As the LHC beams cannot be polarized,introducing a dense polarized gas target at the LHCb experiment at CERN,to be operated concurrently with beam-beam collisions,will facilitate fixed-target interactions to explore a...As the LHC beams cannot be polarized,introducing a dense polarized gas target at the LHCb experiment at CERN,to be operated concurrently with beam-beam collisions,will facilitate fixed-target interactions to explore a new energy regime of spin physics measurements.Unfortunately,typical surface coatings used to avoid polarization losses,such as water,Teflon,or aluminum,are prohibited due to restrictions imposed by vacuum and beam policies.The former atomic beam source for the polarized target at ANKE@COSY(Forschungszentrum Jülich),an accompanying Lamb-shift polarimeter,and a storage cell chamber inside a superconducting magnet provide a perfect test stand to investigate the properties of a storage cell coated with amorphous carbon.A significant recombination rate,ranging from 93% to 100%,and preservation of polarization during recombination surpassing 74% were observed.We successfully produced H2 molecules with a nuclear polarization of P~0.59.In addition,we could produce polarized H3+ions for the first time and observed the shift of the axis of rotation within HD molecules.展开更多
This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an ...This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering usin...The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.展开更多
We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the par...We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the particle-in-cell(PIC) simulation code VLPL(Virtual Laser Plasma Lab) to make theoretical predictions about the behavior of proton spins in laser-induced plasmas. Simulations of spin-polarized targets show that the polarization is conserved during the acceleration process. For the experimental realization, a polarized HCl gas-jet target is under construction using the fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and simultaneously circularly polarized light of the fifth harmonic to photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their degree of polarization is measured with a Lamb-shift polarimeter. The final experiments, aiming at the first observation of a polarized particle beam from laser-generated plasmas, will be carried out at the 10 PW laser system SULF at SIOM, Shanghai.展开更多
The acceleration of polarized electrons,positrons,protons and ions in strong laser and plasma fields is a very attractive option for obtaining polarized beams in the multi-mega-electron volt range.Recently,there has b...The acceleration of polarized electrons,positrons,protons and ions in strong laser and plasma fields is a very attractive option for obtaining polarized beams in the multi-mega-electron volt range.Recently,there has been substantial progress in the understanding of the dominant mechanisms leading to high degrees of polarization,in the numerical modeling of these processes and in their experimental implementation.This review paper presents an overview on the current state of the field,and on the concepts of polarized laser–plasma accelerators and of beam polarimetry.展开更多
The flux of geoneutrinos at any point on the Earth is a function of the abundance and distribution of radioactive elements within our planet. This flux has been successfully detected by the 1-kt Kam LAND and 0.3-kt Bo...The flux of geoneutrinos at any point on the Earth is a function of the abundance and distribution of radioactive elements within our planet. This flux has been successfully detected by the 1-kt Kam LAND and 0.3-kt Borexino detectors, with these measurements being limited by their low statistics. The planned 20-kt JUNO detector will provide an exciting opportunity to obtain a high statistics measurement, which will provide data to address several questions of geological importance. This paper presents the JUNO detector design concept, the expected geo-neutrino signal and corresponding backgrounds. The precision level of geo-neutrino measurements at JUNO is obtained with the standard least-squares method. The potential of the Th/U ratio and mantle measurements is also discussed.展开更多
Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromo...Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromodynamics in various reactions involving light as well as heavy quarks.展开更多
