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Chiral Magnetic Effect
Chiral magnetic effect (CME) is the generation of electric current along an external magnetic field induced by chirality imbalance. Fermions are said to be chiral if they keep a definite projection of spin quantum number on momentum. The CME is a macroscopic quantum phenomenon present in systems with charged chiral fermions, such as the quark–gluon plasma, or Dirac and Weyl semimetals. The CME is a consequence of chiral anomaly in quantum field theory; unlike conventional superconductivity or superfluidity, it does not require a spontaneous symmetry breaking. The chiral magnetic current is non-dissipative, because it is topologically protected: the imbalance between the densities of left-handed and right-handed chiral fermions is linked to the topology of fields in gauge theory by the Atiyah-Singer index theorem. The experimental observation of CME in a Dirac semimetal ZrTe5 was reported in 2014 by a group from Brookhaven National Laboratory and Stony Brook University. The mate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Magnetic Effect ZrTe5 - Resistivity Vs Magnetic Field Vs Angle At 20K
Chirality is a property of asymmetry important in several branches of science. The word ''chirality'' is derived from the Greek language, Greek (''kheir''), "hand", a familiar chiral object. An object or a system is ''chiral'' if it is distinguishable from its mirror image; that is, it cannot be wikt:superimpose, superimposed onto it. Conversely, a mirror image of an ''achiral'' object, such as a sphere, cannot be distinguished from the object. A chiral object and its mirror image are called ''enantiomorphs'' (Greek, "opposite forms") or, when referring to molecules, ''enantiomers''. A non-chiral object is called ''achiral'' (sometimes also ''amphichiral'') and can be superposed on its mirror image. The term was first used by William Thomson, 1st Baron Kelvin, Lord Kelvin in 1893 in the second Robert Boyle Lecture at the Oxford University Junior Scientific Club which was published in 1894: Human hands are perhaps the most recognized example of chirality. The left hand is a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiral Anomaly
In theoretical physics, a chiral anomaly is the anomalous nonconservation of a chiral current. In everyday terms, it is equivalent to a sealed box that contained equal numbers of left and right-handed bolts, but when opened was found to have more left than right, or vice versa. Such events are expected to be prohibited according to classical conservation laws, but it is known there must be ways they can be broken, because we have evidence of charge–parity non-conservation ("CP violation"). It is possible that other imbalances have been caused by breaking of a ''chiral law'' of this kind. Many physicists suspect that the fact that the observable universe contains more matter than antimatter is caused by a chiral anomaly. Research into chiral symmetry breaking laws is a major endeavor in particle physics research at this time. Informal introduction The chiral anomaly originally referred to the anomalous decay rate of the neutral pion, as computed in the current algebra of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euler–Heisenberg Lagrangian
In physics, the Euler–Heisenberg Lagrangian describes the non-linear dynamics of electromagnetic fields in vacuum. It was first obtained by Werner Heisenberg and Hans Heinrich Euler in 1936. By treating the vacuum as a medium, it predicts rates of quantum electrodynamics (QED) light interaction processes. Physics It takes into account vacuum polarization to one loop, and is valid for electromagnetic fields that change slowly compared to the inverse electron mass, :\mathcal =-\mathcal -\frac\int_^\exp\left(-m^s\right)\left es)^\frac\mathcal-\frac(es)^\mathcal - 1\rightfrac. Here is the electron mass, the electron charge, \mathcal=\frac\left(\mathbf^2 - \mathbf^2\right), and \mathcal=\mathbf\cdot\mathbf. In the weak field limit, this becomes :\mathcal = \frac\left(\mathbf^-\mathbf^\right)+\frac\left left(\mathbf^2 - \mathbf^2\right)^ + 7 \left(\mathbf\cdot\mathbf\right)^\right It describes photon–photon scattering in QED; Robert Karplus and Maurice Neuman calculated the f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CERN
The European Organization for Nuclear Research, known as CERN (; ; ), is an intergovernmental organization that operates the largest particle physics laboratory in the world. Established in 1954, it is based in a northwestern suburb of Geneva, on the France–Switzerland border. It comprises 23 member states, and Israel (admitted in 2013) is currently the only non-European country holding full membership. CERN is an official United Nations General Assembly observer. The acronym CERN is also used to refer to the laboratory; in 2019, it had 2,660 scientific, technical, and administrative staff members, and hosted about 12,400 users from institutions in more than 70 countries. In 2016, CERN generated 49 petabytes of data. CERN's main function is to provide the particle accelerators and other infrastructure needed for high-energy physics research — consequently, numerous experiments have been constructed at CERN through international collaborations. CERN is the site of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Large Hadron Collider
The Large Hadron Collider (LHC) is the world's largest and highest-energy particle collider. It was built by the European Organization for Nuclear Research (CERN) between 1998 and 2008 in collaboration with over 10,000 scientists and hundreds of universities and laboratories, as well as more than 100 countries. It lies in a tunnel in circumference and as deep as beneath the France–Switzerland border near Geneva. The first collisions were achieved in 2010 at an energy of 3.5 teraelectronvolts (TeV) per beam, about four times the previous world record. After upgrades it reached 6.5 TeV per beam (13 TeV total collision energy). At the end of 2018, it was shut down for three years for further upgrades. The collider has four crossing points where the accelerated particles collide. Seven detectors, each designed to detect different phenomena, are positioned around the crossing points. The LHC primarily collides proton beams, but it can also accelerate beams of heavy ion ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
