Spin-String Interaction in QCD Strings
| Autor: | Vyas, Vikram |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Phys.Rev.D78:045003,2008 |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1103/PhysRevD.78.045003 |
| Popis: | I consider the question of the interaction between a QCD string and the spin of a quark or an antiquark on whose worldline the string terminates. The problem is analysed from the point of view of a string representation for the expectation value of a Wilson loop for a spin-half particle. A string representation of the super Wilson loop is obtained starting from an effective string representation of a Wilson Loop. The action obtained in this manner is invariant under a worldline supersymmetry and has a boundary term which contains the spin-string interaction. For rectangular loops the spin-string interaction vanishes and there is no spin-spin term in the resulting heavy quark potential. On the other hand if an allowance is made for the finite intrinsic thickness of the flux-tube, by assuming that the spin-string interaction takes place not just at the boundary of the string world-sheet but extends to a distance of the order of the intrinsic thickness of the flux tube, then we do obtain a spin-spin interaction which falls as the fifth power of the distance. Such a term was previously suggested by Kogut and Parisi in the context of a flux-tube model of confinement. Comment: 19 pages, 1 figure; Published version with added discussion and references in section 5 |
| Databáze: | arXiv |
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