example, we confirmed that the coupling constant α of QED became large 1/129 in the high energy region of 60 GeV (*2).
In addition to detector development, we engaged in physics analysis of high-energy two-photon collision reactions as a central task in the laboratory. As a result, we were able to gain new insights, such as clarifying the existence of the Resolved Photon process (* 3). In this way, we continued to actively promote this project until the end of the experiment.
We have been participating in the B factory experiment: Belle experiment (KEK, Japan) aimed at measuring CP violation in B-meson decays since 1994. During the construction period of detectors, we were in charge of multiple works. For example, a production and beam test experiment of the CsI calorimeter prototype, a measurement of radiation damage for CsI crystal scintillators, a monitor system of temperature-humidity-power supply-voltage, and wave shaping electronics. CsI calorimeter can measure the energy of electron and photon.
After the colliding beam experiment began, we started to analyze the decays of B meson and τ lepton. Belle experiment completed data acquisition in 2010 and was upgraded to increase luminosity 40 times and increase the accuracy of the research. The upgraded one was named Belle II experiment. A full-scale physical measurement experiment with Belle II began in March 2019.
Now, we are expanding our activities to the Belle experiment and international joint experiments outside Japan. We currently participated in Belle II experiment at KEK, PHENIX experiment at BNL, and ALICE experiment at CERN. For the detail of these experiment themes, take a look at the link below.
