ILC Workshop on Potential Experiments (ILCX2021)

Probing then minimal U(1)X model at future electron-positron collider via fermion pair production

27 Oct 2021, 15:50

20m

Room #4 (Zoom Meeting ID: 840 3553 0145)

Oral presentation using Zoom Session H: BSM particle production H-2: BSM particle production

Speaker

Arindam Das

Description

The minimal $𝑈(1{)}_{𝑋}$ extension of the Standard Model (SM) is a well-motivated new physics scenario, where the anomaly cancellation requirement dictates the new neutral gauge boson $({𝑍}^{\prime })$ couplings with the SM fermions in terms of two scalar charges (${𝑥}_{𝐻}$ and ${𝑥}_{\mathrm{\Phi }}$). In this paper, we investigate the SM charged fermion pair production mechanism for different values of these scalar charges in the $𝑈(1{)}_{𝑋}$ scenario at future electron-positron colliders, i.e. ${𝑒}^{+}{𝑒}^{-}\to 𝑓\overline{𝑓}$. Apart from the standard photon and 𝑍 boson exchange for this process, this model features a 𝑠-channel (or both $𝑠$ and $𝑡$-channel for $𝑓={𝑒}^{-}$) ${𝑍}^{\prime }$-boson exchange, which interferes with the SM processes. Considering the dilepton and dijet signatures from the heavy resonance we estimate the bounds on the $U(1{)}_{𝑋}$ coupling $({𝑔}^{\prime })$ and the ${𝑍}^{\prime }$ mass $({𝑀}_{𝑍}^{\prime })$. Considering the LEP-II results and prospective International Linear Collider (ILC) bounds on the effective scale for the four fermion interaction we estimate the reach on ${𝑀}_{{𝑍}^{\prime }}$/${𝑔}^{\prime }$ for different center of mass energies. We study the angular distributions, forward-backward (${\mathcal{A}}_{\mathrm{F}\mathrm{B}}$), left-right (${\mathcal{A}}_{\mathrm{L}\mathrm{R}}$) and left-right forward-backward (${\mathcal{A}}_{\mathrm{L}\mathrm{R},\mathrm{F}\mathrm{B}}$) asymmetries of the $𝑓\overline{𝑓}$ final states which can show substantial deviations from the SM results, even for a multi-TeV $𝑍\prime$. This provides a powerful complementary way to probe the heavy ${𝑍}^{\prime }$ parameter space beyond the direct reach of the Large Hadron Collider (LHC), as well as an effective way to determine the 𝑈$(1{)}_{𝑋}$ charges.

Presentation materials

ADAS_ILCX2021_BSM.pdf