Muon Transfer Rates from Muonic Hydrogen Atoms to Gaseous Benzene and Cyclohexane

Abstract

The chemical effect of the muon transfer process from muonic hydrogen atom was examined for benzene and cyclohexane under low pressure gaseous conditions. The muon transfer rates were investigated by measuring the resulting muonic X-rays resulting from muon irradiation of hydrogen and neon gas mixtures. The muon transfer rates to benzene and cyclohexane carbon atoms were very similar in the gaseous state. The results differed from previous results obtained for muon and pion transfer rates to benzene and cyclohexane under high density liquid conditions. It was concluded that the difference originated from the atomic muon state of the muonic hydrogen atoms with a large radius.

Chemical Environmental Effect on Muon Capture Processes for Iron Compounds

“…Muonic X-rays emitted from muonic carbon, nitrogen, potassium and iron atoms (constituting elements of the sample) were clearly identified. Muonic hydrogen X-ray (2 keV) was not observed because the muon capture by a hydrogen atom is quickly transferred to a neighboring atom having larger positive atomic nucleus charge before the muonic hydrogen emits the X-ray [11]. A similar spectrum was obtained for the K 4 [Fe(CN) 6 ]3H 2 O sample.…”

Chemical effect on muonic atom formation through muon transfer reaction in benzene and cyclohexane samples

“…For the muon transfer in the liquid system, the transfer rate to the carbon atoms of the benzene molecule was approximately 1.4 times higher than that to the carbon atoms of the cyclohexane molecule. However, in the muon transfer in the gas system, almost no difference was observed in the transfer rate [34]. In other words, chemical effects were observed in the liquid system but not in the gas system.…”

“…Therefore, the muon transfer rate to the carbon atoms of the cyclohexane molecules was lower than that to the carbon atoms of the benzene molecules. In the gas system, almost no difference was observed in the muon transfer rates to the carbon atoms of benzene and cyclohexane molecules [34]. This might be because the transfers occurred from the excited states of the muonic hydrogen atoms in the liquid system, whereas in the gas system, all the transfers occurred from the 1s state of the muon hydrogen atoms.…”

“…Moreover, the muon transfer reaction in a mixture of hydrogen gas and carbon monoxide or carbon dioxide has been investigated, and no clear difference was observed between the two samples [33]. In a previous study, we conducted an experiment on muonic atom formation in gas mixtures comprising hydrogen, neon, and gaseous benzene or gaseous cyclohexane to investigate the chemical effect on the muon transfer reaction in the gas system [34]. Consequently, a chemical effect on the muon transfer to benzene or cyclohexane in the gaseous system was not observed, unlike pionic transfer in a condensed system.…”

Non-destructive, position-selective, and multi-elemental analysis method involving negative muons

“…However, previous works largely performed qualitative analyses due to a lack of understanding of the muonic atom formation process and difficulty in obtaining good quality data from low-intensity muon beams. In recent years, fundamental research on muonic atom formation has been performed using an intense muon beam source in the Japan Proton Accelerator Research Complex (J-PARC) [27][28][29][30][31] . The use of such intense muon beam sources has made elemental analysis using muonic X-rays increasingly possible and significant progress has been made in applying this method to various samples, such as archeological artifacts, extraterrestrial materials, etc.…”