The ring imaging Cherenkov(RICH) detector for particle identification(PID) is being evaluated for the future super tau-charm facility(STCF) complex. In this work, the prototype readout electronics for the RICH PID det...The ring imaging Cherenkov(RICH) detector for particle identification(PID) is being evaluated for the future super tau-charm facility(STCF) complex. In this work, the prototype readout electronics for the RICH PID detector is designed. The prototype RICH PID detector is based on a thick gas electron multiplier combined with a micromegas detector for Cherenkov light detection. Considering that there will be a large number(~ 690,000) of detector channels in future RICH detector, the readout electronics faces many challenges to precisely measuring time and charge information, such as reducing the noise,increasing density, and improving precision. The requirements of the readout electronics are explored, the downselection of the ASICs is made and thus a prototype readout electronics is designed and implemented. Tests are also conducted to evaluate the performance of the prototype readout electronics, and the results indicate that the time resolution is better than ~ 1 ns(RMS) when the input charge is greater than ~ 12 fC based on the APV25chip, while the time resolution is better than ~ 1 ns(RMS) at an input charge of over ~ 48 fC based on the AGET and STCF ASIC chips, and the equivalent noise charge is better than ~ 0.5 fC(RMS) @ 20 pF based on the three ASICs. The test results indicate that the prototype readout electronics design meets the requirement of the future RICH PID detector and thus provides a reference for future engineering.展开更多
The Fifth China (Quanzhou) Maritime Silk Road International Brand Exposition (MSREXPO2019), the 22nd Straits Textile Cloth-ing Fair (STCF2019) and the 2019 Shishi Fashion Week were held in Shishi City, Fujian Province...The Fifth China (Quanzhou) Maritime Silk Road International Brand Exposition (MSREXPO2019), the 22nd Straits Textile Cloth-ing Fair (STCF2019) and the 2019 Shishi Fashion Week were held in Shishi City, Fujian Province, from Ajpril 18th to 21st, 2019. There are 340 enterprises in 48 countries and regions along the “Maritime Silk Road55, and more than 500 enterprises in textile and apparel upstream and downstream, all of which are present at the three exhibitions. The three exhibitions brought new experiences, better business opportunities and more surprises to global businessmen, and further promote open-ness, development and win-win situation.展开更多
The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of...The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.展开更多
Based on 1.89×10^(8) J/ψ→ΛΛ Monte Carlo(MC)events produced from a longitudinally-polarized electron beam,the sensitivity of the CP violation of A decay is studied using fast simulation software.In addition,th...Based on 1.89×10^(8) J/ψ→ΛΛ Monte Carlo(MC)events produced from a longitudinally-polarized electron beam,the sensitivity of the CP violation of A decay is studied using fast simulation software.In addition,the J/ψ→ΛΛ decay can be used to optimize the detector response using the interface provided by the fast simulation software.In the future,the STCF is expected to obtain 3.4 trillion J/ψevents,and the statistical sensitivity of the CP violation of A decay via the J/ψ→ΛΛ process is expected to reach O(10^(-5))when the electron beam polarization is 80%.展开更多
The prospects to study hyperon-nucleus/nucleon interactions at BESIII and similar e^(+)e^(-)colliders are analyzed in this paper.Utilizing the large quantity of hyperons produced by the decay of 10 billion J/■and 2.7...The prospects to study hyperon-nucleus/nucleon interactions at BESIII and similar e^(+)e^(-)colliders are analyzed in this paper.Utilizing the large quantity of hyperons produced by the decay of 10 billion J/■and 2.7 billion(3686)collected at BESIII,the cross sections of several specific elastic and inelastic hyperon-nucleus reactions can be measured via scattering between hyperons and nucleus in the dense objects of the BESIII detector.Subsequently,the cross sections of the corresponding hyperon-nucleon interactions can be extracted from further phenomenological calculations.The interactions between antihyperons and nucleus/nucleon,including scattering and annihilation,can also be studied using the method proposed in this study.The results will definitely benefit the realization of precise probes for hyperon-nuclei/nucleus interactions and establish constraints to study the potential of strong interaction,the origin of color confinement,a unified model for baryon-baryon interactions,and the internal structure of neutron stars.In addition,the desirable prospects of corresponding studies in the future Super Tau-Charm Factory(STCF)are discussed and estimated in this study.展开更多
QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this...QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this type are the e^(+)e^(-)and μ^(+)e^(-)atoms,which were discovered 64 years ago and remain the sole examples found thus far.We demonstrate that the J_(τ)(τ^(+)τ^(-) atom with J^(PC)=1^(--))atom signal can be observed with a significance larger than 5o including both statistical and systematic uncertainties,via.the process e^(+)e^(-)→X^(+)Y^(-)E(X,Y=e,μ,π,K,or ρ,and E is the missing energy due to unobserved neutri-nos)with 1.5 ab^(-1)data taken around the τ pair production threshold.The τ lepton mass can be measured with a precision of 1 keV with the same data sample.This is within one year's running time of the pro-posed super tau-charm facility in China or super charm-tau factory in Russia.展开更多
We report a feasibility study for violation inτ^(-)→Ksπ^(-)ντdecays at a Super Tau Charm Facility(STCF).With an expected luminosity of 1 ab-1 collected by STCF per year at a center-of-mass energy of 4.26 GeV,the ...We report a feasibility study for violation inτ^(-)→Ksπ^(-)ντdecays at a Super Tau Charm Facility(STCF).With an expected luminosity of 1 ab-1 collected by STCF per year at a center-of-mass energy of 4.26 GeV,the statistical sensitivity for CP violation is determined to be of order 9.7×10^(-4)by measuring the decay-rate differ-ence betweenτ^(+)→Ksπ^(+)ντandτ^(-)→Ksπ^(-)ντ.The analysis is performed using a reliable fast simulation software package,which can describe the detector responses properly and vary the responses flexibly for further optimization.Moreover,the energy-dependent efficiencies for reconstructingτ^(-)→Ksπ^(-)ντare presented.The expected CP sens-itivity is proportional to 1/T in the energy region from 4.0 to 5.0 GeV.The sensitivity of CP violation is of order 3.1×10^(-4)with 10 ab^(-1)integrated luminosity,which is equivalent to ten years'data taking in this energy region at STCF.展开更多
基金supported by the international partnership program of the Chinese Academy of Sciences under Grant No.211134KYSB20200057Double First-Class university project foundation of USTC+1 种基金Youth Innovation Promotion Association CASCAS Center for Excellence in Particle Physics(CCEPP)。
文摘The ring imaging Cherenkov(RICH) detector for particle identification(PID) is being evaluated for the future super tau-charm facility(STCF) complex. In this work, the prototype readout electronics for the RICH PID detector is designed. The prototype RICH PID detector is based on a thick gas electron multiplier combined with a micromegas detector for Cherenkov light detection. Considering that there will be a large number(~ 690,000) of detector channels in future RICH detector, the readout electronics faces many challenges to precisely measuring time and charge information, such as reducing the noise,increasing density, and improving precision. The requirements of the readout electronics are explored, the downselection of the ASICs is made and thus a prototype readout electronics is designed and implemented. Tests are also conducted to evaluate the performance of the prototype readout electronics, and the results indicate that the time resolution is better than ~ 1 ns(RMS) when the input charge is greater than ~ 12 fC based on the APV25chip, while the time resolution is better than ~ 1 ns(RMS) at an input charge of over ~ 48 fC based on the AGET and STCF ASIC chips, and the equivalent noise charge is better than ~ 0.5 fC(RMS) @ 20 pF based on the three ASICs. The test results indicate that the prototype readout electronics design meets the requirement of the future RICH PID detector and thus provides a reference for future engineering.
文摘The Fifth China (Quanzhou) Maritime Silk Road International Brand Exposition (MSREXPO2019), the 22nd Straits Textile Cloth-ing Fair (STCF2019) and the 2019 Shishi Fashion Week were held in Shishi City, Fujian Province, from Ajpril 18th to 21st, 2019. There are 340 enterprises in 48 countries and regions along the “Maritime Silk Road55, and more than 500 enterprises in textile and apparel upstream and downstream, all of which are present at the three exhibitions. The three exhibitions brought new experiences, better business opportunities and more surprises to global businessmen, and further promote open-ness, development and win-win situation.
基金supported by the National Key R&D Program of China under Contract No.2022YFA1602200the International Partnership Program of the Chineses Academy of Sciences under Grant No.211134KYSB20200057the STCF Key Technology Research and Development Project.
文摘The superτ-charm facility(STCF)is an electron–positron collider proposed by the Chinese particle physics community.It is designed to operate in a center-of-mass energy range from 2 to 7 GeV with a peak luminosity of 0.5×10^(35) cm^(–2)·s^(–1) or higher.The STCF will produce a data sample about a factor of 100 larger than that of the presentτ-charm factory—the BEPCII,providing a unique platform for exploring the asymmetry of matter-antimatter(charge-parity violation),in-depth studies of the internal structure of hadrons and the nature of non-perturbative strong interactions,as well as searching for exotic hadrons and physics beyond the Standard Model.The STCF project in China is under development with an extensive R&D program.This document presents the physics opportunities at the STCF,describes conceptual designs of the STCF detector system,and discusses future plans for detector R&D and physics case studies.
