Masayuki Asakawa
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
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Masayuki Asakawa has a total of 32 co-authors. Here are the top co-authors by number of shared publications:
- Masakiyo Kitazawa
Yukawa Institute for Theoretical Physics
31 shared publications - Yukinao Akamatsu
Osaka University
11 shared publications - Tetsuo Hatsuda
RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS) RIKEN 351-0198 Wako Japan
8 shared publications - Hiroshi Suzuki
Kyushu University Department of Physics 744 Motooka, Nishi-ku, Fukuoka 819-0395
7 shared publications - Alexander Rothkopf
University of Stavanger
6 shared publications - Shiori Kajimoto
Department of Physics, Osaka University, Toyonaka, Osaka 560-0043, Japan
5 shared publications
Latest Publications
- Open Access
- 5 February 2026
- Published by American Physical Society (APS) in Physical Review D
- Vol. 113 (3)
Enhancement of the photon emission rate near the QCD critical point
We compute photon emission rate enhancement near the QCD critical point using an effective theory of dynamic critical phenomena and derive a universal photon spectrum. The emission rate scales similar to conductivity, increasing with the correlation length ( ξ ), diverging at the critical point. The spectrum exhibits ω d N γ / d 3 k ∝ ω − 1 / 2 in the scaling regime, with the transition occurring at a frequency comparable to shear damping rate ω ∼ γ η / ξ 2 , reflecting the nonequilibrium properties of the near-critical liquid.
- 5 February 2026
- Published by American Physical Society (APS) in Physical Review D
- Vol. 113 (3)
Open AccessEnhancement of the photon emission rate near the QCD critical point
We compute photon emission rate enhancement near the QCD critical point using an effective theory of dynamic critical phenomena and derive a universal photon spectrum. The emission rate scales similar to conductivity, increasing with the correlation length ( ξ ), diverging at the critical point. The spectrum exhibits ω d N γ / d 3 k ∝ ω − 1 / 2 in the scaling regime, with the transition occurring at a frequency comparable to shear damping rate ω ∼ γ η / ξ 2 , reflecting the nonequilibrium properties of the near-critical liquid.
- 5 October 2022
- Published by American Physical Society (APS) in Physical Review D
- Vol. 106 (7) , 074001
Simulation of Lindblad equations for quarkonium in the quark-gluon plasma
We study the properties of the Lindbladian quantum mechanical evolution of quarkonia with non-Abelian charges (color-singlet and octet) in the quark-gluon plasma. We confirm that heavy quark recoils in the Lindblad equation correctly thermalize quarkonium colorful states within statistical errors from the simulation method. We also demonstrate that the Lindblad equation in the dipole limit can provide an efficient alternative method, which is applicable to a finite time evolution before thermalization and dramatically reduces the numerical cost. Our findings will serve as a foundation for large-scale simulation of quarkonium dynamics in the relativistic heavy-ion collisions.
- 5 October 2022
- Published by American Physical Society (APS) in Physical Review D
- Vol. 106 (7) , 074001
Simulation of Lindblad equations for quarkonium in the quark-gluon plasma
We study the properties of the Lindbladian quantum mechanical evolution of quarkonia with non-Abelian charges (color-singlet and octet) in the quark-gluon plasma. We confirm that heavy quark recoils in the Lindblad equation correctly thermalize quarkonium colorful states within statistical errors from the simulation method. We also demonstrate that the Lindblad equation in the dipole limit can provide an efficient alternative method, which is applicable to a finite time evolution before thermalization and dramatically reduces the numerical cost. Our findings will serve as a foundation for large-scale simulation of quarkonium dynamics in the relativistic heavy-ion collisions.
