Traditionally, in weak interaction, I<sub>3</sub>, Y and four flavour quantum numbers are not conserved but several empirical selection rules work well. Recently, it was found that, in weak interaction, th...Traditionally, in weak interaction, I<sub>3</sub>, Y and four flavour quantum numbers are not conserved but several empirical selection rules work well. Recently, it was found that, in weak interaction, there are three levels of conservation of additive quantum numbers, and fermion quantum number F is conserved in all kinds of interactions. It is known that weak interaction has three types: fermionic, pure hadronic and pure leptonic, corresponding to the first and the second level of conservation of additive quantum numbers respectively. It is demonstrated in this paper that the selection rules in all types of weak interaction can be interpreted by conservation of F, and the formula of relation between Q/e, F and F<sub>0</sub> is more general than Gell-Mann-Nishijima formula. Description of weak interaction becomes simpler, If only we take Q, F<sub>0</sub> and F, based on the conserved physical quantities.展开更多
Purpose The large diameter photon sensors are widely applied in astroparticle physics and neutrino physics experiment.Due to its large size,the geo-magnetic effect cannot be ignored.In this work,one 20-inch MCP-PMT ar...Purpose The large diameter photon sensors are widely applied in astroparticle physics and neutrino physics experiment.Due to its large size,the geo-magnetic effect cannot be ignored.In this work,one 20-inch MCP-PMT are scanned under geo-magnetic field and magnetic shielding environment,and finally,the multi-parameter scanning results are given.Method In order to evaluate the response of MCP-PMTs,an automatic spherical scanning system based on stepper motor and quartz fiber was established.A comprehensive multi-point scanning was performed on the entire 20-inch MCP-PMT,and a multi parameter data scanning model was established.Our self-developed magnetic shielding was used to demonstrate the improvement of magnetic shielding on the ratio of signals,charge uniformity,and time characteristics of the 20-inch MCP-PMT.Results By comparing the results with and without magnetic shielding,it can be concluded that with magnetic shielding,the variation in charge spectrum and the ratio of signals are relatively smaller.At the same time,the composition of photon time spectrum has become simpler.The relative transit time and time spread of photons are reduced to a certain extent,and the uniformity of both is also improved.Conclusion The use of magnetic shielding has improved the various performance of MCP-PMT,preparing for future LHAASO and other experiments.展开更多
Purpose The Large High Altitude Air Shower Observatory(LHAASO)is a hybrid extensive air shower(EAS)array.It consists of 3 types of detector arrays and about 9500 detector units in total.Status information generated by...Purpose The Large High Altitude Air Shower Observatory(LHAASO)is a hybrid extensive air shower(EAS)array.It consists of 3 types of detector arrays and about 9500 detector units in total.Status information generated by data acquisition system(DAQ),including signal count rates of detectors,is stored temporarily in Redis and updated periodically.Redis is an open-source in-memory database.The control interface of DAQ's data flow software is also based on Redis.According to the monitoring and control requirements,status data from DAQ system need to be stored.Overview status of data flow software and detectors should be displayed.For automatic operation mode,common software and hardware faults should be detected and recovered automatically.Methods Status information collection,analysis and automatic operation control are implemented in multiple services.The information collection programs collect the operation status data from the DAQ and monitor the operation status of the computing nodes.All information is cached in Kafka.Kafka is an open-source distributed event streaming platform.The DAQ data flow controller program obtains the status data from Kafka,analyzes the operation status,and tries to recover the fault by modifying the DAQ configuration file and restarting DAQ.In this architecture,the automatic control logic can be easily updated by modifying and restarting a single service.Finally,the monitoring data are structured and stored in MongoDB.Results and Conclusions The software can monitor the detectors,electronics and computing nodes in LHAASO,save monitoring data in MongoDB,and control the DAQ data flow software.When a fault occurs,it can restart the DAQ data flow software.The software meets the auto-control operation requirements of LHAASO.展开更多
文摘Traditionally, in weak interaction, I<sub>3</sub>, Y and four flavour quantum numbers are not conserved but several empirical selection rules work well. Recently, it was found that, in weak interaction, there are three levels of conservation of additive quantum numbers, and fermion quantum number F is conserved in all kinds of interactions. It is known that weak interaction has three types: fermionic, pure hadronic and pure leptonic, corresponding to the first and the second level of conservation of additive quantum numbers respectively. It is demonstrated in this paper that the selection rules in all types of weak interaction can be interpreted by conservation of F, and the formula of relation between Q/e, F and F<sub>0</sub> is more general than Gell-Mann-Nishijima formula. Description of weak interaction becomes simpler, If only we take Q, F<sub>0</sub> and F, based on the conserved physical quantities.
基金supported by the Department of Science and Technology of Sichuan Province under Grant 2021YFSY0030.
文摘Purpose The large diameter photon sensors are widely applied in astroparticle physics and neutrino physics experiment.Due to its large size,the geo-magnetic effect cannot be ignored.In this work,one 20-inch MCP-PMT are scanned under geo-magnetic field and magnetic shielding environment,and finally,the multi-parameter scanning results are given.Method In order to evaluate the response of MCP-PMTs,an automatic spherical scanning system based on stepper motor and quartz fiber was established.A comprehensive multi-point scanning was performed on the entire 20-inch MCP-PMT,and a multi parameter data scanning model was established.Our self-developed magnetic shielding was used to demonstrate the improvement of magnetic shielding on the ratio of signals,charge uniformity,and time characteristics of the 20-inch MCP-PMT.Results By comparing the results with and without magnetic shielding,it can be concluded that with magnetic shielding,the variation in charge spectrum and the ratio of signals are relatively smaller.At the same time,the composition of photon time spectrum has become simpler.The relative transit time and time spread of photons are reduced to a certain extent,and the uniformity of both is also improved.Conclusion The use of magnetic shielding has improved the various performance of MCP-PMT,preparing for future LHAASO and other experiments.
文摘Purpose The Large High Altitude Air Shower Observatory(LHAASO)is a hybrid extensive air shower(EAS)array.It consists of 3 types of detector arrays and about 9500 detector units in total.Status information generated by data acquisition system(DAQ),including signal count rates of detectors,is stored temporarily in Redis and updated periodically.Redis is an open-source in-memory database.The control interface of DAQ's data flow software is also based on Redis.According to the monitoring and control requirements,status data from DAQ system need to be stored.Overview status of data flow software and detectors should be displayed.For automatic operation mode,common software and hardware faults should be detected and recovered automatically.Methods Status information collection,analysis and automatic operation control are implemented in multiple services.The information collection programs collect the operation status data from the DAQ and monitor the operation status of the computing nodes.All information is cached in Kafka.Kafka is an open-source distributed event streaming platform.The DAQ data flow controller program obtains the status data from Kafka,analyzes the operation status,and tries to recover the fault by modifying the DAQ configuration file and restarting DAQ.In this architecture,the automatic control logic can be easily updated by modifying and restarting a single service.Finally,the monitoring data are structured and stored in MongoDB.Results and Conclusions The software can monitor the detectors,electronics and computing nodes in LHAASO,save monitoring data in MongoDB,and control the DAQ data flow software.When a fault occurs,it can restart the DAQ data flow software.The software meets the auto-control operation requirements of LHAASO.
