Dense Baryonic Matter in Hidden Local Symmetry Approach: Half-Skyrmions and Nucleon Mass

Understand

Hadron properties in dense medium are treated in a unified way in a skyrmion model constructed with an effective Lagrangian, in which the rho and omega vector mesons are introduced as hidden gauge bosons, valid up to O(p^4) terms in chiral expansion including the homogeneous Wess-Zumino terms.

• All the low energy constants - apart from f_pi and m_rho - are fixed by the master formula derived from the relation between 5-D hQCD and 4-D HLS.
• This allows one to pin down the density n_1/2 at which the skyrmions in medium fractionize into half-skyrmions, bringing in a drastic change in the EoS of dense matter.
• We find that the U(1) field that figures in the CS term in the hQCD action or equivalently the omega field in the hWZ term in the dimensionally reduced HLS action plays a crucial role in the half-skyrmion phase.