A Large Ion Collider Experiment
ALICE (A Large Ion Collider Experiment) is one of eight detector experiments at the Large Hadron Collider at CERN. The other seven are: ATLAS, CMS, TOTEM, LHCb, LHCf, MoEDAL and FASER. Introduction ALICE is optimized to study heavy-ion ( Pb-Pb nuclei) collisions at a centre of mass energy up to 5.02 TeV per nucleon pair. The resulting temperature and energy density allow exploration of quark–gluon plasma, a fifth state of matter wherein quarks and gluons are freed. Similar conditions are believed to have existed a fraction of the second after the Big Bang before quarks and gluons bound together to form hadrons and heavier particles. ALICE is focusing on the physics of strongly interacting matter at extreme energy densities. The properties of the quark–gluon plasma and the understanding of quark deconfinement are key issues in quantum chromodynamics (QCD). The results obtained by ALICE corroborate the understanding of color confinement and chiral symmetry restoration. Re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 an international team of researchers, it is the only operating particle collider in the US. By using RHIC to collide ions traveling at relativistic speeds, physicists study the primordial form of matter that existed in the universe shortly after the Big Bang. By colliding spin-polarized protons, the spin structure of the proton is explored. RHIC is as of 2019 the second-highest-energy heavy-ion collider in the world. As of November 7, 2010, the Large Hadron Collider (LHC) has collided heavy ions of lead at higher energies than RHIC. The LHC operating time for ions (lead–lead and lead–proton collisions) is limited to about one month per year. In 2010, RHIC physicists published results of temperature measurements from earlier experime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
STAR Detector
The STAR detector (for Solenoidal Tracker at RHIC) is one of the four experiments at the Relativistic Heavy Ion Collider (RHIC) in Brookhaven National Laboratory, United States. The primary scientific objective of STAR is to study the formation and characteristics of the quark–gluon plasma (QGP), a state of matter believed to exist at sufficiently high energy densities. Detecting and understanding the QGP allows physicists to understand better the Universe in the seconds after the Big Bang, when the presently-observed symmetries (and asymmetries) of the Universe were established. Unlike other physics experiments where a theoretical prediction can be tested directly by a single measurement, STAR must make use of a variety of simultaneous studies in order to draw strong conclusions about the QGP. This is due both to the complexity of the system formed in the high-energy nuclear collision and the unexplored landscape of the physics studied. STAR therefore consists of several types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lorentz Force
In physics (specifically in electromagnetism) the Lorentz force (or electromagnetic force) is the combination of electric and magnetic force on a point charge due to electromagnetic fields. A particle of charge moving with a velocity in an electric field and a magnetic field experiences a force of \mathbf = q\,\mathbf + q\,\mathbf \times \mathbf (in SI unitsIn SI units, is measured in teslas (symbol: T). In Gaussian-cgs units, is measured in gauss (symbol: G). See e.g. )The -field is measured in amperes per metre (A/m) in SI units, and in oersteds (Oe) in cgs units. ). It says that the electromagnetic force on a charge is a combination of a force in the direction of the electric field proportional to the magnitude of the field and the quantity of charge, and a force at right angles to the magnetic field and the velocity of the charge, proportional to the magnitude of the field, the charge, and the velocity. Variations on this basic formula describe the magnetic force on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stony Brook University
Stony Brook University (SBU), officially the State University of New York at Stony Brook, is a public research university in Stony Brook, New York. Along with the University at Buffalo, it is one of the State University of New York system's two flagship institutions. Its campus consists of 213 buildings on over of land in Suffolk County and it is the largest public university (by area) in the state of New York. Opened in 1957 in Oyster Bay as the State University College on Long Island, the institution moved to Stony Brook in 1962. In 2001, Stony Brook was elected to the Association of American Universities, a selective group of major research universities in North America. It is also a member of the larger Universities Research Association. It is classified among "R1: Doctoral Universities – Very high research activity". Stony Brook University, in partnership with Battelle, manages Brookhaven National Laboratory, a national laboratory of the United States Depart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 camp. Its name stems from its location within the Town of Brookhaven, approximately 60 miles east of New York City. It is managed by Stony Brook University and Battelle Memorial Institute. Research at BNL includes nuclear and high energy physics, energy science and technology, environmental and bioscience, nanoscience, and national security. The 5,300 acre campus contains several large research facilities, including the Relativistic Heavy Ion Collider and National Synchrotron Light Source II. Seven Nobel Prizes have been awarded for work conducted at Brookhaven Lab. Overview BNL is staffed by approximately 2,750 scientists, engineers, technicians, and support personnel, and hosts 4,000 guest investigators every year. The laboratory has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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