New physics in $B$ meson mixing: future sensitivity and limitations

Abstract

The mixing of neutral mesons is sensitive to some of the highest scales probed in laboratory experiments. In light of the planned LHCb Upgrade II, a possible upgrade of Belle II, and the broad interest in flavor physics in the tera-$Z$ phase of the proposed FCC-ee program, we study constraints on new physics contributions to $B_d$ and $B_s$ mixings which can be obtained in these benchmark scenarios. We explore the limitations of this program, and identify the measurement of $|V_{cb}|$ as one of the key ingredients in which progress beyond current expectations is necessary to maximize future sensitivity. We speculate on possible solutions to this bottleneck. Given the current tension with the standard model (SM) in semileptonic $B$ decays, we explore how its resolution may impact the search for new physics in mixing. Even if new physics has the same CKM and loop suppressions of flavor changing processes as the SM, the sensitivity will reach 2 TeV, and it can be much higher if any SM suppressions are lifted. We illustrate the discovery potential of this program.

References in corpus (12)

• B-physics anomalies: a guide to combined explanations
• Current status of the Standard Model CKM fit and constraints on $\Delta F=2$ New Physics
• Anatomy of New Physics in B-Bbar mixing
• Can the differences in the determinations of $V_{ub}$ and $V_{cb}$ be explained by New Physics?
• Deciphering top flavor violation at the LHC with B factories
• B-meson charged current anomalies: the post-Moriond status
• Next to Minimal Flavor Violation
• CP violation and the CKM matrix
• Tension in the inclusive versus exclusive determinations of $|V_{cb}|$: a possible role of new physics
• Next-to-leading order QCD corrections to paired $B_c$ production in $e^{+}{e}^{-}$ annihilation
• Limits on New Physics from exclusive $B\to D^{(\ast )}\ell \bar{\nu }$ Decays
• Testing the left-handedness of the b \to c transition