The ground and excited levels of the trimer (4He)3 are obtained theoretically by solving the 2-D Faddeev integral equation in the momentum space. In solving the equation, the direct matrix inversion method (I. M.) is ...The ground and excited levels of the trimer (4He)3 are obtained theoretically by solving the 2-D Faddeev integral equation in the momentum space. In solving the equation, the direct matrix inversion method (I. M.) is used instead of the iteration and Pade approximate method. The new HFD-B Aziz potential ν is used in the calculation.展开更多
Effective lambda-proton and lambda-neutron potentials,restored from theoretical scattering phases through Gel'fand–Levitan–Marchenko theory,are tested on a lambda hypertriton through three-body calculations.The ...Effective lambda-proton and lambda-neutron potentials,restored from theoretical scattering phases through Gel'fand–Levitan–Marchenko theory,are tested on a lambda hypertriton through three-body calculations.The lambda hypertriton is treated as a three-body system consisting of lambda-proton,lambda-neutron and proton–neutron subsystems.Binding energy and root mean square radius are computed for the ground state of lambda hypertriton(Jp=12+).In coordinate space,the dynamics of the system is described using a set of coupled hyperradial equations obtained from the differential Faddeev equations.By solving the eigenvalue problem derived from this set of coupled hyperradial equations,the binding energy and root mean square matter radius computed are found to be-2.462 MeV and 7.00 fm,respectively.The potentials are also shown to display a satisfactory convergence behaviour.展开更多
Employing an approach based on the Green functions of Landau-gauge QCD,some selected results from a calculation of meson and baryon properties are presented.A rainbow-ladder truncation to the quark Dyson-Schwinger equ...Employing an approach based on the Green functions of Landau-gauge QCD,some selected results from a calculation of meson and baryon properties are presented.A rainbow-ladder truncation to the quark Dyson-Schwinger equation is used to arrive at a unified description of mesons and baryons by solving BetheSalpeter and covariant Faddeev equations,respectively.展开更多
The neutron-halo nuclei, ^11Li, ^14Be, and ^17B, are studied in the three-body model. The Yukawainteraction is used to describe the interaction of the two-body subsystem. For given parameters ot the twobody interactio...The neutron-halo nuclei, ^11Li, ^14Be, and ^17B, are studied in the three-body model. The Yukawainteraction is used to describe the interaction of the two-body subsystem. For given parameters ot the twobody interaction, the properties of these neutron-halo nuclei are calculated with the Faddeev equations and the results are compared with those in the variational method. It is shown that the method of the Faddeev equations is more accurate. Then the dependencies of the two- and three-body energies on the parameters are studied. We find numerically that two- and three-body correlations differ greatly from each other with the variation of the intrinsic force range.展开更多
Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and...Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and spectroscopy in terms of QCD's elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a Dyson- Schwinger equation perspective on this effort with numerous illustrations, amongst them: an interpretation of string^breaking; a symmetry-preserving truncation for mesons; the nucleon's strangeness σ-term; and the neutron's charge distribution.展开更多
The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li reaction.The d+Li reaction mechanism is descr...The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li reaction.The d+Li reaction mechanism is described using the Faddeev theory for the three-body problem of deuteron-nucleus interaction.This theory is slightly extended for calculation of the stripping processes ^6Li(d,p)^7Li,^7Li(d,p)^8 ,^6Li(d,n)^7 Be,and ^7Li(d,n)^8 Be,as well as fragmentation reactions yielding tritium,a-particles,and continuous neutrons and protons in the initial deuteron kineticenergy region Ed=0.5-20 MeV.The phase shifts found for d+^6Li and d+^7Li elastic scattering,as part of the simple optic model with a complex central potential,were used to find the cross sections for the 6^Li(d,yM)^8 and ^7Li(d,yE1)^9 Be radiation captures.The three-body dynamics role is also summarized to demonstrate its significant influence within the d+^7Li system.展开更多
