The Large High Altitude Air Shower Observatory (LHAASO) Science White Paper

X. Bai, B. Y. Bi, X. J. Bi, Z. Cao, S. Z. Chen, Y. Chen, A. Chiavassa, X. H. Cui, Z. G. Dai, D. della Volpe, T. Di Girolamo, Giuseppe Di Sciascio, Y. Z. Fan 11), J. Giacalone (12), Y. Q. Guo (1), H. H. He (1), T. L. He (5), M. Heller (7), D. Huang (13), Y. F. Huang (6), H. Jia (13), L. T. Ksenofontov (14), D. Leahy (15), F. Li (11), Z. Li (16, 17), E. W. Liang (18), P. Lipari (19), R. Y. Liu (3), Y. Liu (20), S. Liu (11), X. Ma (1), O. Martineau-Huynh (21), D. Martraire (1), T. Montaruli (7), D. Ruffolo (22), Y. V. Stenkin (23, 24), H. Q. Su (5), T. Tam (25), Q. W. Tang (26), W. W. Tian (5), P. Vallania (27, 28), S. Vernetto (29), C. Vigorito (28, 30), J. . C. Wang (31), L. Z. Wang (5), X. Wang (32), X. Y. Wang (3, 6), X. J. Wang (13), Z. X. Wang (33), D. M. Wei (11), J. J. Wei (11), D. Wu (5), H. R. Wu (1), X. F. Wu (11), D. H. Yan (31), A. Y. Yang (5), R. Z. Yang (34), Z. G. Yao (1), L. Q. Yin (1), Q. Yuan (11), B. Zhang (35, 36, 17), B. Zhang (5), L. Zhang (37), M. F. Zhang (5), S. S. Zhang (1), X. Zhang (3), Y. Zhao (1, 38), X. X. Zhou (13), F. R. Zhu (38), H. Zhu (5) (, Key Laboratory of Particle Astrophysics, Institute of High Energy Physics, CAS, Beijing, China, Département de Physique Nucléaire et Corpusculaire, Université de Genève, Genève, Switzerland, Physics Department, South Dakota School of Mines, Technology, Rapid City, SD, Istituto Nazionale di Astrofisica, OATO, Torino, Italy, Dipartimento di Fisica, Università degli Studi di Torino, Italy, National Astronomical Observatories, CAS, Beijing, China, School of Astronomy, Space Sciences, Nanjing University, China, Purple Mountain Observatory, CAS, Nanjing, China, Lunar, Planetary Laboratory, University of Arizona, Tucson AZ, Dipartimento di Fisica dell'Università di Napoli "Federico II", Complesso Universitario di Monte Sant'Angelo, Napoli, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Napoli, Complesso Universitario di Monte Sant'Angelo, Napoli, Italy, School of Physical Science, Technology, Southwest Jiaotong University, Chengdu, China, Laboratoire de Physique Nucléaire et des Hautes Energies, CNRS-IN2P3, Universités VI et VII, France, Yu. G. Shafer Institute of Cosmophysical Research, Aeronomy SB RAS, Yakutsk, Russia, Department of Physics, Astronomy, University of Calgary, Canada, Department of Physics, Guangxi University, Nanning, China, Istituto Nazionale di Fisica Nucleare, Sezione Roma1, Roma, Italy, Department of Astronomy, Nanjing University, Nanjing, China, The School of Physics, Shandong University, Jinan, China, Department of Physics, Faculty of Science, Mahidol University, Bangkok, Thailand, INFN, Sez. Roma Tor Vergata, Roma, Italy, National Research Nuclear University MEPhI, Moscow, Russia, Institute for Nuclear Research, Russian Academy of Sciences, Moscow, Russia, Institute of Astronomy, Space Science, Sun Yat-Sen University, Guangzhou, China, School of Science, Nanchang University, Nanchang, China, Osservatorio Astrofisico di Torino dell'Istituto Nazionale di Astrofisica, Torino, Italy, Istituto Nazionale di Fisica Nucleare, Sezione di Torino, Torino, Italy, Dipartimento di Fisica dell'Università di Torino, Italy, Xinjiang Astronomical Observatory, CAS, China, Department of Physics, Astronomy, University of Nevada, Las Vegas, NV, USA, Department of Astronomy, School of Physics, Peking University, Beijing, China, Kavli Institute of Astronomy, Astrophysics, Peking University, Beijing, Southwest Jiaotong University, Chengdu, Sichuan, China, Key Laboratory for Research in Galaxies, Cosmology, Shanghai Astronomical Observatory, Chinese Academy of Sciences, China, Max-Planck-Institut für Kernphysik, Heidelberg, Germany, Key Laboratory for the Structure, Evolution of Celestial Objects, Yunnan Observatory, Chinese Academy of Sciences, Kunming, China, Key Laboratory of Astroparticle Physics of Yunnan Province, Department of Astronomy, Yunnan University, Kunming, China, Department of Astronomy, School of Physics, Peking University, Beijing, China)

Published 2019-05-07Version 1

The Large High Altitude Air Shower Observatory (LHAASO) project is a new generation multi-component instrument, to be built at 4410 meters of altitude in the Sichuan province of China, with the aim to study with unprecedented sensitivity the spec trum, the composition and the anisotropy of cosmic rays in the energy range between 10$^{12}$ and 10$^{18}$ eV, as well as to act simultaneously as a wide aperture (one stereoradiant), continuously-operated gamma ray telescope in the energy range between 10$^{11}$ and $10^{15}$ eV. The experiment will be able of continuously surveying the TeV sky for steady and transient sources from 100 GeV to 1 PeV, t hus opening for the first time the 100-1000 TeV range to the direct observations of the high energy cosmic ray sources. In addition, the different observables (electronic, muonic and Cherenkov/fluorescence components) that will be measured in LHAASO will allow to investigate origin, acceleration and propagation of the radiation through a measurement of energy spec trum, elemental composition and anisotropy with unprecedented resolution. The remarkable sensitivity of LHAASO in cosmic rays physics and gamma astronomy would play a key-role in the comprehensive general program to explore the High Energy Universe. LHAASO will allow important studies of fundamental physics (such as indirect dark matter search, Lorentz invariance violation, quantum gravity) and solar and heliospheric physics. In this document we introduce the concept of LHAASO and the main science goals, providing an overview of the project.