基金Supported by the National Key R&D Program of China(2022YFA1602200),the Science and Technology Innovation Program of Hunan Province,China(2020RC3054)the International Partnership Program of the Chinese Academy of Sciences(211134KYSB20200057)。
文摘Based on 1.89×10^(8) J/ψ→ΛΛ Monte Carlo(MC)events produced from a longitudinally-polarized electron beam,the sensitivity of the CP violation of A decay is studied using fast simulation software.In addition,the J/ψ→ΛΛ decay can be used to optimize the detector response using the interface provided by the fast simulation software.In the future,the STCF is expected to obtain 3.4 trillion J/ψevents,and the statistical sensitivity of the CP violation of A decay via the J/ψ→ΛΛ process is expected to reach O(10^(-5))when the electron beam polarization is 80%.
基金Supported by the National Natural Science Foundation of China(NSFC)(11935018,11875054,12165022)the Chinese Academy of Sciences(CAS)Key Research Program of Frontier Sciences(QYZDJ-SSW-SLH003)the Fundamental Research Project of Yunnan Province,China(202301AT070162)。
文摘The prospects to study hyperon-nucleus/nucleon interactions at BESIII and similar e^(+)e^(-)colliders are analyzed in this paper.Utilizing the large quantity of hyperons produced by the decay of 10 billion J/■and 2.7 billion(3686)collected at BESIII,the cross sections of several specific elastic and inelastic hyperon-nucleus reactions can be measured via scattering between hyperons and nucleus in the dense objects of the BESIII detector.Subsequently,the cross sections of the corresponding hyperon-nucleon interactions can be extracted from further phenomenological calculations.The interactions between antihyperons and nucleus/nucleon,including scattering and annihilation,can also be studied using the method proposed in this study.The results will definitely benefit the realization of precise probes for hyperon-nuclei/nucleus interactions and establish constraints to study the potential of strong interaction,the origin of color confinement,a unified model for baryon-baryon interactions,and the internal structure of neutron stars.In addition,the desirable prospects of corresponding studies in the future Super Tau-Charm Factory(STCF)are discussed and estimated in this study.
基金supported by National Key Research and Development Program of China(2020YFA0406300)National Natural Science Foundation of China(11975076,12161141008,12135005,12075018,12005040,and 12335004)the Fundamental Research Funds for the Central Universities(RF1028623046).
文摘QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this type are the e^(+)e^(-)and μ^(+)e^(-)atoms,which were discovered 64 years ago and remain the sole examples found thus far.We demonstrate that the J_(τ)(τ^(+)τ^(-) atom with J^(PC)=1^(--))atom signal can be observed with a significance larger than 5o including both statistical and systematic uncertainties,via.the process e^(+)e^(-)→X^(+)Y^(-)E(X,Y=e,μ,π,K,or ρ,and E is the missing energy due to unobserved neutri-nos)with 1.5 ab^(-1)data taken around the τ pair production threshold.The τ lepton mass can be measured with a precision of 1 keV with the same data sample.This is within one year's running time of the pro-posed super tau-charm facility in China or super charm-tau factory in Russia.
基金the Double First-Class university project foundation of USTC,USTC Research Funds of the Double First-Class Initiative YD2030002005the National Natural Science Foundation of China(11625523)+1 种基金the National Natural Science Foundation of China(11805012)the Fundamental Research Funds for the Central Universities。
文摘We report a feasibility study for violation inτ^(-)→Ksπ^(-)ντdecays at a Super Tau Charm Facility(STCF).With an expected luminosity of 1 ab-1 collected by STCF per year at a center-of-mass energy of 4.26 GeV,the statistical sensitivity for CP violation is determined to be of order 9.7×10^(-4)by measuring the decay-rate differ-ence betweenτ^(+)→Ksπ^(+)ντandτ^(-)→Ksπ^(-)ντ.The analysis is performed using a reliable fast simulation software package,which can describe the detector responses properly and vary the responses flexibly for further optimization.Moreover,the energy-dependent efficiencies for reconstructingτ^(-)→Ksπ^(-)ντare presented.The expected CP sens-itivity is proportional to 1/T in the energy region from 4.0 to 5.0 GeV.The sensitivity of CP violation is of order 3.1×10^(-4)with 10 ab^(-1)integrated luminosity,which is equivalent to ten years'data taking in this energy region at STCF.
