Daiki Suenaga

We explore the mass splitting of heavy-light mesons with chiral partner structure in nuclear matter. In our calculation, we employed the heavy hadron chiral perturbation theory with chiral partner structure, and the nuclear matter is constructed by putting Skyrmions from the standard Skyrme model onto the face-centered cubic crystal and regarding the Skyrmion matter as nuclear matter. We find that, although the masses of heavy-light mesons with chiral partner structure are split in matter-free s

We study the Landau gauge gluon propagators in dense two-color QCD at quark chemical potential, ${\ensuremath{\mu}}_{q}$, in the range from 0.5 to 1.0 GeV not reachable by the perturbative method at weak coupling. In order to take into account the nonperturbative effects, at tree level we use a massive Yang-Mills model for the Yang-Mills theory (or the Curci-Ferrari model) which has successfully described the lattice results of the gluon and ghost propagators in the Landau gauge. We couple quark

I investigate modifications of mass and decay width of ${N}^{*}(1535)$ in nuclear matter in a chiral symmetric way. The nucleon and ${N}^{*}(1535)$ are introduced by a parity doublet model, and nuclear matter is constructed by one-loop diagrams of the nucleon and ${N}^{*}(1535)$. The decay width of ${N}^{*}(1535)$ is studied with respect to chiral symmetry. My calculations show that the partial width of ${\mathrm{\ensuremath{\Gamma}}}_{{N}^{*}\ensuremath{\rightarrow}N\ensuremath{\pi}}$ is slight

We investigate the in-medium masses of a $\overline{D}\phantom{\rule{0.16em}{0ex}}({0}^{\ensuremath{-}})$ meson and a ${\overline{D}}_{0}^{*}\phantom{\rule{0.16em}{0ex}}({0}^{+})$ meson, and spectral functions for $\overline{D}$ and ${\overline{D}}_{0}^{*}$ meson channels in nuclear matter. These mesons are introduced as chiral partners in the chiral-symmetry-broken vacuum, hence they are useful to explore the partial restoration of the broken chiral symmetry in nuclear matter. We consider the l

We propose a new type of structure for singly heavy baryons of $Qqq\overline{q}q$ in addition to the conventional one of $Qqq$. Based on chiral symmetry of the light quarks, we show that the $Qqq\overline{q}q$ baryon offers a novel picture for heavy-quark spin-singlet and flavor-antisymmetric baryons. By making use of the effective Lagrangian approach, we find that ${\mathrm{\ensuremath{\Lambda}}}_{c}(2765)$ and ${\mathrm{\ensuremath{\Xi}}}_{c}(2967)$ are mostly $Qqq\overline{q}q$, while ${\math

We present a comprehensive study of mass modifications of scalar, pseudoscalar, vector, and axial-vector mesons in nuclear matter using the three-flavor extended linear $\ensuremath{\sigma}$ model (eLSM) and the two-flavor parity doublet model (PDM). The meson masses in nuclear matter are determined by calculating the one-loop nucleon corrections to the meson mean fields. As a result, we find all spin-0 meson masses except those of the pion, kaon, and the lightest scalar-isoscalar mesons decreas

We investigate modifications of hadron masses at finite quark chemical potential in two-flavor and two-color QCD, data of which are available from lattice simulations, within a linear sigma model based on approximate Pauli-Gursey $SU(4)$ symmetry. The model describes not only ground-state scalar diquarks and pseudoscalar mesons but also the excited pseudoscalar diquarks and scalar mesons; each ground-state diquark (meson) has the corresponding excited diquark (hadron) with opposite parity as a c

We propose to study the mass spectrum of the heavy-light mesons to probe the structure of the spin-isospin correlation in the nuclear medium. We point out that the spin-isospin correlation in the nuclear medium generates a mixing among the heavy-light mesons carrying different spins and isospins such as ${D}^{+}$, ${D}^{0}$, ${D}^{*+}$, and ${D}^{*0}$ mesons. We use two types of correlations motivated by the skyrmion crystal and the chiral density wave as typical examples to obtain the mass spli

We calculate dispersion relations for $\overline{D}({0}^{\ensuremath{-}})$, ${\overline{D}}^{*}({1}^{\ensuremath{-}})$, ${\overline{D}}_{0}^{*}({0}^{+})$, and ${\overline{D}}_{1}({1}^{+})$ mesons in the dual chiral density wave (DCDW), where the chiral symmetry is spontaneously broken by inhomogeneous chiral condensate. Employing the Bloch's theorem, we show that all the modes have opposite group velocity to the momentum in the low-momentum region, and the energy is minimized at nonzero momentum

We investigate the influence of the Kondo effect, namely, the nonperturbative effect induced by heavy impurities, on the chiral separation effect (CSE) in quark matter. We employ a simple effective model incorporating the Kondo condensate made of a light quark and a heavy quark, and compute the response function of the axial current to the magnetic field in the static and dynamical limits. As a result, we find that the Kondo effect catalyzes the CSE in both of the limits, and in particular the C

A bstract We explore the topological susceptibility at finite quark chemical potential and zero temperature in two-color QCD (QC 2 D) with two flavors. Through the Ward-Takahashi identities of QC 2 D, we find that the topological susceptibility in the vacuum solely depends on three observables: the pion decay constant, the pion mass, and the η mass in the low-energy regime of QC 2 D. Based on the identities, we numerically evaluate the topological susceptibility at finite quark chemical potentia

We construct an extended version of the linear sigma model in such a way as to describe spin-1 hadrons as well as spin-0 hadrons in two-color QCD (<a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msub><a:mrow><a:mi>QC</a:mi></a:mrow><a:mrow><a:mn>2</a:mn></a:mrow></a:msub><a:mi mathvariant="normal">D</a:mi></a:mrow></a:math>) by respecting the Pauli-Gürsey <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"><d:mi>S</d:mi><d:mi>U</d:mi><d:mo stret

We study the chiral separation effect (CSE) in two-color and two-flavor QCD to delineate quasiparticle pictures in dense matter from low to high temperatures. Both massless and massive quarks are discussed. We particularly focus on the high density domain where diquarks form a color-singlet condensate with the electric charge $1/3$. The condensate breaks the baryon number and $U(1{)}_{A}$ axial symmetry, and induces the electromagnetic Meissner effects. Within a quark quasiparticle picture, we c

We present a chiral model describing decays of the Roper-like ${\mathrm{\ensuremath{\Lambda}}}_{c}(2765)$ and ${\mathrm{\ensuremath{\Xi}}}_{c}(2970)$ as well as those of the heavy quark spin-doublet ${{\mathrm{\ensuremath{\Sigma}}}_{c}(2455),{\mathrm{\ensuremath{\Sigma}}}_{c}(2520)}$ and ${{\mathrm{\ensuremath{\Xi}}}_{c}^{\ensuremath{'}},{\mathrm{\ensuremath{\Xi}}}_{c}(2645)}$, by focusing on chiral representations of diquarks inside the heavy baryons. Based on our chiral model together with the

Masses of positive-parity and negative-parity diquarks are investigated at finite temperature with a quark chemical potential. We employ the three-flavor Nambu-Jona-Lasinio model, in order to delineate chiral properties of the diquarks, in particular, the mass degeneracy of chiral partners under extreme conditions. We focus on the effects of $U(1{)}_{A}$ axial anomaly on manifestation of the chiral-partner structures. We find that, in the absence of anomaly effects to the diquarks, the mass dege