Prediction of a missing higher charmonium around 4.26 GeV in J/ψJ/\psi family

Inspired by the similarity of mass gaps of $J/\psi$ and $\Upsilon$ families, the prediction of missing higher charmonium with mass $4263$ MeV and very narrow width is made. In addition, the properties of two charmonium-like states, $X(3940)$ and $X(4160)$, and charmonium $\psi(4415)$ are discussed. Here, $X(3940)$ as $\eta_c(3S)$ is established while the explanation of $X(4160)$ to be $\eta_c(4S)$ is fully excluded and $\eta_c(4S)$ is typically a very narrow state. These predictions can be accessible at BESIII, Belle and BelleII in near future.Comment: 5 pages, 5 figures and 1 table. More discussions added. Accepted by Eur. Phys. J.

Nondeterminstic ultrafast ground state cooling of a mechanical resonator

We present an ultrafast feasible scheme for ground state cooling of a mechanical resonator via repeated random time-interval measurements on an auxiliary flux qubit. We find that the ground state cooling can be achieved with \emph{several} such measurements. The cooling efficiency hardly depends on the time-intervals between any two consecutive measurements. The scheme is also robust against environmental noises.Comment: 4 pages, 3 figure

Production of large transverse momentum dileptons and photons in pppp, dAdA and AAAA collisions by photoproduction processes

The production of large $P_{T}$ dileptons and photons originating from photoproduction processes in $pp$, $dA$ and $AA$ collisions is calculated. We find that the contribution of dileptons and photons produced by photoproduction processes is not prominent at RHIC energies. However, the numerical results indicate that the modification of photoproduction processes becomes evident in the large $P_{T}$ region for $pp$, $dA$ and $AA$ collisions at LHC energies.Comment: 10 figure