Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoel...Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoelectron angular distributions and theβasymmetry parameters for He 1s^(2) electrons prove the reliability of our experiment,and the β asymmetry parameters extracted from the angular distributions of Ne 2p^(6) electrons are obtained.By comparing with different theoretical calculations,it is found that the contribution of the electron correlation effect in Ne 2p^(6) single ionization becomes increasingly important as the incident photon energy increases,while the relativistic effect is relatively low in the whole incident energy range.Our experimentalβasymmetry parameters may serve as a significant reference to test the most elaborated theories in the field.The datasets presented in this paper,including the photoelectron angular distributions andβasymmetry parameters,are openly available at https://doi.org/10.57760/sciencedb.j00113.00073.展开更多
In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytic...In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytical expression for the velocity induced by the feedback ratchet, which is a function of several parameters, including the ratio of the two switching temperatures and the asymmetry parameter of the potential field. The motor shows a current inversion when either parameter is varied.展开更多
The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical formula.Using the single-folding formalism with asymmetry-depend-ent nucl...The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical formula.Using the single-folding formalism with asymmetry-depend-ent nuclear radius and surface diffuseness of nuclear matter,the nuclear potential and consequently the half-life are functions of the asymmetry factor.Despite small values of asymmetry in neutron-deficient proton emitters,notice-able changes in the half-lives are observed.The addition of an asymmetry parameter term to the two forms of empir-ical formulas leads to a reduction in the rms error for ground state and isomeric transitions.A noticeable reduction of about 43%is obtained for isomeric transitions in the second form of the empirical formula.Considering ground state transitions in two categories,odd-even and odd-odd emitters,and adopting deformation and asymmetry-dependent empirical formulas,the rms decreases remarkably.The low est values of rms errors,viz.0.1492,0.2312,and 0.1999,are obtained for the aforementioned empirical formulas for ground state transitions of odd-even and odd-odd emit-ters and for all isomeric transitions,respectively.展开更多
The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental result...The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental results will aid in advancing existing theoretical research and establishing new experimental objectives.In this study,we formulate the asymmetric parameters that characterize parity violation,and then derive formulas for the measurement of CP violation.The formulae for the joint angular distribution of the full decay chain as well as the polarization observable of Ξ^(0),Ξ¯^(0),Λ,and Λ¯are also provided for experiments.Lastly,we evaluated the sensitivity of two asymmetric parameters:αΞ0→Λπ0(abbreviated asαΞ0)andαΞ¯0→Λ¯γ(abbreviated asαΞ¯0)for future experimental measurements.展开更多
CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test C...CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test CP symmetry.In this study,we formulateΛ^(+)_(c)→ΦρandΛ^(+)_(c)→ωρdecays for the measurement of their asymmetry parameters in weak decays at the BESII or LHCb experiments.The polarization transfer is analyzed in the two processes of e+e-→Λ^(+)_(c)Λ^(-)_(c)andΛ^(o)_(b)→Λ^(+)_(c)π^(-),and the formulas for the joint angular distribution of these processes are provided.The sensitivity of the measurement of the asymmetry parameters of the above two decay processes is estimated for future experiments.展开更多
Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polari...Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polarization in charmed baryon decays,we investigate the possibility to measure weak decay asymmetry parameters in the e^+e^-→Ξ0cΞ0c process.We analyze the transverse polarization spontaneously produced in this process and the spin transfer in the subsequent Ξc decays.The sensitivity to measure the asymmetry parameters is estimated for the decay Ξc→Ξ0π.展开更多
基金the National Natural Science Foundation of China(Grant Nos.11905089 and U1932133)the National Key Research and Development Program of China(Grant No.2017YFA0402300)。
文摘Fully differential cross-sections of single ionization of He and Ne atoms are studied by linearly polarized extreme ultraviolet(XUV)photons in the energy range of 22.1 e V–43.7 e V,using a reaction microscope.Photoelectron angular distributions and theβasymmetry parameters for He 1s^(2) electrons prove the reliability of our experiment,and the β asymmetry parameters extracted from the angular distributions of Ne 2p^(6) electrons are obtained.By comparing with different theoretical calculations,it is found that the contribution of the electron correlation effect in Ne 2p^(6) single ionization becomes increasingly important as the incident photon energy increases,while the relativistic effect is relatively low in the whole incident energy range.Our experimentalβasymmetry parameters may serve as a significant reference to test the most elaborated theories in the field.The datasets presented in this paper,including the photoelectron angular distributions andβasymmetry parameters,are openly available at https://doi.org/10.57760/sciencedb.j00113.00073.
基金Project supported by the Educational Commission of Henan Province, China (Grant No. 2006140015)the Science and Technology Planning Project of Henan Province, China (Grant No. 092300410142)
文摘In this paper, we present a model of the Brownian motor in a feedback controlled ratchet, in which the application of the flashing potential depends on the state of the particle to be controlled. We derive an analytical expression for the velocity induced by the feedback ratchet, which is a function of several parameters, including the ratio of the two switching temperatures and the asymmetry parameter of the potential field. The motor shows a current inversion when either parameter is varied.
文摘The dependence of proton emission half-lives on the nuclear asymmetry parameter is investigated using the WKB method and two types of empirical formula.Using the single-folding formalism with asymmetry-depend-ent nuclear radius and surface diffuseness of nuclear matter,the nuclear potential and consequently the half-life are functions of the asymmetry factor.Despite small values of asymmetry in neutron-deficient proton emitters,notice-able changes in the half-lives are observed.The addition of an asymmetry parameter term to the two forms of empir-ical formulas leads to a reduction in the rms error for ground state and isomeric transitions.A noticeable reduction of about 43%is obtained for isomeric transitions in the second form of the empirical formula.Considering ground state transitions in two categories,odd-even and odd-odd emitters,and adopting deformation and asymmetry-dependent empirical formulas,the rms decreases remarkably.The low est values of rms errors,viz.0.1492,0.2312,and 0.1999,are obtained for the aforementioned empirical formulas for ground state transitions of odd-even and odd-odd emit-ters and for all isomeric transitions,respectively.
