Elmar P. Biernat
Current Organizations / Institutes
The organizations/institutes from the scholar's latest article
Previous Organizations / Institutes
The organizations / institutes from the scholar's other articles in the past ten years
Research Subjects
Research Interests
Elmar P. Biernat has a total of 32 co-authors. Here are the top co-authors by number of shared publications:
- Alfred Stadler
Universidade de Évora
35 shared publications - M. T. Peña
Centro de Física Teórica e de Partículas (CFTP), Instituto Superior Técnico (IST), Universidade de Lisboa, Avenida Rovisco Pais, 1049-001 Lisboa, Portugal
24 shared publications - Sofia Leitão
CFTP Instituto Superior Técnico Universidade de Lisboa av. Rovisco Pais 1 1049-001 Lisboa Portugal
14 shared publications - Wolfgang Schweiger
Institute of Physics, University of Graz, Graz, Austria
14 shared publications Franz Gross
8 shared publications- Franz Gross
Thomas Jefferson National Accelerator Facility, Newport News, Virginia 23606, USA and College of William and Mary, Williamsburg, Virginia 23185, USA
7 shared publications
Latest Publications
- Open Access
- 1 April 2026
- Published by Jagiellonian University in Acta Physica Polonica B Proceedings Supplement
- Vol. 19 (4)
Heavy and Heavy–Light Tensor and Axial-tensor Mesons in the Covariant Spectator Theory
We present the first calculation of tensor and axial-tensor mesons with total spin \(J\geq 2\) within the Covariant Spectator Theory. We employ a refined quark–antiquark interaction kernel that incorporates the momentum dependence of the strong coupling, replacing the previously used constant term of the kernel. Global fits to the masses of experimentally established heavy and heavy–light meson states yield an excellent description of the mass spectrum for \(J^P=0^\pm , 1^\pm , 2^\pm \), and \(3^\pm \) using only eight adjustable parameters. Published by the Jagiellonian University 2026 authors- 1 April 2026
- Published by Jagiellonian University in Acta Physica Polonica B Proceedings Supplement
- Vol. 19 (4)
Open AccessHeavy and Heavy–Light Tensor and Axial-tensor Mesons in the Covariant Spectator Theory
We present the first calculation of tensor and axial-tensor mesons with total spin \(J\geq 2\) within the Covariant Spectator Theory. We employ a refined quark–antiquark interaction kernel that incorporates the momentum dependence of the strong coupling, replacing the previously used constant term of the kernel. Global fits to the masses of experimentally established heavy and heavy–light meson states yield an excellent description of the mass spectrum for \(J^P=0^\pm , 1^\pm , 2^\pm \), and \(3^\pm \) using only eight adjustable parameters. Published by the Jagiellonian University 2026 authors - Open Access
- 26 December 2024
- Published by American Physical Society (APS) in Physical Review D
- Vol. 110 (11)
Simple high-accuracy method for solving bound-state equations with the Cornell potential in momentum space
The well-known Cornell quark-antiquark potential in momentum space contains singularities both in its one-gluon-exchange (OGE) and linear confining parts, which prevents a direct use of the convenient Nyström method to solve the corresponding bound-state integral equation for the meson masses. While it has been known for a long time how the Coulomb-type singularity in the OGE potential can be treated with a subtraction technique, only very complicated methods have been developed to deal with the stronger singularity in the linear potential. In this work, we present a simple subtraction method to remove this singularity from the kernel, such that the Nyström method becomes applicable. Derivatives of the wave function, that appear as a result of the subtraction, are represented by means of interpolating functions, for which we found Lagrange polynomials to be very efficient. Test calculations show excellent agreement with exactly known energy eigenvalues. By increasing the number of integration points and the order of the Lagrange interpolation polynomials, extremely high accuracy can be achieved. This method can also be extended to relativistic Bethe-Salpeter type equations with singular kernels. Published by the American Physical Society 2024
- 26 December 2024
- Published by American Physical Society (APS) in Physical Review D
- Vol. 110 (11)
Open AccessSimple high-accuracy method for solving bound-state equations with the Cornell potential in momentum space
The well-known Cornell quark-antiquark potential in momentum space contains singularities both in its one-gluon-exchange (OGE) and linear confining parts, which prevents a direct use of the convenient Nyström method to solve the corresponding bound-state integral equation for the meson masses. While it has been known for a long time how the Coulomb-type singularity in the OGE potential can be treated with a subtraction technique, only very complicated methods have been developed to deal with the stronger singularity in the linear potential. In this work, we present a simple subtraction method to remove this singularity from the kernel, such that the Nyström method becomes applicable. Derivatives of the wave function, that appear as a result of the subtraction, are represented by means of interpolating functions, for which we found Lagrange polynomials to be very efficient. Test calculations show excellent agreement with exactly known energy eigenvalues. By increasing the number of integration points and the order of the Lagrange interpolation polynomials, extremely high accuracy can be achieved. This method can also be extended to relativistic Bethe-Salpeter type equations with singular kernels. Published by the American Physical Society 2024
- Open Access
- 6 May 2020
- Published by Sissa Medialab Srl
- Vol. 374, 028
Quark mass function from a OGE-type interaction in Minkowski space
The quark self-energy is calculated in both the spacelike and timelike regions of Minkowski space from an effective one-gluon-exchange and a constant interaction. The gauge dependence of the quark mass function is analysed and the model parameters are fixed by comparison of the results to the available lattice QCD data in the spacelike region.
