Relation between the mass modification of heavy–light mesons and the chiral symmetry structure in dense matter

Abstract

We point out that the study of the density dependences of the masses of heavy-light mesons give some clues to the chiral symmetry structure in nuclear matter. We include the omega meson effect as well as the sigma meson effect at mean field level on the density dependence of the masses of heavylight mesons with chiral partner structure. It is found that the omega meson affects the masses of the heavy-light mesons and their antiparticles in the opposite way, while it affects the masses of chiral partners in the same way. This is because the ω meson is sensitive to the baryon number of the light degrees included in the heavy-light mesons. We also show that the mass difference between chiral partners is proportional to the mean field of sigma, reflecting the partial restoration of chiral symmetry in the nuclear matter. In addition to the general illustration of the density dependence of the heavy-light meson masses, we consider two concrete models for nuclear matter, the parity doublet model and skyrmion crystal model in the sense of mean field approximation.

Spectral functions for D¯ and D¯0* mesons in nuclear matter with partial restoration of chiral symmetry

“…This effect can let the mass ofD andD * 0 increase by a hundred MeV at most at normal nuclear matter density as studied in Ref. [33]. The mass modifications toD andD * 0 mesons from ω contribution is the same, however, so that mass difference betweenD * 0 andD mesons are not changed.…”

“…Later in Ref. [33], ω type mean field were also considered in addition, and it was found that the ω mean field affects the masses of a D meson and aD meson in opposite way, while the ω mean field affects the masses of the chiral partner, aD meson and aD * 0 meson, in the same way. We notice, however, that the degenerate masses of chiral partners can differ from the chiral invariant mass whose value is defined by the averaged mass of chiral partners in vacuum.…”

“…We also note that, in the studies in Refs. [32,33], only the mean fields of a σ meson and a ω meson are taken into account, and the loop corrections from fluctuations were neglected.…”

Interplay between chiral symmetry breaking and the QCD Kondo effect

“…These effects can affect the transport and thermodynamic observables in high-density matter with heavy quarks/hadrons, such as that created by lowenergy heavy-ion collisions at FAIR, NICA, and J-PARC. In particular, since D, D s , and B mesons are promising probes of chiral symmetry restoration at high density [18][19][20][21][22][23][24][25][26][27][28], the competition with the Kondo condensate would play an important role in their observables.…”

Effect of Partial Chiral Symmetry Restoration in Nuclear Matter to Charmed Meson Masses Based on a Chiral Partner Structure

“…In Ref. [2], we studied the charmed meson masses in nuclear matter through the exchange of sigma and omega mesons. In this write-up, I briefly summarize main points of two works.…”