πe3 Form Factor f- Near the Mass Shell
The generalized Ward-Takahashi identity (gWTI) in the pion sector for broken isotopic symmetry is derived and used for the model-independent calculation of the longitudinal form factor f- of the πe3 vector vertex. The on-shell f- is found to be proportional to the mass difference of the pions and th...
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| Format: | Article |
| Language: | English |
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Wiley
2015-01-01
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| Series: | Advances in High Energy Physics |
| Online Access: | http://dx.doi.org/10.1155/2015/656239 |
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| author | M. I. Krivoruchenko |
| author_facet | M. I. Krivoruchenko |
| author_sort | M. I. Krivoruchenko |
| collection | DOAJ |
| description | The generalized Ward-Takahashi identity (gWTI) in the pion sector for broken isotopic symmetry is derived and used for the model-independent calculation of the longitudinal form factor f- of the πe3 vector vertex. The on-shell f- is found to be proportional to the mass difference of the pions and the difference between the vector isospin T=1 and scalar isospin T=2 pion radii. A numerical estimate of the form factor yields a value two times higher than the previous estimate from the quark model. Off-shell form factors are known to be ambiguous because of the gauge dependence and the freedom in the parameterization of the fields. The near-mass-shell f- appears to be an exception, allowing for experimental verification of the consequences of the gWTI. We calculate the near-mass-shell f- using the gWTI and dispersion techniques. The results are discussed in the context of the conservation of vector current (CVC) hypothesis. |
| format | Article |
| id | doaj-art-d5133536e2404cf48ef443aa3c99127c |
| institution | Kabale University |
| issn | 1687-7357 1687-7365 |
| language | English |
| publishDate | 2015-01-01 |
| publisher | Wiley |
| record_format | Article |
| series | Advances in High Energy Physics |
| spelling | doaj-art-d5133536e2404cf48ef443aa3c99127c2025-02-03T01:20:58ZengWileyAdvances in High Energy Physics1687-73571687-73652015-01-01201510.1155/2015/656239656239πe3 Form Factor f- Near the Mass ShellM. I. Krivoruchenko0Institute for Theoretical and Experimental Physics, B. Cheremushkinskaya 25, Moscow 117218, RussiaThe generalized Ward-Takahashi identity (gWTI) in the pion sector for broken isotopic symmetry is derived and used for the model-independent calculation of the longitudinal form factor f- of the πe3 vector vertex. The on-shell f- is found to be proportional to the mass difference of the pions and the difference between the vector isospin T=1 and scalar isospin T=2 pion radii. A numerical estimate of the form factor yields a value two times higher than the previous estimate from the quark model. Off-shell form factors are known to be ambiguous because of the gauge dependence and the freedom in the parameterization of the fields. The near-mass-shell f- appears to be an exception, allowing for experimental verification of the consequences of the gWTI. We calculate the near-mass-shell f- using the gWTI and dispersion techniques. The results are discussed in the context of the conservation of vector current (CVC) hypothesis.http://dx.doi.org/10.1155/2015/656239 |
| spellingShingle | M. I. Krivoruchenko πe3 Form Factor f- Near the Mass Shell Advances in High Energy Physics |
| title | πe3 Form Factor f- Near the Mass Shell |
| title_full | πe3 Form Factor f- Near the Mass Shell |
| title_fullStr | πe3 Form Factor f- Near the Mass Shell |
| title_full_unstemmed | πe3 Form Factor f- Near the Mass Shell |
| title_short | πe3 Form Factor f- Near the Mass Shell |
| title_sort | πe3 form factor f near the mass shell |
| url | http://dx.doi.org/10.1155/2015/656239 |
| work_keys_str_mv | AT mikrivoruchenko pe3formfactorfnearthemassshell |