Do alien particles exist, and can they be detected?

TL;DR

This paper explores the theoretical possibility of detecting 'alien particles' originating from higher-dimensional branes intersecting our universe, discussing their properties and the challenges in identifying them with current detection methods.

Contribution

It introduces a framework for understanding how alien particles from extra-dimensional branes could be identified and distinguished from known matter.

Findings

Alien particles can appear at brane intersections.

Detection depends on their properties and physical laws in the homeland brane.

Current detection techniques may or may not be sufficient to identify alien particles.

Abstract

We may call "alien particles" those particles belonging to the matter/field content of a $d$-dimensional brane other than the $3$-brane (or stack of branes) sweeping the space-time in which we live. They can appear in our space-time at the regions of intersection between our and their brane. They can be identified (or not) as alien matter depending on their properties, on the physical laws governing their evolution in the "homeland" brane, and on the details of our detection techniques.