Measurement of the vertical cosmic muon flux in a region of large rigidity cutoff Original Research Article

The vertical cosmic muon flux has been measured in Hanoi using a segmented scintillator hodoscope. It is the first measurement performed at VATLY, a cosmic ray laboratory recently created in Vietnam and installed in the premises of the Institute for Nuclear Sciences and Techniques. The measurement, performed at sea level in a region where the geomagnetic rigidity cutoff reaches 17 GV, is of interest for the understanding of the development of cosmic ray showers in the earth atmosphere. The result is compared with the prediction of a model widely used in the analysis of atmospheric neutrino data.