In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show t...In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally.展开更多
If there exists a null gradient field in 3 + 1 dimensional space-time, we can set up a kind of light-cone coordinate system in the space-time. In such coordinate system, the metric takes a simple form, which is helpfu...If there exists a null gradient field in 3 + 1 dimensional space-time, we can set up a kind of light-cone coordinate system in the space-time. In such coordinate system, the metric takes a simple form, which is helpful for simplifying and solving the Einstein’s field equation. This light-cone coordinate system has wonderful properties and has been used widely in astrophysics to calculate parameters. We discuss the structure of space-time with light-cone coordinate system in detail. We show how to construct the light-cone coordinate system and obtain the conditions of its existence, and then explain their geometrical and physical meanings.展开更多
We calculate the D → η transition form factor in light-cone sum rules by taking improved current correlators to avoid the pollution from the twist-3 wave function. We get consistent results of the D＋ → η^（＇）l...We calculate the D → η transition form factor in light-cone sum rules by taking improved current correlators to avoid the pollution from the twist-3 wave function. We get consistent results of the D＋ → η^（＇）l＋νl decays with the experimental data. By comparing the difference between the results of the branching ratios of D＋ → η^（＇）l＋νl from a two-pole parameterization model and from a BZ parameterization model, we find that the two-pole model and the BZ model are comparably believable. One way is supposed for the determination of the η-η mixing angle from the dependence of the branching ratios of D＋ → η^（＇）l＋νl decays on the η-η mixing angle.展开更多
In this article, we calculate the form-factors of the transitions B → a1（1260）, b1（1235） in the leading-order approximation using the light-cone QCD sum rules. In calculations, we choose the chiral current to int...In this article, we calculate the form-factors of the transitions B → a1（1260）, b1（1235） in the leading-order approximation using the light-cone QCD sum rules. In calculations, we choose the chiral current to interpolate the B-meson, which has the outstanding advantage that the twist-3 light-cone distribution amplitudes of the axial-vector mesons makes no contributions, and the resulting sum rules for the form-factors suffer from far fewer uncertainties. Then we study the semi-leptonic decays B → a1（1260） lvl, b1（1235） lvl （l=e,μ,τ）, and make predictions for the differential decay widths and decay widths, which can be compared with the experimental data in the coming future展开更多
Light-cone distribution amplitudes(LCDAs)are essential nonperturbative quantities for theoretical predictions of exclusive highenergy processes in quantum chromodynamics(QCD).We demonstrate the prospect of calculating...Light-cone distribution amplitudes(LCDAs)are essential nonperturbative quantities for theoretical predictions of exclusive highenergy processes in quantum chromodynamics(QCD).We demonstrate the prospect of calculating LCDAs on a quantum computer by applying a recently proposed quantum algorithm,with staggered fermions,to the simulation of the LCDA in the(1+1)-dimensional Nambu-Jona-Lasinio(NJL)model on classical hardware.The agreement between the result from the classical simulation of the quantum algorithm and that from exact diagonalization justifies the proposed quantum algorithm.We find that the resulting LCDA in the NJL model exhibits features shared with the LCDAs obtained from the QCD.展开更多
