Open Questions: CP Symmetry Violation

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Prerequisites: The standard model

See also: Matter/antimatter asymmetry -- The vacuum -- Higgs physics

Introduction

Spin and statistics

CPT theorem

Experimental results

Time reversal asymmetry

Matter-antimatter asymmetry

CP symmetry and the strong force -- axions


Recommended references: Web sites

Recommended references: Magazine/journal articles

Recommended references: Books

Introduction


Spin and statistics


CPT theorem


Matter-antimatter asymmetry


CP symmetry and the strong force

Strong interactions are invariant under CP.
Total CP violation is interpreted as value of a spinless quantum field of the axion.
Axion solution requires existence of a global Peccei-Quinn symmetry.
Spontaneous breaking of Peccei-Quinn symmetry implies Goldstone boson, which is the axion.


Recommended references: Web sites

Site indexes

CP Violation in B Decay: Related Links
Part of the CP News site. Contains links to some survey articles and research facilities which investigate B meson decay and CP violation.


Sites with general resources

CP News
Published by the University of Cincinnati CP group. Main features are the informative FAQ list, news, a short glossary, and some external links.
Belle Collaboration
Home page for a research group that is studing the origin of CP violation. Belle experiments use the KEK B-factory electron-positron collider in Japan.
BaBar Collaboration Home Page
BaBar is SLAC's primary high-energy physics program to investigate matter-antimatter asymmetry in nature. Information for the general public is at the BaBar Public Web Home Page.
CERN Axion solar Telescope
CAST is an experiment located at CERN that is attmpting to detect axions which may be generated in the Sun. The site includes information on axions, publications of the CAST group, and related links.
The Large Hadron Collider beauty experiment
Home page of LHC experiment for precise measurements of CP violation and rare decays. Includes some reference material on relevant physics.


Surveys, overviews, tutorials

CPT symmetry
Article from Wikipedia. See also C-symmetry, P-symmetry, T-symmetry, CP-symmetry.
The low-energy frontier
Summary of August 2007 article from Physics World, by Axel Lindner and Andreas Ringwald. "Particle physicists are hoping to find a host of new low-mass particles that might hint at physics beyond the Standard Model. The authors describe the unusually small-scale experiments being built to hunt for this "hidden sector" of reality."
A triangle that matters
April 2007 article from Physics World, by Tim Gershon. "Physicists at "B-factories" in the US and Japan are closing in on an abstract diagram called the unitarity triangle in the quest to explain the difference between matter and antimatter. But such measurements could also point the way to the discovery of new fundamental particles."
Nature's flawed mirror
July 2003 article from Physics World, by Paul Harrison. "Two experiments on opposite sides of the world have measured charge-parity violation - the key to understanding why there is more matter than antimatter in the universe."
Big break for charge symmetry
June 2003 article from Physics World, by Gerald A. Miller and Ubirajara van Kolck. "Two new experiments have detected charge-symmetry breaking, the mechanism responsible for protons and neutrons having different masses."
Spin, Statistics, CPT and All That Jazz
"A little grab-bag of proofs of the spin-statistic relations, with some stuff about CPT thrown in", by John Baez.
CP-Violation, B-Physics, and the Early Universe
Brief but useful overview, by Larry Gladney.
Why does CP violation matter to the universe?
September 1999 article by John Ellis. Gives an explanation of the relationship between CP violation and the asymmetry of matter and antimatter.
What exactly is the 'spin' of subatomic particles?
Several answers to the question in a Scientific American Ask the Experts article.
CP Violation
Lecture notes by Steve Lloyd, from a course on Elementary Particle Physics.
What is an axion?
Answer provided by Leslie J. Rosenberg.
Background information on Lorentz and CPT violation
Theory and experimental tests related to the possibility that CPT symmetry (and hence Lorentz symmetry) might be violated. Questions and answers by Alan Kostelecky.
TASI Lectures on The Strong CP Problem
A technical paper by Michael Dine. Full paper available in PDF and other formats.
A violation of CP symmetry in B meson decays
May/June 2002 article from Europhysics News, by Yannis Karyotakis and Gautier Hamel de Monchenault concerning CP assymetries in the decay of neutral B mesons. The article provides a good technical explanation of both relevant background and the new results.
In Search of Antimatter
August 2001 article from Scientific American Explore, subtitled "Two international collaborations have announced definitive answers to one small piece of the universe's matter-antimatter asymmetry problem."
B factories go into overdrive
March 2001 news article from PhysicsWeb.
CERN confirms direct CP violation
June 22, 1999 PhysicsWeb news article.
A Hint of Axions
July 2006 Scientific American article, subtitled "An experiment may have seen an elusive new particle."
Direct CP symmetry violation and matter-antimatter asymmetry: new findings from an experiment at CERN
June 28, 1999 press release about CP symmetry violations observed in neutral kaon experiments at CERN.
Experiment sees the arrow of time - at last!
December 1998 article from Physics World, by Nick Mavromatos. "The classical laws of physics cannot distinguish between the past and the future, but now experiments at CERN have confirmed that time-reversal symmetry is broken in neutral kaons."
Time's arrow seen in particle decays
November 16, 1998 PhysicsWeb news article.


Technical papers

On CPT Symmetry: Cosmological, Quantum-Gravitational and other possible violations and their phenomenology
2003 ArXiv paper (hep-ph/0309221) by Nick E. Mavromatos. Discusses various ways in which CPT symmetry may be violated, and their phenomenology in current or immediate future experimental facilities, both terrestrial and astrophysical. Considers CPT violation due to breaking of Lorentz symmetry and some string theory models.


Recommended references: Magazine/journal articles

The Asymmetry between Matter and Antimatter
Helen R. Quinn, Michael S. Witherell
Scientific American, October 1998, pp. 76-81
Violations of CP (charge-parity) symmetry test the Standard Model of particle physics and help explain the excess of matter over antimatter in the universe.
The Pool-Table Analogy with Axion Physics
Pierre Sikivie
Physics Today, December 1996, pp. 22-27
An analogy illuminates the problem of CP symmetry violation and helps explain the search for the hypothetical axion particle, which may be a component of cosmic dark matter.
A Flaw in a Universal Mirror
Robert K. Adair
Scientific American, February 1988, pp. 50-56
A very slight violation of CP symmetry is known to exist, and the existence of matter in the universe seems to depend on it. But a deeper reason for this symmetry violation remains unknown.
An Atomic Preference Between Left and Right
Marie-Anne Bouchiat; Lionel Pottier
Scientific American, June 1884, pp. 100-111
It has long been known that violation of partity occurs in particle interactions involving the weak force. The effect has now been demonstrated at an atomic level.


Recommended references: Books


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