The PHENIX detector (for Pioneering High Energy Nuclear Interaction eXperiment) is the largest of the four experiments that have taken data at the
Relativistic Heavy Ion Collider
The Relativistic Heavy Ion Collider (RHIC ) is the first and one of only two operating heavy- ion colliders, and the only spin-polarized proton collider ever built. Located at Brookhaven National Laboratory (BNL) in Upton, New York, and used by ...
(RHIC) in
Brookhaven National Laboratory
Brookhaven National Laboratory (BNL) is a United States Department of Energy national laboratory located in Upton, Long Island, and was formally established in 1947 at the site of Camp Upton, a former U.S. Army base and Japanese internment c ...
, United States.
Overview
PHENIX is an exploratory experiment for the investigation of high energy collisions of heavy ions and protons, and is designed specifically to measure direct probes of the collisions such as
electron
The electron (, or in nuclear reactions) is a subatomic particle with a negative one elementary electric charge. Electrons belong to the first generation of the lepton particle family,
and are generally thought to be elementary partic ...
s,
muon
A muon ( ; from the Greek letter mu (μ) used to represent it) is an elementary particle similar to the electron, with an electric charge of −1 '' e'' and a spin of , but with a much greater mass. It is classified as a lepton. As wi ...
s, and
photon
A photon () is an elementary particle that is a quantum of the electromagnetic field, including electromagnetic radiation such as light and radio waves, and the force carrier for the electromagnetic force. Photons are Massless particle, massless ...
s. The primary goal of PHENIX is to discover and study a new state of matter called
quark–gluon plasma
Quark–gluon plasma (QGP) or quark soup is an interacting localized assembly of quarks and gluons at thermal (local kinetic) and (close to) chemical (abundance) equilibrium. The word ''plasma'' signals that free color charges are allowed. In a ...
(QGP). Detecting and understanding the QGP allows us to understand better the universe in the moments after the
Big Bang
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from t ...
.
The PHENIX Experiment consists of a collection of detectors, each of which perform a specific role in the measurement of the results of a heavy ion collision. The detectors are grouped into two central arms, which are capable of measuring a variety of particles including
pion
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 gen ...
s,
protons,
kaon
KAON (Karlsruhe ontology) is an ontology infrastructure developed by the University of Karlsruhe and the Research Center for Information Technologies in Karlsruhe.
Its first incarnation was developed in 2002 and supported an enhanced version o ...
s,
deuteron
Deuterium (or hydrogen-2, symbol or deuterium, also known as heavy hydrogen) is one of two Stable isotope ratio, stable isotopes of hydrogen (the other being Hydrogen atom, protium, or hydrogen-1). The atomic nucleus, nucleus of a deuterium ato ...
s, photons, and electrons, and two muon arms which focus on the measurement of muon particles. There are also additional event characterization detectors that provide additional information about a collision, and a set of three huge magnets that bend the trajectories of the charged particles. These detectors work together in an advanced high-speed data acquisition system to collect information about the event and subsequently investigate properties of the QGP.
The experiment consists of a collaboration of more than 400 scientists and engineers from around the world. The collaboration is led by a spokesperson, elected by members every three years, along with a team of deputies and other appointed members who oversee various aspects of operating the detector and managing the large group of scientist and institutions affiliated with it. Past and present spokespeople include
Shoji Nagamiya
A is a door, window or room divider used in traditional Japanese architecture, consisting of translucent (or transparent) sheets on a lattice frame. Where light transmission is not needed, the similar but opaque ''fusuma'' is used (oshiire/ ...
(1992–1998),
William Allen Zajc
William Allen Zajc is a U.S. physicist and the I.I. Rabi Professor of Physics at Columbia University in New York, USA, where he has worked since 1987.
Early life
Born in Barstow, California, on November 14, 1953, and raised in Brookfield, Wis ...
(1998–2006), and
Barbara Jacak
Barbara Jacak () is a nuclear physicist who uses heavy ion collisions for fundamental studies of hot, dense nuclear matter. She is director of the Nuclear Science Division, Lawrence Berkeley National Laboratory, and a professor of physics at UC ...
(2007–2012).
The physics of PHENIX
The PHENIX collaboration performs basic research with high energy collisions of heavy ions and protons. The primary mission of PHENIX is the following:
*Search for a new state of matter called the
quark–gluon plasma
Quark–gluon plasma (QGP) or quark soup is an interacting localized assembly of quarks and gluons at thermal (local kinetic) and (close to) chemical (abundance) equilibrium. The word ''plasma'' signals that free color charges are allowed. In a ...
, which is believed to be the state of matter existing in the universe shortly after the
Big Bang
The Big Bang event is a physical theory that describes how the universe expanded from an initial state of high density and temperature. Various cosmological models of the Big Bang explain the evolution of the observable universe from t ...
. PHENIX data suggest that a new form of matter has indeed been discovered, and that it behaves like a perfect fluid. PHENIX scientists are now working to study its properties.
*Study matter under extreme conditions of temperature and pressure.
*Learn where the proton gets its spin.
*Study the most basic building blocks of nature and the forces that govern them.
*Create a map of the
quantum chromodynamics
In theoretical physics, quantum chromodynamics (QCD) is the theory of the strong interaction between quarks mediated by gluons. Quarks are fundamental particles that make up composite hadrons such as the proton, neutron and pion. QCD is a ty ...
phase diagram.
See also
*
Relativistic Heavy Ion Collider
The Relativistic Heavy Ion Collider (RHIC ) is the first and one of only two operating heavy- ion colliders, and the only spin-polarized proton collider ever built. Located at Brookhaven National Laboratory (BNL) in Upton, New York, and used by ...
Further reading
References
External links
PHENIX webpagePHENIX experimentrecord on
INSPIRE-HEP INSPIRE-HEP is an open access digital library for the field of high energy physics (HEP). It is the successor of the Stanford Physics Information Retrieval System (SPIRES) database, the main literature database for high energy physics since the 1970 ...
Particle experiments
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