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Energy spectrum of cosmic protons and helium nuclei by a hybrid measurement at 4300 m a.s.l.

Author: The LHAASO Collaboration
The ARGO YBJ Collaboration
MARI Stefano Maria
Publication venue
Publication date: 01/01/2014
Field of study

The energy spectrum of cosmic Hydrogen and Helium nuclei has been measured below the so-called “knee” by using a hybrid experiment with a wide field-of-view Cherenkov telescope and the Resistive Plate Chamber (RPC) array of the ARGO-YBJ experiment at 4300 m above sea level. The Hydrogen and Helium nuclei have been well separated from other cosmic ray components by using a multi-parameter technique. A highly uniform energy resolution of about 25% is achieved throughout the whole energy range (100–700 TeV). The observed energy spectrum is compatible with a single power law with index γ =−2.63±0.0

Archivio della Ricerca - Università di Roma 3

Exploring Lorentz Invariance Violation from Ultra-high-energy Gamma Rays Observed by LHAASO

Author: The LHAASO Collaboration
Aharonian F.
Publication venue
Publication date: 03/02/2022
Field of study

Recently the LHAASO Collaboration published the detection of 12 ultra-high-energy gamma-ray sources above 100 TeV, with the highest energy photon reaching 1.4 PeV. The first detection of PeV gamma rays from astrophysical sources may provide a very sensitive probe of the effect of the Lorentz invariance violation (LIV), which results in decay of high-energy gamma rays in the superluminal scenario and hence a sharp cutoff of the energy spectrum. Two highest energy sources are studied in this work. No signature of the existence of LIV is found in their energy spectra, and the lower limits on the LIV energy scale are derived. Our results show that the first-order LIV energy scale should be higher than about 10^5 times the Planck scale M_{pl} and that the second-order LIV scale is >10^{-3}M_{pl}. Both limits improve by at least one order of magnitude the previous results

MPG.PuRe

Stringent Tests of Lorentz Invariance Violation from LHAASO Observations of GRB 221009A

Author: The LHAASO collaboration
Publication venue
Publication date: 25/08/2024
Field of study

Very recently, the Large High Altitude Air Shower Observatory (LHAASO) reported the observation of the very early TeV afterglow of the brightest-of-all-time GRB 221009A, recording the highest photon statistics in the TeV band ever from a gamma-ray burst. We use this unique observation to place stringent constraints on an energy dependence of the speed of light in vacuum, a manifestation of Lorentz invariance violation (LIV) predicted by some quantum gravity (QG) theories. Our results show that the 95% confidence level lower limits on the QG energy scales are

E_{\mathrm{QG},1}>10

times of the Planck energy

E_\mathrm{Pl}

for the linear, and

E_{\mathrm{QG},2}>6\times10^{-8}E_\mathrm{Pl}

for the quadratic LIV effects, respectively. Our limits on the quadratic LIV case improve previous best bounds by factors of 5--7.7pages, 5 figure

arXiv.org e-Print Archive

Extended Very-High-Energy Gamma-Ray Emission Surrounding PSR J0622+3749 Observed by LHAASO-KM2A

