Amon Ilakovac
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Amon Ilakovac has a total of 8 co-authors. Here are the top co-authors by number of shared publications:
- Dominik Stöckinger
Institut für Kern- und Teilchenphysik, TU Dresden
6 shared publications - Hermès Bélusca-Maïto
Department of Physics University of Zagreb Bijenička cesta 32 HR-10000 Zagreb Croatia
6 shared publications - Marija Mađor-Božinović
Department of Physics University of Zagreb Bijenička cesta 32 HR-10000 Zagreb Croatia
6 shared publications - Paul Kühler
TU Dresden
4 shared publications - Marko Kolanović
Department of Theoretical Physics University of Zagreb Bijenička c.32 POB 162 10001 Zagreb Croatia
3 shared publications - Predrag Dominis Prester
University of Rijeka
3 shared publications
Latest Publications
- Open AccessIntroduction to Renormalization Theory and Chiral Gauge Theories in Dimensional Regularization with Non-Anticommuting $γ_5$This review provides a detailed introduction to chiral gauge theories, renormalization theory, and the application of dimensional regularization with the non-anticommuting BMHV scheme for $γ_5$. One goal is to show how chiral gauge theories can be renormalized despite the spurious breaking of gauge invariance and how to obtain the required symmetry-restoring counterterms. A second goal is to familiarize the reader with the theoretical basis of the renormalization of chiral gauge theories, the theorems that guarantee the existence of renormalized chiral gauge theories at all orders as consistent quantum theories. Relevant topics include BPHZ renormalization, Slavnov-Taylor identities, the BRST formalism and algebraic renormalization, as well as the theorems guaranteeing that dimensional regularization is a consistent regularization/renormalization scheme. All of these, including their proofs and interconnections, are explained and discussed in detail. Further, these theoretical concepts are illustrated in practical applications with the example of an Abelian and a non-Abelian chiral gauge theory. Not only the renormalization procedure for such chiral gauge theories is explained step by step, but also the results of all counterterms, including the symmetry-restoring ones, necessary for the consistent renormalization are explicitly provided.Open AccessIntroduction to Renormalization Theory and Chiral Gauge Theories in Dimensional Regularization with Non-Anticommuting $γ_5$This review provides a detailed introduction to chiral gauge theories, renormalization theory, and the application of dimensional regularization with the non-anticommuting BMHV scheme for $γ_5$. One goal is to show how chiral gauge theories can be renormalized despite the spurious breaking of gauge invariance and how to obtain the required symmetry-restoring counterterms. A second goal is to familiarize the reader with the theoretical basis of the renormalization of chiral gauge theories, the theorems that guarantee the existence of renormalized chiral gauge theories at all orders as consistent quantum theories. Relevant topics include BPHZ renormalization, Slavnov-Taylor identities, the BRST formalism and algebraic renormalization, as well as the theorems guaranteeing that dimensional regularization is a consistent regularization/renormalization scheme. All of these, including their proofs and interconnections, are explained and discussed in detail. Further, these theoretical concepts are illustrated in practical applications with the example of an Abelian and a non-Abelian chiral gauge theory. Not only the renormalization procedure for such chiral gauge theories is explained step by step, but also the results of all counterterms, including the symmetry-restoring ones, necessary for the consistent renormalization are explicitly provided.