- Open Access
Simulation of Lindblad equations for quarkonium in the quark-gluon plasma
We study the properties of the Lindbladian quantum mechanical evolution of quarkonia with non-Abelian charges (color-singlet and octet) in the quark-gluon plasma. We confirm that heavy quark recoils in the Lindblad equation correctly thermalize quarkonium colorful states within statistical errors from the simulation method. We also demonstrate that the Lindblad equation in the dipole limit can provide an efficient alternative method, which is applicable to a finite time evolution before thermalization and dramatically reduces the numerical cost. Our findings will serve as a foundation for large-scale simulation of quarkonium dynamics in the relativistic heavy-ion collisions.
Open AccessSimulation of Lindblad equations for quarkonium in the quark-gluon plasma
We study the properties of the Lindbladian quantum mechanical evolution of quarkonia with non-Abelian charges (color-singlet and octet) in the quark-gluon plasma. We confirm that heavy quark recoils in the Lindblad equation correctly thermalize quarkonium colorful states within statistical errors from the simulation method. We also demonstrate that the Lindblad equation in the dipole limit can provide an efficient alternative method, which is applicable to a finite time evolution before thermalization and dramatically reduces the numerical cost. Our findings will serve as a foundation for large-scale simulation of quarkonium dynamics in the relativistic heavy-ion collisions.
- 31 March 2022
- Published by American Physical Society (APS) in Physical Review D
- Vol. 105 (5) , 054036
Dynamics of in-medium quarkonia in SU(3) and SU(2) gauge theories
Decoherence dynamics of quarkonia is studied in the high-temperature deconfined phase of gauge theories. In particular, we analyze the symmetry properties of stochastic potential model and find a novel “event-by-event” symmetry for the case, similar to the -parity of hadronic systems. This novel symmetry constrains the relation between diagonal and off-diagonal components of quarkonium density matrix, leaving the latter to be finite at late times. We also present a one-dimensional numerical simulation of the model, which indicates the usefulness of the complex potential simulations for the quarkonium survival probabilities in relativistic heavy-ion collisions, provided that the effect of dissipation can be neglected.- 31 March 2022
- Published by American Physical Society (APS) in Physical Review D
- Vol. 105 (5) , 054036
Dynamics of in-medium quarkonia in SU(3) and SU(2) gauge theories
Decoherence dynamics of quarkonia is studied in the high-temperature deconfined phase of gauge theories. In particular, we analyze the symmetry properties of stochastic potential model and find a novel “event-by-event” symmetry for the case, similar to the -parity of hadronic systems. This novel symmetry constrains the relation between diagonal and off-diagonal components of quarkonium density matrix, leaving the latter to be finite at late times. We also present a one-dimensional numerical simulation of the model, which indicates the usefulness of the complex potential simulations for the quarkonium survival probabilities in relativistic heavy-ion collisions, provided that the effect of dissipation can be neglected.- Open Access
Dynamics of in-medium quarkonia in SU(3) and SU(2) gauge theories
Decoherence dynamics of quarkonia is studied in the high-temperature deconfined phase of SU($N_c$) gauge theories. In particular, we analyze the symmetry properties of SU($N_c$) stochastic potential model and find a novel "event-by-event" symmetry for $N_c=2$ case, similar to the $G$-parity of hadronic systems. This novel symmetry constrains the relation between diagonal and off-diagonal components of quarkonium density matrix, leaving the latter to be finite at late times. We also present one-dimensional numerical simulation of the model, which indicates the usefulness of the complex potential simulations for the quarkonium survival probabilities in relativistic heavy-ion collisions, provided that the effect of dissipation can be neglected.Open AccessDynamics of in-medium quarkonia in SU(3) and SU(2) gauge theories
Decoherence dynamics of quarkonia is studied in the high-temperature deconfined phase of SU($N_c$) gauge theories. In particular, we analyze the symmetry properties of SU($N_c$) stochastic potential model and find a novel "event-by-event" symmetry for $N_c=2$ case, similar to the $G$-parity of hadronic systems. This novel symmetry constrains the relation between diagonal and off-diagonal components of quarkonium density matrix, leaving the latter to be finite at late times. We also present one-dimensional numerical simulation of the model, which indicates the usefulness of the complex potential simulations for the quarkonium survival probabilities in relativistic heavy-ion collisions, provided that the effect of dissipation can be neglected. - Open Access
