# Vertex Displacements for Acausal Particles: Testing the Lee-Wick Standard Model at the LHC

## TL;DR

This paper proposes a novel experimental signature for acausal effects in the Lee-Wick Standard Model, suggesting that wrong displaced vertices could be observed at the LHC as evidence of microscopic causality violation.

## Contribution

It introduces the concept of wrong displaced vertices as a signature for acausal particles and analyzes their observability in the Lee-Wick Standard Model at the LHC.

## Key findings

- Wrong vertices can be produced by Lee-Wick partners of the electron.
- Measurable acausal vertex displacements are possible for masses below 450 GeV.
- Monte Carlo simulations indicate potential detection at the LHC.

## Abstract

We propose to search for wrong displaced vertices, where decay products of the secondary vertex move towards the primary vertex instead of away from it, as a signature for microscopic violation of causality. We analyze in detail the leptonic sector of the recently proposed Lee-Wick Standard Model, which provides a well motivated framework to study acausal effects. We find that, assuming Minimal Flavor Violation, the Lee-Wick partners of the electron, {\tilde l}^e and \tilde e, can produce measurable wrong vertices at the LHC, the most promising channel being q \bar{q} --> \bar{\tilde l}^e {\tilde l}^e --> e^+ e^- jjjj. A Monte-Carlo simulation using MadGraph/MadEvent suggests that for M_l < 450 GeV the measurement of these acausal vertex displacements should be accessible in the LHC era.