- Open Access
Introduction to Renormalization Theory and Chiral Gauge Theories in Dimensional Regularization with Non-Anticommuting γ5
This review provides a detailed introduction to chiral gauge theories, renormalization theory, and the application of dimensional regularization with the non-anticommuting BMHV scheme for . One goal was to show how chiral gauge theories can be renormalized despite the spurious breaking of gauge invariance and how to obtain the required symmetry-restoring counterterms. A second goal was to familiarize the reader with the theoretical basis of the renormalization of chiral gauge theories, the theorems that guarantee the existence of renormalized chiral gauge theories at all orders as consistent quantum theories. Relevant topics include BPHZ renormalization, Slavnov–Taylor identities, the BRST formalism, and algebraic renormalization, as well as the theorems guaranteeing that dimensional regularization is a consistent regularization/renormalization scheme. All of these, including their proofs and interconnections, are explained and discussed in detail. Further, these theoretical concepts are illustrated in practical applications with the example of an Abelian and a non-Abelian chiral gauge theory. Not only the renormalization procedure for such chiral gauge theories is explained step by step, but also the results of all counterterms, including the symmetry-restoring ones, necessary for the consistent renormalization, are explicitly provided.Open AccessIntroduction to Renormalization Theory and Chiral Gauge Theories in Dimensional Regularization with Non-Anticommuting γ5
This review provides a detailed introduction to chiral gauge theories, renormalization theory, and the application of dimensional regularization with the non-anticommuting BMHV scheme for . One goal was to show how chiral gauge theories can be renormalized despite the spurious breaking of gauge invariance and how to obtain the required symmetry-restoring counterterms. A second goal was to familiarize the reader with the theoretical basis of the renormalization of chiral gauge theories, the theorems that guarantee the existence of renormalized chiral gauge theories at all orders as consistent quantum theories. Relevant topics include BPHZ renormalization, Slavnov–Taylor identities, the BRST formalism, and algebraic renormalization, as well as the theorems guaranteeing that dimensional regularization is a consistent regularization/renormalization scheme. All of these, including their proofs and interconnections, are explained and discussed in detail. Further, these theoretical concepts are illustrated in practical applications with the example of an Abelian and a non-Abelian chiral gauge theory. Not only the renormalization procedure for such chiral gauge theories is explained step by step, but also the results of all counterterms, including the symmetry-restoring ones, necessary for the consistent renormalization, are explicitly provided. - Open Access
- 22 November 2021
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2021 (11) , 1-32
Two-loop application of the Breitenlohner-Maison/’t Hooft-Veltman scheme with non-anticommuting γ5: full renormalization and symmetry-restoring counterterms in an abelian chiral gauge theory
We apply the BMHV scheme for non-anticommuting γ5 to an abelian chiral gauge theory at the two-loop level. As our main result, we determine the full structure of symmetry-restoring counterterms up to the two-loop level. These counterterms turn out to have the same structure as at the one-loop level and a simple interpretation in terms of restoration of well-known Ward identities. In addition, we show that the ultraviolet divergences cannot be canceled completely by counterterms generated by field and parameter renormalization, and we determine needed UV divergent evanescent counterterms. The paper establishes the two-loop methodology based on the quantum action principle and direct computations of Slavnov-Taylor identity breakings. The same method will be applicable to nonabelian gauge theories.
- 22 November 2021
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2021 (11) , 1-32
Open AccessTwo-loop application of the Breitenlohner-Maison/’t Hooft-Veltman scheme with non-anticommuting γ5: full renormalization and symmetry-restoring counterterms in an abelian chiral gauge theory
We apply the BMHV scheme for non-anticommuting γ5 to an abelian chiral gauge theory at the two-loop level. As our main result, we determine the full structure of symmetry-restoring counterterms up to the two-loop level. These counterterms turn out to have the same structure as at the one-loop level and a simple interpretation in terms of restoration of well-known Ward identities. In addition, we show that the ultraviolet divergences cannot be canceled completely by counterterms generated by field and parameter renormalization, and we determine needed UV divergent evanescent counterterms. The paper establishes the two-loop methodology based on the quantum action principle and direct computations of Slavnov-Taylor identity breakings. The same method will be applicable to nonabelian gauge theories.
