NA61/SHINE (standing for "SPS Heavy Ion and Neutrino Experiment") is a

particle physics Particle physics or high energy physics is the study of fundamental particles and forces that constitute matter and radiation. The fundamental particles in the universe are classified in the Standard Model as fermions (matter particles) an ...

experiment at the Super Proton Synchrotron (SPS) at the European Organization for Nuclear Research (CERN). The experiment studies the

hadron In particle physics, a hadron (; grc, ἁδρός, hadrós; "stout, thick") is a composite subatomic particle made of two or more quarks held together by the strong interaction. They are analogous to molecules that are held together by the ...

ic final states produced in interactions of various beam particles (

pions In particle physics, a pion (or a pi meson, denoted with the Greek letter pi: ) is any of three subatomic particles: , , and . Each pion consists of a quark and an antiquark and is therefore a meson. Pions are the lightest mesons and, more gene ...

protons A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron m ...

and

beryllium Beryllium is a chemical element with the symbol Be and atomic number 4. It is a steel-gray, strong, lightweight and brittle alkaline earth metal. It is a divalent element that occurs naturally only in combination with other elements to for ...

argon Argon is a chemical element with the symbol Ar and atomic number 18. It is in group 18 of the periodic table and is a noble gas. Argon is the third-most abundant gas in Earth's atmosphere, at 0.934% (9340 ppmv). It is more than twice a ...

, and

xenon Xenon is a chemical element with the symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as the ...

nuclei) with a variety of fixed nuclear targets at the SPS energies. About 135 physicists from 14 countries and 35 institutions work in NA61/SHINE, led by Marek Gazdzicki. NA61/SHINE is the second largest fixed target experiment at CERN.

Physics program

The NA61/SHINE physics program has been designed to measure

production in three different types of collisions: *In

nucleus Nucleus ( : nuclei) is a Latin word for the seed inside a fruit. It most often refers to: * Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucl ...

–nucleus (

heavy ion High-energy nuclear physics studies the behavior of nuclear matter in energy regimes typical of high-energy physics. The primary focus of this field is the study of heavy-ion collisions, as compared to lighter atoms in other particle accelerator ...

) collisions, in particular the measurement of fluctuations and long range correlations, with the aim to identify the properties of the

onset of deconfinement The onset of deconfinement refers to the beginning of the creation of deconfined states of strongly interacting matter produced in nucleus-nucleus collisions with increasing collision energy (a quark–gluon plasma). The onset of deconfinemen ...

and find evidence for the critical point of strongly interacting matter. *In

proton A proton is a stable subatomic particle, symbol , H+, or 1H+ with a positive electric charge of +1 ''e'' elementary charge. Its mass is slightly less than that of a neutron and 1,836 times the mass of an electron (the proton–electron mass ...

–proton and proton–nucleus interactions needed as reference data for better understanding of nucleus–nucleus reactions; in particular with regards to correlations, fluctuations and high transverse momenta. *In hadron–nucleus interactions needed for neutrino ( T2K, NOvA and future

DUNE A dune is a landform composed of wind- or water-driven sand. It typically takes the form of a mound, ridge, or hill. An area with dunes is called a dune system or a dune complex. A large dune complex is called a dune field, while broad, f ...

) and cosmic-ray experiments (

Pierre Auger Observatory The Pierre Auger Observatory is an international cosmic ray observatory in Argentina designed to detect ultra-high-energy cosmic rays: sub-atomic particles traveling nearly at the speed of light and each with energies beyond 1018 eV. In Ear ...

and

KASCADE KASCADE was a European physics experiment started in 1996 at Forschungszentrum Karlsruhe, Germany (now Karlsruher Institut für Technologie), an extensive air shower experiment array to study the cosmic ray primary composition and the hadro ...

Detector

The NA61/SHINE experiment uses a large acceptance hadron spectrometer located on the H2 beam line in the North Area of CERN. It consist of components used by the heavy ion

NA49 experiment The NA49 experiment ("North Area experiment 49") was a particle physics experiment that investigated the properties of quark–gluon plasma. It took place in the North Area of the Super Proton Synchrotron at CERN from 1991-2002. It used a large-ac ...

as well as those designed and constructed for NA61/SHINE. The main tracking devices are four large volume

time projection chamber In physics, a time projection chamber (TPC) is a type of particle detector that uses a combination of electric fields and magnetic fields together with a sensitive volume of gas or liquid to perform a three-dimensional reconstruction of a partic ...

s (TPCs), which are capable of detecting up to 70% of all charged particles created in the studied reactions. Two of them are located in the magnetic field of two super-conducting dipole magnets with maximum bending powers of 9 Tesla meters. Two others are positioned downstream of the magnets symmetrically with respect to the beam line. Additionally, four small volume TPCs placed directly along the beamline region are used in case of hadron and light ion beams. The setup is supplemented by time of flight detector walls, which extend particle identification to low momenta ( < p ). Furthermore, the Projectile Spectator Detector (a calorimeter) is positioned downstream of the time of flight detectors to measure energy of projectile fragments.

Collected data

Extended program: after Long Shutdown 2

In 2018 the NA61/SHINE collaboration published an addendum presenting an intent to upgrade the experimental facility and perform a new set of measurements after Long Shutdown 2. As in the original program, the new one proposes studies of hadron-nucleus and nucleus-nucleus interactions for heavy ions, neutrino and cosmic-ray physics. The heavy ions program will focus on study of

charm Charm may refer to: Social science * Charisma, a person or thing's pronounced ability to attract others * Superficial charm, flattery, telling people what they want to hear Science and technology * Charm quark, a type of elementary particle * Ch ...

hadron production (mostly

D meson The D mesons are the lightest particle containing charm quarks. They are often studied to gain knowledge on the weak interaction. The strange D mesons (Ds) were called "F mesons" prior to 1986. Overview The D mesons were discovere ...

s) in lead-lead interactions. In 2020 the SPS and PS Experiments Committee (SPSC) recommended approval of beam time in 2021. The Research Board endorsed these recommendations.

References

External links

NA61/SHINE Collaboration web-site

NA61/SHINE proposal

NA49 Collaboration web-site

NA61/SHINE Collaboration official instagram

CERN-NA-061
experiment record on

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