From the LHC to the Cosmos: Forward Neutrinos, Hadronic Interactions, and New Physics

by Felix Kling (DESY)

Thursday 18 Dec 2025, 15:00 → 16:30 Europe/Berlin

seminar room 3 (bldg. 1b)

Forward particle production plays a central role in astroparticle physics, governing cosmic-ray air showers and atmospheric neutrino fluxes, yet it remains poorly constrained by collider data. Recently, two dedicated forward LHC experiments, FASER and SND@LHC, have begun operation, and larger experiments are planned for the HL-LHC era. This provides an opportunity to probe this regime by measuring TeV-scale neutrinos and particles produced at very small angles. In this talk, I will give an overview of this new experimental program; discuss how forward neutrino measurements constrain pion, kaon, and charm production in previously inaccessible kinematic regions; how this helps improve air-shower and neutrino-flux predictions; and how the program benefits from advances in QCD calculations and Monte Carlo generators. I will further discuss how this program enables sensitive searches for feebly interacting particles and other new physics.