The even light QCD axion called the ZN axion can both solve the strong CP problem and account for the dark matter (DM). We point out that the single and double level crossings can naturally take place in the mass mixing between the ZN axion and axionlike particle (ALP). The first level crossing occurs much earlier than the QCD phase transition. while the second level crossing occurs e... https://partnersspigenes.shop/product-category/protective-cases/