We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuu...We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuum-to-D-meson correlation function are considered,and the NLP corrections from the high-twist D-meson LCDAs and the SU(3)breaking effect from a strange quark mass are investigated.Adopting the exponential model of the D-meson LCDAs,the SU(3)flavor symmetry breaking effects are predicted as R+,0 SU(3)=1.12 and R T SU(3)=1.39,respectively,confirming the results obtained from LCSR with pion LCDA.The numerical predictions of the form factors show that the contribution from two-particle higher-twist contributions is of great importance and the uncertainties are dominated by the inverse moment ofϕ+D(ω,μ).With the obtained form factors,the predicted Cabibbo-Kobayashi-Maskawa(CKM)matrix elements are|Vcd|=0.151+0.091−0.043|th.+0.017−0.02|exp.and|Vcs|=0.89+0.467−0.234|th.+0.008−0.008|exp..展开更多
In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representati...In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representation of the correlation function,we isolate both the Λ_(c) and Λ_(c)^(∗) states so that the Λ_(b)→Λ_(c) form factors can be obtained without ambiguity.We investigate the P-type and A-type currents to interpolate light baryons for comparison because the interpolation current for the baryon state is not unique.We also employ three parametrization models for the DAs of Λ_(b) in the numerical calculation.We present the numerical predictions for the Λ_(b)→Λ_(c) form factors and branching fractions,averaged forward-backward asymmetry,averaged final hadron polarization,and averaged lepton polarization of the Λ_(b)→Λ_(c)ℓμ decays,as well as the ratio of the branching ratios RΛ_(c).The predicted RΛ_(c) is consistent with LHCb data.展开更多
We present an improved calculation of the strong coupling constants gD*Dp and gB*Bp in light-cone sum rules,including one-loop QCD corrections of leading power with meson distribution amplitudes.We further compute sub...We present an improved calculation of the strong coupling constants gD*Dp and gB*Bp in light-cone sum rules,including one-loop QCD corrections of leading power with meson distribution amplitudes.We further compute subleading-power corrections from two-particle and three-particle higher-twist contributions at leading order up to twist-4 accuracy.The next-to-leading order corrections to the leading power contribution numerically offset the subleading-power corrections to a certain extent,and our numerical results are consistent with those of previous studies on sum rules.A comparison between our results and existing model-dependent estimations is also made.展开更多
In this article, we take the point of view that the light scalar meson a0（980） is a conventional qqstate, and calculate the coupling constants ga0ηπ0 and ga0ηπ0 with the light-cone QCD sum rules. The central val...In this article, we take the point of view that the light scalar meson a0（980） is a conventional qqstate, and calculate the coupling constants ga0ηπ0 and ga0ηπ0 with the light-cone QCD sum rules. The central value of the coupling constant ga0ηπ0 is consistent with that extracted from the radiative decay φ（1020） → a0（980）γ→ηπ0γ. The central value and lower bound of the decay width Γa0→ηπ0 =127＋8448 MeV are compatible with the experimental data of the total decay width Γa0（980） = （50-100） MeV from the Particle Data Group with a very model dependent estimation （the decay width can be much larger）, while the upper bound is too large. We give a possible explanation for the discrepancy between the theoretical calculation and experimental data.展开更多
近视患病率逐年攀升,已成为全球性的重大公共卫生问题之一。目前的近视防控措施,如角膜塑形镜、离焦框架眼镜、软性离焦角膜接触镜、低浓度阿托品滴眼液均存在不足之处。重复低强度红光(RLRL)近年来成为儿童近视控制的手段之一。多项临...近视患病率逐年攀升,已成为全球性的重大公共卫生问题之一。目前的近视防控措施,如角膜塑形镜、离焦框架眼镜、软性离焦角膜接触镜、低浓度阿托品滴眼液均存在不足之处。重复低强度红光(RLRL)近年来成为儿童近视控制的手段之一。多项临床研究结果均表明,RLRL照射能够抑制儿童青少年近视的快速增长。近期一篇研究报告"Cone Density Changes After Repeated Low-Level Red Light Treatment in Children With Myopia"(《重复低强度红光治疗后近视儿童的视锥细胞密度变化》),在近视儿童的家长中引起了广泛讨论。本文详细分析此文章研究方法及结果,探讨是否能得出RLRL会影响近视儿童黄斑视锥细胞密度的结论。展开更多
