Measurement of the charge ratio of atmospheric muons with the CMS detector A. Calderón for the CMS Collaboration Instituto de Física de Cantabria (CSIC-UC), Santander, Spain
Received: 13 Oct 2010 – Revised: 22 Dec 2010 – Accepted: 29 Dec 2010 – Published: 14 Mar 2011
Abstract. We present a measurement of the ratio of positive to negative muon fluxes
from cosmic ray interactions in the atmosphere, using data collected by the
CMS detector both at ground level and in the underground experimental cavern
at the CERN LHC. Muons were detected in the momentum range from 5 GeV/c to 1 TeV/c.
The surface flux ratio is measured to be 1.2766 ± 0.0032 (stat.) ± 0.0032 (syst.),
independent of the muon momentum, below 100 GeV/c. This is the most precise
measurement to date. At higher momenta the data are consistent with an increase
of the charge ratio, in agreement with cosmic ray shower models and compatible
with previous measurements by underground experiments.
Citation: Calderón for the CMS Collaboration, A.: Measurement of the charge ratio of atmospheric muons with the CMS detector, Astrophys. Space Sci. Trans., 7, 79-83, doi:10.5194/astra-7-79-2011, 2011.