- Open Access
Two-loop application of the Breitenlohner-Maison/'t Hooft-Veltman scheme with non-anticommuting $γ_5$: Full renormalization and symmetry-restoring counterterms in an abelian chiral gauge theory
We apply the BMHV scheme for non-anticommuting $\gamma_5$ to an abelian chiral gauge theory at the two-loop level. As our main result, we determine the full structure of symmetry-restoring counterterms up to the two-loop level. These counterterms turn out to have the same structure as at the one-loop level and a simple interpretation in terms of restoration of well-known Ward identities. In addition, we show that the ultraviolet divergences cannot be canceled completely by counterterms generated by field and parameter renormalization, and we determine needed UV divergent evanescent counterterms. The paper establishes the two-loop methodology based on the quantum action principle and direct computations of Slavnov-Taylor identity breakings. The same method will be applicable to nonabelian gauge theories.Open AccessTwo-loop application of the Breitenlohner-Maison/'t Hooft-Veltman scheme with non-anticommuting $γ_5$: Full renormalization and symmetry-restoring counterterms in an abelian chiral gauge theory
We apply the BMHV scheme for non-anticommuting $\gamma_5$ to an abelian chiral gauge theory at the two-loop level. As our main result, we determine the full structure of symmetry-restoring counterterms up to the two-loop level. These counterterms turn out to have the same structure as at the one-loop level and a simple interpretation in terms of restoration of well-known Ward identities. In addition, we show that the ultraviolet divergences cannot be canceled completely by counterterms generated by field and parameter renormalization, and we determine needed UV divergent evanescent counterterms. The paper establishes the two-loop methodology based on the quantum action principle and direct computations of Slavnov-Taylor identity breakings. The same method will be applicable to nonabelian gauge theories. - Open Access
- 6 August 2020
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2020 (8) , 1-71
Dimensional regularization and Breitenlohner-Maison/’t Hooft-Veltman scheme for γ5 applied to chiral YM theories: full one-loop counterterm and RGE structure
We study the application of the Breitenlohner-Maison-’t Hooft-Veltman (BMHV) scheme of Dimensional Regularization to the renormalization of chiral gauge theories, focusing on the specific counterterm structure required by the non-anticommuting Dirac γ 5 matrix and the breaking of the BRST invariance. Calculations are performed at the one-loop level in a massless chiral Yang-Mills theory with chiral fermions and real scalar fields. We discuss the setup and properties of the regularized theory in detail. Our central results are the full counterterm structures needed for the correct renormalization: the singular UV-divergent counterterms, including evanescent counterterms that have to be kept for consistency of higher-loop calculations. We find that the required singular, evanescent counterterms associated with vector and scalar fields are uniquely determined but are not gauge invariant. Furthermore, using the framework of algebraic renormalization, we determine the symmetry-restoring finite counterterms, that are required to restore the BRST invariance, central to the consistency of the theory. These are the necessary building blocks in one-loop and higher-order calculations. Finally, renormalization group equations are derived within this framework, and the derivation is compared with the more customary calculation in the context of symmetry-invariant regularizations. We explain why, at one-loop level, the extra BMHV-specific counterterms do not change the results for the RGE. The results we find complete those that have been obtained previously in the literature in the absence of scalar fields.
- 6 August 2020
- Published by Springer Nature in Journal of High Energy Physics
- Vol. 2020 (8) , 1-71
Open AccessDimensional regularization and Breitenlohner-Maison/’t Hooft-Veltman scheme for γ5 applied to chiral YM theories: full one-loop counterterm and RGE structure
We study the application of the Breitenlohner-Maison-’t Hooft-Veltman (BMHV) scheme of Dimensional Regularization to the renormalization of chiral gauge theories, focusing on the specific counterterm structure required by the non-anticommuting Dirac γ 5 matrix and the breaking of the BRST invariance. Calculations are performed at the one-loop level in a massless chiral Yang-Mills theory with chiral fermions and real scalar fields. We discuss the setup and properties of the regularized theory in detail. Our central results are the full counterterm structures needed for the correct renormalization: the singular UV-divergent counterterms, including evanescent counterterms that have to be kept for consistency of higher-loop calculations. We find that the required singular, evanescent counterterms associated with vector and scalar fields are uniquely determined but are not gauge invariant. Furthermore, using the framework of algebraic renormalization, we determine the symmetry-restoring finite counterterms, that are required to restore the BRST invariance, central to the consistency of the theory. These are the necessary building blocks in one-loop and higher-order calculations. Finally, renormalization group equations are derived within this framework, and the derivation is compared with the more customary calculation in the context of symmetry-invariant regularizations. We explain why, at one-loop level, the extra BMHV-specific counterterms do not change the results for the RGE. The results we find complete those that have been obtained previously in the literature in the absence of scalar fields.
