Novel Method to Reliably Determine the Photon Helicity in B→K_{1}γ

Area of Science:

• Particle Physics
• High Energy Physics
• Beyond Standard Model Physics

Background:

• Photon polarization in b→sγ decays is a sensitive probe for new physics beyond the Standard Model.
• Previous methods for extracting photon helicity faced ambiguities due to hadronic uncertainties.

Purpose of the Study:

• To propose a novel method for unambiguously extracting photon helicity in b→sγ decays.
• To introduce a ratio of up-down asymmetries in D→K_{1}e^{+}ν decays to quantify hadronic effects.
• To provide an experimental strategy for measuring this ratio at facilities like BESIII, Belle-II, and LHCb.

Main Methods:

• Combining measurements from the B→K_{1}γ and the Cabibbo-favored D→K_{1}e^{+}ν decay channels.
• Defining a ratio of up-down asymmetries in D→K_{1}e^{+}ν to cancel hadronic uncertainties.
• Discussing the measurement of partial decay widths required for the ratio.

Main Results:

• The proposed method allows for unambiguous extraction of photon helicity in b→sγ.
• The ratio of asymmetries in D→K_{1}e^{+}ν serves as a reliable tool to control hadronic effects.
• The angular distribution for photon polarization extraction in the presence of kaon resonances is provided.

Conclusions:

• The developed method offers a robust way to search for new physics signals through photon polarization in b→sγ.
• Experimental verification of this method at current and future colliders is feasible and encouraged.
• This approach enhances the precision of searches for physics beyond the Standard Model.