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...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±0.06.展开更多
An effort to search for Kolar-like events within the data set of the L3＋C experiment is reported. From a total of 0.89×10^10 triggered events there are no reliable two-prong Kolar-like events observed. The corre...An effort to search for Kolar-like events within the data set of the L3＋C experiment is reported. From a total of 0.89×10^10 triggered events there are no reliable two-prong Kolar-like events observed. The corresponding event flux upper limit 7.1 × 10^-13 cm^-2. s^-1 . sr^-1 at 90% confidence level is deduced based on some reasonable assumptions.展开更多
A soft-hard two-component approach to the description of high energy hadronic interactions is proposed.It shows the important role of parton hard scattering in explanation of the chief characteristics of high energy h...A soft-hard two-component approach to the description of high energy hadronic interactions is proposed.It shows the important role of parton hard scattering in explanation of the chief characteristics of high energy hadronic interactions.展开更多
ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory （4300 m a.s.l., Tibet, China）, is a full coverage air shower array, with an energy threshold of -300 GeV for gamma-ray astronomy. Most of the recorded event...ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory （4300 m a.s.l., Tibet, China）, is a full coverage air shower array, with an energy threshold of -300 GeV for gamma-ray astronomy. Most of the recorded events are single front showers, satisfying the trigger requirement of at least 20 particles detected in a given time window. However, in -11.5% of the events, two randomly arriving showers may be recorded in the same time window, and the second one, generally smaller, does not need to satisfy the trigger condition. These events are called double shower front events. By using these small showers, well under the trigger threshold, the detector primary energy threshold can be lowered to a few tens of GeV. In this paper, the angular resolution that can be achieved with these events is evaluated by a full Monte Carlo simulation. The ARGO-YBJ sensitivity in detecting gamma-ray bursts （GRBs） by using double shower front events is also studied for various cutoff energies, time durations, and zenith angles of GRBs in ARGO＇s field of view.展开更多
Ⅰ. INTRODUCTION Owing to the rapid decrease of primary cosmic ray intensity with increasing energy, the detectors for recording super-high energy events must have very large acceptance. To study the super-high energy...Ⅰ. INTRODUCTION Owing to the rapid decrease of primary cosmic ray intensity with increasing energy, the detectors for recording super-high energy events must have very large acceptance. To study the super-high energy hadronic interaction at 1015—1017 eV, a large emulsion chamber with 150 m2 of sensitive area and one year’s sensitive time in one experimental period has been built on the top of Mt. Kanbala （5500 m a. s. 1.）展开更多
基金Supported by NSFC(10975145,11075170)Knowledge Innovation Fund(H85451D0U2)of IHEP+2 种基金Chinese Ministry of Science and Technology,Chinese Academy of Science,Key Laboratory of Particle Astrophysics,CASin Italy by the Istituto Nazionale di Fisica Nucleare(INFN)Ministero dell’Istruzione,dell’Università e della Ricerca(MIUR)
文摘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±0.06.
基金Supported by National Natural Science Foundation of China,Ministry of Science and Technology of China and Bureau of International Cooperation,Chinese Academy of Science
文摘An effort to search for Kolar-like events within the data set of the L3＋C experiment is reported. From a total of 0.89×10^10 triggered events there are no reliable two-prong Kolar-like events observed. The corresponding event flux upper limit 7.1 × 10^-13 cm^-2. s^-1 . sr^-1 at 90% confidence level is deduced based on some reasonable assumptions.
文摘A soft-hard two-component approach to the description of high energy hadronic interactions is proposed.It shows the important role of parton hard scattering in explanation of the chief characteristics of high energy hadronic interactions.
基金Supported by National Natural Science Foundation of China(11475141)Fundamental Research Funds for Central Universities(2682014CX091)
文摘ARGO-YBJ, located at the Yangbajing Cosmic Ray Observatory （4300 m a.s.l., Tibet, China）, is a full coverage air shower array, with an energy threshold of -300 GeV for gamma-ray astronomy. Most of the recorded events are single front showers, satisfying the trigger requirement of at least 20 particles detected in a given time window. However, in -11.5% of the events, two randomly arriving showers may be recorded in the same time window, and the second one, generally smaller, does not need to satisfy the trigger condition. These events are called double shower front events. By using these small showers, well under the trigger threshold, the detector primary energy threshold can be lowered to a few tens of GeV. In this paper, the angular resolution that can be achieved with these events is evaluated by a full Monte Carlo simulation. The ARGO-YBJ sensitivity in detecting gamma-ray bursts （GRBs） by using double shower front events is also studied for various cutoff energies, time durations, and zenith angles of GRBs in ARGO＇s field of view.
文摘Ⅰ. INTRODUCTION Owing to the rapid decrease of primary cosmic ray intensity with increasing energy, the detectors for recording super-high energy events must have very large acceptance. To study the super-high energy hadronic interaction at 1015—1017 eV, a large emulsion chamber with 150 m2 of sensitive area and one year’s sensitive time in one experimental period has been built on the top of Mt. Kanbala （5500 m a. s. 1.）