In this short review, I discuss the sensitivity of the generation of the light and the life-relevant elements such as carbon and oxygen under changes of the parame- ters of the Standard Model pertinent to nuclear phys...In this short review, I discuss the sensitivity of the generation of the light and the life-relevant elements such as carbon and oxygen under changes of the parame- ters of the Standard Model pertinent to nuclear physics. Chiral effective field theory allows for a systematic and precise description of the forces between two, three and four nucleons. In this framework, variations under the light quark masses and the electromagnetic fine-structure constant can also be consistently calculated. Combining chiral nuclear effective field theory with Monte Carlo simulations allows to further calculate the properties of nuclei, in particular of the Hoyle state in carbon, that plays a crucial role in the gener- ation of the life-relevant elements in hot, old stars. The dependence of the triple-alpha process on the fundamental constants of nature is calculated, and some implications for our anthropic view of the Universe are discussed.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK...The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.展开更多
JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)...JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)θ_(13) oscillation parameters using reactor antineutrinos,which is one of the primary physics goals of the experiment.The sensitivities are obtained using the best knowledge available to date on the location and overburden of the experimental site,the nuclear reactors in the surrounding area and beyond,the detector response uncertainties,and the reactor antineutrino spectral shape constraints expected from the TAO satellite detector.It is found that the △m_(21)^(2) and sin^(2)θ_(12) oscillation parameters will be determined to 0.5%precision or better in six years of data collection.In the same period,the △m_(31)^(2) parameter will be determined to about 0.2%precision for each mass ordering hypothesis.The new precision represents approximately an order of magnitude improvement over existing constraints for these three parameters.展开更多
The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neut...The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.展开更多
基金funding from the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation)-533904660。
文摘As the LHC beams cannot be polarized,introducing a dense polarized gas target at the LHCb experiment at CERN,to be operated concurrently with beam-beam collisions,will facilitate fixed-target interactions to explore a new energy regime of spin physics measurements.Unfortunately,typical surface coatings used to avoid polarization losses,such as water,Teflon,or aluminum,are prohibited due to restrictions imposed by vacuum and beam policies.The former atomic beam source for the polarized target at ANKE@COSY(Forschungszentrum Jülich),an accompanying Lamb-shift polarimeter,and a storage cell chamber inside a superconducting magnet provide a perfect test stand to investigate the properties of a storage cell coated with amorphous carbon.A significant recombination rate,ranging from 93% to 100%,and preservation of polarization during recombination surpassing 74% were observed.We successfully produced H2 molecules with a nuclear polarization of P~0.59.In addition,we could produce polarized H3+ions for the first time and observed the shift of the axis of rotation within HD molecules.
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+20 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the"Excellence of Science-EOS"in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID Millennium Science Initiative Program—ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn University and Suranaree University of Technology in Thailandthe University of California at Irvinethe National Science Foundation in USA。
文摘This paper presents an energy resolution study of the JUNO experiment,incorporating the latest knowledge acquired during the detector construction phase.The determination of neutrino mass ordering in JUNO requires an exceptional energy resolution better than 3% at 1 MeV.To achieve this ambitious goal,significant efforts have been undertaken in the design and production of the key components of the JUNO detector.Various factors affecting the detection of inverse beta decay signals have an impact on the energy resolution,extending beyond the statistical fluctuations of the detected number of photons,such as the properties of the liquid scintillator,performance of photomultiplier tubes,and the energy reconstruction algorithm.To account for these effects,a full JUNO simulation and reconstruction approach is employed.This enables the modeling of all relevant effects and the evaluation of associated inputs to accurately estimate the energy resolution.The results of this study reveal an energy resolution of 2.95% at 1 Mev.Furthermore,this study assesses the contribution of major effects to the overall energy resolution budget.This analysis serves as a reference for interpreting future measurements of energy resolution during JUNO data collection.Moreover,it provides a guideline for comprehending the energy resolution characteristics of liquid scintillator-based detectors.
