The contribution of new physics on the exclusive W boson hadronic decays in the final state at muon colliders in the Randall-Sundrum model

Abstract

An attempt is made to present the effect of new physics in the exclusive decays of W boson at high energy colliders in the Randall-Sundrum (RS) model. By using Feynman diagram techniques we have evaluated the influence of the scalar unparticle, polarization and anomalous couplings on the exclusive W boson hadronic decays of $W^{\pm }\to {\pi }^{\pm }\gamma$, $W^{\pm }\to K^{\pm }\gamma$ and $W^{\pm }\to {\rho }^{\pm }\gamma$ at the high energy muon colliders in the RS model. The result shows that with fixed collision energies, the total cross-section for hadronic productions in the final state depends strongly on the parameters of the unparticle physics, muon beam polarizes and also anomalous couplings. With a center-of-mass energy of 10 TeV, the total cross-sections achieve the maximum value when the benchmark signal point as $({\Lambda }_U,d_U)$ $=(1\text{TeV},1.9)$ and the polarization coefficient as $(P_{{\mu }^{-}},P_{{\mu }^{+}})=(1,1)$. The numerical evaluation shows that with the contribution of new physics in the RS model, the effect is greatly enhanced at high energy colliders. The statistical significance can reach $1\sigma -7\sigma$ in case of using the W branching ratio at the experimental bounds of $\mathcal{O}(10^{-6})$. To clarify the contribution of new physics, we use a ${\chi }^2$ analysis with systematic errors to determine the sensitivities of the new contributions. The result indicates that the sensitivities on the anomalous coupling $WW\gamma$ are much larger than that on the anomalous coupling $WWZ$ under the same conditions.

Comments: 13 pages, 6 figures, 4 tables