Author: Yang J.
Levochkin K.
Liu Z.
Wang J.
Xin Y.
Jia H.
Masood A.
Liu J.
Zeng W.
Wang Z.
Zhang P.
Cui X.
Pang B.
Cai H.
Piazzoli B.
Bi Y.
Ma X.
Zhu H.
Geng L.
You X.
Huang D.
Li B.
Qi M.
Wang Y.
Hu S.
Zheng F.
Fan Y.
Zhang S.
Lv H.
Wu C.
Bao Y.
Feng C.
Xin G.
Bi X.
Chen T.
Wang L.
Dai H.
Li C.
Ruffolo D.
Pei Z.
Tian W.
Zhai X.
Zhang B.
Danzengluobu
Wu S.
Chang J.
Guo X.
Feng S.
Liang Y.
Zhou X.
Cai J.
Cheng N.
Kuleshov D.
Liu M.
Zeng T.
Zhang R.
Fan Z.
Zhu F.
Chen S.
Yuan Q.
Xiang G.
Chen B.
Bai L.
Dai Z.
Cui S.
Ma B.
Dai B.
He Y.
Yang F.
Axikegu
Cheng Y.
Hor Y.
Hu X.
Mitthumsiri W.
Zha M.
Huang Q.
Zhou P.
Aharonian F.
Stepanov V.
Chen Q.
Wen T.
Xia J.
He J.
Stenkin Y.
Zeng Z.
Yu Y.
Zhao S.
Zhu C.
Xue L.
Hou X.
Ji F.
Yang C.
Zhou R.
Sheng X.
Wei D.
Yang S.
Zeng H.
Bai Y.
Gao W.
Sun Q.
Tam P.
Zhao B.
Zhou B.
Shao L.
Liu R.
Rulev V.
Wang R.
Yin N.
Lin S.
Li Y.
Ji X.
Yang R.
Zhang Y.
Chen M.
Liu B.
Ye Y.
Sun X.
Tang Z.
Zhang H.
Wei J.
Li Z.
Nan Y.
Liu S.
Zhang X.
Fang J.
An Q.
Chen L.
Xiao G.
Gao Q.
Han Y.
Ge M.
Li J.
Liu C.
Cao Z.
Hou C.
Gao B.
Volpe D.
Song H.
Xi S.
Yin L.
Huang Z.
Wang C.
Xiao H.
Wei Y.
Li K.
Ma L.
Liu D.
Zhang J.
Gao C.
Hu H.
He X.
Feng L.
Chen J.
Wang B.
Zuo X.
He H.
Xu R.
Jiang K.
Guo J.
Lu R.
Huang X.
Yao Z.
Fan J.
Gou Q.
Yan D.
Zhang L.
Feng Y.
Wu H.
Chen Y.
Mao J.
Liu W.
Yang M.
Gu M.
Zhou H.
Wu X.
Li F.
Montaruli T.
Bastieri D.
Guo Y.
Xing Y.
Zhao L.
Gong G.
Pattarakijwanich P.
Cui Y.
Heller M.
Li W.
Liang E.
Fang K.
Chen X.
Wang H.
He S.
Shchegolev O.
Yang L.
Wu W.
Xu D.
Shi J.
Liu H.
Sun Z.
Wang X.
Huang W.
Long W.
Liu Y.
Zheng Y.
Chang X.
Li X.
Zhou J.
Zhu K.
Yao Y.
Jin C.
Sáiz A.
Dong X.
Jiang Z.
Wang W.
Li H.
Zhao J.
You Z.
Publication venue
Publication date: 16/06/2021
Field of study

We report the discovery of an extended very-high-energy (VHE) gamma-ray source around the location of the middle-aged (207.8 kyr) pulsar PSR J0622 + 3749 with the Large High-Altitude Air Shower Observatory (LHAASO). The source is detected with a significance of 8.2 sigma for E > 25 TeV assuming a Gaussian template. The best-fit location is (right ascension, declination) = (95.47 degrees +/- 0.11 degrees, 37.92 degrees +/- 0.09 degrees), and the extension is 0.40 degrees +/- 0.07 degrees. The energy spectrum can be described by a power-law spectrum with an index of -2.92 +/- 0.17(st)(at) +/- 0.02(sys). No clear extended multiwavelength counterpart of the LHAASO source has been found from the radio to sub-TeV bands. The LHAASO observations arc consistent with the scenario that VHE electrons escaped from the pulsar, diffused in the interstellar medium, and scattered the interstellar radiation field. If interpreted as the pulsar halo scenario, the diffusion coefficient, inferred for electrons with median energies of similar to 160 TeV, is consistent with those obtained from the extended halos around Geminga and Monogem and much smaller than that derived from cosmic ray secondaries. The LHAASO discovery of this source thus likely enriches the class of so-called pulsar halos and confirms that high-energy particles generally diffuse very slowly in the disturbed medium around pulsars

