Abstract: Motivated by the b to c tau nu anomalies, we study sensitivity of non-resonant searches for new physics at the large hadron collider (LHC) in a high-energetic and hadronically decaying tau lepton with a b-jet and large missing transverse momentum final states (pp to tau_h b + E_ T^miss). Such searches can investigate the g c to b tau nu transition which is also directly related to b to c tau nu anomalies. The talk is based on 1810.05843, 2011.02486, and 2111.04748.