Harald Fritzsch (born 10 February 1943 in
Zwickau
Zwickau (; is, with around 87,500 inhabitants (2020), the fourth-largest city of Saxony after Leipzig, Dresden and Chemnitz and it is the seat of the Zwickau District. The West Saxon city is situated in the valley of the Zwickau Mulde (German: ...
, Germany, died 16 August 2022 in
München) was a German theoretical
physicist
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe.
Physicists generally are interested in the root or ultimate cau ...
known for his contributions to the theory of
quarks
A quark () is a type of elementary particle and a fundamental constituent of matter. Quarks combine to form composite particles called hadrons, the most stable of which are protons and neutrons, the components of atomic nuclei. All commonly ...
, the development of
Quantum Chromodynamics and the great unification of the
standard model of particle physics.
Education and career
After completing his education in Zwickau 1961, he became Soldier of the
Nationale Volksarmee
The National People's Army (german: Nationale Volksarmee, ; NVA ) were the armed forces of the German Democratic Republic (GDR) from 1956 to 1990.
The NVA was organized into four branches: the (Ground Forces), the (Navy), the (Air Force) an ...
of the
GDR. He studied Physics in
Leipzig
Leipzig ( , ; Upper Saxon: ) is the most populous city in the German state of Saxony. Leipzig's population of 605,407 inhabitants (1.1 million in the larger urban zone) as of 2021 places the city as Germany's eighth most populous, as ...
from 1963 to 1968. After fleeing to
West Germany
West Germany is the colloquial term used to indicate the Federal Republic of Germany (FRG; german: Bundesrepublik Deutschland , BRD) between its formation on 23 May 1949 and the German reunification through the accession of East Germany on 3 O ...
, he continued his studies in
Munich
Munich ( ; german: München ; bar, Minga ) is the capital and most populous city of the German state of Bavaria. With a population of 1,558,395 inhabitants as of 31 July 2020, it is the third-largest city in Germany, after Berlin and Ha ...
where he finished his
Ph.D.
A Doctor of Philosophy (PhD, Ph.D., or DPhil; Latin: or ') is the most common degree at the highest academic level awarded following a course of study. PhDs are awarded for programs across the whole breadth of academic fields. Because it is ...
under the supervision of
Heinrich Mitter.
In 1970 Fritzsch visited the
Aspen Center for Physics
The Aspen Center for Physics is a non-profit Center for research in Physics based in Aspen, Colorado, United States. The Center organizes workshops and conferences to facilitate interactions among research physicists.
The Center was founded in 19 ...
, where he met
Murray Gell-Mann
Murray Gell-Mann (; September 15, 1929 – May 24, 2019) was an American physicist who received the 1969 Nobel Prize in Physics for his work on the theory of elementary particles. He was the Robert Andrews Millikan Professor of Theoretical ...
. They started a collaboration, first in Aspen, later at the California Institute of Technology. In 1971 they introduced the concept of the
colour charge
Color charge is a property of quarks and gluons that is related to the particles' strong interactions in the theory of quantum chromodynamics (QCD).
The "color charge" of quarks and gluons is completely unrelated to the everyday meanings of colo ...
quantum number which allowed them in collaboration with
William A. Bardeen
William Allan Bardeen (born September 15, 1941 in Washington, Pennsylvania) is an American theoretical physicist at Fermi National Accelerator Laboratory. He is the son of John Bardeen and Jane Maxwell Bardeen.
Biography
After graduating from Co ...
to explain the decay rate of
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 gene ...
s. In the fall of 1971 Fritzsch and Gell-Mann moved to Geneva in Switzerland, where they worked together at
CERN. They proposed a
gauge theory for the
strong interaction, which now is called Quantumchromodynamics. In September 1972 they moved back to Caltech. In 1975 Fritzsch published a paper together with
Peter Minkowski
Peter Minkowski (born 10 May 1941) is a Swiss theoretical physicist. He is primarily known for his proposal, with Harald Fritzsch, of SO(10) as the group of a grand unified theory and for his independent proposal, more-or-less simultaneously with ...
in which they proposed the symmetry group
SO(10)
In particle physics, SO(10) refers to a grand unified theory (GUT) based on the spin group Spin(10). The shortened name SO(10) is conventional among physicists, and derives from the Lie algebra or less precisely the Lie group of SO(10), which ...
as the symmetry of the
grand unified theory
A Grand Unified Theory (GUT) is a model in particle physics in which, at high energies, the three gauge interactions of the Standard Model comprising the electromagnetic, weak, and strong forces are merged into a single force. Although this ...
which has become a standard theory. In 1976 Fritzsch moved to CERN. After working for one year at the University of Wuppertal and the University of Bern, Fritzsch became professor at the
Ludwig Maximilian University of Munich in 1980.
Fritzsch worked also on "composite models" of leptons and quarks, mass matrices of quarks and leptons, weak decays of heavy quarks, cosmology and the fundamental constants of physics. He retired in 2008 and died 16 August 2022 in
München.
In 1971 Fritzsch married Brigitte Goralski. They had two children.
Works
* ''Quarks: The Stuff of Matter'' (1989, )
* ''The Creation of Matter: The Universe from Beginning to End'' (1984, )
(1997, )
''The Curvature of Spacetime: Newton, Einstein, and Gravitation''(2005, )
* ''Elementary Particles: Building Blocks of Matter'' (2005, )
* ''Escape From Leipzig'' (2008, )
(2009, (paperback))
''You Are Wrong, Mr Einstein!: Newton, Einstein, Heisenberg and Feynman Discussing Quantum Mechanics''(2011, )
''Microcosmos: The World of Elementary Particles: Fictional Discussions between Einstein, Newton, and Gell-Mann''(2013, )
* ''50 Years of Quarks'' (with Murray Gell-Mann, 2015, )
References
{{DEFAULTSORT:Fritzsch, Harald
1943 births
Living people
20th-century German physicists
Theoretical physicists
Ludwig Maximilian University of Munich faculty
People associated with CERN
21st-century German physicists