- Open AccessDimensional Regularization and Breitenlohner-Maison / 't Hooft-Veltman Scheme for $γ_5$ applied to Chiral YM Theories: Full One-Loop Counterterm and RGE StructureWe study the application of the Breitenlohner-Maison-'t Hooft-Veltman (BMHV) scheme of Dimensional Regularization to the renormalization of chiral gauge theories, focusing on the specific counterterm structure required by the non-anticommuting Dirac $\gamma_5$ matrix and the breaking of the BRST invariance. Calculations are performed at the one-loop level in a massless chiral Yang-Mills theory with chiral fermions and real scalar fields. We discuss the setup and properties of the regularized theory in detail. Our central results are the full counterterm structures needed for the correct renormalization: the singular UV-divergent counterterms, including evanescent counterterms that have to be kept for consistency of higher-loop calculations. We find that the required singular, evanescent counterterms associated with vector and scalar fields are uniquely determined but are not gauge invariant. Furthermore, using the framework of algebraic renormalization, we determine the symmetry-restoring finite counterterms, that are required to restore the BRST invariance, central to the consistency of the theory. These are the necessary building blocks in one-loop and higher-order calculations. Finally, renormalization group equations are derived within this framework, and the derivation is compared with the more customary calculation in the context of symmetry-invariant regularizations. We explain why, at one-loop level, the extra BMHV-specific counterterms do not change the results for the RGE. The results we find complete those that have been obtained previously in the literature in the absence of scalar fields.Open AccessDimensional Regularization and Breitenlohner-Maison / 't Hooft-Veltman Scheme for $γ_5$ applied to Chiral YM Theories: Full One-Loop Counterterm and RGE StructureWe study the application of the Breitenlohner-Maison-'t Hooft-Veltman (BMHV) scheme of Dimensional Regularization to the renormalization of chiral gauge theories, focusing on the specific counterterm structure required by the non-anticommuting Dirac $\gamma_5$ matrix and the breaking of the BRST invariance. Calculations are performed at the one-loop level in a massless chiral Yang-Mills theory with chiral fermions and real scalar fields. We discuss the setup and properties of the regularized theory in detail. Our central results are the full counterterm structures needed for the correct renormalization: the singular UV-divergent counterterms, including evanescent counterterms that have to be kept for consistency of higher-loop calculations. We find that the required singular, evanescent counterterms associated with vector and scalar fields are uniquely determined but are not gauge invariant. Furthermore, using the framework of algebraic renormalization, we determine the symmetry-restoring finite counterterms, that are required to restore the BRST invariance, central to the consistency of the theory. These are the necessary building blocks in one-loop and higher-order calculations. Finally, renormalization group equations are derived within this framework, and the derivation is compared with the more customary calculation in the context of symmetry-invariant regularizations. We explain why, at one-loop level, the extra BMHV-specific counterterms do not change the results for the RGE. The results we find complete those that have been obtained previously in the literature in the absence of scalar fields.
- 12 July 2000
- Published by American Physical Society (APS) in Physical Review D
- Vol. 62 (3) , 036010
Lepton flavor violation in the standard model extended by heavy singlet Dirac neutrinos
Low-energy neutrinoless lepton flavor-violating (LFV) processes are studied in an extension of the standard model (SM) by heavy singlet Dirac neutrinos. An upper-bound procedure is elaborated for the evaluation of amplitudes. A comment on the extraction of heavy-neutrino mixings from astrophysical observations is given. For processes not treated in the model applied, the formalism for evaluating the branching ratios (BR’s) is presented. The processes previously studied in the model are examined and some results are improved. The structure of the amplitudes and BR’s as well as the relations between BR’s of different LFV processes are examined. The decoupling of heavy neutrinos is discussed and it is explicitly shown that very heavy neutrinos decouple when the upper-bound procedure is applied. The LFV decays are shown to be unsuitable for finding upper bounds on “diagonal” LFV parameters. Comparing the theoretical BR’s with curent experimental upper bounds, a few processes interesting for the search for LFV are proposed. Particularly, B-meson LFV processes are suggested for the search of LFV in future B factories.- 12 July 2000
- Published by American Physical Society (APS) in Physical Review D
- Vol. 62 (3) , 036010
Lepton flavor violation in the standard model extended by heavy singlet Dirac neutrinos
