Interplay of Coulomb and symmetry potential in peak fragment production in asymmetric collisions

Role of the nuclear symmetry potential and Coulomb potential is explored on the peak energy of intermediate mass fragments ([Formula: see text]) and on peak multiplicity ([Formula: see text]) and their dependence on mass asymmetry of the reaction is also investigated. The calculations are done using Isospin-dependent Quantum Molecular Dynamics (IQMD) model. We also showed that the momentum-dependent interactions have uniform effects of [Formula: see text] and these effects are independent of mass asymmetry of the reaction. Further, we see that isospin effects that enter through the Coulomb and symmetry potential show much significant role as one increases the mass asymmetry of reaction. Mass asymmetric reactions thus serve a sensitive tool to investigate the nuclear symmetry energy effects.

Duality rules for more mixed-symmetry potentials

$T$ - and $S$-duality rules among the gauge potentials in type II supergravities are studied. In particular, by following the approach of [J. J. Fernández-Melgarejo et al., arXiv:1909.01335], we determine the $T$- and $S$-duality rules for certain mixed-symmetry potentials, which couple to supersymmetric branes with tension $T\propto g_s^{-n}$ ($n\leq 4$). Although the $T$-duality rules are rather intricate, we find a certain redefinition of potentials which considerably simplifies the duality rules. After the redefinition, potentials are identified with components of the $T$-duality-covariant potentials, which have been predicted by the $E_{11}$ conjecture. Since our approach is based on $U$-duality, we can also determine the 11D uplifts of the mixed-symmetry potential, unlike the $T$-duality-covariant approach known in the literature. We also study the field strengths of the mixed-symmetry potentials.