Year: 2019
Type: article
Abstract: We clarify and extend further the idea we developed before that baryonic matter at high density has an emergent ``pseudoconformal symmetry.'' It is argued that as baryonic density exceeds $n\ensuremath{\simeq}{n}_{1/2}\ensuremath{\gtrsim}2{n}_{0}$, a topology change mimicking the baryon-quark continuity takes place at ${n}_{1/2}$. In terms of skyrmions, this corresponds to the transition from skyrmions to half-skyrmions and impacts on the equation of state of dense baryonic matter. The emergence in medium at ${n}_{1/2}$ of parity-doublet symmetry---which is invisible in QCD in a matter-free vacuum---plays the crucial role. The consequence of the topology change is that massive compact stars carry the ``pseudoconformal sound velocity'' ${v}_{s}^{2}/{c}^{2}\ensuremath{\approx}1/3$ at $n\ensuremath{\gtrsim}{n}_{1/2}$ signaling a precursor to the precocious emergence of scale symmetry as well as a local symmetry hidden in QCD in the matter-free vacuum. A highly significant prediction of this work is that the topology change density from normal matter to half-skyrmion matter, up to date inaccessible either by QCD proper or by terrestrial experiments, could possibly be pinned down within the range $2<{n}_{1/2}/{n}_{0}<4$, commensurate with the range expected for a continuous hadrons-to-quarks or -gluons transition.
Authors: Yong-Liang Ma, Mannque Rho
Language: English
Subfield: Nuclear and High Energy Physics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Awards: G3759741706, 基于skyrmion晶格的核物质性质的理论研究
OpenAlex ID: W2896102426