Near-BPS Skyrmions: Constant baryon density

Abstract

Although it provides a relatively good picture of the nucleons, the Skyrme Model is unable to reproduce the small binding energy in nuclei. This suggests that Skyrme-like models that nearly saturate the Bogomol'nyi bound may be more appropriate since their mass is roughly proportional to the baryon number A. For that purpose, we propose a near-BPS Skyrme Model. It consists of terms up to order six in derivatives of the pion fields, including the nonlinear and Skyrme terms which are assumed to be relatively small. For our special choice of mass term, we obtain well-behaved analytical BPS-type solutions with constant baryon density configurations, as opposed to the more complex shell-like configurations found in most extensions of the Skyrme Model. Fitting the four model parameters, we find a remarkable agreement for the binding energy per nucleon B/A with respect to experimental data. These results support the idea that nuclei could be near-BPS Skyrmions.Comment: Matches version to bepublished in Nucl.Phys. B. arXiv admin note: substantial text overlap with arXiv:1205.141

Magnetothermodynamics of BPS baby skyrmions

“…Further, finite binding energies have been recently derived by taking into account the semiclassical quantization of the spin-isospin degrees of freedom, the Coulomb interaction as well as the isospin breaking potential. The obtained values are in very good agreement with the nuclear data and the semi-empirical (Weizsäcker) formula, especially for higher nuclei [17][18][19][20][21]. This result allows to consider the BPS Skyrme model as a serious candidate for a lowest order approximation of the correct effective model of QCD at low energies, especially for the bulk quantities.…”

Oscillons in a perturbed signum-Gordon model

“…After this transformation has been performed (5.6) becomes 8) in which the primes have been removed. Hence, this extra coupling constant can always be scaled away.…”

Constructing Near-BPS Skyrmions with Constant Baryon Densities

“…The mass of a nucleus, E tot = E s + E r + E C + E I , then depends on the four parameters of the model and the baryon number (see Ref. [4] for more details).…”