Neutron-antineutron(n−n)oscillations in the deuteron are considered.Specifically,the deuteron lifetime is calculated in terms of the free-space n−n oscillation time τn−n based on NN and NN interactions derived within...Neutron-antineutron(n−n)oscillations in the deuteron are considered.Specifically,the deuteron lifetime is calculated in terms of the free-space n−n oscillation time τn−n based on NN and NN interactions derived within chiral effective field theory(EFT).This results in(2.6±0.1)×10^22τ2^n−n s,which is close to the value obtained by Dover and collaborators more than three decades ago,but disagrees with recent EFT calculations that were performed within the perturbative scheme proposed by Kaplan,Savage,and Wise.Possible reasons for the difference are discussed.展开更多
The complexity of threshold phenomena is exemplified on a prominent and long-known case-the structure in theΛp cross section(invariant mass spectrum)at the opening of the∑N channel.The mass splitting between the∑ba...The complexity of threshold phenomena is exemplified on a prominent and long-known case-the structure in theΛp cross section(invariant mass spectrum)at the opening of the∑N channel.The mass splitting between the∑baryons together with the angular momentum coupling in the^(3)S_(1)-^(3)D_(1)partial wave imply that,in principle,up to six channels are involved.Utilizing hyperon-nucleon potentials that provide an excellent description of the available low-energy Λp and∑N scattering data,the shape of the resulting Λp cross section is discussed and the poles near the ∑N threshold are determined.Evidence for a strangeness S=-1 dibaryon is provided,in the form of a(unstable)∑N bound state in the vicinity of the ∑N threshold.Predictions for level shifts and widths of ∑^(-)p atomic states are given.展开更多
基金supported by Joint Large Scale Scientific Facility Funds of the National Natural Science Foundation of China(NSFC)and Chinese Academy of Sciences(CAS)(U1932110,NSFC(11805059,11805012,11675051,12322502),and 12335002)Fundamental Research Funds for the central Universities+3 种基金supported by Deutsche Forschungsgemeinschaft(DFG)(TRR110)NSFC through funds provided to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”(11621131001)supported in part by VolkswagenStiftung(93562)by the CAS President’s International Fellowship Initiative(PIFI)(2018DM0034)。
基金supported in part by the DFG and the NSFC through funds provided to the Sino-German CRC 110"Symmetries and the Emergence of Structure in QCD"(DFG grant.no.TRR 110)the VolkswagenStiftung(93562)supported in part by The Chinese Academy of Sciences(CAS)President’s International Fellowship Initiative(PIFI)(2018DM0034)
文摘Neutron-antineutron(n−n)oscillations in the deuteron are considered.Specifically,the deuteron lifetime is calculated in terms of the free-space n−n oscillation time τn−n based on NN and NN interactions derived within chiral effective field theory(EFT).This results in(2.6±0.1)×10^22τ2^n−n s,which is close to the value obtained by Dover and collaborators more than three decades ago,but disagrees with recent EFT calculations that were performed within the perturbative scheme proposed by Kaplan,Savage,and Wise.Possible reasons for the difference are discussed.
基金Supported in part by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)the Sino-German Collaborative Research Center CRC 110"Symmetries and the Emergence of Structure in QCD"(DFG Project-ID 196253076-TRR 110,Grant No.12070131001)+2 种基金the EU(STRONG2020)the Chinese Academy of Sciences(CAS)President's International Fellowship Initiative(PIFI)(2018DM0034)VolkswagenStiftung(93562)。
文摘The complexity of threshold phenomena is exemplified on a prominent and long-known case-the structure in theΛp cross section(invariant mass spectrum)at the opening of the∑N channel.The mass splitting between the∑baryons together with the angular momentum coupling in the^(3)S_(1)-^(3)D_(1)partial wave imply that,in principle,up to six channels are involved.Utilizing hyperon-nucleon potentials that provide an excellent description of the available low-energy Λp and∑N scattering data,the shape of the resulting Λp cross section is discussed and the poles near the ∑N threshold are determined.Evidence for a strangeness S=-1 dibaryon is provided,in the form of a(unstable)∑N bound state in the vicinity of the ∑N threshold.Predictions for level shifts and widths of ∑^(-)p atomic states are given.
