A Rephasing Invariant Formula for the Dirac CP Phase and General Perturbative Expansion: Prospects for DUNE and T2HK

2025/07/07 by Yang, Masaki J. S. · 1 citation
#FOS: Physical sciences #High Energy Physics - Phenomenology (hep-ph)

paper · doi:10.48550/arxiv.2507.04720

Abstract

We present a formula for the Dirac CP phase δ= arg ( U_e1 U_e2 U_μ3 U_τ3 / U_e3 det U_{\rm MNS} ), directly derived from the lepton mixing matrix in an arbitrary basis of phases. In contrast to the numerically suppressed Jarlskog invariant, this expression is computationally simple and less sensitive to approximations. We apply the formula to derive general perturbative corrections from charged-lepton mixing s_ij^e to the underlying CP phase of neutrinos δ_ν. A compact analytic expressions δ= δ_ν + s₁₂^e D₁₂ + s₁₃^e D₁₃ + s₂₃^e D₂₃ shows that these corrections can substantially exceed O(10^∘), potentially within the reach of future long-baseline experiments such as DUNE and T2HK.

Citations

• Almost general analysis of CKM and MNS matrices for hierarchical Yukawa structure and interpretation of Dirac CP phase probed by DUNE and T2HK

Cited by

• New rephasing invariants and CP violation built from the trios of the CKM or PMNS matrix elements

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