We investigate low-lying bound states of the neutron-rich nucleus ^15B by assuming it is a three-body system made of an inert core 13 B and two valence neutrons. The three-body wave functions are obtained using the Fa...We investigate low-lying bound states of the neutron-rich nucleus ^15B by assuming it is a three-body system made of an inert core 13 B and two valence neutrons. The three-body wave functions are obtained using the Faddeev formalism. Special attention is paid to the excited state at 3.48(6) MeV observed in the 13 C(14 C,12 N)15 B reaction, whose properties are less clear theoretically. In our three-body model, besides the ground state 3/21, a second 3/22^-state is discovered at around 3.61 MeV, which might be identified with the excited state observed at3.48(6) MeV. We study this 3/22^-state in detail. It turns out to be a two-neutron halo state with a large matter radius rm≈4.770 fm. &nbsp展开更多
The coupledΛΛnn-Ξ-pnn system was studied to investigate whether the inclusion of channel coupling is able to bind theΛΛnn system.We use a separable potential three-body model of the coupledΛΛnn-Ξ-pnn system an...The coupledΛΛnn-Ξ-pnn system was studied to investigate whether the inclusion of channel coupling is able to bind theΛΛnn system.We use a separable potential three-body model of the coupledΛΛnn-Ξ-pnn system and a variational four-body calculation with realistic interactions.Our results exclude the possibility of aΛΛnn bound state by a large margin.Instead,we found aΞ-t quasibound state above theΛΛnn threshold.展开更多
We use an existing model of theΛΛN−ΞNN three-body system based on two-body separable interactions to study the(I,JP)=(1/2,1/2+)three-body channel.For theΛΛ,ΞN,andΛΛ−ΞN amplitudes,we have constructed separable...We use an existing model of theΛΛN−ΞNN three-body system based on two-body separable interactions to study the(I,JP)=(1/2,1/2+)three-body channel.For theΛΛ,ΞN,andΛΛ−ΞN amplitudes,we have constructed separable potentials based on the most recent results of the HAL QCD Collaboration.They are characterized by the existence of a resonance just below or above theΞN threshold in the H-dibaryon channel,(i,jp)=(0,0+).A three-body resonance appears 2.3 MeV above theΞd threshold.We show that if theΛΛ−ΞN H-dibaryon channel is not considered,theΛΛN−ΞNN S wave resonance disappears.Thus,the possible existence of aΛΛN−ΞNN resonance would be sensitive to theΛΛ−ΞN interaction.The existence or nonexistence of this resonance could be evidenced by measuring,for example,theΞd cross section.展开更多
文摘The ground and excited levels of the trimer (4He)3 are obtained theoretically by solving the 2-D Faddeev integral equation in the momentum space. In solving the equation, the direct matrix inversion method (I. M.) is used instead of the iteration and Pade approximate method. The new HFD-B Aziz potential ν is used in the calculation.
文摘Effective lambda-proton and lambda-neutron potentials,restored from theoretical scattering phases through Gel'fand–Levitan–Marchenko theory,are tested on a lambda hypertriton through three-body calculations.The lambda hypertriton is treated as a three-body system consisting of lambda-proton,lambda-neutron and proton–neutron subsystems.Binding energy and root mean square radius are computed for the ground state of lambda hypertriton(Jp=12+).In coordinate space,the dynamics of the system is described using a set of coupled hyperradial equations obtained from the differential Faddeev equations.By solving the eigenvalue problem derived from this set of coupled hyperradial equations,the binding energy and root mean square matter radius computed are found to be-2.462 MeV and 7.00 fm,respectively.The potentials are also shown to display a satisfactory convergence behaviour.
基金Supported by Austrian Science Fund FWF (P20592-N16,P20496-N16)Doctoral Program (W1203)European Union (Hadron Physics2 project 'Study of strongly interacting matter')
文摘Employing an approach based on the Green functions of Landau-gauge QCD,some selected results from a calculation of meson and baryon properties are presented.A rainbow-ladder truncation to the quark Dyson-Schwinger equation is used to arrive at a unified description of mesons and baryons by solving BetheSalpeter and covariant Faddeev equations,respectively.
基金Supported by National Natural Science Foundation of China (10535010, 10775068) 973 National Major State Basic Research and Development of China (2007CB815004)+2 种基金CAS Knowledge Innovation Project (KJCX2-SW-N02) Research Fund of Education Ministry under contract RFDP (20070284016)Green-Blue Project of Jiangsu Province
文摘The neutron-halo nuclei, ^11Li, ^14Be, and ^17B, are studied in the three-body model. The Yukawainteraction is used to describe the interaction of the two-body subsystem. For given parameters ot the twobody interaction, the properties of these neutron-halo nuclei are calculated with the Faddeev equations and the results are compared with those in the variational method. It is shown that the method of the Faddeev equations is more accurate. Then the dependencies of the two- and three-body energies on the parameters are studied. We find numerically that two- and three-body correlations differ greatly from each other with the variation of the intrinsic force range.
