dc.contributor.author | Andersen, Jens Oluf | |
dc.contributor.author | Zhou, Hua | |
dc.contributor.author | Yu, Qing | |
dc.date.accessioned | 2024-02-28T07:41:00Z | |
dc.date.available | 2024-02-28T07:41:00Z | |
dc.date.created | 2024-02-22T17:06:45Z | |
dc.date.issued | 2024 | |
dc.identifier.issn | 0556-2821 | |
dc.identifier.uri | https://hdl.handle.net/11250/3120201 | |
dc.description.abstract | We consider pion condensation in QCD at finite isospin density μI and zero temperature using two-flavor chiral perturbation theory (χPT). The pressure is calculated to next-to-leading order (NLO) in the low-energy expansion. In the nonrelativistic limit, we recover the classic result by Lee, Huang, and Yang for the energy density of a dilute Bose gas with an s-wave scattering length that includes loop corrections from χPT. In the chiral limit, higher-order calculations are tractable. We calculate the pressure to next-to-next-to-leading order (NNLO) in the low-energy expansion, which is an expansion in powers of μ2I/(4π)2f2, where f is the (bare) pion decay constant. The spontaneous breakdown of the global internal symmetry U(1)I3 gives rise to a massless Goldstone boson or phonon. We discuss the properties of the low-energy effective theory describing this mode. Finally, we compare our results for the pressure and the speed of sound with recent lattice simulations with 2+1 flavors. The agreement is very good for isospin chemical potentials up to 180–200 MeV, depending on the physical quantity. | en_US |
dc.language.iso | eng | en_US |
dc.publisher | American Physical Society | en_US |
dc.rights | Navngivelse 4.0 Internasjonal | * |
dc.rights.uri | http://creativecommons.org/licenses/by/4.0/deed.no | * |
dc.title | Pion condensation in QCD at finite isospin density, the dilute Bose gas, and speedy Goldstone bosons | en_US |
dc.title.alternative | Pion condensation in QCD at finite isospin density, the dilute Bose gas, and speedy Goldstone bosons | en_US |
dc.type | Journal article | en_US |
dc.description.version | publishedVersion | en_US |
dc.source.journal | Physical Review D. Particles and fields | en_US |
dc.identifier.doi | https://doi.org/10.1103/PhysRevD.109.034022 | |
dc.identifier.cristin | 2248945 | |
cristin.ispublished | true | |
cristin.fulltext | original | |
cristin.qualitycode | 0 | |