SHiP experiment

SHiP experiment
Name	SHiP experiment
Location	CERN, Meyrin, Switzerland
Status	Proposed / R&D
Collaboration	SHiP Collaboration
Facility	Super Proton Synchrotron
Target	Tungsten/Ta target station
Detectors	Emulsion cloud chamber, spectrometer, calorimeter, muon detector
Start	Proposed (2015–2025 R&D)

SHiP experiment

The SHiP experiment is a proposed fixed-target particle physics facility at the CERN Super Proton Synchrotron complex designed to search for feebly interacting particles and to study tau neutrino physics. It aims to exploit high-intensity, high-energy proton interactions to probe hidden sectors and rare processes beyond the Standard Model while complementing searches at the Large Hadron Collider and efforts at intensity-frontier facilities such as Spallation Neutron Source, J-PARC, and Fermilab. The project interfaces with detector-development programs and accelerator upgrades associated with the CERN Neutrino Platform and broader European particle-physics initiatives including the European Strategy for Particle Physics.

Overview

SHiP was conceived to operate downstream of the Super Proton Synchrotron using a dedicated slow-extraction multi-MW proton beam to illuminate a dense target, producing a large flux of heavy-flavor mesons such as D mesons and B mesons and yielding potential portals to hidden-sector states like heavy neutral leptons, dark photons, and light scalars. The conceptual design integrates an active muon shield and a long decay volume followed by a suite of precision trackers and calorimeters derived from technologies developed for experiments such as OPERA, NA62, LHCb, and ATLAS. Community studies and feasibility reports were presented in forums including the SPSC and workshops organized by the CERN Physics Beyond Colliders study group.

Scientific goals and physics case

The primary physics case targets searches for long-lived particles predicted in extensions of the Standard Model such as right-handed neutrinos in the seesaw mechanism, dark-sector mediators predicted in models related to dark matter, and light scalar or pseudoscalar bosons from portals like the Higgs portal or vector portal. Key targets include heavy neutral leptons linked to explanations of neutrino masses and baryogenesis reminiscent of scenarios discussed in connection with the νMSM and leptogenesis frameworks originally motivated by studies related to the Sakharov conditions. SHiP also proposes precision measurements of tau-neutrino interactions, extending results from experiments such as DONuT and OPERA, and contributing to tests of lepton universality and nucleon structure relevant to interpretations involving Parton distribution functions exploited by the CTEQ and NNPDF collaborations. Sensitivities complement direct-detection programs exemplified by XENON, LUX-ZEPLIN, and accelerator-based dark-photon searches like those from BaBar and Belle II.

Detector design and instrumentation

The baseline detector architecture couples a high-rate primary target and hadron absorber with an active magnetic muon shield followed by a 50–100 m evacuated decay volume and a downstream spectrometer. Tracking employs an emulsion cloud chamber technology developed for OPERA alongside silicon pixel and gaseous micro-pattern detectors such as GEM and Micromegas variants tested in CERN RD51. Momentum measurement and particle identification leverage dipole spectrometers inspired by LHCb and calorimetry concepts from ATLAS and CMS, while muon identification uses instrumented iron systems akin to those in MINOS and NOvA. Radiation-hard electronics developments draw on programs at CERN Microelectronics Group and industry partners engaged by the EUDET and AIDA-2020 initiatives. The instrument suite is optimized to reconstruct displaced vertices, measure time-of-flight, and perform high-efficiency veto tagging to suppress backgrounds from residual muons and neutrino interactions.

Beamline, target and experimental site

The proposed site is on the CERN Meyrin campus utilizing slow-extracted protons from the Super Proton Synchrotron with beam parameters informed by upgrade studies related to the CERN Accelerator Complex and future plans associated with the High-Luminosity LHC. The target design contemplates dense materials such as tungsten or tantalum with downstream hadron absorbers and active monitors influenced by technologies used at the CNGS project and experiments like NA61/SHINE. Beam dump and shielding geometry are optimized with simulations using codes and toolkits such as GEANT4 and FLUKA validated against measurements from facilities including PSI and BNL. Environmental and radiological assessments follow protocols coordinated with entities like the IAEA and national regulatory authorities.

Data acquisition and analysis methods

SHiP envisages a triggerless or highly flexible trigger architecture to handle large streaming data rates from emulsion readout, silicon pixels, calorimeters, and muon systems, building on methodologies pioneered by LHCb and the ALICE upgrade. Real-time data reduction uses FPGA-based processing and GPU-accelerated reconstruction pipelines tested in projects like ATLAS TDAQ upgrades and CERN OpenLab collaborations. Analysis frameworks will integrate software from community efforts such as ROOT, Gaudi, and machine-learning toolkits similar to those applied in DeepMind-adjacent studies and pattern-recognition work at CERN. Background estimation relies on control samples drawn from beam-off and beam-dump configurations and Monte Carlo campaigns coordinated with international groups including the MCnet network.

Collaboration, timeline and funding

The collaboration includes institutes from Europe, Asia, and the Americas with institutional memberships resembling those in experiments such as LHCb, NA62, and OPERA. Funding and timeline are contingent on prioritization in the European Strategy for Particle Physics and on resource allocation by agencies such as the European Commission, national research councils, and CERN Council member states. Key milestones have included conceptual design reports, technical design studies, and detector R&D phases aligned with coordination meetings hosted by the SPS Committee and working groups in the CERN Physics Beyond Colliders program. Future decisions depend on reviews by advisory bodies like the PSC and endorsement through CERN governance.

Category:Particle physics experiments