MPG.PuRe

A dynamic range extension system for LHAASO WCDA-1

Author: Yang J.
Levochkin K.
Liu Z.
Wang J.
Guo F.
Xin Y.
Chen E.
Jia H.
Masood A.
Liu J.
Zeng W.
Wang Z.
Zhang P.
Cui X.
∥
Pang B.
Cai H.
Piazzoli B.
Bi Y.
Ma X.
Zhu H.
Geng L.
You X.
Huang D.
Li B.
Min Z.
Qi M.
Wang Y.
Hu S.
Zheng F.
Fan Y.
Zhang S.
Lv H.
Wu C.
Bao Y.
Feng C.
Xin G.
Bi X.
Chen T.
Wang L.
Dai H.
Li C.
Ruffolo D.
Pei Z.
Tian W.
Zhai X.
Zhang B.
Danzengluobu
Wu S.
Chang J.
Guo X.
Feng S.
Liang Y.
Zhou X.
Cai J.
Cheng N.
Qiao B.
Kuleshov D.
Liu M.
Zeng T.
Zhang R.
Fan Z.
Zhu F.
Chen S.
Yuan Q.
Xiang G.
Chen B.
Bai L.
Dai Z.
Cui S.
Ma B.
Dai B.
He Y.
Yang F.
Axikegu
Cheng Y.
Hor Y.
Hu X.
Mitthumsiri W.
Zha M.
Huang Q.
Zhou P.
Aharonian F.
Stepanov V.
Chen Q.
Wen T.
Xia J.
He J.
Stenkin Y.
Zeng Z.
Yu Y.
Zhao S.
Zhu C.
Su Y.
Xue L.
Ke T.
Ji F.
Yang C.
Zhou R.
Sheng X.
Wei D.
Yang S.
Zeng H.
Bai Y.
Gao W.
Sun Q.
Tam P.
Zhao B.
Zhou B.
Shao L.
Liu R.
Rulev V.
Wang R.
Yin N.
Lin S.
Li Y.
Ji X.
Yang R.
Zhang Y.
Chen M.
Liu B.
Ye Y.
Sun X.
Tang Z.
Zhang H.
Wei J.
Li Z.
Nan Y.
Liu S.
Zhang X.
Fang J.
An Q.
Chen L.
Xiao G.
Gao Q.
Han Y.
Ge M.
Li J.
Liu C.
Cao Z.
Hou C.
Gao B.
Volpe D.
Song H.
Xi S.
Yin L.
Huang Z.
Wang C.
Xiao H.
Wei Y.
Li K.
Ma L.
Liu D.
Zhang J.
Gao C.
Hu H.
He X.
Yan J.
Feng L.
Chen J.
Wang B.
Zuo X.
He H.
Xu R.
Jiang K.
Guo J.
Lu R.
Huang X.
Yao Z.
Fan J.
Gou Q.
Yan D.
Zhang L.
Gao L.
Feng Y.
Wu H.
Chen Y.
Mao J.
Liu W.
Yang M.
Gu M.
Zhou H.
Wu X.
Li F.
Qi Y.
Montaruli T.
Bastieri D.
Guo Y.
Xing Y.
Zhao L.
Gong G.
Pattarakijwanich P.
Cui Y.
Heller M.
Li W.
Liang E.
Fang K.
Chen X.
Wang H.
He S.
Shchegolev O.
Yang L.
Xiao D.
Wu W.
Xu D.
Shi J.
Liu H.
Sun Z.
Wang X.
Huang W.
Duan K.
Long W.
Qin J.
Liu Y.
Zheng Y.
Li X.
Zhou J.
Zhu K.
Yao Y.
Jin C.
Sáiz A.
Dong X.
Jiang Z.
Wang W.
Li H.
Zhao J.
You Z.
Publication venue
Publication date: 04/09/2021
Field of study