In this paper,we calculate the scalar a_(0)(980)-meson leading-twist wave function by using the light-cone harmonic oscillator model(LCHO),where the model parameters are determined by fitting theξ-moments■of its lig...In this paper,we calculate the scalar a_(0)(980)-meson leading-twist wave function by using the light-cone harmonic oscillator model(LCHO),where the model parameters are determined by fitting theξ-moments■of its light-cone distribution amplitudes.Then,the a_(0)(980)-meson leading-twist light-cone distribution amplitudes with three different scalesζ=(1.0,2.0,5.2)Ge V are given.After constructing the relationship between the a_(0)(980)-meson leading-twist parton distribution functions/valence quark distribution function and its LCHO wave function,we exhibit the■(x,ζ)and■(x,ζ)with different scales.Furthermore,we also calculate the Mellin moments of the a_(0)(980)-meson’s valence quark distribution function■with n=(1,2,3),i.e.■=0.027,■=0.018 and■=0.013.Finally,the scale evolution for the ratio of the Mellin moments x■are presented.展开更多
It is noted that in the new Particle Data Group(PDG) version the rare decays of the Λ_(b) baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process...It is noted that in the new Particle Data Group(PDG) version the rare decays of the Λ_(b) baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process Λ_(b)→Λ_(γ) Lgbare larger than those of experiments. With the improved higher-order light-cone distribution amplitudes of the Λ baryon, we reanalyze the process in the framework of light-cone quantum chromodynamics sum rules and the branching ratio is estimated to be Br (Λ_(b)→Λ_(γ))=(7.38-0.39+0.40)×10^(16), which is consistent with the new experimental result. Furthermore, another process Λ_(b)→Λl+l- is also analyzed in the same frame. The final branching ratio is calculated to be Br (Λ_(b)→Λl+l-)=1.20×10^(-6), which is in good accordance with the data from the PDG and other theoretical predictions.展开更多
基金supported by the National Natural Science Foundation of China (Grant No 10775051)the Program for New Century Excellent Talents in University of China (Grant No NCET-07-0282)
文摘In this article, we calculate the contribution from the nonfactorizable soft hadronic matrix element to the decay B^0→Xc1π^0 with the light-cone quantum chromo-dynamic （QCD） sum rules. The numerical results show that its contribution is rather large and should not be neglected. The total amplitudes lead to a branching fraction which is in agreement with the experimental data marginally.
文摘If there exists a null gradient field in 3 + 1 dimensional space-time, we can set up a kind of light-cone coordinate system in the space-time. In such coordinate system, the metric takes a simple form, which is helpful for simplifying and solving the Einstein’s field equation. This light-cone coordinate system has wonderful properties and has been used widely in astrophysics to calculate parameters. We discuss the structure of space-time with light-cone coordinate system in detail. We show how to construct the light-cone coordinate system and obtain the conditions of its existence, and then explain their geometrical and physical meanings.
基金Supported by National Natural Science Foundation of China (11047014)
文摘We calculate the D → η transition form factor in light-cone sum rules by taking improved current correlators to avoid the pollution from the twist-3 wave function. We get consistent results of the D＋ → η^（＇）l＋νl decays with the experimental data. By comparing the difference between the results of the branching ratios of D＋ → η^（＇）l＋νl from a two-pole parameterization model and from a BZ parameterization model, we find that the two-pole model and the BZ model are comparably believable. One way is supposed for the determination of the η-η mixing angle from the dependence of the branching ratios of D＋ → η^（＇）l＋νl decays on the η-η mixing angle.
