X. Y. Zhang
A5058170550- Particle physics theoretical and experimental studies
- Quantum Chromodynamics and Particle Interactions
- High-Energy Particle Collisions Research
- Astrophysics and Cosmic Phenomena
- Dark Matter and Cosmic Phenomena
- Solid State Laser Technologies
- Solar and Space Plasma Dynamics
- Particle Detector Development and Performance
- Neutrino Physics Research
- Computational Physics and Python Applications
- Black Holes and Theoretical Physics
- Radio Astronomy Observations and Technology
- Advanced Fiber Laser Technologies
- Gamma-ray bursts and supernovae
- Photorefractive and Nonlinear Optics
- Particle Accelerators and Free-Electron Lasers
- Laser Design and Applications
- Atomic and Subatomic Physics Research
- Pulsars and Gravitational Waves Research
- Stochastic processes and statistical mechanics
- Ionosphere and magnetosphere dynamics
- Luminescence Properties of Advanced Materials
- Radiation Therapy and Dosimetry
- advanced mathematical theories
- Radiation Detection and Scintillator Technologies
Shandong University
2015-2024
Shanghai Jiao Tong University
2024
Institute of High Energy Physics
1998-2024
Liaoning University
2024
Huzhou University
2024
University of Electronic Science and Technology of China
2024
Soochow University
2022-2023
Peking University
2018
Chinese Academy of Sciences
2006-2017
Tibet University
2007-2016
The intensity of Galactic cosmic rays is nearly isotropic because the influence magnetic fields in Milky Way. Here, we present two-dimensional high-precision anisotropy measurement for energies from a few to several hundred teraelectronvolts (TeV), using large data sample Tibet Air Shower Arrays. Besides revealing finer details known anisotropies, new component ray sidereal time uncovered around Cygnus region direction. For cosmic-ray up TeV, all components anisotropies fade away, showing...
The events recorded by ARGO-YBJ in more than five years of data collection have been analyzed to determine the diffuse gamma-ray emission Galactic plane at longitudes 25° < l 100° and latitudes . energy range covered this analysis, from ∼350 GeV ∼2 TeV, allows connection region explored Fermi with multi-TeV measurements carried out Milagro. Our analysis has focused on two selected regions plane, i.e., 40° 65° 85° (the Cygnus region), where Milagro observed an excess respect predictions...
Raman lasers based on c-Nd:YVO4 crystals can generate 1178 nm Stokes line, which be frequency-doubled to realize 589 sodium lasers. We make comparative experimental studies of c-Nd:YVO4/YVO4 and self-Raman About these two kinds lasers, the output characteristics power, center wavelength beam quality are measured compared.
The ARGO-YBJ detector is an extensive air shower array that has been used to monitor the northern $\gamma$-ray sky at energies above 0.3 TeV from 2007 November 2013 January. In this paper, we present results of a survey in declination band $-10^{\circ}$ $70^{\circ}$, using data recorded over past five years. With integrated sensitivity ranging 0.24 $\sim$1 Crab units depending on declination, six sources have detected with statistical significance greater than 5 standard deviations. Several...
Abstract We report on the analysis of 10–1000 TeV large-scale sidereal anisotropy Galactic cosmic rays (GCRs) with data collected by Tibet Air Shower Array from 1995 October to 2010 February. In this analysis, we improve energy estimate and extend decl. range down −30°. find that maps above 100 are distinct at a multi-TeV band. The so-called tail-in loss-cone features identified low energies get less significant, new component appears ∼100 TeV. spatial distribution GCR intensity an excess...
This paper reports on the measurement of large-scale anisotropy in distribution cosmic-ray arrival directions using data collected by air shower detector ARGO-YBJ from 2008 January to 2009 December, during minimum solar activity between cycles 23 and 24. In this period, more than 2 × 1011 showers were recorded with energies ∼1 30 TeV. The observed two-dimensional cosmic rays is characterized two wide regions excess deficit, respectively, both relative intensity ∼10−3 respect a uniform flux,...
ARGO-YBJ is an air shower detector array with a fully covered layer of resistive plate chambers. It operated high duty cycle and large field view. continuously monitors the northern sky at energies above 0.3 TeV. In this paper, we report long-term monitoring Mrk 421 over period from 2007 November to 2010 February. This source was observed by satellite-borne experiments Rossi X-ray Timing Explorer Swift in band. especially active first half 2008. Many flares are both γ-ray bands...
As one of the brightest active blazars in both X-ray and very high energy $\gamma$-ray bands, Mrk 501 is useful for physics associated with jets from AGNs. The ARGO-YBJ experiment monitoring it $\gamma$-rays above 0.3 TeV since November 2007. Starting October 2011 largest flare 2005 observed, which lasts to about April 2012. In this paper, a detailed analysis reported. During flaring episodes 17 22, 2011, an excess event rate over 6 $\sigma$ detected by direction 501, corresponding increase...
