Continuous spin particle explained

In theoretical physics, a continuous spin particle (CSP), sometimes called an infinite spin particle, is a massless particle never observed before in nature. This particle is one of Poincaré group's massless representations which, along with ordinary massless particles, was classified by Eugene Wigner in 1939.^[1] Historically, a compatible theory that could describe this elementary particle was unknown; however, 75 years after Wigner's classification, the first local action principle for bosonic continuous spin particles was introduced in 2014,^[2] and the first local action principle for fermionic continuous spin particles was suggested in 2015.^[3] It has been illustrated that this particle can interact with matter in flat spacetime.^{[4] [5]} Supersymmetric continuous spin gauge theory has been studied in three^[6] and four^{[7] [8]} spacetime dimensions.

In condensed matter systems, CSPs can be understood as massless generalizations of the anyon.^[9]

Notes and References

1. Wigner . E. . On Unitary Representations of the Inhomogeneous Lorentz Group . Annals of Mathematics . 1939 . 40 . 1 . 149–204 . 10.2307/1968551 . 1968551 . 1939AnMat..40..149W . 0003-486X.
2. Schuster . Philip . Toro . Natalia . Continuous-spin particle field theory with helicity correspondence . Physical Review D . 23 January 2015 . 91 . 2 . 025023 . 10.1103/PhysRevD.91.025023 . 2015PhRvD..91b5023S .
3. Bekaert . Xavier . Najafizadeh . Mojtaba . Setare . M.R. . A gauge field theory of fermionic continuous-spin particles . Physics Letters B . 10 September 2016 . 760 . 320–323 . 10.1016/j.physletb.2016.07.005 . 1506.00973 . 2016PhLB..760..320B . 119120293 . en . 0370-2693. free .
4. Metsaev . R. R. . Cubic interaction vertices for continuous-spin fields and arbitrary spin massive fields . Journal of High Energy Physics . 29 November 2017 . 2017 . 11 . 197 . 10.1007/JHEP11(2017)197 . 1709.08596 . 2017JHEP...11..197M . 119208687 . en . 1029-8479. free .
5. Bekaert . Xavier . Mourad . Jihad . Najafizadeh . Mojtaba . Continuous-spin field propagator and interaction with matter . Journal of High Energy Physics . 20 November 2017 . 2017 . 11 . 113 . 10.1007/JHEP11(2017)113 . 1710.05788 . 2017JHEP...11..113B . 119482451 . en . 1029-8479. free .
6. Zinoviev . Yurii M. . Infinite Spin Fields in d = 3 and Beyond . Universe . 2017 . 3 . 3 . 63 . 10.3390/universe3030063 . 1707.08832 . 2017Univ....3...63Z . 2442288 . en. free .
7. Buchbinder . I.L. . Khabarov . M.V. . Snegirev . T.V. . Zinoviev . Yu.M. . Lagrangian formulation for the infinite spin N = 1 supermultiplets in d = 4 . Nuclear Physics B . 1 September 2019 . 946 . 114717 . 10.1016/j.nuclphysb.2019.114717 . 1904.05580 . 2019NuPhB.94614717B . 118982636 . en . 0550-3213. free .
8. Najafizadeh . Mojtaba . Supersymmetric continuous spin gauge theory . Journal of High Energy Physics . 4 March 2020 . 2020 . 3 . 27 . 10.1007/JHEP03(2020)027. 1912.12310 . 2020JHEP...03..027N . 209515928 . en . 1029-8479. free .
9. Schuster . Philip . Toro . Natalia . A new class of particle in 2 + 1 dimensions . Physics Letters B . April 2015 . 743 . 224–227 . 10.1016/j.physletb.2015.02.050. 1404.1076 . 2015PhLB..743..224S . free .