MPG.PuRe

Line-of-shower trigger method to lower energy threshold for GRB detection using LHAASO-WCDA

Author: Yang J.
Levochkin K.
Liu Z.
Wang J.
Guo F.
Xin Y.
Chen E.
Jia H.
Masood A.
Liu J.
Zeng W.
Wang Z.
Zhang P.
Cui X.
∥
Pang B.
Cai H.
Piazzoli B.
Bi Y.
Ma X.
Zhu H.
Geng L.
You X.
Huang D.
Li B.
Min Z.
Qi M.
Wang Y.
Hu S.
Zheng F.
Fan Y.
Zhang S.
Lv H.
Wu C.
Bao Y.
Feng C.
Xin G.
Bi X.
Chen T.
Wang L.
Dai H.
Li C.
Ruffolo D.
Pei Z.
Tian W.
Zhai X.
Zhang B.
Danzengluobu
Wu S.
Chang J.
Guo X.
Feng S.
Liang Y.
Zhou X.
Cai J.
Cheng N.
Qiao B.
Kuleshov D.
Liu M.
Zeng T.
Zhang R.
Fan Z.
Zhu F.
Chen S.
Yuan Q.
Xiang G.
Chen B.
Bai L.
Dai Z.
Cui S.
Ma B.
Dai B.
He Y.
Yang F.
Axikegu
Cheng Y.
Hor Y.
Hu X.
Mitthumsiri W.
Zha M.
Huang Q.
Zhou P.
Aharonian F.
Stepanov V.
Chen Q.
Wen T.
Xia J.
He J.
Stenkin Y.
Zeng Z.
Yu Y.
Zhao S.
Zhu C.
Su Y.
Xue L.
Ke T.
Ji F.
Yang C.
Zhou R.
Sheng X.
Wei D.
Yang S.
Zeng H.
Bai Y.
Gao W.
Sun Q.
Tam P.
Zhao B.
Zhou B.
Shao L.
Liu R.
Rulev V.
Wang R.
Yin N.
Lin S.
Li Y.
Ji X.
Yang R.
Zhang Y.
Chen M.
Liu B.
Ye Y.
Sun X.
Tang Z.
Zhang H.
Wei J.
Li Z.
Nan Y.
Liu S.
Zhang X.
Fang J.
An Q.
Chen L.
Xiao G.
Gao Q.
Han Y.
Ge M.
Li J.
Liu C.
Cao Z.
Hou C.
Gao B.
Volpe D.
Song H.
Xi S.
Yin L.
Huang Z.
Wang C.
Xiao H.
Wei Y.
Li K.
Ma L.
Liu D.
Zhang J.
Gao C.
Hu H.
He X.
Yan J.
Feng L.
Chen J.
Wang B.
Zuo X.
He H.
Xu R.
Jiang K.
Guo J.
Lu R.
Huang X.
Yao Z.
Fan J.
Gou Q.
Yan D.
Zhang L.
Gao L.
Feng Y.
Wu H.
Chen Y.
Mao J.
Liu W.
Yang M.
Gu M.
Zhou H.
Wu X.
Li F.
Qi Y.
Montaruli T.
Bastieri D.
Guo Y.
Xing Y.
Zhao L.
Gong G.
Pattarakijwanich P.
Cui Y.
Heller M.
Li W.
Liang E.
Fang K.
Chen X.
Wang H.
He S.
Shchegolev O.
Yang L.
Xiao D.
Wu W.
Xu D.
Shi J.
Liu H.
Sun Z.
Wang X.
Huang W.
Duan K.
Long W.
Qin J.
Liu Y.
Zheng Y.
Li X.
Zhou J.
Zhu K.
Yao Y.
Jin C.
Sáiz A.
Dong X.
Jiang Z.
Wang W.
Li H.
Zhao J.
You Z.
Publication venue
Publication date: 24/11/2021
Field of study

