Design of a Very Low Energy Beamline for NA61/SHINE

A new, low-energy beamline branch is currently under consideration for the H₂ beamline at the CERN North Area. This new branch would extend the capabilities of the current infrastructure enabling the study of particles in the very low, 1-13 GeV/c, momentum range. The design of this new beamline involves various stages. Firstly, a study of the secondary targets to maximise the yield of secondary hadrons. Secondly, the development of high acceptance transverse optics with high momentum resolution on the order of a few %. Finally, we discuss the first considerations on instrumentation to enable particle identification and background rejection. The first experiment to profit from this new line could be NA61/SHINE, but other possible future fixed target experiments or test-beams installed in the downstream zones could also use the low-energy particles provided. The aim is to arrive at a complete design of this branch by the end of 2021, which, pending the approval of the CERN scientific committees, could be envisaged for construction after 2024. This timescale is compatible with requests for measurements by various large international collaborations, in the next 10-year horizon.