Speaker
Description
FASER is an experiment located 480 m from the ATLAS collision point. Its primary goals are the detection of high-energy neutrinos and searches of feebly interacting new particles predicted by extensions of the Standard Model, produced in proton–proton collisions at a center-of-mass energy of 13.6 TeV. The FASER$\nu$ subdetector consists of over 700 layers of emulsion films interleaved with tungsten plates, which enables full 3-flavour tagging of neutrino interactions and observation of decays of short-lived particles such as charm hadrons and tau leptons.
In neutrino interactions, charm hadrons are primarily produced through charged current interactions of the neutrino with a strange quark, creating a charm quark which then hadronizes to create a charm hadron. Charm production in neutrino interactions are therefore fundamental for deepening our understanding of the structure of the nucleon and the weak force. In particular, it is a direct probe of the strange quark content of the nucleon, the hadronization process of heavy quarks, and cross section measurements for neutrino-nucleus interactions. It can also be used to indirectly probe intrinsic charm components of the nucleon, which would dramatically alter our understanding of the structure of nucleons. Lastly, no charm production has ever been observed for electron neutrino interactions, and can therefore be used as a test of lepton flavour universality.
In this poster, the results from the first ever search for charm hadrons produced from neutrino interactions at the TeV energy range are presented. The results were obtained by analyzing a FASER$\nu$ module that was used for data-taking in 2022, which was exposed to 9.5/fb of proton-proton collisions. The method for searching for these charm hadrons, background sources and selection criteria, and the results of this search of charm hadrons are presented. Lastly, an outlook and future plan for searches for short-lived particles produced from neutrino interactions in FASER$\nu$ are outlined.