Dark Scalars and Heavy Neutral Leptons at DarkQuest

TL;DR

DarkQuest is a proposed upgrade to SeaQuest/SpinQuest that aims to detect dark sector particles like heavy neutral leptons and Higgs-mixed scalars, offering new discovery opportunities in a relatively short timeframe.

Contribution

This paper evaluates DarkQuest's potential to explore dark sector particles, including detailed production mechanisms and detector acceptance, highlighting its unique sensitivity compared to other experiments.

Findings

DarkQuest can probe new regions of parameter space for heavy neutral leptons.

It can detect light scalars produced via bremsstrahlung and gluon fusion.

The experiment offers promising near-term discovery prospects.

Abstract

The proposed DarkQuest beam dump experiment, a modest upgrade to the existing SeaQuest/SpinQuest experiment, has great potential for uncovering new physics within a dark sector. We explore both the near-term and long-term prospects for observing two distinct, highly-motivated hidden sector benchmark models: heavy neutral leptons and Higgs-mixed scalars. We comprehensively examine the particle production and detector acceptance at DarkQuest, including an updated treatment of meson production, and light scalar production through both bremsstrahlung and gluon-gluon fusion. In both benchmark models, DarkQuest will provide an opportunity to probe previously inaccessible interesting regions of parameter space on a fairly short timescale when compared to other proposed experiments.