  Analysis on the daily variations of cosmic ray muons with $E_{\mu}\geq 0.2
GeV$ based on the data of two directional muon telescopes at sea level and with
a rigidity of response to cosmic proton spectrum above 0.4 GV is presented. The
analysis covers two months of observations and in 60% of days, abrupt
transitions between a low to a high muon intensity and vice-verse is observed,
the period of high muon intensity is from $\sim 8.0h$ up to $\sim 19.0h$ (local
time) and coincides with the period when the interplanetary magnetic field
(IMF) lines overtake the Earth. This behavior strongly suggest that the high
muon intensity is due to a contribution of solar protons (ions) on the muon
intensity produced by the galactic cosmic rays, responsible for the low muon
intensity. This implies that the solar particle spectrum extends to energies
beyond 1 GeV. We show that this picture can explain the solar daily variation
origin, and it is a most accurate scenario than the assumption of corotating
galactic cosmic ray with the IMF lines, specially in the high rigidity region.
Obtained results are consistent with the data reported in others papers. Some
aspects on the sensitivity of our muon telescopes are also presented.
