English

Taming Penguins: Towards High Precision Measurements in $\phi_d$ and $\phi_s$

High Energy Physics - Phenomenology 2025-01-17 v1

Abstract

Experimentally, the phases ϕd\phi_d and ϕs\phi_s are determined from CP asymmetry measurements in the "golden modes" Bd0J/ψKS0B_d^0\to J/\psi K_{\mathrm{S}}^0 and Bs0J/ψϕB_s^0\to J/\psi\phi. At leading order, the theoretical interpretation of these measurements is straightforward. However, to reach high precision determinations of ϕd\phi_d and ϕs\phi_s, which is essential in view of the searches for signs of beyond the SM physics, corrections from next-to-leading order effects need to be accounted for. These corrections primarily originate from so-called penguin topologies. Using the SU(3)SU(3) flavour symmetry, these corrections can be determined using suitably chosen control modes. Recent new CP asymmetry measurements from LHCb in BDDB\to DD and Belle-II in Bd0J/ψπ0B_d^0\to J/\psi\pi^0 decays greatly improve our knowledge on the parameters describing the contribution from penguin topologies. These proceedings will discuss the current constraints on the penguin parameters in BJ/ψXB\to J/\psi X and BDDB\to DD decays, provide corrected determinations for ϕd\phi_d and ϕs\phi_s, and highlight what can be expected at the end of the HL-LHC and Belle-II programmes.

Keywords

Cite

@article{arxiv.2501.09414,
  title  = {Taming Penguins: Towards High Precision Measurements in $\phi_d$ and $\phi_s$},
  author = {Kristof De Bruyn and Robert Fleischer and Eleftheria Malami},
  journal= {arXiv preprint arXiv:2501.09414},
  year   = {2025}
}

Comments

7 pages, 4 figures, Contribution to the Proceedings of the 9th Symposium on Prospects in the Physics of Discrete Symmetries (DISCRETE 2024), 2-6 December 2024, Ljubljana, Slovenia