Constraints on New Physics from decays of polarized $Λ_b^0$ baryons at the FCC-ee

Anja Beck, Mero Elmarassy, Asher Sabbagh, Michal Kreps, Eluned Smith

公開日: 2025/10/2

Abstract

The $Z^0$ bosons produced in electron-positron collisions at the potential Future Circular Collider (FCC-ee) provide unique opportunities for flavour physics. The non-zero polarization of \Lb baryons produced in $Z^0$ decays enables access to a much larger set of observables than at the LHC, where the \Lb baryons are produced unpolarized. This paper presents a toy angular analysis of $\Lambda_b^0\to \Lambda(\to p\pi^-)\mu^+\mu^-$ decays using simulation samples of collisions at the FCC-ee reconstructed using the IDEA detector concept and assuming a dataset of $6\times 10^{12}$ $Z^0$ bosons. While the statistical sensitivity achieved for individual angular observables is not expected to significantly exceed that from the LHCb Upgrade II experiment, the addition of the polarized observables leads to a significant improvement of the knowledge on the Wilson coefficients $C_9$ and $C_{10}$.

Constraints on New Physics from decays of polarized $Λ_b^0$ baryons at the FCC-ee | SummarXiv | SummarXiv