基金Supported by National Natural Science Foundation of China(10735080,10805082,10675098,11075053)the Fundamental Research Funds for the Central Universities
文摘In this article, we calculate the form-factors of the transitions B → a1（1260）, b1（1235） in the leading-order approximation using the light-cone QCD sum rules. In calculations, we choose the chiral current to interpolate the B-meson, which has the outstanding advantage that the twist-3 light-cone distribution amplitudes of the axial-vector mesons makes no contributions, and the resulting sum rules for the form-factors suffer from far fewer uncertainties. Then we study the semi-leptonic decays B → a1（1260） lvl, b1（1235） lvl （l=e,μ,τ）, and make predictions for the differential decay widths and decay widths, which can be compared with the experimental data in the coming future
基金supported by the National Natural Science Foundation of China(Grant Nos.12022512,12035007,12175016,12005065,12074180)the Guangdong Major Project of Basic and Applied Basic Research(Grant No.2020B0301030008)+3 种基金the Key-Area Research and Development Program of Guangdong Province(Grant No.2019B030330001)the Guangdong Basic and Applied Basic Research Fund(Grant No.2021A1515010317)the Key Project of Science and Technology of Guangzhou(Grant No.2019050001)the National Special Support Program for High-level Talents。
文摘Light-cone distribution amplitudes(LCDAs)are essential nonperturbative quantities for theoretical predictions of exclusive highenergy processes in quantum chromodynamics(QCD).We demonstrate the prospect of calculating LCDAs on a quantum computer by applying a recently proposed quantum algorithm,with staggered fermions,to the simulation of the LCDA in the(1+1)-dimensional Nambu-Jona-Lasinio(NJL)model on classical hardware.The agreement between the result from the classical simulation of the quantum algorithm and that from exact diagonalization justifies the proposed quantum algorithm.We find that the resulting LCDA in the NJL model exhibits features shared with the LCDAs obtained from the QCD.
基金the National Natural Science Foundation of China(11675082,11735010)the Natural Science Foundation of Tianjin(19JCJQJC61100)。
文摘We calculate the D→P transition form factors within the framework of the light-cone QCD sum rules(LCSR)with the D-meson light-cone distribution amplitudes(LCDAs).The next-to-leading power(NLP)corrections to the vacuum-to-D-meson correlation function are considered,and the NLP corrections from the high-twist D-meson LCDAs and the SU(3)breaking effect from a strange quark mass are investigated.Adopting the exponential model of the D-meson LCDAs,the SU(3)flavor symmetry breaking effects are predicted as R+,0 SU(3)=1.12 and R T SU(3)=1.39,respectively,confirming the results obtained from LCSR with pion LCDA.The numerical predictions of the form factors show that the contribution from two-particle higher-twist contributions is of great importance and the uncertainties are dominated by the inverse moment ofϕ+D(ω,μ).With the obtained form factors,the predicted Cabibbo-Kobayashi-Maskawa(CKM)matrix elements are|Vcd|=0.151+0.091−0.043|th.+0.017−0.02|exp.and|Vcs|=0.89+0.467−0.234|th.+0.008−0.008|exp..
基金Supported in part by the National Natural Science Foundation of China(12175218,11975112)the Natural Science Foundation of Shandong province with(ZR2020MA093)supported by the National Natural Science Foundation of China(12147118)。
文摘In this study,we calculate the transition form factors of Λ_(b) decaying into Λ_(c) within the framework of light-cone sum rules with the distribution amplitudes(DAs)of the Λ_(b)-baryon.In the hadronic representation of the correlation function,we isolate both the Λ_(c) and Λ_(c)^(∗) states so that the Λ_(b)→Λ_(c) form factors can be obtained without ambiguity.We investigate the P-type and A-type currents to interpolate light baryons for comparison because the interpolation current for the baryon state is not unique.We also employ three parametrization models for the DAs of Λ_(b) in the numerical calculation.We present the numerical predictions for the Λ_(b)→Λ_(c) form factors and branching fractions,averaged forward-backward asymmetry,averaged final hadron polarization,and averaged lepton polarization of the Λ_(b)→Λ_(c)ℓμ decays,as well as the ratio of the branching ratios RΛ_(c).The predicted RΛ_(c) is consistent with LHCb data.
