Quantum color screening in external magnetic field

We calculate color screening mass in a thermalized and magnetized QCD matter in the frame of loop resummation theory at finite temperature and magnetic field. Different from the normal Debye screening in classical electrodynamics, the color screening mass in an external magnetic field is characterized by the quantized quark transverse energy $\epsilon_n^2=2n|qB|$, similar to the Landau energy levels derived in quantum mechanics. Our calculation without constriction to the temperature and magnetic field strengths comes back to the well-known results in the limits of weak and strong magnetic field.Comment: 9 pages, 1 figur

Heavy-quark potential in Gribov-Zwanziger approach around deconfinement phase transition

The interaction potential between a pair of heavy quarks is calculated with resummed perturbation method in Gribov-Zwanziger approach at finite temperature. The resummed loop correction makes the potential complex. While the real part is, as expected, screened and becomes short-ranged in hot medium, the strength of the imaginary part increases with temperature and is comparable with the real part, which is very different from the previous calculation in HTL approach. This means that, both the color screening and Landau damping play important role in the dissociation of heavy flavor hadrons in hot medium.Comment: 6 pages, 7 figure

Robust Method for the Detection of Abnormal Data in Hydrography

Blunder detection is a topic of great interest to hydrographers because undetected blunders significantly distort the observed parameters, e.g., soundings. Based on an analysis of the characteristic of marine surveying, a robust method for the detection of abnormal data (include blunders) in hydrography is proposed in this paper, which is called the robust interpolation comparison test based on robust Mestimation by an iterative calculation procedure. Some questions involved in the implement of the suggested method are discussed in detail. Compared to the existing methods, the new method has more strong capacity of locating abnormal data. A simulation study and an actual numerical example for the process of multibeam soundings are given to test the performance of the proposed method. The results have illustrated the effectiveness of the method in the detection and identification of multiple blunders. The use of the new method will play an important role in improving the quality and reliability of marine measurements in our country

The Influence of Carrier's Attitude and the Position Reduction in Multibeam Echosounding and Airborne Laser Depth Sounding

Having finished the development of the multibeam echosounding system, China is making a great effort to develop an airborne laser depth sounding system. According to the principle of the two kinds of sounding system mentioned above, a series of position reduction formulas and their error equations are developed in this paper. The dynamic effect of marine sounding, i.e., the influence of carrier's attitude, is taken into full account in developing the equations. Finally, the real parameters of the two sounding systems developed by China are used to calculate the position reductions and their accuracies at different heading angles. The results show that the accuracies of depths and positions in multibeam echosounding and airborne laser depth sounding are dependent not only on their own sensors but also on the additional sensors

Modeling Multi-wavelength Pulse Profiles of Millisecond Pulsar PSR B1821-24

PSR B1821$-$24 is a solitary millisecond pulsar (MSP) which radiates multi-wavelength pulsed photons. It has complex radio, X-ray and $\gamma$-ray pulse profiles with distinct peak phase-separations that challenge the traditional caustic emission models. Using the single-pole annular gap model with suitable magnetic inclination angle ($\alpha=40^\circ$) and viewing angle ($\zeta=75^\circ$), we managed to reproduce its pulse profiles of three wavebands. It is found that the middle radio peak is originated from the core gap region at high altitudes, and the other two radio peaks are originated from the annular gap region at relatively low altitudes. Two peaks of both X-ray and $\gamma$-ray wavebands are fundamentally originated from annular gap region, while the $\gamma$-ray emission generated from the core gap region contributes somewhat to the first $\gamma$-ray peak. Precisely reproducing the multi-wavelength pulse profiles of PSR B1821$-$24 enables us to understand emission regions of distinct wavebands and justify pulsar emission models.Comment: Accepted for publication in Ap