Novel $|V_{cb}|$ extraction via Lorentz-boosted $bc$-tagging at the LHC

We present a novel method for measuring the CKM matrix element $|V_{cb}|$ at general-purpose experiments at the LHC using an advanced boosted-jet tagger to identify "$bc$ signatures". The approach reconstructs the $W\to cb$ decay products within a single large-radius jet, capturing the full hadronic system in the Lorentz-boosted regime. The boosted topology substantially suppresses backgrounds and effectively reduces flavour-tagging uncertainties through an in-situ calibration technique, critical for enhancing measurement precision. The proposed approach provides complementary sensitivity to the conventional approach based on small-radius jets, yielding a ~30% improvement in overall $|V_{cb}|$ precision under HL-LHC projections when both channels are combined. This offers a new avenue to address the long-standing tension between exclusive and inclusive $|V_{cb}|$ determinations.