2021 Fiscal Year Annual Research Report
Anomalous Casimir effect in axion electrodynamics
Project/Area Number |
20J20974
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Research Institution | Keio University |
Principal Investigator |
QIU Zebin 慶應義塾大学, 自然科学研究教育センター(日吉), 特別研究員(PD)
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Project Period (FY) |
2020-04-24 – 2023-03-31
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Keywords | Skyrme Model / Chiral Soliton Lattice / Topological Soliton |
Outline of Annual Research Achievements |
I ventured into the study on topological phases of hadronic matter in the light of the recent hot topic centered around meson domain walls and chiral soliton lattices. I adopted a gauged Skyrme model featuring the Wess-Zumino term to study hadron properties under an external magnetic field. Importantly, the Wess-Zumino-Witten (WZW) term encodes the chiral anomaly which has nontrivial interplay with the magnetic field. In our scenario, we discovered that the WZW term is responsible for the energy split of nucleons induced by the magnetic moment coupling. Furthermore, the multi-Skyrmion crystal description of dense hadronic matter accomodates both baryonic and pionic phases, which are of distinguished homotopy classes. The phase diagram of these two phases are established for the first time.
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Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
Logically we made smooth progress yet the study did cost immense time and efforts technically. The main challenge lied in the numerical solving of the soliton (Skyrmion) profile. By the current edition of Mathematica (the platform we employ for numerical solutions), the built-in function to solve the partial differential equation (PDE) bears defects which force us to go into more fundamental level of coding in Mathematica. We spent sevearl months tackling this issue and finally we made it. Once this is overcome, we moved on to further analysis following a rather standard procedure which could be referred to from previous literatures. Certainly, there arise nontrivial physical properties especially when we innovatively put Skyrmion and pion domain wall into a common framework.
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Strategy for Future Research Activity |
This is only the first step of serial studies. We are still trying to figure out how to alter the topology of a single Skyrmion with the magnetic field, instead of realizing that in multi-Skyrmion crystal. Also, nucleon properties can be further detailed, in addition to the energy/mass. Particularly, the pressure might have a bearing on the confinement from the perspective of hadrons. Moreover, other phases including charged pions typified by the charged pion condensate, have not yet been taken into account when considering the phase diagram. We would further stretch out to higher density regime to probe richer phase structures.
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Research Products
(2 results)