Dispersion relations for unphysical particles
Generalized dispersion relations are discussed for unphysical particles, e.g. confined degrees of freedom that are not present in the physical spectra but can give rise to observable bound states. While in general the propagator of the unphysical particles can have complex poles and cannot be recons...
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| Format: | Article |
| Language: | English |
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EDP Sciences
2017-01-01
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| Series: | EPJ Web of Conferences |
| Online Access: | https://doi.org/10.1051/epjconf/201713713017 |
| _version_ | 1818912485811421184 |
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| author | Siringo Fabio |
| author_facet | Siringo Fabio |
| author_sort | Siringo Fabio |
| collection | DOAJ |
| description | Generalized dispersion relations are discussed for unphysical particles, e.g. confined degrees of freedom that are not present in the physical spectra but can give rise to observable bound states. While in general the propagator of the unphysical particles can have complex poles and cannot be reconstructed from the knowledge of the imaginary part, under reasonable assumptions the missing piece of information is shown to be in the rational function that contains the poles and must be added to the integral representation. For pure Yang-Mills theory, the rational part and the spectral term are identified in the explicit analytical expressions provided by the massive expansion of the gluon propagator. The multi particle spectral term turns out to be very small and the simple rational part provides, from first principles, an approximate propagator that is equivalent to the tree-level result of simple phenomenological models like the refined Gribov-Zwanziger model. |
| first_indexed | 2024-12-19T23:15:21Z |
| format | Article |
| id | doaj.art-d54b23cb66064550a9cf6030de2ce925 |
| institution | Directory Open Access Journal |
| issn | 2100-014X |
| language | English |
| last_indexed | 2024-12-19T23:15:21Z |
| publishDate | 2017-01-01 |
| publisher | EDP Sciences |
| record_format | Article |
| series | EPJ Web of Conferences |
| spelling | doaj.art-d54b23cb66064550a9cf6030de2ce9252022-12-21T20:02:07ZengEDP SciencesEPJ Web of Conferences2100-014X2017-01-011371301710.1051/epjconf/201713713017epjconf_conf2017_13017Dispersion relations for unphysical particlesSiringo Fabio0Dipartimento di Fisica e Astronomia dell’Università di Catania, INFN Sezione di CataniaGeneralized dispersion relations are discussed for unphysical particles, e.g. confined degrees of freedom that are not present in the physical spectra but can give rise to observable bound states. While in general the propagator of the unphysical particles can have complex poles and cannot be reconstructed from the knowledge of the imaginary part, under reasonable assumptions the missing piece of information is shown to be in the rational function that contains the poles and must be added to the integral representation. For pure Yang-Mills theory, the rational part and the spectral term are identified in the explicit analytical expressions provided by the massive expansion of the gluon propagator. The multi particle spectral term turns out to be very small and the simple rational part provides, from first principles, an approximate propagator that is equivalent to the tree-level result of simple phenomenological models like the refined Gribov-Zwanziger model.https://doi.org/10.1051/epjconf/201713713017 |
| spellingShingle | Siringo Fabio Dispersion relations for unphysical particles EPJ Web of Conferences |
| title | Dispersion relations for unphysical particles |
| title_full | Dispersion relations for unphysical particles |
| title_fullStr | Dispersion relations for unphysical particles |
| title_full_unstemmed | Dispersion relations for unphysical particles |
| title_short | Dispersion relations for unphysical particles |
| title_sort | dispersion relations for unphysical particles |
| url | https://doi.org/10.1051/epjconf/201713713017 |
| work_keys_str_mv | AT siringofabio dispersionrelationsforunphysicalparticles |