The production of neutral N∗(11052)N^*(11052) resonance with hidden beauty from π−p\pi^-p scattering

We investigate the discovery potential of the predicted neutral hidden beauty $N^*(11052)$ resonance through $\pi^- p$ scattering within an effective Lagrangian approach. Two reactions $\pi^-p\rightarrow K^-\Sigma^+$ and $\pi^-p\rightarrow \eta_bn$ are studied in this work, with nucleon pole exchange as the background. It is found that the contributions of the $N^*(11052)$ resonance give clear peak structures in the magnitude of 1 $\mu b$ near the threshold of the $N^*(11052)$ in the total cross sections. The numerical results indicate that the center of mass energy $W\simeq$ 11-11.1 GeV would be a best energy window for searching the $N^*(11052)$ resonance, where the $N^*(11052)$ signal can be easily distinguished from the background. The COMPASS experiment at CERN's Super Proton Synchrotron (SPS) with pion beam of $\simeq$ 280 GeV will be an ideal platform for searching the super-heavy resonance with hidden beauty, which is hopeful to test the theoretical results

Terahertz Antiferromagnetic Spin Hall Nano-Oscillator

We consider the current-induced dynamics of insulating antiferromagnets in a spin Hall geometry. Sufficiently large in-plane currents perpendicular to the N\'{e}el order trigger spontaneous oscillations at frequencies between the acoustic and the optical eigenmodes. The direction of the driving current determines the chirality of the excitation. When the current exceeds a threshold, the combined effect of spin pumping and current-induced torques introduces a dynamic feedback that sustains steady-state oscillations with amplitudes controllable via the applied current. The ac voltage output is calculated numerically as a function of the dc current input for different feedback strengths. Our findings open a route towards terahertz antiferromagnetic spin-torque oscillators.Comment: 5+ pages, 4 figure

The quantum spin Hall effect and topological insulators

In topological insulators, spin-orbit coupling and time-reversal symmetry combine to form a novel state of matter predicted to have exotic physical properties.Comment: 7 pages, 5 figures, an introduction of the quantum spin Hall effect and topological insulators. For a video introduction of topological insulators, see http://www.youtube.com/watch?v=Qg8Yu-Ju3V