基金Supported by the Chinese Academy of Sciences,the National Key R&D Program of Chinathe CAS Center for Excellence in Particle Physics,Wuyi University,and the TsungDao Lee Institute of Shanghai Jiao Tong University in China+3 种基金the Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Italian-Chinese collaborative research program MAECI-NSFC,the Fond de la Recherche Scientifique(F.R.S-FNRS)and FWO under the“Excellence of Science–EOS”in Belgium,the Conselho Nacional de Desenvolvimento Cient´ıfico e Tecnol`ogico in Brazil,the Agencia Nacional de Investigacion y Desarrollo and ANID-Millennium Science Initiative Program-ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Association,and the Cluster of Excellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR)and Lomonosov Moscow State University in Russia,the joint Russian Science Foundation(RSF)and National Natural Science Foundation of China(NSFC)research program,the MOST and MOE in Taiwan,China,the Chulalongkorn University and Suranaree University of Technology in Thailand,University of California at Irvine and the National Science Foundation in the US。
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a multi-purpose neutrino experiment under construction in South China.This paper presents an updated estimate of JUNO’s sensitivity to neutrino mass ordering using the reactor antineutrinos emitted from eight nuclear reactor cores in the Taishan and Yangjiang nuclear power plants.This measurement is planned by studying the fine interference pattern caused by quasi-vacuum oscillations in the oscillated antineutrino spectrum at a baseline of 52.5 km and is completely independent of the CP violating phase and neutrino mixing angleθ_(23).The sensitivity is obtained through a joint analysis of JUNO and Taishan Antineutrino Observatory(TAO)detectors utilizing the best available knowledge to date about the location and overburden of the JUNO experimental site,local and global nuclear reactors,JUNO and TAO detector responses,expected event rates and spectra of signals and backgrounds,and systematic uncertainties of analysis inputs.We find that a 3σmedian sensitivity to reject the wrong mass ordering hypothesis can be reached with an exposure of about 6.5 years×26.6 GW thermal power.
基金the JuSPARC(Julich Short-Pulse Particle and Radiation Center)projectsupported by the ATHENA(Accelerator Technology HElmholtz iNfrAstructure)consortiumgrant VSR-JPGI61 on the supercomputer JURECA
文摘We report on the concept of an innovative source to produce polarized proton/deuteron beams of a kinetic energy up to several GeV from a laser-driven plasma accelerator. Spin effects have been implemented into the particle-in-cell(PIC) simulation code VLPL(Virtual Laser Plasma Lab) to make theoretical predictions about the behavior of proton spins in laser-induced plasmas. Simulations of spin-polarized targets show that the polarization is conserved during the acceleration process. For the experimental realization, a polarized HCl gas-jet target is under construction using the fundamental wavelength of a Nd:YAG laser system to align the HCl bonds and simultaneously circularly polarized light of the fifth harmonic to photo-dissociate, yielding nuclear polarized H atoms. Subsequently, their degree of polarization is measured with a Lamb-shift polarimeter. The final experiments, aiming at the first observation of a polarized particle beam from laser-generated plasmas, will be carried out at the 10 PW laser system SULF at SIOM, Shanghai.
基金carried out in the framework of the JuSPARC(Jülich Short-Pulse Particle and Radiation Center)projectsupported by the ATHENA(Accelerator Technology HElmholtz iNfrAstructure)consortium+3 种基金support through the Ministry of Science and Technology of the Peoples Republic of China(Nos.2018YFA0404803 and 2016YFA0401102)the Strategic Priority Research Program of Chinese Academy of Sciences(No.XDB16010000)the National Natural Science Foundation of China(Nos.11875307,11674339,11922515,and 1193500)the Innovation Program of Shanghai Municipal Education Commission and the Recruitment Program for Young Professionals。
文摘The acceleration of polarized electrons,positrons,protons and ions in strong laser and plasma fields is a very attractive option for obtaining polarized beams in the multi-mega-electron volt range.Recently,there has been substantial progress in the understanding of the dominant mechanisms leading to high degrees of polarization,in the numerical modeling of these processes and in their experimental implementation.This review paper presents an overview on the current state of the field,and on the concepts of polarized laser–plasma accelerators and of beam polarimetry.
基金Supported in part by National Natural Science Foundation of China(11405056,11305193,11205176,21504063)National Science Foundation of U.S.(EAR 1067983/1068097)+1 种基金Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No.XDA10010100 CAS Center for Excellence in Particle Physics(CCEPP)
文摘The flux of geoneutrinos at any point on the Earth is a function of the abundance and distribution of radioactive elements within our planet. This flux has been successfully detected by the 1-kt Kam LAND and 0.3-kt Borexino detectors, with these measurements being limited by their low statistics. The planned 20-kt JUNO detector will provide an exciting opportunity to obtain a high statistics measurement, which will provide data to address several questions of geological importance. This paper presents the JUNO detector design concept, the expected geo-neutrino signal and corresponding backgrounds. The precision level of geo-neutrino measurements at JUNO is obtained with the standard least-squares method. The potential of the Th/U ratio and mantle measurements is also discussed.
