Constraints on Unparticle Interactions from Particle and Antiparticle Oscillations

Understand

We study unparticle effects on particle and antiparticle osillations in meson-antimeson, and muonium-antimuonium systems.

• Unlike usual tree level contributions to meson oscillations from heavy particle exchange with small $\Gamma_{12}$, the unparticle may have sizeable contributions to both $M_{12}$ and $\Gamma_{12}$ due to fractional dimension $d_\U$ of the unparticle.
• We find that very stringent constraints on the unparticle and particle interactions can be obtained.
• If unparticle effect dominates the contributions (which may happen in $D^0-\bar D^0$ mixing) to meson mixing parameters $x$ and $y$, we find that $x/y =\cot(\pi d_\U)$.