arXiv subjects

Rento Yamada

Publications and source records attributed to Rento Yamada.

2 recordsLinked to original sources

arXiv2026

The Silicon Tracking System of the E16 experiment at J-PARC: construction, installation and commissioning in beam test experiments

The J-PARC E16 experiment aims to search for signatures of chiral symmetry restoration. It studies in-medium modifications of vector mesons that decay via the dielectron channel. The measurements use a high-intensity 30 GeV proton beam with C and Cu targets at rates up to 10 MHz. To achieve this, the experiment upgrades its tracking, by introducing innermost detector modules constructed with the same technology and procedures as the modules of the Silicon Tracking System (STS) of the Compressed Baryonic Matter (CBM) experiment at Facility for Antiproton and Ion Research (FAIR). A total of 15 modules were assembled, tested, characterized and then installed in the E16 detector setup. The detector was commissioned in a beam test experiment at Tsukuba, where the detector modules could be exposed to a 3 GeV electron beam. In preparation for the beam test the modules were characterized and calibrated, and performance studies were accomplished to assess the quality of the setup. During beamtime, three modules were operated and illuminated in two planes by the electron beam. This paper presents the results of the construction, characterization, commissioning, and operation of the E16-STS modules in beam test experiments.

physics.ins-det↗

arXiv2026

First measurement of $\phi$ meson production in 30 GeV proton-nucleus reactions via di-electron decay at J-PARC

We present the first measurement of the production of the $\phi$ meson in 30 GeV proton-nucleus interactions on carbon and copper targets via the di-electron decay channel. The measurement was conducted at the high-momentum beamline of the J-PARC Hadron Experimental Facility, which was commissioned in 2020. The $e^+e^-$ pairs were detected using the E16 spectrometer, during a commissioning run of the J-PARC E16 experiment. The $\phi$ mesons are successfully reconstructed on all experimental targets. The obtained yields are converted to the total production cross section, assuming a kinematical distribution of the event generator JAM. The total cross sections derived are 2.0 $\pm$ 0.9 (stat.) $\pm$ 1.0 (syst.) mb on the carbon target and 10.3 $\pm$ 4.4 (stat.) $\pm$ 4.4 (syst.) mb on the copper target. The mass-number dependence of the cross section is discussed using the parameter $\alpha$, defined as $\sigma \propto A^\alpha$, resulting in $\alpha = $ 0.99 $\pm$ 0.38 (stat.) $\pm$ 0.34 (syst.). The extrapolation to $A=1$, which means that the cross section of proton-proton reactions, is in good agreement with the existing measurements at comparable energies.

nucl-ex↗