Observed since the 1950s, the seasonal effect on underground muons is a well studied phenomenon. The interaction height of incident cosmic rays changes as the temperature of the atmosphere changes, which affects the production height of mesons (mostly pions and kaons). The decay of these mesons produces muons that can be detected underground. The production of muons is dominated by pion decay, and previous work did not include the effect of kaons. In this work, the methods of Barrett and MACRO are extended to include the effect of kaons. These efforts give rise to a new method to measure the atmospheric K / π ratio at energies beyond the reach of current fixed target experiments. These methods were applied to data from the MINOS far detector. A method is developed for making these measurements at other underground detectors, including OPERA, Super-K, IceCube, Baksan and the MINOS near detector.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Apr 2010|
Bibliographical noteFunding Information:
We thank our many colleagues who provided vital input as these methods were developed, especially Tom Kelley for providing comments on the presentation of the mathematics. This work was supported by the US Department of Energy, the UK Science and Technologies Facilities Council, the US National Science Foundation, the Center for Cosmology and AstroParticle Physics at Ohio State University and the University of Minnesota. We also acknowledge the BADC and the ECMWF for providing the environmental data for this project.
- Cosmic rays
- Seasonal effect