2024/08/05 by Gaoqing Cao · 2 citations
Physics and Astronomy · #CP violation #Condensed matter physics #High-Energy Particle Collisions Research #Particle physics #Particle physics theoretical and experimental studies #Physics #Pion #Quantum Chromodynamics and Particle Interactions #Quantum chromodynamics #Superfluidity
paper · pdf · doi:10.1103/physrevd.110.034004
published in Physical review. D/Physical review. D. 110(3) (American Physical Society)
openalex publication_date 2024/08/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Previously, it was found that pion superfluidity could be realized in the quantum chromodynamics (QCD) epoch of the early Universe, when lepton flavor asymmetry <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mrow> <a:mo stretchy="false">|</a:mo> <a:msub> <a:mrow> <a:mi>l</a:mi> </a:mrow> <a:mrow> <a:mi mathvariant="normal">e</a:mi> </a:mrow> </a:msub> <a:mo>+</a:mo> <a:msub> <a:mrow> <a:mi>l</a:mi> </a:mrow> <a:mrow> <a:mi>μ</a:mi> </a:mrow> </a:msub> <a:mo stretchy="false">|</a:mo> </a:mrow> </a:math> is large enough to generate a charge chemical potential <f:math xmlns:f="http://www.w3.org/1998/Math/MathML" display="inline"> <f:mo stretchy="false">|</f:mo> <f:msub> <f:mi>μ</f:mi> <f:mi mathvariant="normal">Q</f:mi> </f:msub> <f:mo stretchy="false">|</f:mo> </f:math> larger than vacuum pion mass. By following the same logic, kaon superfluidity might also be possible when <k:math xmlns:k="http://www.w3.org/1998/Math/MathML" display="inline"> <k:mo stretchy="false">|</k:mo> <k:msub> <k:mi>l</k:mi> <k:mi mathvariant="normal">e</k:mi> </k:msub> <k:mo>+</k:mo> <k:msub> <k:mi>l</k:mi> <k:mi>μ</k:mi> </k:msub> <k:mo stretchy="false">|</k:mo> </k:math> is so large that <p:math xmlns:p="http://www.w3.org/1998/Math/MathML" display="inline"> <p:mo stretchy="false">|</p:mo> <p:msub> <p:mi>μ</p:mi> <p:mi mathvariant="normal">Q</p:mi> </p:msub> <p:mo stretchy="false">|</p:mo> </p:math> becomes larger than vacuum kaon mass. Such a possibility is checked by adopting Ginzburg-Landau approximation within the three-flavor Polyakov–Nambu–Jona-Lasinio model. Consider the case with full chemical balance, though kaon superfluidity could be stable compared to the chiral phases with only <u:math xmlns:u="http://www.w3.org/1998/Math/MathML" display="inline"> <u:mi>σ</u:mi> </u:math> condensations, it would get killed by the more favored homogeneous pion superfluidity. If we introduce mismatch between <w:math xmlns:w="http://www.w3.org/1998/Math/MathML" display="inline"> <w:mi>s</w:mi> </w:math> and <y:math xmlns:y="http://www.w3.org/1998/Math/MathML" display="inline"> <y:mi>d</y:mi> </y:math> quarks, kaon superfluidity would require so large <ab:math xmlns:ab="http://www.w3.org/1998/Math/MathML" display="inline"> <ab:mi>s</ab:mi> </ab:math> quark density that such a state is impossible in the early Universe. Published by the American Physical Society 2024