Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the qu...Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the quark content■.The correlation matrices of two types of operators with JPC=0++,0-+,1++and 1--are simulated to extract the masses of the hexaquark candidates,which are subsequently extrapolated to the physical pion mass and continuum limit.The results indicate that ground state masses are below the■threshold and provide a characteristic signal for the experimental discovery of hexaquark candidates,which may enrich the versatile structure of multiquarks;moreover,it is an indispensable step to decipher the nonperturbative nature of the fundamental interactions of quarks and gluons.展开更多
We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by usi...We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by using the Ferrenberg-Swendsen reweighting method, we determine the critical β = 6/g^2 where the transition occurs, g is the coupling constant. On lattice 8^2 × 20 × 4, by using the axial vector Ward-Takahashi identity, we calculate the current quark mass amq, a is the lattice spacing. Assuming the O（4） scaling, the critical β in the chiral limit is determined. We calculate the p meson mass amp at zero temperature on lattice 8^3 × 20. By using the experimental p meson mass to set the scale, we obtain 194（1） MeV for the transition temperature in the chiral limit.展开更多
Updated September 2013 by S. Hashimoto （KEK）, J. Laiho （Syracuse University）, and S.R. Sharpe （University of Washington）. 18.1. Lattice regularization of QCD
The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighti...The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighting technique.Under the positive fermion determinant,i.e.,the chemical potential is pure imaginary,the simulations are performed at hopping parameter κ = 0.165.The comparison between the reweighting technique and the conventional point-by-point scanning method is presented.The results prove that the reweighting technique is an effective and efficient method in investigating the critical phenomenon.展开更多
Using lattice configurations for quantum chromodynamics(QCD)generated with three domain-wall fermions at a physical pion mass,we obtain a parameter-free prediction of QCD’s renormalisation-group-invariant process-ind...Using lattice configurations for quantum chromodynamics(QCD)generated with three domain-wall fermions at a physical pion mass,we obtain a parameter-free prediction of QCD’s renormalisation-group-invariant process-independent effective charge,α^(k2).Owing to the dynamical breaking of scale invariance,evident in the emergence of a gluon mass-scale,m0=0.43(1)GeV,this coupling saturates at infrared momenta:α^(0)/π=0.97(4).Amongst other things:α^(k2)is almost identical to the process-dependent(PD)effective charge defined via the Bjorken sum rule;and also that PD charge which,employed in the one-loop evolution equations,delivers agreement between pion parton distribution functions computed at the hadronic scale and experiment.The diversity of unifying roles played byα^(k^2)suggests that it is a strong candidate for that object which represents the interaction strength in QCD at any given momentum scale;and its properties support a conclusion that QCD is a mathematically well-defined quantum field theory in four dimensions.展开更多
为了找到一种获得K-π相移的有效方法,并从格点计算得到的能级中获取K*介子的性质,首先使用手征幺正理论研究了有限体积中的P波K-π相互作用.这种方法曾在无限空间中成功地应用于计算K-π相移.然后用这种方法计算得到作为立方体盒子尺...为了找到一种获得K-π相移的有效方法,并从格点计算得到的能级中获取K*介子的性质,首先使用手征幺正理论研究了有限体积中的P波K-π相互作用.这种方法曾在无限空间中成功地应用于计算K-π相移.然后用这种方法计算得到作为立方体盒子尺寸和π介子质量的函数的P波K-π散射振幅的能级;并计算了K-π散射的相移以及基于该结果的K*介子的物理性质.最后,为了和格点量子色动力学(QCD)计算结果进行比较,又在π介子取非物理质量时计算得到了K*介子的能级.比较表明:文中方法与格点QCD得到的结果基本一致.当介子能量为266 Me V时,本文方法得到的两个能级分别为924.0 Me V和1 483.0 Me V,其结果与格点QCD得到的915.6 Me V和1 522.3 Me V的两个能级符合得很好.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11735010,11975127,11911530088,U2032102,12005130,12125503,and 12335003)supported by the Natural Science Foundation of Shanghai(Grant No.15DZ2272100)+2 种基金supported by Jiangsu Specially Appointed Professor Programsupported by the Strategic Priority Research Program of Chinese Academy of Sciences(Grant Nos.XDB34030303,and XDPB15)supported by the National Natural Science Foundation of China(NSFC)and Deutsche Forschungsgemeinschaft(DFG)joint grant(Grant No.12061131006)。
文摘Based on five different ensembles of newly generated(2+1)-flavor configurations with pion mass of approximately mπ■(140-310)MeV,we present a lattice analysis of hidden-charm and hidden-strange hexaquarks with the quark content■.The correlation matrices of two types of operators with JPC=0++,0-+,1++and 1--are simulated to extract the masses of the hexaquark candidates,which are subsequently extrapolated to the physical pion mass and continuum limit.The results indicate that ground state masses are below the■threshold and provide a characteristic signal for the experimental discovery of hexaquark candidates,which may enrich the versatile structure of multiquarks;moreover,it is an indispensable step to decipher the nonperturbative nature of the fundamental interactions of quarks and gluons.