- 30 December 2020
- Published by American Physical Society (APS) in Physical Review D
- Vol. 102 (11) , 114522
Distribution of energy-momentum tensor around a static quark in the deconfined phase of SU(3) Yang-Mills theory
The energy-momentum tensor (EMT) characterizes the response of the vacuum as well as the thermal medium under the color electromagnetic fields. We define the EMT by means of the gradient-flow formalism and study its spatial distribution around a static quark in the deconfined phase of SU(3) Yang-Mills theory on the lattice. Although no significant difference can be seen between the EMT distributions in the radial and transverse directions except for the sign, the temporal component is substantially different from the spatial ones near the critical temperature . This is in contrast to the prediction of the leading-order thermal perturbation theory. The lattice data of the EMT distribution also indicate the thermal screening at long distance and the perturbative behavior at short distance.- 30 December 2020
- Published by American Physical Society (APS) in Physical Review D
- Vol. 102 (11) , 114522
Open AccessDistribution of energy-momentum tensor around a static quark in the deconfined phase of SU(3) Yang-Mills theory
The energy-momentum tensor (EMT) characterizes the response of the vacuum as well as the thermal medium under the color electromagnetic fields. We define the EMT by means of the gradient-flow formalism and study its spatial distribution around a static quark in the deconfined phase of SU(3) Yang-Mills theory on the lattice. Although no significant difference can be seen between the EMT distributions in the radial and transverse directions except for the sign, the temporal component is substantially different from the spatial ones near the critical temperature . This is in contrast to the prediction of the leading-order thermal perturbation theory. The lattice data of the EMT distribution also indicate the thermal screening at long distance and the perturbative behavior at short distance. - Open Access
Distribution of Energy-Momentum Tensor around a Static Quark in the Deconfined Phase of SU(3) Yang-Mills Theory
Energy momentum tensor (EMT) characterizes the response of the vacuum as well as the thermal medium under the color electromagnetic fields. We define the EMT by means of the gradient flow formalism and study its spatial distribution around a static quark in the deconfined phase of SU(3) Yang-Mills theory on the lattice. Although no significant difference can be seen between the EMT distributions in the radial and transverse directions except for the sign, the temporal component is substantially different from the spatial ones near the critical temperature $T_c$. This is in contrast to the prediction of the leading-order thermal perturbation theory. The lattice data of the EMT distribution also indicate the thermal screening at long distance and the perturbative behavior at short distance.Open AccessDistribution of Energy-Momentum Tensor around a Static Quark in the Deconfined Phase of SU(3) Yang-Mills Theory
Energy momentum tensor (EMT) characterizes the response of the vacuum as well as the thermal medium under the color electromagnetic fields. We define the EMT by means of the gradient flow formalism and study its spatial distribution around a static quark in the deconfined phase of SU(3) Yang-Mills theory on the lattice. Although no significant difference can be seen between the EMT distributions in the radial and transverse directions except for the sign, the temporal component is substantially different from the spatial ones near the critical temperature $T_c$. This is in contrast to the prediction of the leading-order thermal perturbation theory. The lattice data of the EMT distribution also indicate the thermal screening at long distance and the perturbative behavior at short distance. - 18 March 2020
- Published by American Physical Society (APS) in Physical Review C
- Vol. 101 (3) , 034913
Issues with the search for critical point in QCD with relativistic heavy ion collisions
A systematic search for a critical point in the phase diagram of QCD matter is under way at the Relativistic Heavy Ion Collider (RHIC) and is planned at several future facilities. Its existence, if confirmed, and its location will greatly enhance our understanding of QCD. In this article, we emphasize several important issues that are often not fully recognized in theoretical interpretations of experimental results relevant to the critical point search. We discuss ways in which our understanding on these issues can be improved.
