We report a measurement of cross section σðνμ þ nucleus → μ− þ XÞ and the first measurements of the
cross section σðν¯μ þ nucleus → μþ þ XÞ and their ratio Rð
σðν¯Þ
σðνÞ
Þ at (anti) neutrino energies below 1.5 GeV.
We determine the single momentum bin cross section measurements, averaged over the T2K ν¯=ν-flux, for
the detector target material (mainly carbon, oxygen, hydrogen and copper) with phase space restricted
laboratory frame kinematics of θμ < 32° and pμ > 500 MeV=c. The results are σðν¯Þ ¼
ð0.900 0.029ðstatÞ 0.088ðsystÞÞ × 10−39 and σðνÞ¼ð2.41 0.022ðstatÞ 0.231ðsystÞÞ × 10−39 in
units of cm2=nucleon and Rð
σðν¯Þ
σðνÞ
Þ ¼ 0.373 0.012ðstatÞ 0.015ðsystÞ.