Enhanced CP asymmetries in $$B \rightarrow K \mu ^+ \mu ^-$$

Abstract

We show that the current values of $$R_K^\mathrm {exp}$$ R K exp and $$R_{K^*}^\mathrm {exp}$$ R K ∗ exp can be accommodated by allowing a nonzero New Physics coupling $$\delta C_9^{\mu \mu }$$ δ C 9 μ μ to be complex, both in the scenario in which only $$\delta C_9^{\mu \mu }$$ δ C 9 μ μ is affected, and in the scenario with complex $$\delta C_{9,10}^{\mu \mu }$$ δ C 9 , 10 μ μ satisfying $$\delta C_{9}^{\mu \mu }=-\delta C_{10}^{\mu \mu }$$ δ C 9 μ μ = - δ C 10 μ μ . A presence of the weak CP-violating phase can then be tested by measuring the CP-asymmetry, $$\mathcal {A}_\mathrm {CP}$$ A CP . We show that this asymmetry is enhanced around the peak of each $$c\bar{c}$$ c c ¯ -resonance, and in fact more pronounced in the close vicinity of $$J/\psi $$ J / ψ and $$\psi (2S)$$ ψ ( 2 S ) . Therefore, measuring $$\mathcal {A}_\mathrm {CP}$$ A CP before and after the resonances’ peak could be revelatory of the CP-violation that originates from beyond the Standard Model, or to be a significant constrain when building a realistic scenario of New Physics.

LFU and CP violation in $b \to s \mu \mu$

“…[20], reporting results consistent with the SM prediction. However, A CP can be enhanced in the vicinity of narrow charmonium resonances in the spectrum [10,22]. These regions have been vetoed in the analysis presented in Ref.…”

“…LFU and CP violation in 𝑏 → 𝑠𝜇𝜇 Aleks Smolkovič of 𝑞 2 ∈ [8, 9] GeV 2 and 𝑞 2 ∈ [10, 11] GeV 2 , which could lead to a significant enhancement of the sensitivity of such measurements to CP violating NP effects , which could be further enhanced by exploiting the asymmetric behavior of A CP by measuring 8,9] − Γ [10,11] + Γ [10,11] Γ [8,9] + Γ [8,9] + Γ [10,11] + Γ [10,11] .…”

“…A modification of the purely left-handed effective operator O 9 − O 10 ∝ ( s𝐿 𝛾 𝜇 𝑏 𝐿 ) ( μ𝐿 𝛾 𝜇 𝜇 𝐿 ) can explain both the LFUV anomalies, as well as other discrepancies related to 𝑏 → 𝑠ℓℓ [8,9]. Moreover, the 𝛿𝐶 9 = −𝛿𝐶 10 Wilson coefficient can in full generality be complex and thus provide a new source of CP violation [9,10]. Measurements of CP violating observables, such as the 𝑇 N -odd angular observables 𝐴 7,8,9 in 𝐵 → 𝐾 * 𝜇𝜇 [11], might furthermore provide a discriminating power among various possible NP scenarios behind the 𝑅 𝐾 ( * ) anomalies [9,12].…”

New Perspectives for Testing Electron-Muon Universality

“…However, taking this average assumes that the asymmetry is constant across the spectrum. This is not the case, as the asymmetry will be enhanced near cc resonance peaks [49], regions that were vetoed in the LHCb study. For this reason, we use a more conservative constraint…”

$Λ_b\rightarrow Λ(\to p π^-) \ell^+\ell^-$ as probe of CP-violating New Physics

“…A combined measurements of CPviolating and CP-conserving observables therefore provide a more powerful method to understand the CP properties of NP. In literature, several works have investigated the CP asymmetries in B → K * µ + µ − angular distributions to probe NP [30][31][32][33][34][35][36][37][38], and as illustrated in Ref. [35], the CP asymmetries are capable of distinguishing between NP models that address the b → s + − anomalies.…”