2017/09/25 by Michael Thies · 4 citations
Physics and Astronomy · #Baryon #Baryon number #Black Holes and Theoretical Physics #Cold Atom Physics and Bose-Einstein Condensates #Fermion #Massless particle #Mathematical physics #Particle physics #Physics #Quantum Chromodynamics and Particle Interactions #cond-mat.str-el #hep-ph #hep-th
paper · pdf · doi:10.1103/physrevd.96.116018
published in Physical review. D/Physical review. D. 96(11) (American Physical Society) · 12 pages, 8 figures; v2: typo in caption of Fig. 3 corrected
openalex created_date 2017/09/15 · arxiv created 2017/09/25 · openalex publication_date 2017/12/26 · arxiv updated 2018/01/03 · openalex updated_date 2026/08/05
Twisted kinks in the massless NJL2 model interpolate between two distinct vacua on the chiral circle. If one approaches the chiral limit from finite bare fermion masses m0, the vacuum is unique and twist cannot exist. This issue is studied analytically in the nonrelativistic limit, using a no-sea effective theory. We conclude that even in the massless limit, the interpretation of the twisted kink has to be revised. One has to attribute the fermion number of the valence state to the twisted kink. Fermion density is spread out over the whole space due to the massless pion field. The result can be pictured as a composite of a twisted kink (carrying energy, but no fermion number) and a partial winding of the chiral spiral (carrying fermion number, but no energy). This solves at the same time the puzzle of missing baryons with fermion number Nf<N in the massless NJL2 model.