# L46: ISOSPIN BREAKING — m_d - m_u

**Category:** library_prompt | **Kernel:** PHAT v1.27.5 | **Status:** PENDING

## Prompt

ISOSPIN BREAKING — m_d - m_u
The isospin breaking m_d - m_u ~ 2.5 MeV: Using Z2 mixing, parameterize the u-d mass splitting. Show whether the splitting ratio m_d/m_u ~ 2.16 is predicted from the octonion e3/f3 asymmetry or is a free parameter. Compare to lattice QCD results. #SuperGrokTOE #IsospinBreaking