NLO oriented event-shape distributions for massive quarks
Abstract In this article we compute the cross section for the process e + e − → Q Q ¯ + X $$ {e}^{+}{e}^{-}\to Q\overline{Q}+X $$ , with Q a heavy quark, differential in a given event shape e and the angle θ T between the thrust axis and the beam direction. These observables are usually referred to...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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SpringerOpen
2023-02-01
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| Series: | Journal of High Energy Physics |
| Subjects: | |
| Online Access: | https://doi.org/10.1007/JHEP02(2023)247 |
| _version_ | 1797779123794345984 |
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| author | Alejandro Bris Nestor G. Gracia Vicent Mateu |
| author_facet | Alejandro Bris Nestor G. Gracia Vicent Mateu |
| author_sort | Alejandro Bris |
| collection | DOAJ |
| description | Abstract In this article we compute the cross section for the process e + e − → Q Q ¯ + X $$ {e}^{+}{e}^{-}\to Q\overline{Q}+X $$ , with Q a heavy quark, differential in a given event shape e and the angle θ T between the thrust axis and the beam direction. These observables are usually referred to as oriented event shapes, and it has been shown that the θ T dependence can be split in two structures, dubbed the unoriented and angular terms. Since the unoriented part is already known, we compute the differential and cumulative distributions in fixed-order for the angular part up to O $$ \mathcal{O} $$ (α s ). Our results show that, for the vector current, there is a non-zero O α s 0 $$ \mathcal{O}\left({\alpha}_s^0\right) $$ contribution, in contrast to the axial-vector current or for massless quarks. This entails that for the vector current one should expect singular terms at O $$ \mathcal{O} $$ (α s ) as well as infrared divergences in real- and virtual-radiation diagrams that should cancel when added up. On the phenomenological side, and taking into account that electroweak factors enhance the vector current, it implies that finite bottom-mass effects are an important correction since they are not damped by a power of the strong coupling and therefore cannot be neglected in precision studies. Finally, we show that the total angular distribution for the vector current has a Sommerfeld enhancement at threshold. |
| first_indexed | 2024-03-12T23:27:13Z |
| format | Article |
| id | doaj.art-74a546fd556f4f2792f57080c4b8a08a |
| institution | Directory Open Access Journal |
| issn | 1029-8479 |
| language | English |
| last_indexed | 2024-03-12T23:27:13Z |
| publishDate | 2023-02-01 |
| publisher | SpringerOpen |
| record_format | Article |
| series | Journal of High Energy Physics |
| spelling | doaj.art-74a546fd556f4f2792f57080c4b8a08a2023-07-16T11:05:39ZengSpringerOpenJournal of High Energy Physics1029-84792023-02-012023214210.1007/JHEP02(2023)247NLO oriented event-shape distributions for massive quarksAlejandro Bris0Nestor G. Gracia1Vicent Mateu2Departamento de Física Teórica, Universidad Autónoma de MadridDepartamento de Física Fundamental e IUFFyM, Universidad de SalamancaDepartamento de Física Fundamental e IUFFyM, Universidad de SalamancaAbstract In this article we compute the cross section for the process e + e − → Q Q ¯ + X $$ {e}^{+}{e}^{-}\to Q\overline{Q}+X $$ , with Q a heavy quark, differential in a given event shape e and the angle θ T between the thrust axis and the beam direction. These observables are usually referred to as oriented event shapes, and it has been shown that the θ T dependence can be split in two structures, dubbed the unoriented and angular terms. Since the unoriented part is already known, we compute the differential and cumulative distributions in fixed-order for the angular part up to O $$ \mathcal{O} $$ (α s ). Our results show that, for the vector current, there is a non-zero O α s 0 $$ \mathcal{O}\left({\alpha}_s^0\right) $$ contribution, in contrast to the axial-vector current or for massless quarks. This entails that for the vector current one should expect singular terms at O $$ \mathcal{O} $$ (α s ) as well as infrared divergences in real- and virtual-radiation diagrams that should cancel when added up. On the phenomenological side, and taking into account that electroweak factors enhance the vector current, it implies that finite bottom-mass effects are an important correction since they are not damped by a power of the strong coupling and therefore cannot be neglected in precision studies. Finally, we show that the total angular distribution for the vector current has a Sommerfeld enhancement at threshold.https://doi.org/10.1007/JHEP02(2023)247Jets and Jet SubstructureQuark MassesTop Quark |
| spellingShingle | Alejandro Bris Nestor G. Gracia Vicent Mateu NLO oriented event-shape distributions for massive quarks Journal of High Energy Physics Jets and Jet Substructure Quark Masses Top Quark |
| title | NLO oriented event-shape distributions for massive quarks |
| title_full | NLO oriented event-shape distributions for massive quarks |
| title_fullStr | NLO oriented event-shape distributions for massive quarks |
| title_full_unstemmed | NLO oriented event-shape distributions for massive quarks |
| title_short | NLO oriented event-shape distributions for massive quarks |
| title_sort | nlo oriented event shape distributions for massive quarks |
| topic | Jets and Jet Substructure Quark Masses Top Quark |
| url | https://doi.org/10.1007/JHEP02(2023)247 |
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