Measurement of the muon transfer rate from muonic hydrogen to oxygen in the range 70-336 K

•Muon transfer rate from muonic hydrogen to oxygen measured at RIKEN RAL (UK).•Rise with the temperature of the muon transfer rate from muonic hydrogen to oxygen.•Use of LaBr3 fast scintillator counters read by photomultiplier.•Important basis to measure the hyperfine splitting of muonic hydrogen. The first measurement of the temperature dependence of the muon transfer rate from muonic hydrogen to oxygen was performed by the FAMU collaboration in 2016. The results provide evidence that the transfer rate rises with the temperature in the range 104-300 K. This paper presents the results of the experiment done in 2018 to extend the measurements towards lower (70 K) and higher (336 K) temperatures. The 2018 results confirm the temperature dependence of ΛpO observed in 2016 and sets firm ground for comparison with the theoretical predictions.