基金Supported in part by National Natural Science Foundation of China(11521505)。
文摘We present an improved calculation of the strong coupling constants gD*Dp and gB*Bp in light-cone sum rules,including one-loop QCD corrections of leading power with meson distribution amplitudes.We further compute subleading-power corrections from two-particle and three-particle higher-twist contributions at leading order up to twist-4 accuracy.The next-to-leading order corrections to the leading power contribution numerically offset the subleading-power corrections to a certain extent,and our numerical results are consistent with those of previous studies on sum rules.A comparison between our results and existing model-dependent estimations is also made.
基金Supported by NSFC (10775051)Program for New Century Excellent Talents in University (NCET-07-0282)
文摘In this article, we take the point of view that the light scalar meson a0（980） is a conventional qqstate, and calculate the coupling constants ga0ηπ0 and ga0ηπ0 with the light-cone QCD sum rules. The central value of the coupling constant ga0ηπ0 is consistent with that extracted from the radiative decay φ（1020） → a0（980）γ→ηπ0γ. The central value and lower bound of the decay width Γa0→ηπ0 =127＋8448 MeV are compatible with the experimental data of the total decay width Γa0（980） = （50-100） MeV from the Particle Data Group with a very model dependent estimation （the decay width can be much larger）, while the upper bound is too large. We give a possible explanation for the discrepancy between the theoretical calculation and experimental data.
文摘近视患病率逐年攀升,已成为全球性的重大公共卫生问题之一。目前的近视防控措施,如角膜塑形镜、离焦框架眼镜、软性离焦角膜接触镜、低浓度阿托品滴眼液均存在不足之处。重复低强度红光(RLRL)近年来成为儿童近视控制的手段之一。多项临床研究结果均表明,RLRL照射能够抑制儿童青少年近视的快速增长。近期一篇研究报告"Cone Density Changes After Repeated Low-Level Red Light Treatment in Children With Myopia"(《重复低强度红光治疗后近视儿童的视锥细胞密度变化》),在近视儿童的家长中引起了广泛讨论。本文详细分析此文章研究方法及结果,探讨是否能得出RLRL会影响近视儿童黄斑视锥细胞密度的结论。
基金supported in part by the National Natural Science Foundation of China under Grant No.12265010,No.12265009the Project of Guizhou Provincial Department of Science and Technology under Grant No.ZK[2021]024the Project of Guizhou Provincial Department of Education under Grant No.KY[2021]030。
文摘In this paper,we calculate the scalar a_(0)(980)-meson leading-twist wave function by using the light-cone harmonic oscillator model(LCHO),where the model parameters are determined by fitting theξ-moments■of its light-cone distribution amplitudes.Then,the a_(0)(980)-meson leading-twist light-cone distribution amplitudes with three different scalesζ=(1.0,2.0,5.2)Ge V are given.After constructing the relationship between the a_(0)(980)-meson leading-twist parton distribution functions/valence quark distribution function and its LCHO wave function,we exhibit the■(x,ζ)and■(x,ζ)with different scales.Furthermore,we also calculate the Mellin moments of the a_(0)(980)-meson’s valence quark distribution function■with n=(1,2,3),i.e.■=0.027,■=0.018 and■=0.013.Finally,the scale evolution for the ratio of the Mellin moments x■are presented.
文摘It is noted that in the new Particle Data Group(PDG) version the rare decays of the Λ_(b) baryon have been revised with more accuracy. The new results show that most of the existing theoretical results on the process Λ_(b)→Λ_(γ) Lgbare larger than those of experiments. With the improved higher-order light-cone distribution amplitudes of the Λ baryon, we reanalyze the process in the framework of light-cone quantum chromodynamics sum rules and the branching ratio is estimated to be Br (Λ_(b)→Λ_(γ))=(7.38-0.39+0.40)×10^(16), which is consistent with the new experimental result. Furthermore, another process Λ_(b)→Λl+l- is also analyzed in the same frame. The final branching ratio is calculated to be Br (Λ_(b)→Λl+l-)=1.20×10^(-6), which is in good accordance with the data from the PDG and other theoretical predictions.
