Cecilia Jarlskog (born in 1941) is a Swedish 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 caus ...
, working mainly on elementary
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 ...
CP violation
In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge symmetry) and P-symmetry ( parity symmetry). CP-symmetry states that the laws of physics should be the ...
Standard Model
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetism, electromagnetic, weak interaction, weak and strong interactions - excluding gravity) in the universe and classifying a ...
, introducing what is known as the Jarlskog invariant, and for her work on
grand unified theories
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 ...
Cecilia Jarlskog is mainly known for her study and expertise in theoretical particle physics. Her studies include research on the ways that sub-atomic and electronic constituents of matter cohere or lose their symmetry, matter and antimatter asymmetry, mathematical physics, neutrino physics, and grand unification.
The Jarlskog invariant or rephasing-invariant
CP violation
In particle physics, CP violation is a violation of CP-symmetry (or charge conjugation parity symmetry): the combination of C-symmetry (charge symmetry) and P-symmetry ( parity symmetry). CP-symmetry states that the laws of physics should be the ...
parameter, is an invariant quantity in particle physics, which is in the order of ±2.8 x 10−5. This parameter is related to the unitarity conditions of the
Cabibbo–Kobayashi–Maskawa matrix
In the Standard Model of particle physics, the Cabibbo–Kobayashi–Maskawa matrix, CKM matrix, quark mixing matrix, or KM matrix is a unitary matrix which contains information on the strength of the flavour-changing weak interaction. Technica ...
, which can be expressed as
triangles
A triangle is a polygon with three edges and three vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC.
In Euclidean geometry, any three points, when non-collinear ...
whose sides are products of different elements of the matrix. As such, the Jarlskog invariant can be written as J = ±Im(VusVcbVV), which amounts to twice the area of the unitarity triangle. Because the area vanishes for the specific parameters in the
Standard Model
The Standard Model of particle physics is the theory describing three of the four known fundamental forces (electromagnetism, electromagnetic, weak interaction, weak and strong interactions - excluding gravity) in the universe and classifying a ...
for which there would be no CP violation, this invariant is thus very useful to quantify the non-conservation of the CP-symmetry in elementary particle physics. It is one of Jarlskog's foremost contributions to physics, the other being the many years that she was an active member of
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 Gene ...
.
She recalls her appreciation of CERN's (European Organization for Nuclear Research) international atmosphere. Being a part of this community gave her great opportunities to meet and talk with inspiring physicists from across the world. She noted that she felt fortunate to have 'lived in a period when the amount of information revealed about the nature of the elementary constituents of matter and their interactions has been mind-boggling'.
At CERN, the European Organization for Nuclear Research, physicists and engineers probe the fundamental structure of the universe. The world's largest and most complex scientific instruments are employed to study the basic constituents of matter – fundamental particles. The particles are caused to collide at close to the speed of light, which affords physicists clues about the interactions of particles, and insights into the fundamental laws of nature.
Career
Jarlskog was appointed professor at the
University of Bergen
The University of Bergen ( no, Universitetet i Bergen, ) is a research-intensive state university located in Bergen, Norway. As of 2019, the university has over 4,000 employees and 18,000 students. It was established by an act of parliament in 194 ...
, Norway, in 1976. In 1985 she switched to the
University of Stockholm
Stockholm University ( sv, Stockholms universitet) is a public research university in Stockholm, Sweden, founded as a college in 1878, with university status since 1960. With over 33,000 students at four different faculties: law, humanities, soci ...
, Sweden, staying there until 1994. Since then, Jarlskog has been a professor at
Lund University
, motto = Ad utrumque
, mottoeng = Prepared for both
, established =
, type = Public research university
, budget = SEK 9 billion alma mater, where she had graduated in 1970 with a PhD in theoretical particle physics.
Jarlskog worked as a member of CERN from 1970 to 1972. In addition, she served on the CERN Scientific Policy committee from 1982 to 1988. In her remaining 6 years at CERN, she served as the Advisor to the Director General of CERN on Member States, from 1998 to 2004. Jarlskog was recognized by the Swedish Academy of Science community and was appointed as one of the 5 members of the Swedish
Nobel Committee for Physics
The Nobel Committee for Physics is the Nobel Committee responsible for proposing laureates for the Nobel Prize for Physics.
from 1989 to 2000, serving as chairman of that committee in 1999, when the prize was awarded to
Gerard 't Hooft
Gerardus (Gerard) 't Hooft (; born July 5, 1946) is a Dutch theoretical physicist and professor at Utrecht University, the Netherlands. He shared the 1999 Nobel Prize in Physics with his thesis advisor Martinus J. G. Veltman "for elucidating the ...
and
Martinus J. G. Veltman
Martinus Justinus Godefriedus "Tini" Veltman (; 27 June 1931 – 4 January 2021) was a Dutch theoretical physicist. He shared the 1999 Nobel Prize in physics with his former PhD student Gerardus 't Hooft for their work on particle theory.
Biogr ...
.
Jarlskog is an Honorary Professor at three universities in China and received an honorary degree from the
University College Dublin
University College Dublin (commonly referred to as UCD) ( ga, Coláiste na hOllscoile, Baile Átha Cliath) is a public research university in Dublin, Ireland, and a collegiate university, member institution of the National University of Ireland ...
.
She was also Member of the Swedish Academy of Sciences (1984), Member of the Norwegian Academy of Sciences (1987), Member of the Board of Trustees of the Nobel Foundation (1996) and Member of the
Academia Europaea
The Academia Europaea is a pan-European Academy of Humanities, Letters, Law, and Sciences.
The Academia was founded in 1988 as a functioning Europe-wide Academy that encompasses all fields of scholarly inquiry. It acts as co-ordinator of Europea ...
(2005).
Books and articles
Cecilia Jarlskog wrote the book, Portrait of
Gunnar Källén Anders Olof Gunnar Källén (13 February 1926 in Kristianstad, Sweden – 13 October 1968 in Hanover, West Germany in a plane accident) was a leading Swedish theoretical physicist and a professor at Lund University until his death at the age of 42.
...
: A Physics Shooting Star and Poet of Early Quantum Field Theory, while a member of CERN. Here she relates the accomplishments of a comparatively unknown physicist in quantum physics. Jarlskog has written many articles in her lifetime, among them are "Invariations of Lepton Mass Matrices and CP and T violation in Neutrino Oscillations", "On the Wings of Physics" and "Ambiguities Pertaining to Quark-Lepton Complementarity."
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 ...