Study the property of $W^{\prime}$ at future $e^-p$ collider

TL;DR

This work assesses the discovery potential for a heavy charged gauge boson $W^{\prime}$ at future electron-proton colliders by analyzing two production modes: a simple $W^{\prime}$-mediated $e^-u\to\nu_e d$ in a $W^{\prime}$ Effective Model and a lepton-number-violating $e^-u\to e^{\pm}jjj$ in the Effective Left–Right Symmetric Model. It computes cross sections, angular distributions, forward–backward asymmetries, and signal significances across a multi-parameter space including $M_{W^{\prime}}$, $M_N$, and right-handed couplings $\kappa_R^{\ell}$, $\kappa_R^{q}$, highlighting strong sensitivity to initial-state polarization and centre-of-mass energy. The analysis shows that at $\sqrt{s}=5.29$ TeV with $L=100$–$2000$ fb$^{-1}$, the detectable $W^{\prime}$ mass reaches about $9$–$11$ TeV in the LRSM channel, and that the SM-forbidden $e^-u\to e^+jjj$ process provides a clean, distinctive signature of LRSM physics. The results establish that $e^-p$ colliders, notably FCC-he, offer a valuable and complementary avenue to LHC searches for probing TeV-scale $W^{\prime}$ bosons and LRSM dynamics.

Abstract

As a strong candidate for new physics beyond the Standard Model, the exotic charged gauge boson $W^{\prime}$ has attracted extensive research interest. In this work we investigate the interactions of the $W^{\prime}$ boson at the electron-proton colliders. The process $e^- u \to ν_e d$ and $e^- u \to e^\pm jjj$ with $t$-channel $W^{\prime}$ exchange are studied. The polarization of the initial-state electrons has a significant impact on the cross section of the studied process, while the angular distribution of the final-state leptons serves as an important observable for the interactions of the $W^{\prime}$ boson. In some specific regions of the parameter space, the detectable mass range for the $W^{\prime}$ boson can reach around 10 TeV, and the coupling strength can achieve a precision of approximately 1\% relative to the interaction strength of the Standard Model. Especially, $e^- u \to e^+ jjj$ process is forbidden within the Standard Model, which would constitute important evidence in the search for the Left-Right Symmetric Model.

Figures (10)

• Figure 1: In the $W^{\prime}$ Effective Model, the distribution of cross section varies with $M_{W^{\prime}}$ based on the energy requirements of electrons and protons in LHeC and FCC-he.
• Figure 2: The distribution of the cross section varying with polarization of initial-state electrons in the process $e^- u \rightarrow \nu_e d$. (a) $M_{W'}=1~\text{TeV}$. (b) $\sqrt{s} = 5.29~\text{TeV}$.
• Figure 3: The distribution of cross section varies with the increase of $\kappa_R$. (a) $M_{W^{\prime}}$=1 TeV. (b) $\sqrt{s} = 5.29~\text{TeV}$.
• Figure 4: The Feynman diagram of the $e^{-}u\to N d \to e^{\pm}jjj$ process.
• Figure 5: The distribution of cross section varies with different values of $M_{W^\prime}$ and $M_N$ in the process of $e^ -u \rightarrow e^\pm j j j$ with $\sqrt{s}=5.29~\text{TeV}$.