Speaker
Description
At the high-momentum beamline of the J-PARC Hadron Experimental Facility, efforts are underway to develop a secondary beam mode. In the secondary mode, we will be able to utilize meson beams such as pions and kaons as well as anti-protons up to 20 GeV/$c$ for various experiments in hadron physics and other research fields. Charmed-baryon spectroscopy with a 20 GeV/$c$ $\pi^−$ beam (E50) will become possible, and systematic studies of baryon excited states can be pursued through $\Xi$ baryon spectroscopy with $K^−$ beams (E97). In addition, multi-GeV muon beams could be transported, offering promising opportunities for interdisciplinary applications such as muon radiography.
In the test experiment T106, conducted in January 2025, positively charged secondary particles produced at the Lambertson magnet in the branching section were successfully transported and measured for the first time, providing a proof of principle for the secondary beam mode of the high-momentum beamline. As the next step for the secondary beam mode, the T112 and T113 experiments are expected to be scheduled for November 2026. The T112 experiment will transport negatively charged secondary particles $(\pi^−,~K^−,~\overline{p})$ likewise produced at the Lambertson magnet and will systematically evaluate beamline performance for negative beams—including momentum resolution, beam intensity, and particle composition. The T113 experiment seeks to demonstrate muon radiography using a multi-GeV muon beam obtained from in-flight pion decay.
This talk reports on the current status of secondary beam development and the prospects it opens for hadron physics and interdisciplinary research.
| Collaboration | J-PARC MARQ |
|---|