- 18 March 2020
- Published by American Physical Society (APS) in Physical Review C
- Vol. 101 (3) , 034913
Issues with the search for critical point in QCD with relativistic heavy ion collisions
A systematic search for a critical point in the phase diagram of QCD matter is under way at the Relativistic Heavy Ion Collider (RHIC) and is planned at several future facilities. Its existence, if confirmed, and its location will greatly enhance our understanding of QCD. In this article, we emphasize several important issues that are often not fully recognized in theoretical interpretations of experimental results relevant to the critical point search. We discuss ways in which our understanding on these issues can be improved.
- Open Access
Issues with Search for Critical Point in QCD with Relativistic Heavy Ion Collisions
A systematic search for a critical point in the phase diagram of QCD matter is underway at the Relativistic Heavy Ion Collider (RHIC) and is planned at several future facilities. Its existence, if confirmed, and its location will greatly enhance our understanding of QCD. In this note we emphasize several important issues that are often not fully recognized in theoretical interpretations of experimental results relevant to the critical point search. We discuss ways in which our understanding on these issues can be improved.
Open AccessIssues with Search for Critical Point in QCD with Relativistic Heavy Ion Collisions
A systematic search for a critical point in the phase diagram of QCD matter is underway at the Relativistic Heavy Ion Collider (RHIC) and is planned at several future facilities. Its existence, if confirmed, and its location will greatly enhance our understanding of QCD. In this note we emphasize several important issues that are often not fully recognized in theoretical interpretations of experimental results relevant to the critical point search. We discuss ways in which our understanding on these issues can be improved.
- 11 February 2020
- Published by American Physical Society (APS) in Physical Review D
- Vol. 101 (3) , 034011
Quantum Brownian motion of a heavy quark pair in the quark-gluon plasma
In this paper we study the real-time evolution of heavy quarkonium in the quark-gluon plasma (QGP) on the basis of the open quantum systems approach. In particular, we shed light on how quantum dissipation affects the dynamics of the relative motion of the quarkonium state over time. To this end we present a novel nonequilibrium master equation for the relative motion of quarkonium in a medium, starting from Lindblad operators derived systematically from quantum field theory. In order to implement the corresponding dynamics, we deploy the well established quantum state diffusion method. In turn we reveal how the full quantum evolution can be cast in the form of a stochastic nonlinear Schrödinger equation. This for the first time provides a direct link from quantum chromodynamics to phenomenological models based on nonlinear Schrödinger equations. Proof of principle simulations in one dimension show that dissipative effects indeed allow the relative motion of the constituent quarks in a quarkonium at rest to thermalize. Dissipation turns out to be relevant already at early times well within the QGP lifetime in relativistic heavy ion collisions.
- 11 February 2020
- Published by American Physical Society (APS) in Physical Review D
- Vol. 101 (3) , 034011
Quantum Brownian motion of a heavy quark pair in the quark-gluon plasma
In this paper we study the real-time evolution of heavy quarkonium in the quark-gluon plasma (QGP) on the basis of the open quantum systems approach. In particular, we shed light on how quantum dissipation affects the dynamics of the relative motion of the quarkonium state over time. To this end we present a novel nonequilibrium master equation for the relative motion of quarkonium in a medium, starting from Lindblad operators derived systematically from quantum field theory. In order to implement the corresponding dynamics, we deploy the well established quantum state diffusion method. In turn we reveal how the full quantum evolution can be cast in the form of a stochastic nonlinear Schrödinger equation. This for the first time provides a direct link from quantum chromodynamics to phenomenological models based on nonlinear Schrödinger equations. Proof of principle simulations in one dimension show that dissipative effects indeed allow the relative motion of the constituent quarks in a quarkonium at rest to thermalize. Dissipation turns out to be relevant already at early times well within the QGP lifetime in relativistic heavy ion collisions.