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Standard-Model Extension (SME) is an effective field theory that contains the Standard Model, general relativity, and all possible operators that break Lorentz symmetry.〔 D. Colladay and V.A. Kostelecký, ''CPT Violation and the Standard Model'', Phys. Rev. D 55, 6760 (1997).〕〔D. Colladay and V.A. Kostelecký, ''Lorentz-Violating Extension of the Standard Model'', Phys. Rev. D 58, 116002 (1998).〕〔V.A. Kostelecký, ''Gravity, Lorentz Violation, and the Standard Model'', Phys. Rev. D 69, 105009 (2004)〕〔''(Is Special Relativity Wrong? )'' by Phil Schewe and Ben Stein, AIP Physics News Update Number 712 #1, December 13, 2004.〕〔''(Special Relativity Reconsidered )'' by Adrian Cho, Science, Vol. 307. no. 5711, p. 866, 11 February 2005.〕〔''(Has time run out on Einstein's theory? )'', CNN, June 5, 2002.〕〔''(Was Einstein Wrong? Space Station Research May Find Out )'', JPL News, May 29, 2002.〕〔''(Peering Over Einstein's Shoulders )'' by J.R. Minkel, Scientific American Magazine, June 24, 2002.〕 Violations of this fundamental symmetry can be studied within this general framework. CPT violation implies the breaking of Lorentz symmetry,〔O. Greenberg, ''CPT Violation Implies Violation of Lorentz Invariance'', Phys. Rev. Lett. 89, 231602 (2002).〕 and the SME includes operators that both break and preserve CPT symmetry.〔Kostelecký, Alan. ''(The Search for Relativity Violations )''. Scientific American Magazine.〕〔Russell, Neil. ''(Fabric of the final frontier )'', New Scientist Magazine issue 2408, 16 August 2003. 〕〔''(Time Slows When You're on the Fly )'' by Elizabeth Quill, Science, November 13, 2007.〕 ==Development== In 1989, Alan Kostelecký and Stuart Samuel proved that interactions in string theories could lead to the spontaneous breaking of Lorentz symmetry.〔V.A. Kostelecký and S. Samuel, ''Spontaneous Breaking of Lorentz Symmetry in String Theory'', Phys. Rev. D 39, 683 (1989).〕 Later studies have indicated that loop-quantum gravity, non-commutative field theories, brane-world scenarios, and random dynamics models also involve the breakdown of Lorentz invariance.〔(Breaking Lorentz symmetry ), Physics World, Mar 10, 2004.〕 Interest in Lorentz violation has grown rapidly in the last decades because it can arise in these and other candidate theories for quantum gravity. In the early 1990s, it was shown in the context of bosonic superstrings that string interactions can also spontaneously break CPT symmetry. This work〔V.A. Kostelecký and R. Potting, ''CPT and strings'', Nucl. Phys. B 359, 545 (1991).〕 suggested that experiments with kaon interferometry would be promising for seeking possible signals of CPT violation due to their high sensitivity. The SME was conceived to facilitate experimental investigations of Lorentz and CPT symmetry, given the theoretical motivation for violation of these symmetries. An initial step, in 1995, was the introduction of effective interactions.〔V.A. Kostelecký and R. Potting, ''CPT, Strings, and Meson Factories'', Phys. Rev. D 51, 3923 (1995).〕〔(IU Physicist offers foundation for uprooting a hallowed principle of physics ), Indiana University News Room, January 5, 2009.〕 Although Lorentz-breaking interactions are motivated by constructs such as string theory, the low-energy effective action appearing in the SME is independent of the underlying theory. Each term in the effective theory involves the expectation of a tensor field in the underlying theory. These coefficients are small due to Planck-scale suppression, and in principle are measurable in experiments. The first case considered the mixing of neutral mesons, because their interferometric nature makes them highly sensitive to suppressed effects. In 1997 and 1998, two papers by Don Colladay and Alan Kostelecký gave birth to the minimal SME in flat spacetime.〔〔 This provided a framework for Lorentz violation across the spectrum of standard-model particles, and provided information about types of signals for potential new experimental searches.〔''(New Ways Suggested to Probe Lorentz Violation )'', American Physical Society News, June 2008.〕〔''(Quantum gravity: Back to the future )'', Nature 427, 482-484 (5 February 2004).〕〔''(Lorentz Violations? Not Yet )'' by Phil Schewe, James Riordon, and Ben Stein, Number 623 #2, February 5, 2003.〕〔''(Relativity: Testing times in space )'', Nature 416, 803-804, (25 April 2002).〕〔''(Catching relativity violations with atoms )'' by Quentin G. Bailey, APS Viewpoint, Physics 2, 58 (2009).〕 In 2004, the leading Lorentz-breaking terms in curved spacetimes were published,〔 thereby completing the picture for the minimal SME. In 1999, Sidney Coleman and Sheldon Glashow presented a special isotropic limit of the SME.〔S. Coleman and S.L. Glashow, ''High-energy tests of Lorentz invariance'', Phys. Rev. D 59, 116008 (1999).〕 Higher-order Lorentz violating terms have been studied in various contexts, including electrodynamics.〔V.A. Kostelecký and M. Mewes, ''Electrodynamics with Lorentz-Violating Operators of Arbitrary Dimension'', Phys. Rev. D 80, 015020 (2009).〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Standard-Model Extension」の詳細全文を読む スポンサード リンク
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