Speaker
Description
Abstract
The model-independent measurement of the inclusive (ZH) production cross section using the recoil-mass technique is a flagship measurement at future (e^+e^-) Higgs factories, providing a unique and model-independent normalization for Higgs couplings. However, the precision of this method is significantly affected by energy loss from beamstrahlung and initial-state radiation (ISR), an increasingly important limitation at higher center-of-mass energies.
In this talk, we introduce a novel approach that enables the energy loss to be calibrated on an event-by-event basis, while retaining the model-independent nature of the inclusive (ZH) cross-section measurement. More importantly, the method allows the actual center-of-mass energy, (\sqrt{s'}), of each collision event to be reconstructed. This effectively transforms a fixed-energy measurement into a continuous scan of the (ZH) production cross section over a broad range of accessible (\sqrt{s'}) within a single dataset.
Such an energy-dependent measurement provides additional information beyond the conventional inclusive cross section. The resulting (\sigma(e^+e^-\to ZH)) lineshape can help disentangle otherwise degenerate effects from different sources of new physics, thereby enhancing the sensitivity of this leading Higgs production channel to deviations from the Standard Model.