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

Abstract

The Search for Hidden Particles (SHiP) Collaboration has shown that the CERN SPS accelerator with its 400 GeV/c proton beam offers a unique opportunity to explore the Hidden Sector [1–3]. 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 super-weakly interacting particles with masses up to 𝒪(10) GeV/c2 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.

Direct detection and complementary constraints for sub-GeV dark matter

“…Values of sin θ just below the current sensitivity will be tested by LHCb in the high luminosity phase and we estimate the corresponding sensitivity (see appendix A for details). For smaller values of sin θ the SHiP experiment [17,19,99] and MATHUSLA [21,23] have the best sensitivities m S 5 GeV [8].…”

“…Both experiments aim at working in the background-free regime (see Refs. [18,19] for detailed simulations for SHiP and Refs. [22,23,100,101] for MATHUSLA).…”

“…At the intensity frontier, in particular, there is a plethora of both ongoing and planned activities that aim to explore new physics in the sub-GeV range. Prominent examples for the latter include, but are not limited to, planned upgrades to current experiments such as NA62 [9] and NA64 [10], the recently approved LHC add-on FASER [11][12][13][14][15] as well as dedicated new experiments like LDMX [16] and SHiP [17][18][19] that are planned to be run at the new Beam Dump Facility at CERN. Finally there are proposals for LHC based intensity frontier experiments such CODEX-b [20] and MATHUSLA [21][22][23][24].…”

Sensitivity of the intensity frontier experiments for neutrino and scalar portals: analytic estimates

“…It turns out that the ratio between the sensitivities of the experiments to a great extent does not depend on the specific model of new physics, and is determined mainly by the geometry and collision energies of the experiments, which allow a comparison of the sensitivities in a largely model-independent way. To illustrate this point, we compare the potentials of two proposed experiments: the LHC-based MATHUSLA experiment [18,19,[32][33][34] and a proton fixed target experiment using the proton beam of the Super Proton Synchrotron (SPS) at CERN -SHiP [35][36][37]. We analyze their sensitivity to the neutrino [38][39][40][41][42][43] and scalar [44][45][46][47][48][49][50][51] portals.…”

Search for Hidden Particles in Intensity Frontier Experiment SHiP

“…Theoretical background, main channels of production and decay of new particles, preliminary estimations for sensitivity region for different portals for the SHiP experiment were considered in 2016 [5]. Somewhat later, works of a clarifying and complementary nature were published also [10,11,12,13]. Currently, SHiP collaboration [14] includes nearly 250 scientist from 53 institutions.…”