Antihelium identification and antihypertriton observation with LHCb

The production of helium and anti-helium nuclei is studied for the first time with the LHCb detector in pp collisions at √s =13 TeV. The used dataset was collected between the years 2016 to 2018 and corresponds to an integrated luminosity of L = 5.5/fb. The helium nuclei are identified using ionization losses in the silicon sensors of the VELO and ST detectors, alongside timing measurements in the OT drift tubes. A total of 10^5 prompt helium and anti-helium are identified with negligible background contamination. First application of this method is the reconstruction of  hypertritons via the 2-body decay into Helium-3 and a charged pion.  A total of 10^2 hypertriton candidates are found. This example proves the feasibility of a rich program of measurements of QCD and astrophysics interest involving light nuclei.