# Suppression of light nuclei production in collisions of small systems at the Large Hadron Collider

## TL;DR

This paper explains the suppression of light nuclei production in small collision systems at the LHC by modeling nucleon coalescence at kinetic freeze-out, highlighting size effects on wave function overlap.

## Contribution

It introduces a coalescence model that accounts for size-dependent suppression of light nuclei in small systems at the LHC, extending to hypertriton predictions.

## Key findings

- Deuteron and helium-3 yields are suppressed in small systems due to size effects.
- Triton is less suppressed than helium-3 because of its smaller size.
- Hypertriton shows even greater suppression owing to its larger size.

## Abstract

We show that the recently observed suppression of the yield ratio of deuteron to proton and of helium-3 to proton in p+p collisions compared to those in p+Pb or Pb+Pb collisions by the ALICE Collaboration at the Large Hadron Collider (LHC) can be explained if light nuclei are produced from the coalescence of nucleons at the kinetic freeze-out of these collisions. This suppression is attributed to the non-negligible sizes of deuteron and helium-3 compared to the size of the nucleon emission source in collisions of small systems, which reduces the overlap of their internal wave functions with those of nucleons. The same model is also used to study the production of triton and hypertriton in heavy-ion collisions at the LHC. Compared to helium-3 in events of low charged particle multiplicity, the triton is less suppressed due to its smaller size and the hypertriton is even more suppressed as a result of its much larger size.