Primary and atmospheric cosmic-ray spectra were precisely measured with the BESS-TeV spectrometer. The spectrometer was upgraded from BESS-98 to achieve seven times higher resolution in momentum measurement. We report absolute fluxes of primary protons and helium nuclei in the energy ranges, 1–540 GeV and 1– 250 GeV/n, respectively, and absolute flux of… (More)
Different RNA species are rigorously discriminated and exported by distinct export factors, but this discrimination mechanism remains largely unknown. We previously showed, by RNA microinjection experiments, that intronless mRNAs are discriminated from U snRNAs based on their difference in RNA length. However, it was unclear how they are discriminated in… (More)
The vertical absolute fluxes of atmospheric muons and muon charge ratio have been measured precisely at different geomagnetic locations by using the BESS spectrometer. The observations had been performed at sea level (30 m above sea level) in Tsukuba, Japan, and at 360 m above sea level in Lynn Lake, Canada. The vertical are 11.4 GV and 0.4 GV,… (More)
The BESS-Polar spectrometer had its first successful balloon flight over Antarc-tica in December 2004. During the 8.5-day long-duration flight, almost 0.9 billion events were recorded and 1,520 antiprotons were detected in the energy range 0.1– 4.2 GeV. In this paper, we report the antiproton spectrum obtained, discuss the origin of cosmic-ray antiprotons,… (More)
Cosmic-ray proton and antiproton spectra were measured at mountain altitude, 2770 m above sea level. We observed more than 2 × 10 5 protons and 10 2 antiprotons in a kinetic energy range between 0.25 and 3.3 GeV. The zenith-angle dependence of proton flux was obtained. The observed spectra were compared with theoretical predictions.
We report new measurements of the atmospheric muons at mountain altitude. The measurement was carried out with the BESS detector at the top of Mt. Norikura, Japan. The altitude is 2,770 m above sea level. Comparing our results with predictions given by some interaction models, a further appropriate model has been investigated. It would improve accuracy of… (More)
We measured low energy cosmic-ray proton and helium spectra in the kinetic energy range 0.215 – 21.5 GeV/n at different solar activities during a period from 1997 to 2002. The observations were carried out with the BESS spectrometer launched on a balloon at Lynn Lake, Canada. A calculation for the correction of secondary particle backgrounds from the… (More)
The cosmic-ray proton, helium, and muon spectra at small atmospheric depths of 4.5 – 28 g/cm 2 were precisely measured during the slow descending period of the BESS-2001 balloon flight. The variation of atmospheric secondary particle fluxes as a function of atmospheric depth provides fundamental information to study hadronic interactions of the primary… (More)