The Tibet-III air shower array, consisting of 533 scintillation detectors, has been operating successfully at Yangbajing in Tibet, China since 1999. Using the data set collected by this array from 1999 November through 2005 November, we obtained energy spectrum γ-rays Crab Nebula, expressed a power law as (dJ/dE) = (2.09 ± 0.32) × 10−12(E/3 TeV)−2.96±0.14 cm−2 s−1 TeV−1 range 1.7–40 TeV. This result is consistent with other independent γ-ray observations imaging Cherenkov telescopes. In...
The ARGO-YBJ air shower detector monitored the Crab Nebula gamma ray emission from 2007 November to 2013 February. integrated signal, consisting of $\sim$3.3 $\times$ 10$^5$ events,reached statistical significance 21.1 standard deviations. obtained energy spectrum in range 0.3-20 TeV can be described by a power law function dN/dE = I$_0$ (E / 2 TeV)$^{-\alpha}$, with flux normalization (5.2 $\pm$ 0.2) 10$^{-12}$ photons cm$^{-2}$ s$^{-1}$ TeV$^{-1}$ and $\alpha$ 2.63 0.05, corresponding an...
Abstract This paper reports on the observation of sidereal large-scale anisotropy cosmic rays using data collected by ARGO-YBJ experiment over 5 years (2008–2012). analysis extends previous work limited to period from 2008 January 2009 December, near minimum solar activity between cycles 23 and 24. With new sample, cycle 24 maximum is investigated. A method used improve energy reconstruction, allowing us cover a much wider range, 4 520 TeV. Below 100 TeV, dominated two wide regions,...
Results on steady TeV $\gamma$-ray point source search using data taken from the Tibet HD (Feb. 1997 -- Sep. 1999) and III (Nov. 1999 Oct. 2001) arrays are presented. From $0^{\circ}$ to $60^{\circ}$ in declination, significant excesses well-known Crab Nebula high state of flare type Markarian 421 observed. Because levels significance other positions not sufficiently high, 90% confidence level upper limits flux set assuming different power law spectra. To allow crosschecking, two...
Several strong TeV γ-ray flares were detected from Mrk 421 in the years 2000 and 2001 by Tibet III air shower array at a level of statistical significance 5.1 σ. was unprecedentedly active X-ray energies during this period, positive correlation found between change all-sky monitor Rossi X-Ray Timing Explorer flux flux. When power-law energy spectrum for γ-rays source is assumed, spectral index calculated to be -3.24 ± 0.69 most phase 2001. The observed consistent with those obtained via...
The extended gamma-ray source MGRO J1908+06, discovered by the Milagro air shower detector in 2007, has been observed for ∼4 years ARGO-YBJ experiment at TeV energies, with a statistical significance of 6.2 standard deviations. peak signal is found position consistent pulsar PSR J1907+0602. Parameterizing shape two-dimensional Gauss function, we estimate an extension σext = 049 ± 022, which previous measurement Cherenkov Array H.E.S.S. energy spectrum dN/dE 6.1 1.4 × 10−13 (E/4 TeV)−2.54...
We report on the extensive multi-wavelength observations of blazar Markarian 421 (Mrk 421) covering radio to gamma-rays, during 4.5 year period ARGO-YBJ and Fermi common operation time, from August 2008 February 2013. In particular, thanks data, whole energy range 100 MeV 10 TeV is covered without any gap. observation period, Mrk showed both low high activity states at all wavebands. The correlations among flux variations in different wavebands were analyzed. Seven large flares, including...
The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured, below the so-called "knee", by using a hybrid experiment with wide field-of-view Cherenkov telescope Resistive Plate Chamber (RPC) array ARGO-YBJ at 4300 m above sea level. have well separated from other ray components multi-parameter technique. A highly uniform resolution about 25% is achieved throughout whole range (100 TeV - 700 TeV). observed compatible single power law index gamma=-2.63+/-0.06.
We report the observation of a very high energy γ-ray source whose position is coincident with HESS J1841−055. This has been observed for 4.5 years by ARGO-YBJ experiment from 2007 November to 2012 July. Its emission detected statistical significance 5.3 standard deviations. Parameterizing shape two-dimensional Gaussian function, we estimate an extension , which consistent measurement. The spectrum dN/dE = (9.0 ± 1.6) × 10−13(E/5 TeV)−2.32 0.23 photons cm−2 s−1 TeV−1, in range 0.9–50 TeV....
A 100 m2 muon detector (MD) was successfully constructed under the existing Tibet air shower (AS) array in late fall of 2007. The sensitivity AS to cosmic gamma rays can be improved by selecting muon-poor events with MD. Our MC simulation MD response reasonably agrees experimental data terms charge distribution for one-muon and background rejection power. Using collected taken from 2008 March 2010 February, we search continuous gamma-ray emission Crab Nebula above ∼100 TeV. No significant...