基金Supported by DFG (SFB/TR-16)EU FP7 HadronPhysics2,HGF VH-VI-231BMBF (grant 06BN9006)
文摘Isospin violation is driven through the light quark mass difference and electromagnetic effects.I review recent progress in extracting the light quark mass difference and tests of the chiral dynamics of Quantum Chromodynamics in various reactions involving light as well as heavy quarks.
基金supported in part by DFG and NSFC (Sino-German CRC 110)Helmholtz Association (contract VHVI-417)+2 种基金BMBF (grant 05P12PDFTE)the EU (Hadron Physics3 project)LENPIC (DEC-2103/10/M/ST2/00420)
文摘In this short review, I discuss the sensitivity of the generation of the light and the life-relevant elements such as carbon and oxygen under changes of the parame- ters of the Standard Model pertinent to nuclear physics. Chiral effective field theory allows for a systematic and precise description of the forces between two, three and four nucleons. In this framework, variations under the light quark masses and the electromagnetic fine-structure constant can also be consistently calculated. Combining chiral nuclear effective field theory with Monte Carlo simulations allows to further calculate the properties of nuclei, in particular of the Hoyle state in carbon, that plays a crucial role in the gener- ation of the life-relevant elements in hot, old stars. The dependence of the triple-alpha process on the fundamental constants of nature is calculated, and some implications for our anthropic view of the Universe are discussed.
基金supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+22 种基金the CAS Center for Excellence in Particle PhysicsWuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules (IN2P3) in Francethe Istituto Nazionale di Fisica Nucleare (INFN) in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique (F.R.S-FNRS)FWO under the "Excellence of Science-EOS" in Belgiumthe Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo in Chilethe Charles University Research Centrethe Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft (DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+ in Germanythe Joint Institute of Nuclear Research (JINR)Lomonosov Moscow State University in Russiathe joint Russian Science Foundation (RSF)National Natural Science Foundation of China (NSFC) research programthe MOST and MOE in Taiwan,Chinathe Chulalongkorn UniversitySuranaree University of Technology in Thailandthe University of California at Irvine in USA
文摘The Jiangmen Underground Neutrino Observatory(JUNO)is a large liquid scintillator detector designed to explore many topics in fundamental physics.In this study,the potential of searching for proton decay in the p→νK^(+)mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification.Moreover,the excellent energy resolution of JUNO permits suppression of the sizable background caused by other delayed signals.Based on these advantages,the detection efficiency for the proton decay via p→νK^(+)is 36.9%±4.9%with a background level of 0.2±0.05(syst)±0.2(stat)events after 10 years of data collection.The estimated sensitivity based on 200 kton-years of exposure is 9.6×1033 years,which is competitive with the current best limits on the proton lifetime in this channel and complements the use of different detection technologies.
基金Supported by the Chinese Academy of Sciencesthe National Key R&D Program of China+18 种基金the CAS Center for Excellence in Particle Physics,Wuyi Universitythe Tsung-Dao Lee Institute of Shanghai Jiao Tong University in Chinathe Institut National de Physique Nucléaire et de Physique de Particules(IN2P3)in Francethe Istituto Nazionale di Fisica Nucleare(INFN)in Italythe Italian-Chinese collaborative research program MAECI-NSFCthe Fond de la Recherche Scientifique(F.R.S-FNRS)FWO under the“Excellence of Science-EOS in Belgium”the Conselho Nacional de Desenvolvimento Científico e Tecnològico in Brazilthe Agencia Nacional de Investigacion y Desarrollo and ANID-Millennium Science Initiative Program-ICN2019_044 in Chilethe Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republicthe Deutsche Forschungsgemeinschaft(DFG)the Helmholtz Associationthe Cluster of Excellence PRISMA+in Germanythe Joint Institute of Nuclear Research(JINR)and Lomonosov Moscow State University in Russiathe joint Russian Science Foundation(RSF)National Natural Science Foundation of China(NSFC)research programthe MOST and MOE in Taiwanthe Chulalongkorn University and Suranaree University of Technology in Thailand,University of California at Irvinethe National Science Foundation in USA。
文摘JUNO is a multi-purpose neutrino observatory under construction in the south of China.This publication presents new sensitivity estimates for the measurement of the △m_(31)^(2),△m_(21)^(2),sin^(2)θ_(12),and sin^(2)θ_(13) oscillation parameters using reactor antineutrinos,which is one of the primary physics goals of the experiment.The sensitivities are obtained using the best knowledge available to date on the location and overburden of the experimental site,the nuclear reactors in the surrounding area and beyond,the detector response uncertainties,and the reactor antineutrino spectral shape constraints expected from the TAO satellite detector.It is found that the △m_(21)^(2) and sin^(2)θ_(12) oscillation parameters will be determined to 0.5%precision or better in six years of data collection.In the same period,the △m_(31)^(2) parameter will be determined to about 0.2%precision for each mass ordering hypothesis.The new precision represents approximately an order of magnitude improvement over existing constraints for these three parameters.