MPG.PuRe

Absolute calibration of LHAASO WFCTA camera based on LED

Author: Yang J.
Levochkin K.
Liu Z.
Wang J.
Guo F.
Xin Y.
Chen E.
Jia H.
Masood A.
Liu J.
Zeng W.
Wang Z.
Zhang P.
Cui X.
∥
Pang B.
Cai H.
Piazzoli B.
Bi Y.
Ma X.
Zhu H.
Geng L.
You X.
Huang D.
Li B.
Min Z.
Qi M.
Wang Y.
Hu S.
Zheng F.
Fan Y.
Zhang S.
Lv H.
Wu C.
Bao Y.
Feng C.
Xin G.
Bi X.
Chen T.
Wang L.
Dai H.
Li C.
Ruffolo D.
Pei Z.
Tian W.
Zhai X.
Zhang B.
Danzengluobu
Wu S.
Chang J.
Guo X.
Feng S.
Liang Y.
Zhou X.
Cai J.
Cheng N.
Qiao B.
Kuleshov D.
Liu M.
Zeng T.
Zhang R.
Fan Z.
Zhu F.
Chen S.
Yuan Q.
Xiang G.
Chen B.
Bai L.
Dai Z.
Cui S.
Ma B.
Dai B.
He Y.
Yang F.
Axikegu
Cheng Y.
Hor Y.
Hu X.
Mitthumsiri W.
Zha M.
Huang Q.
Zhou P.
Aharonian F.
Stepanov V.
Chen Q.
Wen T.
Xia J.
He J.
Stenkin Y.
Zeng Z.
Yu Y.
Zhao S.
Zhu C.
Su Y.
Xue L.
Ke T.
Ji F.
Yang C.
Zhou R.
Sheng X.
Wei D.
Yang S.
Zeng H.
Bai Y.
Gao W.
Sun Q.
Tam P.
Zhao B.
Zhou B.
Shao L.
Liu R.
Rulev V.
Wang R.
Yin N.
Lin S.
Li Y.
Ji X.
Yang R.
Zhang Y.
Chen M.
Liu B.
Ye Y.
Sun X.
Tang Z.
Zhang H.
Wei J.
Li Z.
Nan Y.
Liu S.
Zhang X.
Fang J.
An Q.
Chen L.
Xiao G.
Gao Q.
Han Y.
Ge M.
Li J.
Liu C.
Cao Z.
Hou C.
Gao B.
Volpe D.
Song H.
Xi S.
Yin L.
Huang Z.
Wang C.
Xiao H.
Wei Y.
Li K.
Ma L.
Liu D.
Zhang J.
Gao C.
Hu H.
He X.
Yan J.
Feng L.
Chen J.
Wang B.
Zuo X.
He H.
Xu R.
Jiang K.
Guo J.
Lu R.
Huang X.
Yao Z.
Fan J.
Gou Q.
Yan D.
Zhang L.
Gao L.
Feng Y.
Wu H.
Chen Y.
Mao J.
Liu W.
Yang M.
Gu M.
Zhou H.
Wu X.
Li F.
Qi Y.
Montaruli T.
Bastieri D.
Guo Y.
Xing Y.
Zhao L.
Gong G.
Pattarakijwanich P.
Cui Y.
Heller M.
Li W.
Liang E.
Fang K.
Chen X.
Wang H.
He S.
Shchegolev O.
Yang L.
Xiao D.
Wu W.
Xu D.
Shi J.
Liu H.
Sun Z.
Wang X.
Huang W.
Duan K.
Long W.
Qin J.
Liu Y.
Zheng Y.
Li X.
Zhou J.
Zhu K.
Yao Y.
Jin C.
Sáiz A.
Dong X.
Jiang Z.
Wang W.
Li H.
Zhao J.
You Z.
Publication venue
Publication date: 01/01/2022
Field of study

MPG.PuRe