Feasibility studies on a nuclei trigger using the ALICE-TRD

At the Large Hadron Collider (LHC) at CERN significant production rates of light (anti-)(hyper-)nuclei have been measured in Pb-Pb collisions. The production of such nuclei has recently become a topic of high interest. For instance the measured lifetime of the lightest hypernucleus, the hypertriton (a bound state of a proton, a neutron and a Λ hyperon), is significantly below the expectation of state-of-the-art theory calculations which expect the lifetime to be very close to the Λ lifetime. Therefore, it is important to also measure these rare nuclei in p-p collisions. Due to their short lifetime, only its decay products can be measured, e.g. the charged two body decay channel _Λ³H → ³He + π^-. In order to be able to measure these rare (anti-)fragments also in p-p and p-Pb collisions, it is essential to increase the statistics by employing a trigger on nuclei. Using the data on Pb-Pb collisions at √(s_NN) = 2.76 TeV it turned out that particles with Z > 1 in the TRD show a behavior that can be used to implement such a nuclei trigger. In this talk the physics case of a nuclei trigger is elaborated as well as the exctracted efficiencies and purities for the different light nuclei. In addition, first results of triggered data on p-Pb collisions at √(s_NN) = 8.16 TeV and on pp collisions at √(s) = 13 TeV are presented.