On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution
We discuss the prescription for the Dirac matrix γ5 in dimensional regularization used in most second- and third-order QCD calculations of collider cross sections. We provide an alternative implementation of this approach that avoids the use of an explicit form of γ5 and of its (anti-)commutation re...
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Elsevier
2015-09-01
|
| Series: | Physics Letters B |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0370269315005377 |
| _version_ | 1828876789369274368 |
|---|---|
| author | S. Moch J.A.M. Vermaseren A. Vogt |
| author_facet | S. Moch J.A.M. Vermaseren A. Vogt |
| author_sort | S. Moch |
| collection | DOAJ |
| description | We discuss the prescription for the Dirac matrix γ5 in dimensional regularization used in most second- and third-order QCD calculations of collider cross sections. We provide an alternative implementation of this approach that avoids the use of an explicit form of γ5 and of its (anti-)commutation relations in the most important case of no more than one γ5 in each fermion trace. This treatment is checked by computing the third-order corrections to the structure functions F2 and g1 in charged-current deep-inelastic scattering with axial-vector couplings to the W-bosons. We derive the so far unknown third-order helicity-difference splitting function ΔPns(2)s that contributes to the next-to-next-to-leading order (NNLO) evolution of the polarized valence quark distribution of the nucleon. This function is negligible at momentum fractions x≳0.3 but relevant at x≪1. |
| first_indexed | 2024-12-13T08:27:51Z |
| format | Article |
| id | doaj.art-8b7e79546e224a9ea5ec1c0ff25f7f30 |
| institution | Directory Open Access Journal |
| issn | 0370-2693 1873-2445 |
| language | English |
| last_indexed | 2024-12-13T08:27:51Z |
| publishDate | 2015-09-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Physics Letters B |
| spelling | doaj.art-8b7e79546e224a9ea5ec1c0ff25f7f302022-12-21T23:53:50ZengElsevierPhysics Letters B0370-26931873-24452015-09-01748C43243810.1016/j.physletb.2015.07.027On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distributionS. Moch0J.A.M. Vermaseren1A. Vogt2II. Institute for Theoretical Physics, Hamburg University, D-22761 Hamburg, GermanyNikhef Theory Group, Science Park 105, 1098 XG Amsterdam, The NetherlandsDepartment of Mathematical Sciences, University of Liverpool, Liverpool L69 3BX, United KingdomWe discuss the prescription for the Dirac matrix γ5 in dimensional regularization used in most second- and third-order QCD calculations of collider cross sections. We provide an alternative implementation of this approach that avoids the use of an explicit form of γ5 and of its (anti-)commutation relations in the most important case of no more than one γ5 in each fermion trace. This treatment is checked by computing the third-order corrections to the structure functions F2 and g1 in charged-current deep-inelastic scattering with axial-vector couplings to the W-bosons. We derive the so far unknown third-order helicity-difference splitting function ΔPns(2)s that contributes to the next-to-next-to-leading order (NNLO) evolution of the polarized valence quark distribution of the nucleon. This function is negligible at momentum fractions x≳0.3 but relevant at x≪1.http://www.sciencedirect.com/science/article/pii/S0370269315005377 |
| spellingShingle | S. Moch J.A.M. Vermaseren A. Vogt On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution Physics Letters B |
| title | On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution |
| title_full | On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution |
| title_fullStr | On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution |
| title_full_unstemmed | On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution |
| title_short | On γ5 in higher-order QCD calculations and the NNLO evolution of the polarized valence distribution |
| title_sort | on γ5 in higher order qcd calculations and the nnlo evolution of the polarized valence distribution |
| url | http://www.sciencedirect.com/science/article/pii/S0370269315005377 |
| work_keys_str_mv | AT smoch ong5inhigherorderqcdcalculationsandthennloevolutionofthepolarizedvalencedistribution AT jamvermaseren ong5inhigherorderqcdcalculationsandthennloevolutionofthepolarizedvalencedistribution AT avogt ong5inhigherorderqcdcalculationsandthennloevolutionofthepolarizedvalencedistribution |