基金Supported by National Natural Science Foundation of China (10705002)Department of Energy, Office of Nuclear Physics(DE-FG03-97ER4014, DE-AC02-06CH11357)
文摘Two basic motivations for an upgraded JLab facility are the needs: to determine the essential nature of light-quark confinement and dynamical chiral symmetry breaking (DCSB); and to understand nucleon structure and spectroscopy in terms of QCD's elementary degrees of freedom. During the next ten years a programme of experiment and theory will be conducted that can address these questions. We present a Dyson- Schwinger equation perspective on this effort with numerous illustrations, amongst them: an interpretation of string^breaking; a symmetry-preserving truncation for mesons; the nucleon's strangeness σ-term; and the neutron's charge distribution.
基金The reported study was funded by RFBR,(20-02-00004)。
文摘The problem of the deuteron interaction with lithium nuclei,treated as a system of two coupled pointlike clusters,is formulated to calculate the cross sections of the d+Li reaction.The d+Li reaction mechanism is described using the Faddeev theory for the three-body problem of deuteron-nucleus interaction.This theory is slightly extended for calculation of the stripping processes ^6Li(d,p)^7Li,^7Li(d,p)^8 ,^6Li(d,n)^7 Be,and ^7Li(d,n)^8 Be,as well as fragmentation reactions yielding tritium,a-particles,and continuous neutrons and protons in the initial deuteron kineticenergy region Ed=0.5-20 MeV.The phase shifts found for d+^6Li and d+^7Li elastic scattering,as part of the simple optic model with a complex central potential,were used to find the cross sections for the 6^Li(d,yM)^8 and ^7Li(d,yE1)^9 Be radiation captures.The three-body dynamics role is also summarized to demonstrate its significant influence within the d+^7Li system.
基金Supported by National Natural Science Foundation of China(Grant No.11535004,11761161001,11375086,11120101005,11175085and 11235001)the National Major State Basic Research and Development of China,Grant No.2016YFE0129300the Science and Technology Development Fund of Macao under Grant No.068/2011/A
文摘We investigate low-lying bound states of the neutron-rich nucleus ^15B by assuming it is a three-body system made of an inert core 13 B and two valence neutrons. The three-body wave functions are obtained using the Faddeev formalism. Special attention is paid to the excited state at 3.48(6) MeV observed in the 13 C(14 C,12 N)15 B reaction, whose properties are less clear theoretically. In our three-body model, besides the ground state 3/21, a second 3/22^-state is discovered at around 3.61 MeV, which might be identified with the excited state observed at3.48(6) MeV. We study this 3/22^-state in detail. It turns out to be a two-neutron halo state with a large matter radius rm≈4.770 fm. &nbsp
基金partially funded by COFAA-IPN(México)Ministerio de Economía,Industria y Competitividad and EU FEDER(FPA2016-77177)
文摘The coupledΛΛnn-Ξ-pnn system was studied to investigate whether the inclusion of channel coupling is able to bind theΛΛnn system.We use a separable potential three-body model of the coupledΛΛnn-Ξ-pnn system and a variational four-body calculation with realistic interactions.Our results exclude the possibility of aΛΛnn bound state by a large margin.Instead,we found aΞ-t quasibound state above theΛΛnn threshold.
基金This work has been partially funded by COFAA-IPN(Mexico)and by Ministerio de Ciencia e Innovacion and EU FEDER(FPA2016-77177-C2-2-P,PID2019-105439GB-C22,RED2018-102572-T)。
文摘We use an existing model of theΛΛN−ΞNN three-body system based on two-body separable interactions to study the(I,JP)=(1/2,1/2+)three-body channel.For theΛΛ,ΞN,andΛΛ−ΞN amplitudes,we have constructed separable potentials based on the most recent results of the HAL QCD Collaboration.They are characterized by the existence of a resonance just below or above theΞN threshold in the H-dibaryon channel,(i,jp)=(0,0+).A three-body resonance appears 2.3 MeV above theΞd threshold.We show that if theΛΛ−ΞN H-dibaryon channel is not considered,theΛΛN−ΞNN S wave resonance disappears.Thus,the possible existence of aΛΛN−ΞNN resonance would be sensitive to theΛΛ−ΞN interaction.The existence or nonexistence of this resonance could be evidenced by measuring,for example,theΞd cross section.