The proton charge radius rP is a fundamental quantity in particle physics,as it challenges our understanding of the so successful Standard Model in the non-perturbative regime of the strong interactions.It is defined ...The proton charge radius rP is a fundamental quantity in particle physics,as it challenges our understanding of the so successful Standard Model in the non-perturbative regime of the strong interactions.It is defined by the slope of the proton charge form factor GE p etT at zero momentum transfer,with t the invariant four-momentum transfer squared.The proton charge radius was first indirectly measured in the Nobel prize winning electron scattering experiments by Hofstadter et al.[1,2],who fitted the form factor data with a dipole form and extracted the radius from the slope of the dipole.展开更多
We give a pedagogical analysis on K-matrix models describing theπN scattering amplitude,in S11 channel at low energies.We show how the correct use of analyticity in the s-channel and crossing symmetry in t-and u-chan...We give a pedagogical analysis on K-matrix models describing theπN scattering amplitude,in S11 channel at low energies.We show how the correct use of analyticity in the s-channel and crossing symmetry in t-and u-channels leads to a much improved analytic behavior in the negative s region,in agreement with the prediction from chiral perturbation amplitudes in its validity region.The analysis leads again to the conclusion that a genuine N^*(890)resonance exists.展开更多
In this exploratory study, near-threshold scattering of D and ■ meson is investigated using lattice QCD with N f = 2 + 1 + 1 twisted mass fermion configurations. The calculation is performed in the coupled-channel L&...In this exploratory study, near-threshold scattering of D and ■ meson is investigated using lattice QCD with N f = 2 + 1 + 1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Lüscher finite-size formalism. The study focuses on the channel with IG(JPC) = 1+(1+-) where the resonance-like structure Zc（3900） was discovered. We first identify the two most relevant channels and the lattice study is performed in the two-channel scattering model. Combined with the two-channel Ross-Shaw theory, scattering parameters are extracted from the energy levels by solving the generalized eigenvalue problem. Our results for the scattering length parameters suggest that for the particular lattice parameters that we studied, the best fit parameters do not correspond to the peak in the elastic scattering cross-section near the threshold. Furthermore, in the zero-range Ross-Shaw theory,the scenario of a narrow resonance close to the threshold is disfavored beyond the 3σ level.展开更多
Weakly bound states often occur in nuclear physics.To precisely understand their properties,the coupling to the continuum should be worked out explicitly.As the first step,we use a simple nuclear model in the continuu...Weakly bound states often occur in nuclear physics.To precisely understand their properties,the coupling to the continuum should be worked out explicitly.As the first step,we use a simple nuclear model in the continuum and on a lattice to investigate the influence of a third particle on a loosely bound state of a particle and a heavy core.Our approach is consistent with the Lüscher formalism.展开更多
The electric radius,rE,and the magnetic radius,rM,of the proton are fundamental quantities of low-energy QCD,as they are a measure of the probe-dependent size of the proton.
In this paper we propose a dispersive method to describe two-body scattering with unitarity imposed. This approach is applied to elastic ππ scattering. The amplitudes keep single-channel unitarity and describe the e...In this paper we propose a dispersive method to describe two-body scattering with unitarity imposed. This approach is applied to elastic ππ scattering. The amplitudes keep single-channel unitarity and describe the experimental data well, and the low-energy amplitudes are consistent with that of chiral perturbation theory. The pole locations of the σ, f0(980), ρ(770) and f2(1270) and their couplings to ππ are obtained. A virtual state appearing in the isospin-two S-wave is confirmed. The correlations between the left(and right) hand cut and the poles are discussed. Our results show that the poles are more sensitive to the right hand cut rather than the left hand cut. The proposed method could be used to study other two-body scattering processes.展开更多
基金supported in part by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)-Projektnummer 279384907-CRC 1245the DFG and the NSFC through funds provided to the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”+2 种基金supported by the Chinese Academy of Sciences(CAS)President’s International Fellowship Initiative(PIFI)(2018DM0034)by Volkswagen Stiftung(93562)supported by the German Federal Ministry of Education and Research(BMBF)(05P18RDFN1).
文摘The proton charge radius rP is a fundamental quantity in particle physics,as it challenges our understanding of the so successful Standard Model in the non-perturbative regime of the strong interactions.It is defined by the slope of the proton charge form factor GE p etT at zero momentum transfer,with t the invariant four-momentum transfer squared.The proton charge radius was first indirectly measured in the Nobel prize winning electron scattering experiments by Hofstadter et al.[1,2],who fitted the form factor data with a dipole form and extracted the radius from the slope of the dipole.
基金supported in part by the National Nature Science Foundations of China under contract numbers 11975028 and 10925522by the Sino-German CRC 110(Grant No.TRR110)。
文摘We give a pedagogical analysis on K-matrix models describing theπN scattering amplitude,in S11 channel at low energies.We show how the correct use of analyticity in the s-channel and crossing symmetry in t-and u-channels leads to a much improved analytic behavior in the negative s region,in agreement with the prediction from chiral perturbation amplitudes in its validity region.The analysis leads again to the conclusion that a genuine N^*(890)resonance exists.