基金This work was supported by the Chinese Academy of Sciences,the National Key R&D Program of China,the CAS Center for Excellence in Particle Physics,the Joint Large Scale Scientific Facility Funds of the NSFC and CAS,Wuyi University,and the Tsung-Dao Lee Instiute of Shanghai Jiao Tong University in China,the In stiut National de Physique Nucleaire et de Physique de Particules(IN2P3)in France,the Istituto Nazionale di Fisica Nucleare(INFN)in Italy,the Fond de la Recherche Scintifique(F.R.S-FNRS)and FWO under the"Excellence of Science-EOS"in Belgium,the Conselho Nacional de Desenvolvimento Cientificoce Tecnologico in Brazil,the Agencia Nacional de Investigacion y Desrrollo in Chile,the Charles University Research Centre and the Ministry of Education,Youth,and Sports in Czech Republic,the Deutsche Forschungsgemeinschaft(DFG),the Helmholtz Association,and the Cluster of Exellence PRISMA+in Germany,the Joint Institute of Nuclear Research(JINR),Lomonosov Moscow State University,and Russian Foundation for Basic Research(RFBR)in Russia,the MOST and MOE in Taiwan,the Chu-lalongkorm University and Suranaree University of Technology in Thailand,and the University of aliformia at Irvine in USA.
文摘The Jiangmen Underground Neutrino Observatory(JUNO)features a 20 kt multi-purpose underground liquid scintillator sphere as its main detector.Some of JUNO's features make it an excellent location for^8B solar neutrino measurements,such as its low-energy threshold,high energy resolution compared with water Cherenkov detectors,and much larger target mass compared with previous liquid scintillator detectors.In this paper,we present a comprehensive assessment of JUNO's potential for detecting^8B solar neutrinos via the neutrino-electron elastic scattering process.A reduced 2 MeV threshold for the recoil electron energy is found to be achievable,assuming that the intrinsic radioactive background^(238)U and^(232)Th in the liquid scintillator can be controlled to 10^(-17)g/g.With ten years of data acquisition,approximately 60,000 signal and 30,000 background events are expected.This large sample will enable an examination of the distortion of the recoil electron spectrum that is dominated by the neutrino flavor transformation in the dense solar matter,which will shed new light on the inconsistency between the measured electron spectra and the predictions of the standard three-flavor neutrino oscillation framework.IfDelta m^(2)_(21)=4.8times10^(-5);(7.5times10^(-5))eV^(2),JUNO can provide evidence of neutrino oscillation in the Earth at approximately the 3sigma(2sigma)level by measuring the non-zero signal rate variation with respect to the solar zenith angle.Moreover,JUNO can simultaneously measureDelta m^2_(21)using^8B solar neutrinos to a precision of 20% or better,depending on the central value,and to sub-percent precision using reactor antineutrinos.A comparison of these two measurements from the same detector will help understand the current mild inconsistency between the value of Delta m^2_(21)reported by solar neutrino experiments and the KamLAND experiment.
