The experimental facility for the Search for Hidden Particles at the CERN SPS

TL;DR

The paper describes the design and feasibility of a new experimental facility at CERN SPS aimed at searching for hidden particles with long lifetimes, utilizing high-intensity beams and innovative background suppression techniques.

Contribution

It introduces a novel experimental setup for detecting light long-lived hidden particles, including new beam extraction, delivery, and background suppression methods.

Findings

Feasibility of the experimental facility confirmed

Potential to explore wide parameter space for hidden particles

Innovative background suppression techniques developed

Abstract

The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 $\mathrm{\small GeV/c}$ proton beam offers a unique opportunity to explore the Hidden Sector. The proposed experiment is an intensity frontier experiment which is capable of searching for hidden particles through both visible decays and through scattering signatures from recoil of electrons or nuclei. The high-intensity experimental facility developed by the SHiP collaboration is based on a number of key features and developments which provide the possibility of probing a large part of the parameter space for a wide range of models with light long-lived superweakly interacting particles with masses up to O(10) $\mathrm{\small GeV/c^2}$ in an environment of extremely clean background conditions. This paper describes the proposal for the experimental facility together with the most important feasibility studies. The paper focuses on the challenging new ideas behind the beam extraction and beam delivery, the proton beam dump, and the suppression of beam-induced background.