Low-energy neutrinoless lepton flavor-violating (LFV) processes are studied in an extension of the standard model (SM) by heavy singlet Dirac neutrinos. An upper-bound procedure is elaborated for the evaluation of amplitudes. A comment on the extraction of heavy-neutrino mixings from astrophysical observations is given. For processes not treated in the model applied, the formalism for evaluating the branching ratios (BR’s) is presented. The processes previously studied in the model are examined and some results are improved. The structure of the amplitudes and BR’s as well as the relations between BR’s of different LFV processes are examined. The decoupling of heavy neutrinos is discussed and it is explicitly shown that very heavy neutrinos decouple when the upper-bound procedure is applied. The LFV decays are shown to be unsuitable for finding upper bounds on “diagonal” LFV parameters. Comparing the theoretical BR’s with curent experimental upper bounds, a few processes interesting for the search for LFV are proposed. Particularly, B-meson LFV processes are suggested for the search of LFV in future B factories.- Open Access
Lepton Flavor Violation in the Standard Model Extended by Heavy Singlet Dirac Neutrinos
Low energy neutrinoless lepton flavor violating (LFV) processes are studied in an extension of the Standard Model (SM) by heavy SU(2)xU(1) singlet Dirac neutrinos. An upper bound procedure is elaborated for the evaluation of amplitudes. A comment on the extraction of heavy neutrino mixings from astrophysical observations is given. For processes not treated in the applied model the formalism not treated in the applied model the formalism for evaluating the branching ratios (BRs) is presented. The processes previously studied in the model are carefully examined. Some of the previous results are improved. Special attention is paid to the structure of the amplitudes and BRs as well as to the relations between BRs of different LFV processes. Numerical analysis of the BRs is done. The decoupling of heavy neutrinos is discussed and it is explicitely shown that the very heavy neutrinos decouple when the upper bound procedure is applied. The upper limits of the BRs are compared with the current experimental upper bounds and the processes interesting for the search for LFV are proposed. The LFV decays are shown to be unsuitable for finding upper bounds on "diagonal" LFV parameters. The B-meson LFV processes are suggested for the search of LFV in future B-factories.
Open AccessLepton Flavor Violation in the Standard Model Extended by Heavy Singlet Dirac Neutrinos
Low energy neutrinoless lepton flavor violating (LFV) processes are studied in an extension of the Standard Model (SM) by heavy SU(2)xU(1) singlet Dirac neutrinos. An upper bound procedure is elaborated for the evaluation of amplitudes. A comment on the extraction of heavy neutrino mixings from astrophysical observations is given. For processes not treated in the applied model the formalism not treated in the applied model the formalism for evaluating the branching ratios (BRs) is presented. The processes previously studied in the model are carefully examined. Some of the previous results are improved. Special attention is paid to the structure of the amplitudes and BRs as well as to the relations between BRs of different LFV processes. Numerical analysis of the BRs is done. The decoupling of heavy neutrinos is discussed and it is explicitely shown that the very heavy neutrinos decouple when the upper bound procedure is applied. The upper limits of the BRs are compared with the current experimental upper bounds and the processes interesting for the search for LFV are proposed. The LFV decays are shown to be unsuitable for finding upper bounds on "diagonal" LFV parameters. The B-meson LFV processes are suggested for the search of LFV in future B-factories.
- 1 September 1999
- Published by American Physical Society (APS) in Physical Review B
- Vol. 60 (10) , 7271-7277
Violation of the string hypothesis and the Heisenbergspin chainIn this paper we count the numbers of real and complex solutions to Bethe constraints in the two-particle sector of the model. We find the exact number of exceptions to the string conjecture and total number of solutions that is required for completeness.- 1 September 1999
- Published by American Physical Society (APS) in Physical Review B
- Vol. 60 (10) , 7271-7277
Violation of the string hypothesis and the Heisenbergspin chainIn this paper we count the numbers of real and complex solutions to Bethe constraints in the two-particle sector of the model. We find the exact number of exceptions to the string conjecture and total number of solutions that is required for completeness.- Open Access
On Bethe strings in the two-particle sector of the closed SU(2)q invariant spin chain
In this paper we investigate complex solutions of the Bethe equations in the two-particle sector both for arbitrary finite number of sites and for the thermodynamic limit . We find the number of complex solutions (strings) and compare it with the string conjecture prediction. Some simple properties of these solutions like position in the spectrum, crossing of levels, connection to the ground state and transformation to the real solutions are discussed. Counting both real and complex solutions we find expected number of highest weight Bethe states.
Open AccessOn Bethe strings in the two-particle sector of the closed SU(2)q invariant spin chain
In this paper we investigate complex solutions of the Bethe equations in the two-particle sector both for arbitrary finite number of sites and for the thermodynamic limit . We find the number of complex solutions (strings) and compare it with the string conjecture prediction. Some simple properties of these solutions like position in the spectrum, crossing of levels, connection to the ground state and transformation to the real solutions are discussed. Counting both real and complex solutions we find expected number of highest weight Bethe states.