Theoretical investigation of the molecular nature of Ds0∗(2317)D_{s0}^*(2317) and Ds1(2460)D_{s1}(2460) and the possibility of observing the DDˉKD\bar{D}K bound state Kccˉ(4180)K_{c\bar{c}}(4180) in inclusive e+e−→ccˉe^+e^-\to c\bar{c} collisions

Searching for exotic multiquark states and elucidating their nature remains a central topic in understanding quantum chromodynamics--the underlying theory of the strong interaction. Two of the most studied such states are the charm-strange states $D_{s0}^*(2317)$ and $D_{s1}(2460)$. In this letter, we show for the first time that their prompt production yields in inclusive $e^+e^-\to c\bar{c}$ collisions near $\sqrt{s}=10.6$ GeV measured by the BABAR Collaboration, $Y(D_{s0}^*(2317))$ and $Y(D_{s1}(2460))$, in particular the ratio $R=Y(D_{s0}^*(2317))/Y(D_{s1}(2460))$, can be well explained in the molecular picture, which provide a highly nontrivial verification of their nature being $DK/D^*K$ molecules. On the contrary, treating them as pure $c\bar{s}$ $P-$wave states, the statistical model predicts a ratio $R$ smaller than unity, in contrast with the experimental central value, though in agreement with it considering its relatively large uncertainty. In addition, we predict the production yield of the $D\bar{D}K$ three-body bound state, $K_{c\bar{c}}(4180)$, in $e^+e^-\to c\bar{c}$ collisions and find that it is within the reach of the ongoing Belle II experiment. The present study demonstrates the feasibility of a novel method to unravel the nature of exotic hadrons and the potential of electron-positron collisions in this regard.Comment: 8 pages, 3 figures; more discussions and comparison with the statistical model adde

A Comparative Study on Spin-Orbit Torque Efficiencies from W/ferromagnetic and W/ferrimagnetic Heterostructures

It has been shown that W in its resistive form possesses the largest spin-Hall ratio among all heavy transition metals, which makes it a good candidate for generating efficient dampinglike spin-orbit torque (DL-SOT) acting upon adjacent ferromagnetic or ferrimagnetic (FM) layer. Here we provide a systematic study on the spin transport properties of W/FM magnetic heterostructures with the FM layer being ferromagnetic Co$_{20}$Fe$_{60}$B$_{20}$ or ferrimagnetic Co$_{63}$Tb$_{37}$ with perpendicular magnetic anisotropy. The DL-SOT efficiency $|\xi_{DL}|$, which is characterized by a current-induced hysteresis loop shift method, is found to be correlated to the microstructure of W buffer layer in both W/Co$_{20}$Fe$_{60}$B$_{20}$ and W/Co$_{63}$Tb$_{37}$ systems. Maximum values of $|\xi_{DL}|\approx 0.144$ and $|\xi_{DL}|\approx 0.116$ are achieved when the W layer is partially amorphous in the W/Co$_{20}$Fe$_{60}$B$_{20}$ and W/Co$_{63}$Tb$_{37}$ heterostructures, respectively. Our results suggest that the spin Hall effect from resistive phase of W can be utilized to effectively control both ferromagnetic and ferrimagnetic layers through a DL-SOT mechanism