Dominant Spin-Flip Effects for the Hadronic Produced J/ψJ/\psi Polarization at TEVATRON

Dominant spin-flip effects for the direct and prompt $J/\psi$ polarizations at TEVATRON run II with collision energy 1.96 TeV and rapidity cut $|y^{J/\psi}|<0.6$, have been systematically studied, especially, the spin-flip effect for the transition of $(c\bar{c})_8[^3S_1]$ into $J/\psi$ has been carefully discussed. It is found that the spin-flip effect shall always dilute the $J/\psi$ polarization, and with a suitable choice of the parameters $a_{0,1}$ and $c_{0,1,2}$, the $J/\psi$ polarization puzzle can be solved to a certain degree. At large transverse momentum $p_t$, $\alpha$ for the prompt $J/\psi$ is reduced by $\sim50$ for $f_0 = v^2$ and by $\sim80$ for $f_0=1$. We also study the indirect $J/\psi$ polarization from the $b$-decays, which however is slightly affected by the same spin-flip effect and then shall provide a better platform to determine the color-octet matrix elements.Comment: 19 pages, 5 figures. References added. Revised version to be published in Phys.Rev.

Electromagnetic counterparts of high-frequency gravitational waves having additional polarization states: distinguishing and probing tensor-mode, vector-mode and scalar-mode gravitons

GWs from extra dimensions, very early universe, and some high-energy astrophysical process, might have at most six polarizations: plus- and cross-type (tensor-mode gravitons), x-, y-type (vector-mode), and b-, l-type (scalar-mode). Peak or partial peak regions of some of such GWs are just distributed in GHz or higher frequency band, which would be optimal band for electromagnetic(EM) response. In this paper we investigate EM response to such high-frequency GWs(HFGWs) having additional polarizations. For the first time we address:(1)concrete forms of analytic solutions for perturbed EM fields caused by HFGWs having all six possible polarizations in background stable EM fields; (2)perturbed EM signals of HFGWs with additional polarizations in three-dimensional-synchro-resonance-system(3DSR system) and in galactic-extragalactic background EM fields. These perturbative EM fields are actually EM counterparts of HFGWs, and such results provide a novel way to simultaneously distinguish and display all possible six polarizations. It is also shown: (i)In EM response, pure cross-, x-type and pure y-type polarizations can independently generate perturbative photon fluxes(PPFs, signals), while plus-, b- and l-type polarizations produce PPFs in different combination states. (ii) All such six polarizations have separability and detectability. (iii)In EM response to HFGWs from extra-dimensions, distinguishing and displaying different polarizations would be quite possible due to their very high frequencies, large energy densities and special properties of spectrum. (iv)Detection band(10^8 to 10^12 Hz or higher) of PPFs by 3DSR and observation range(7*10^7 to 3*10^9 Hz) of PPFs by FAST (Five-hundred-meter-Aperture-Spherical Telescope, China), have a certain overlapping property, so their coincidence experiments will have high complementarity.Comment: 27 pages, 16 figure

Collimated directional emission from a peanut-shaped microresonator

Collimated directional emission is essentially required an asymmetric resonant cavity. In this paper, we theoretically investigate a type of peanut-shaped microcavity which can support highly directional emission with the emission divergence as small as 2.5o. The mechanism of the collimated emission is explained with the short-term ray trajectory and the intuitive lens model in detail. Wave simulation also confirms these results. This extremely narrow divergence of the emission holds a great potential in highly collimated lasing from on-chip microcavities