- 6 May 2020
- Published by Sissa Medialab Srl
- Vol. 374, 028
Open AccessQuark mass function from a OGE-type interaction in Minkowski space
The quark self-energy is calculated in both the spacelike and timelike regions of Minkowski space from an effective one-gluon-exchange and a constant interaction. The gauge dependence of the quark mass function is analysed and the model parameters are fixed by comparison of the results to the available lattice QCD data in the spacelike region.
- 7 January 2020
- Published by Springer Nature in Springer Proceedings in Physics
- p. 723-727
Masses and Structure of Heavy Quarkonia and Heavy-Light Mesons in a Relativistic Quark Model
- 7 January 2020
- Published by Springer Nature in Springer Proceedings in Physics
- p. 723-727
Masses and Structure of Heavy Quarkonia and Heavy-Light Mesons in a Relativistic Quark Model
- Open Access
Quark mass function from a one-gluon-exchange-type interaction in Minkowski space
We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon-exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement.
Open AccessQuark mass function from a one-gluon-exchange-type interaction in Minkowski space
We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon-exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement.
- Open Access
- 27 December 2018
- Published by American Physical Society (APS) in Physical Review D
- Vol. 98 (11) , 114033
Quark mass function from a one-gluon-exchange-type interaction in Minkowski space
We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon-exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement.
- 27 December 2018
- Published by American Physical Society (APS) in Physical Review D
- Vol. 98 (11) , 114033
Open AccessQuark mass function from a one-gluon-exchange-type interaction in Minkowski space
We present first results for the quark mass function in Minkowski space in both the spacelike and timelike regions calculated from the same quark-antiquark interaction kernel used in the latest meson calculations using the Gross equation. This kernel consists of a Lorentz vector effective one-gluon-exchange-type interaction, a vector constant, and a mixed scalar-pseudoscalar covariant linear confining interaction that does not contribute to the mass function. We analyze the gauge dependence of our results, prove the gauge independence of the constituent quark mass and mass gap equation, and identify the Yennie gauge as the appropriate gauge to be used in CST calculations. We compare our results in the spacelike region to lattice QCD data and find good agreement.
- Open Access
- 18 December 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 60 (1) , 13
Constituent-Quark Model with Pionic Contributions: Electromagnetic ${\varvec{N\rightarrow \varDelta }}$ N → Δ Transition- 18 December 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 60 (1) , 13
Open AccessConstituent-Quark Model with Pionic Contributions: Electromagnetic ${\varvec{N\rightarrow \varDelta }}$ N → Δ Transition - 24 May 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 59 (5) , 80
Quark Mass Functions and Pion Structure in the Covariant Spectator Theory
- 24 May 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 59 (5) , 80
Quark Mass Functions and Pion Structure in the Covariant Spectator Theory
- Open AccessConstituent-quark model with pionic contributions: electromagnetic $N\rightarrowΔ$ transitionWe report on ongoing work to determine the pion-cloud contribution to the electromagnetic $N\rightarrow\Delta$ transition form factors. The starting point is an $SU(6)$ spin-flavor symmetric constituent-quark model with instantaneous confinement that is augmented by dynamical pions which couple directly to the quarks. This system is treated in a relativistically invariant way within the framework of point-form quantum mechanics using a multichannel formulation. The first step is to determine the electromagnetic form factors of the bare particles that consist only of three quarks. These form factors are basic ingredients for calculating the pion-cloud contributions. Already without the pion cloud, electromagnetic nucleon and $N\rightarrow \Delta$ transition form factors compare reasonably well with the data. By inclusion of the pion-cloud contribution coming from the $\pi$-$N$ intermediate state the reproduction of the data is further improved.Open AccessConstituent-quark model with pionic contributions: electromagnetic $N\rightarrowΔ$ transitionWe report on ongoing work to determine the pion-cloud contribution to the electromagnetic $N\rightarrow\Delta$ transition form factors. The starting point is an $SU(6)$ spin-flavor symmetric constituent-quark model with instantaneous confinement that is augmented by dynamical pions which couple directly to the quarks. This system is treated in a relativistically invariant way within the framework of point-form quantum mechanics using a multichannel formulation. The first step is to determine the electromagnetic form factors of the bare particles that consist only of three quarks. These form factors are basic ingredients for calculating the pion-cloud contributions. Already without the pion cloud, electromagnetic nucleon and $N\rightarrow \Delta$ transition form factors compare reasonably well with the data. By inclusion of the pion-cloud contribution coming from the $\pi$-$N$ intermediate state the reproduction of the data is further improved.
- 8 March 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 59 (3) , 32
Heavy and Heavy-Light Mesons in the Covariant Spectator Theory
- 8 March 2018
- Published by Springer Nature in Few-Body Systems
- Vol. 59 (3) , 32
Heavy and Heavy-Light Mesons in the Covariant Spectator Theory