FIBER (detector)

from Wikipedia, the free encyclopedia
Large Hadron Collider (LHC) Arrangement of the various accelerators and detectors of the LHC
Arrangement of the various accelerators and detectors of the LHC
Detectors
 Partly built up:
Pre-accelerator

The FIBER (acronym for F orw A rd S earch E xpe R iment ) is one of the eight detectors at the large hadron collider of CERN . The FASER detector should search for hypothetical , light, weakly interacting elementary particles and measure the interaction rate of high- energy neutrinos .

The experiment is located in the TI12 side tunnel, 480 meters from the collision point of the ATLAS experiment. This tunnel was previously used to inject the electron beam from the SPS into the LEP accelerator and does not currently house any LHC infrastructure. The TI12 tunnel is located in a strongly collimated and intense beam of both high-energy neutrinos and possible new particles. In addition, only a small amount of background radiation is effective in the TI12 , as it is shielded from the collision point in ATLAS by around 100 meters of rock and concrete. The FASER experiment was approved in 2019 and data collection is expected to begin in 2021.

Search for new particles

The main aim of the FASER experiment is to search for hypothetical, as yet undiscovered, light and weakly interacting elementary particles, such as dark photons , axion-like particles and sterile neutrinos . If these particles are light enough, they can be produced in rare decays of hadrons . Such particles are therefore mainly generated in the forward direction along the collision axis of the proton beams. They form a strongly collimated beam and can absorb a large part of the LHC proton beam energy. In addition, due to their weak coupling to the particles of the Standard Model and their high speed , these particles are very long-lived. They can therefore move easily through several hundred meters of matter without interacting with it before they break down into known particles of the Standard Model. These decays lead to a clearly identifiable signal, the appearance of very high-energy particles in the TI12 tunnel, which FASER can detect.

Neutrino measurements

The LHC is the most powerful and most energetic particle accelerator in the world and therefore also the source of the most energetic neutrinos that are generated in a laboratory environment. Collisions at the LHC lead to a large number of high-energy neutrinos of all generations that flow along the collision axis and thus through the FASER detector. The special sub-detector FASERν serves to detect these neutrinos and is supposed to record and examine thousands of neutrino interactions. This makes it possible to measure the interaction rates of neutrinos with energies in the teraelectron volt range .

detector

Structure of the FASER experiment

The neutrino detector FASERν is located at the front end of FASER. This consists of layers of emulsion films that are nested with tungsten plates as collision material for neutrino interactions. Behind FASERν and at the entrance to the main detector there is a veto for charged particles, which consists of plastic scintillators . This is followed by a 1.5 meter long empty decay volume and a 2 meter long spectrometer , which are located in a 0.55 Tesla magnetic field. The spectrometer comprises three stations of precision silicon - strip detectors which detect charged particles from the decay of long-lived elementary particles are produced. At the end there is an electromagnetic calorimeter .

Web links

Individual evidence

  1. ↑ FIBER: CERN approves new experiment to look for long-lived, exotic particles. Retrieved January 1, 2020 .
  2. ↑ Particle physics: CERN approves new LHC detector. Retrieved January 5, 2020 .
  3. ↑ FASER's new detector expected to catch first collider neutrino. Retrieved January 1, 2020 .
  4. ↑ Jonathan L. Feng, Iftah Galon, Felix Kling, Sebastian Trojanowski: ForwArd Search ExpeRiment at the LHC . In: Physical Review D . tape 97 , no. 3 , February 5, 2018, p. 035001 , doi : 10.1103 / PhysRevD.97.035001 , arxiv : 1708.09389 (English, arxiv.org [PDF; accessed on January 1, 2020]).
  5. ↑ Ariga et al. (FASER collaboration): FASER's physics reach for long-lived particles . In: Physical Review D . tape 99 , no. 9 , May 15, 2019, ISSN  2470-0010 , p. 095011 , doi : 10.1103 / PhysRevD.99.095011 , arxiv : 1811.12522 (English, arxiv.org [PDF; accessed on January 1, 2020]).
  6. ↑ Abreu et al. (FASER Collaboration): Detecting and Studying High-Energy Collider Neutrinos with FASER at the LHC . August 6, 2019, arxiv : 1908.02310 (English, arxiv.org [PDF; accessed January 1, 2020]).
  7. ↑ Ariga et al. (FASER Collaboration): Letter of Intent for FASER: ForwArd Search ExpeRiment at the LHC . November 26, 2018, arxiv : 1811.10243 (English, arxiv.org [PDF; accessed January 1, 2020]).
  8. ↑ Ariga et al. (FASER Collaboration): Technical Proposal for FASER: ForwArd Search Experiment at the LHC . December 21, 2018, arxiv : 1812.09139 (English, arxiv.org [PDF; accessed January 1, 2020]).