2016 Fiscal Year Annual Research Report
Topological Solitons and Non-perturbative Effects in Field Theory
| Project/Area Number |
16F16322
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| Research Institution | Keio University |
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Principal Investigator |
新田 宗土 慶應義塾大学, 商学部(日吉), 教授 (60433736)
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| Co-Investigator(Kenkyū-buntansha) |
CHATTERJEE CHANDRASEKHAR 慶應義塾大学, 自然科学研究教育センター, 外国人特別研究員
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| Project Period (FY) |
2016-11-07 – 2019-03-31
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| Keywords | 高密度ＱＣＤ / トポロジカル・ソリトン / 渦 / 核物質 / 中性子超流動 / 中性子星 / アリス・ストリング |
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| Outline of Annual Research Achievements |
1. When a charged particle encircles around an Alice string, it changes the sign of the electric charge. We found a BPS-saturated Alice string in U(1)×SO(3)gauge theory. After performing BPS completion we solved the BPS equations numerically. We further embeded the Alice string into an N=1 supersymmetric gauge theory to show that it is half BPS.
2. Color symmetry is spontaneously broken in quark matter at high density as a consequence of di-quark condensations with exhibiting color superconductivity. Non-Abelian vortices or color magnetic flux tubes stably exist in the color-flavor locked phase at asymptotically high density. We constructed the effective worldsheet theory of a non-Abelian vortex in regular gauge, confirming the previous results in the singular gauge. As a byproduct of our analysis, we found that non-Abelian vortices in high-density QCD do not suffer from any obstruction for the global definition of a symmetry breaking.
3. We discussed collective excitations of quantized superfluid vortices in neutron 3P2 superfluids, which likely exist in high density neutron matter such as neutron stars. We found a gapfull mode whose low-energy description takes the simple form of a double sine-Gordon model. The associated kink solution and its effects on spontaneous magnetization inside the vortex core were analyzed in detail.
4. We found that a recently proposed interaction involving the vorticity current of electrons, which radiatively induces a photon mass in 3+1 dimensions in the low-energy effective theory, corresponds to confining strings between electrons.
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| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
今年度は、論文を数本プレプリントではあるが、出している。計画書に書いた、高密度ＱＣＤについては、非アーベリアン渦の有効理論を構築して、論文Phys.Rev. D95 (2017) no.8, 085013を出版した。中性子超流動については、渦の有効理論を構築し、プレプリントではあるが、e-Print: arXiv:1612.05588 [nucl-th] を出している。
また、予定していなかった進展として、BPS Aliceストリングを発見し、プレプリントではあるがe-Print: arXiv:1703.08971 [hep-th]を書いた。
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| Strategy for Future Research Activity |
1.Alice string: An Alice string has a non-trivial topological property that charged particles flip the sign of the electric charge after encircling the string once, and as a consequence the charge becomes globally undefined. Since the discovery there was no explicit Bogomol'nyi-Prasad-Sommerfield(BPS) or minimum energy construction of Alice string so far. Recently we proposed a BPS construction of Alice string. Alice string contains an U(1) zero mode and we are computing the effective action for the scalar zero mode. There will be fermion zero modes also and we are planing to show an index theorem for Alice string. Our BPS Alice string is a single vortex construction. The next step will be constructing multi-vortex configurations. We want to generalize the system for SU(N) and SO(N) gauge theories.
2.Dense QCD: Quark matter at high density may exhibit color superconductivity. At asymptotically large density the ground state is found to be the most symmetric three-flavor color-superconductivity called the color-flavor-locked(CFL) phase due to the condensation of quark-quark pairing. The physics is under theoretical control in this regime because the QCD coupling constant is weak due to the asymptotic freedom. The breaking of the global baryon number, color and flavor symmetry generates non-Abelian superfluid vortices which carry color-magnetic flux. The situation is dual to hadronic phase. Dual confinement of magnetic monopole by color-magnetic flux-tube has been shown to exist. I would like to analyze tis system closely in the presence of fermions.
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