文摘We present the results for the transition temperature of quantum chromodynamics （QCD） with two degenerate flavours （Nf = 2） of Wilson quarks. On lattice 8^3 × 4 with 4 representing the temporal extent, by using the Ferrenberg-Swendsen reweighting method, we determine the critical β = 6/g^2 where the transition occurs, g is the coupling constant. On lattice 8^2 × 20 × 4, by using the axial vector Ward-Takahashi identity, we calculate the current quark mass amq, a is the lattice spacing. Assuming the O（4） scaling, the critical β in the chiral limit is determined. We calculate the p meson mass amp at zero temperature on lattice 8^3 × 20. By using the experimental p meson mass to set the scale, we obtain 194（1） MeV for the transition temperature in the chiral limit.
文摘Updated September 2013 by S. Hashimoto （KEK）, J. Laiho （Syracuse University）, and S.R. Sharpe （University of Washington）. 18.1. Lattice regularization of QCD
基金Supported by the National Natural Science Foundation of China (10847137)the Science Foundation of Jiangsu University (1283000345)
文摘The transition points of lattice quantum chromodynamics（QCD） with two degenerate flavors of Wilson quarks at finite temperature T and small imaginary quark chemical potential μ are determined by using the reweighting technique.Under the positive fermion determinant,i.e.,the chemical potential is pure imaginary,the simulations are performed at hopping parameter κ = 0.165.The comparison between the reweighting technique and the conventional point-by-point scanning method is presented.The results prove that the reweighting technique is an effective and efficient method in investigating the critical phenomenon.
文摘Using lattice configurations for quantum chromodynamics(QCD)generated with three domain-wall fermions at a physical pion mass,we obtain a parameter-free prediction of QCD’s renormalisation-group-invariant process-independent effective charge,α^(k2).Owing to the dynamical breaking of scale invariance,evident in the emergence of a gluon mass-scale,m0=0.43(1)GeV,this coupling saturates at infrared momenta:α^(0)/π=0.97(4).Amongst other things:α^(k2)is almost identical to the process-dependent(PD)effective charge defined via the Bjorken sum rule;and also that PD charge which,employed in the one-loop evolution equations,delivers agreement between pion parton distribution functions computed at the hadronic scale and experiment.The diversity of unifying roles played byα^(k^2)suggests that it is a strong candidate for that object which represents the interaction strength in QCD at any given momentum scale;and its properties support a conclusion that QCD is a mathematically well-defined quantum field theory in four dimensions.
文摘为了找到一种获得K-π相移的有效方法,并从格点计算得到的能级中获取K*介子的性质,首先使用手征幺正理论研究了有限体积中的P波K-π相互作用.这种方法曾在无限空间中成功地应用于计算K-π相移.然后用这种方法计算得到作为立方体盒子尺寸和π介子质量的函数的P波K-π散射振幅的能级;并计算了K-π散射的相移以及基于该结果的K*介子的物理性质.最后,为了和格点量子色动力学(QCD)计算结果进行比较,又在π介子取非物理质量时计算得到了K*介子的能级.比较表明:文中方法与格点QCD得到的结果基本一致.当介子能量为266 Me V时,本文方法得到的两个能级分别为924.0 Me V和1 483.0 Me V,其结果与格点QCD得到的915.6 Me V和1 522.3 Me V的两个能级符合得很好.
