High-energy nuclear physics
Nuclear physics |
---|
High-energy nuclear physics studies the behavior of nuclear matter in energy regimes typical of
Previous high-energy nuclear
High-energy nuclear physics experiments are continued at the
The
History
The exploration of hot hadron matter and of multiparticle production has a long history initiated by theoretical work on multiparticle production by Enrico Fermi in the US and Lev Landau in the USSR. These efforts paved the way to the development in the early 1960s of the thermal description of multiparticle production and the statistical bootstrap model by Rolf Hagedorn. These developments led to search for and discovery of quark-gluon plasma. Onset of the production of this new form of matter remains under active investigation.
First collisions
The first heavy-ion collisions at modestly relativistic conditions were undertaken at the Lawrence Berkeley National Laboratory (LBNL, formerly LBL) at Berkeley, California, U.S.A., and at the Joint Institute for Nuclear Research (JINR) in Dubna, Moscow Oblast, USSR. At the LBL, a transport line was built to carry heavy ions from the heavy-ion accelerator HILAC to the Bevatron. The energy scale at the level of 1–2 GeV per nucleon attained initially yields compressed nuclear matter at few times normal nuclear density. The demonstration of the possibility of studying the properties of compressed and excited nuclear matter motivated research programs at much higher energies in accelerators available at BNL and CERN with relativist beams targeting laboratory fixed targets. The first collider experiments started in 1999 at RHIC, and LHC begun colliding heavy ions at one order of magnitude higher energy in 2010.
CERN operation
The
In August 2012 ALICE scientists announced that their experiments produced quark–gluon plasma with temperature at around 5.5 trillion kelvins, the highest temperature achieved in any physical experiments thus far.[5] This temperature is about 38% higher than the previous record of about 4 trillion kelvins, achieved in the 2010 experiments at the Brookhaven National Laboratory.[5] The ALICE results were announced at the August 13 Quark Matter 2012 conference in Washington, D.C. The quark–gluon plasma produced by these experiments approximates the conditions in the universe that existed microseconds after the Big Bang, before the matter coalesced into atoms.[6]
Objectives
There are several scientific objectives of this international research program:
- The formation and investigation of a new state of matter made of quarks and gluons, the quark–gluon plasma QGP, which prevailed in early universe in first 30 microseconds.
- The study of color confinement and the transformation of color confining = quark confining vacuum state to the excited state physicists call perturbative vacuum, in which quarks and gluons can roam free, which occurs at Hagedorn temperature;
- The study the origins of hadron (proton, neutron etc.) matter mass believed to be related to the phenomenon of quark confinement and vacuum structure.
Experimental program
This experimental program follows on a decade of research at the
at BNL. This experimental program has already confirmed that the extreme conditions of matter necessary to reach QGP phase can be reached. A typical temperature range achieved in the QGP createdis more than 100000 times greater than in the center of the Sun. This corresponds to an energy density
- .
The corresponding relativistic-matter pressure is
More information
- Rutgers University Nuclear Physics Home Page
- Publications - High Energy Nuclear Physics (HENP)
- https://web.archive.org/web/20101212105542/http://www.er.doe.gov/np/
References
- ^ "Rutgers University Nuclear Physics Home Page". www.physics.rutgers.edu. Retrieved 5 February 2019.
- ^ "Publications - High Energy Nuclear Physics (HENP)". www.physics.purdue.edu. Archived from the original on 29 July 2012. Retrieved 5 February 2019.
- ^ "Office of Nuclear Physics - redirect". Archived from the original on 2010-12-12. Retrieved 2009-08-18.
- ^ "Quark Matter 2018". Indico. Retrieved 2020-04-29.
- ^ a b Eric Hand (13 Aug 2012). "Hot stuff: CERN physicists create record-breaking subatomic soup". Nature News Blog. Retrieved 5 Jan 2019.
- ^ Will Ferguson (14 August 2012). "LHC primordial matter is hottest stuff ever made". New Scientist. Retrieved 15 August 2012.