Study of new boson W_1~± in the Minimal Higgsless Model at the LHC

The Minimal Higgsless Model predicts the existence of new vector gauge boson W1± . By the process PP → W1± qq → W±Z0qq, Z0 → l+l-, W±→ qq (l=e,μ; q is hadronized to be jets), we study the sensitivity of searching for this possible vector gauge boson in the level of generator events of signal and backgrounds, then give integrated luminosity required to discover 5σ signal as a function of W1± mass. The generator for the signal PP→W1± qq→W±Z0qq at tree level is developed with the Minimal Higgsless Model and th...     

Search for exotic state 1－+ π1(1400) at BESⅢ

The J/ψ hadronic decays provide good laboratory to search for the hybrid states with exotic quantum numbers. A full Partial Wave Analysis (PWA) is performed to the generated Monte Carlo J/ψ→ρηπ data, based on the design of BESⅢ detector, to study the sensitivity of searching for a possible exotic state at BESⅢ.     

Application of the parametric for mulae for electromagnetic showers in unconverted γ/π~0 discrimination

In the LHC experiment, the neutral pions produced during jet fragmentation are the background sources for all physics channels with high-energy photons in their final state. In this paper, the application of the three-dimensional parametric formula for electromagnetic (EM) showers, which we developed in the Alpha Magnetic Spectrometer II experiment, is presented to distinguish the unconverted photons from the neutral pions. With the constructed electromagnetic calorimeter (ECAL) in a GEANT4 simulation, the parametric formulae were validated and the unconverted γπ⁰ discrimination was performed with the Toolkit for Multivariate Data Analysis (TMVA) package in ROOT for different transverse energies ranging from 15 GeV to 75 GeV, which is the most sensitive region for light Higgs (with mass ～120 GeV) searches with the channel H→γγ. With this discrimination method and the selected transverse energy region, we can reject π⁰ with the efficiency from ～40% (65--75 GeV) to ～90% (15--25 GeV) when keeping 90% γ efficiency.     

Study of typical space wave–particle coupling events possibly related with seismic activity

Based on the DEMETER satellite, we found two space wave-particle coupling events during February 2010 that took place in the range of the McIlwain parameter L （1.27-- 1.37）. There are strong spatial and temporal correlation between the particle bursts （PBs） and the electromagnetic disturbances of the coupling events. The two PBs show different energy spectrum characteristics, while the corresponding electromagnetic disturbances concentrated on different frequency ranges. In agreement with the prediction of the theory of wave-particle interaction, we conclude that the two wave-particle inter- actions can be probably explained as follows： one is electron-dominant precipitation with energy of 0.09 MeV,-~0.2 MeV induced by a VLF electromagnetic wave with the frequencies of 14 kHz,-20 kHz, and another is proton-dominant precip- itation with energies of 0.65 MeV--2.85 MeV induced by a VLF electromagnetic wave with the frequency of ≤ 100 Hz. For the first time, these particle bursts＇ origins, from electrons or protons detected by the Instrument for the Detection of Particles （IDP） on board, are inferred by theoretical calculation, although the instrument has no ability to identify the particle species.     

Study of new boson W±1 in the Minimal Higgsless Model at the LHC

The Minimal Higgsless Model predicts the existence of new vector gauge boson W1^±, By the process PP →W1^±qq →W^±Z^0qq, Z^0→ 1^＋1^-, W^±→ qq （1=e,μ; q is hadronized to be jets）, we study the sensitivity of searching for this possible vector gauge boson in the level of generator events of signal and backgrounds, then give integrated luminosity required to discover 5σ signal as a function of W1^± mass. The generator for the signal PP → W1^±qq →W^±Z^0qq at tree level is developed with the Minimal Higgsless Model and then interfaced with PYTHIA for the patton showers and hadronization. The backgrounds are produced with MadGraph and PYTHIA.     

North west cape-induced electron precipitation and theoretical simulation

Enhancement of the electron fluxes in the inner radiation belt,which is induced by the powerful North West Cape(NWC) very-low-frequency(VLF) transmitter,have been observed and analyzed by several research groups.However,all of the previous publications have focused on NWC-induced 100-keV electrons only,based on observations from the Detection of Electro-Magnetic Emissions Transmitted from Earthquake Regions(DEMETER) and the Geostationary Operational Environmental Satellite(GOES) satellites.Here,we present flux enhancements with 30-100-keV electrons related to NWC transmitter for the first time,which were observed by the GOES satellite at night.Similar to the 100-300-keV precipitated-electron behavior,the low energy 30-100-keV electron precipitation is primarily located east of the transmitter.However,the latter does not drift eastward to the same extent as the former,possibly because of the lower electron velocity.The 30-100-keV electrons are distributed in the L = 1.8-2.1 L-shell range,in contrast to the100-300-keV electrons which are at L= 1.67-1.9.This is consistent with the perspective that the energy of the VLF-waveinduced electron flux enhancement decreases with higher L-shell values.We expand upon the rationality of the simultaneous enhancement of the 30-100- and 100-300-keV electron fluxes through comparison with the cyclotron resonance theory for the quasi-linear wave-particle interaction.In addition,we interpret the asymmetry characteristics of NWC electric power distribution in north and south hemisphere by ray tracing model.Finally,we present considerable discussion and show that good agreement exists between the observation of satellites and theory.     

准线性扩散系数与空间高能电子特征物理量的关系研究

研究已经证实,地面电磁波进入电离层与高能粒子发生波粒相互作用,通过改变其投掷角、动量等发生扩散,导致粒子沉降,进而形成粒子暴.近几十年来,从卫星观测到很多电离层中的粒子暴与地震有关系.本文利用波粒回旋共振耦合理论,结合低轨卫星的观测范围,研究场向电磁波的准线性投掷角扩散系数分布与VLF电磁波频率、带宽、电子能量(0.1—50 MeV)、磁壳层(L=1.1—3)等特征物理量的关系,并研究在某个确定的投掷角条件下,电磁波频率与其所引发的电子沉降对应的最小耦合能量的关系.利用这些物理量之间的关系,为卫星观测的高能粒子沉降事例提供理论解释,为从卫星高能粒子探测中提取与地震相关的信息提供理论支持,也为我国计划2016年底将发射的电磁监测试验卫星的数据分析奠定基础.