We have studied the possible signals of unparticle in atomic parity violation (APV) along an isotope chain and in the NuTeV experiment. The effects of unparticle physics could be observed in APV, if the uncertainty in relative neutron/proton radius shift $\delta (\Delta \frac{R_N}{R_P})$ is less than a few times ${10}^{-4}$ by measuring the parity violating electron scattering. The constraints imposed by the NuTeV experiment on unparticle physics are discussed in detail. If the NuTeV results are confirmed by future experiments, we suggest that unparticle could account for a part of the NuTeV anomaly. There exist certain regions for the unparticle parameters (${\Lambda }_{\mathcal{U}}$, $d_{\mathcal{U}}$, $c_{V\mathcal{U}}$, and $c_{A\mathcal{U}}$), where the NuTeV discrepancy could be completely explained by unparticle effects and the strange quark asymmetry, even with or without the contributions from the isoscalarity violation, etc. It is remarkable that these parameter regions are consistent with the constraints from $b\to s\gamma$.

• Received 29 January 2008

DOI:https://doi.org/10.1103/PhysRevD.78.075015