基金Supported in part by the Ministry of Science and Technology of China(MSTC)under 973 project"Systematic studies on light hadron spectroscopy"(2015CB856702)supported in part by the DFG and the NSFC through funds provided to the Sino-Germen CRC 110"Symmetries and the Emergence of Structure in QCD",DFG grant no.TRR 110 and NSFC(11621131001)+2 种基金supported in part by the National Science Foundation of China(NSFC)(11775229,11875169)the Youth Innovation Promotion Association of CAS(2015013)the support from the Key Research Program of the Chinese Academy of Sciences(XDPB09)
文摘In this exploratory study, near-threshold scattering of D and ■ meson is investigated using lattice QCD with N f = 2 + 1 + 1 twisted mass fermion configurations. The calculation is performed in the coupled-channel Lüscher finite-size formalism. The study focuses on the channel with IG(JPC) = 1+(1+-) where the resonance-like structure Zc（3900） was discovered. We first identify the two most relevant channels and the lattice study is performed in the two-channel scattering model. Combined with the two-channel Ross-Shaw theory, scattering parameters are extracted from the energy levels by solving the generalized eigenvalue problem. Our results for the scattering length parameters suggest that for the particular lattice parameters that we studied, the best fit parameters do not correspond to the peak in the elastic scattering cross-section near the threshold. Furthermore, in the zero-range Ross-Shaw theory,the scenario of a narrow resonance close to the threshold is disfavored beyond the 3σ level.
基金financial support from the Deutsche Forschungsgemeinschaft (SFB/TRR 110,"Symmetries and the Emergence of Structure in QCD",grant no. TRR 110)by the Chinese Academy of Sciences (CAS) President’s International Fellowship Initiative (PIFI)(2018DM0034)+1 种基金by Volkswagen Stiftung (93562)by the Fundamental Research Funds for the Central Universities
文摘Weakly bound states often occur in nuclear physics.To precisely understand their properties,the coupling to the continuum should be worked out explicitly.As the first step,we use a simple nuclear model in the continuum and on a lattice to investigate the influence of a third particle on a loosely bound state of a particle and a heavy core.Our approach is consistent with the Lüscher formalism.
基金supported in part by the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation)(279384907-CRC 1245)the DFG(196253076-TRR 110)+4 种基金the National Natural Science Foundation of China(12070131001)within the framework of the Sino-German CRC 110“Symmetries and the Emergence of Structure in QCD”supported by the Chinese Academy of Sciences(CAS)President’s International Fellowship Initiative(PIFI)(2018DM0034)the VolkswagenStiftung(93562)the EU Horizon 2020 research and innovation programme,STRONG-2020 project(824093).
文摘The electric radius,rE,and the magnetic radius,rM,of the proton are fundamental quantities of low-energy QCD,as they are a measure of the probe-dependent size of the proton.
基金Supported by National Natural Science Foundation of China uder Grant Nos.11805059,11805012,11805037Fundamental Research Funds for the Central Universities+6 种基金the Joint Large Scale Scientific Facility Funds of the NSFCChinese Academy of Sciences(CAS)under Grant No.U1832121Shanghai Pujiang Program under Grant No.18PJ1401000Open Research Program of Large Research Infrastructures(2017)CAS,the DFG(SFB/TR 110,“Symmetries and the Emergence of Structure in QCD”)the Chinese Academy of Sciences(CAS) President’s International Fellowship Initiative(PIFI)under Grant No.2018DM0034Volkswagen Stiftung under Grant No.93562
文摘In this paper we propose a dispersive method to describe two-body scattering with unitarity imposed. This approach is applied to elastic ππ scattering. The amplitudes keep single-channel unitarity and describe the experimental data well, and the low-energy amplitudes are consistent with that of chiral perturbation theory. The pole locations of the σ, f0(980), ρ(770) and f2(1270) and their couplings to ππ are obtained. A virtual state appearing in the isospin-two S-wave is confirmed. The correlations between the left(and right) hand cut and the poles are discussed. Our results show that the poles are more sensitive to the right hand cut rather than the left hand cut. The proposed method could be used to study other two-body scattering processes.
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partly supported by the National Natural Science Foundation of China(NSFC,12035007)Guangdong Provincial funding(2019QN01X172)+4 种基金Guangdong Major Project of Basic and Applied Basic Research(2020B0301030008)supported by the NSFC(12070131001)the Deutsche Forschungsgemeinschaft(DFG,German Research Foundation,Project-ID 196253076-TRR110)through the funds provided to the Sino-German Collaborative Research Center TRR110"Symmetries and the Emergence of Structure in QCD"supported by the Chinese Academy of Sciences(CAS)President’s International Fellowship Initiative(PIFI)(2018DM0034)Volkswagen Stiftung(93562)。