基金Supported by the National Natural Science Foundation of China(12175244,11875262,11805037,U1832121)National Key Research and Development Program of China(2020YFA0406301)。
文摘The measurement of decay parameters is one of the important goals of particle physics experiments,and the measurement serves as a probe to search for evidence of CP violation in baryonic decays.The experimental results will aid in advancing existing theoretical research and establishing new experimental objectives.In this study,we formulate the asymmetric parameters that characterize parity violation,and then derive formulas for the measurement of CP violation.The formulae for the joint angular distribution of the full decay chain as well as the polarization observable of Ξ^(0),Ξ¯^(0),Λ,and Λ¯are also provided for experiments.Lastly,we evaluated the sensitivity of two asymmetric parameters:αΞ0→Λπ0(abbreviated asαΞ0)andαΞ¯0→Λ¯γ(abbreviated asαΞ¯0)for future experimental measurements.
基金Supported by the National Natural Science Foundation of China(12175244,11875262,11805037,U1832121)the National Key Research and Development ProgramofChina(2020YFA0406301)。
文摘CP violation in baryonic decays has not been significantly observed.With large data events accumulated at e+e-colliders or the Large Hadron Collider,charmed baryon decays would provide a promising laboratory to test CP symmetry.In this study,we formulateΛ^(+)_(c)→ΦρandΛ^(+)_(c)→ωρdecays for the measurement of their asymmetry parameters in weak decays at the BESII or LHCb experiments.The polarization transfer is analyzed in the two processes of e+e-→Λ^(+)_(c)Λ^(-)_(c)andΛ^(o)_(b)→Λ^(+)_(c)π^(-),and the formulas for the joint angular distribution of these processes are provided.The sensitivity of the measurement of the asymmetry parameters of the above two decay processes is estimated for future experiments.
基金supported by the Ministry of Education, Culture, Sports, Science, and Technology (MEXT) of Japanthe Japan Society for the Promotion of Science (JSPS)+29 种基金the Tau-Lepton Physics Research Center of Nagoya Universitythe Australian Research Council including grants DP180102629, DP170102389, DP170102204, DE220100462, DP150103061, FT130100303Austrian Federal Ministry of Education, Science and Research (FWF) and FWF Austrian Science Fund No. P 31361-N36the National Natural Science Foundation of China under Contracts No. 11675166, No. 11705209No. 11805064No. 11975076No. 12135005No. 12175041No. 12161141008Key Research Program of Frontier Sciences, Chinese Academy of Sciencess (CAS), Grant No. QYZDJ-SSW-SLH011the Shanghai Science and Technology Committee (STCSM) under Grant No. 19ZR1403000the Ministry of Education, Youth and Sports of the Czech Republic under Contract No. LTT17020the Czech Science Foundation Grant No. 22-18469SHorizon 2020 ERC Advanced Grant No. 884719 and ERC Starting Grant No. 947006 ‘‘Inter Leptons” (European Union)the Carl Zeiss Foundation, the Deutsche Forschungsgemeinschaft, the Excellence Cluster Universe, and the Volkswagen Stiftungthe Department of Atomic Energy (Project Identification No. RTI 4002)the Department of Science and Technology of Indiathe Istituto Nazionale di Fisica Nucleare of ItalyNational Research Foundation (NRF) of Korea Grant Nos. 2016R1D1A1B02012900, 2018R1A2B3003643, 2018R1A6A1A060 24970, RS202200197659, 2019R1I1A3A01058933, 2021R1A6A1A03043957, 2021R1F1A1060423, 2021R1F1A1064008, 2022R1A2C 1003993Radiation Science Research Institute, Foreign Large-size Research Facility Application Supporting projectthe Global Science Experimental Data Hub Center of the Korea Institute of Science and Technology Information and KREONET/GLORIADthe Polish Ministry of Science and Higher Education and the National Science Centerthe Ministry of Science and Higher Education of the Russian Federation, Agreement 14.W03.31.0026the HSE University Basic Research Program, MoscowUniversity of Tabuk research grants S-1440-0321, S-0256-1438, and S-0280-1439 (Saudi Arabia)the Slovenian Research Agency Grant Nos. J19124 and P1-0135Ikerbasque, Basque Foundation for Science, Spainthe Swiss National Science Foundationthe Ministry of Education and the Ministry of Science and Technology of Taiwanthe United States Department of Energy and the National Science Foundation。
基金Supported by the National Natural Science Foundation of China(11875262,11805037,11705078)Joint Large-Scale Scientific Facility Funds of the NSFC and CAS(U1832121)+1 种基金Shanghai Pujiang Program(18PJ1401000)Open Research Program of Large Research Infrastructures(2017),Chinese Academy of Sciences
文摘Measurements of decay asymmetry parameters of charmed baryons,e.g.,Ξ0c,provide more data to test the W-emission and W-exchange mechanisms controlled by strong and weak interactions.Taking advantage of the spin polarization in charmed baryon decays,we investigate the possibility to measure weak decay asymmetry parameters in the e^+e^-→Ξ0cΞ0c process.We analyze the transverse polarization spontaneously produced in this process and the spin transfer in the subsequent Ξc decays.The sensitivity to measure the asymmetry parameters is estimated for the decay Ξc→Ξ0π.