Fragmentation-fraction ratio fΞb/fΛbf_{\Xi_b}/f_{\Lambda_b} in bb- and cc-baryon decays

We study the ratio of fragmentation fractions, $f_{\Xi_b}/f_{\Lambda_b}$, from the measurement of $\Xi_b^0\to \Xi_c^+\pi^-$ and $\Lambda_b^0\to \Lambda_c^+\pi^-$ with $\Xi_{c}^{+}/\Lambda_{c}^{+}\to p K^-\pi^+$. With the branching fraction $\mathcal{B}(\Xi_c^+\to pK^-\pi^+)=(2.2\pm0.8)\%$ obtained under the U-spin symmetry, the fragmentation ratio is determined as $f_{\Xi_b}/f_{\Lambda_b}$=$0.054\pm0.020$. To reduce the above uncertainties, we suggest to measure the branching fractions of $\Xi_c^+\to p \overline K^{*0}$ and $\Lambda_c^+\to \Sigma^+ K^{*0}$ at BESIII, Belle(II) and LHCb.Comment: 13 pages, 1 table, 1 figure. Version published in EPJ

Characteristic length of a Holographic Superconductor with dd-wave gap

After the discovery of the $s$-wave and $p$-wave holographic superconductors, holographic models of $d$-wave superconductor have also been constructed recently. We study analytically the perturbation of the dual gravity theory to calculate the superconducting coherence length $\xi$ of the $d$-wave holographic superconductor near the superconducting phase transition point. The superconducting coherence length $\xi$ divergents as $(1-T/T_c)^{-1/2}$ near the critical temperature $T_c$. We also obtain the magnetic penetration depth $\lambda\propto(T_c-T)^{-1/2}$ by adding a small external homogeneous magnetic field. The results agree with the $s$-wave and $p$-wave models, which are also the same as the Ginzburg-Landau theory.Comment: last version, 10 pages, accepted by PR