The quantum chromodynamics(QCD) coupling αs is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling α_(s)^(g)1)(Q) defined from the Bjorken sum rules as a...The quantum chromodynamics(QCD) coupling αs is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling α_(s)^(g)1)(Q) defined from the Bjorken sum rules as a basis, we suggest a novel self-consistency way to fix the αs at all scales: The QCD light-front holographic model is adopted for its infrared behavior, and the fixed-order p QCD prediction under the principle of maximum conformality(PMC) is used for its high-energy behavior. Using the PMC scheme-and-scale independent perturbative series,and by transforming it into the one under the physical V scheme, we observe that a precise αs running behavior in both the perturbative and nonperturbative domains with a smooth transition from small to large scales can be achieved.展开更多
The principle of maximum conformality(PMC)provides a systematic approach to solve the conventional renormalization scheme and scale ambiguities.Scale-fixed predictions of physical observables using the PMC are indepen...The principle of maximum conformality(PMC)provides a systematic approach to solve the conventional renormalization scheme and scale ambiguities.Scale-fixed predictions of physical observables using the PMC are independent of the choice of renormalization scheme–a key requirement for renormalization group invariance.In this paper,we derive new degeneracy relations based on the renormalization group equations that involve both the usualβ-function and the quark mass anomalous dimensionγm-function.These new degeneracy relations enable improved PMC scale-setting procedures for correct magnitudes of the strong coupling constant and MS¯-running quark mass to be determined simultaneously.By using these improved PMC scale-setting procedures,the renormalization scale dependence of the MS¯-on-shell quark mass relation can be eliminated systematically.Consequently,the top-quark on-shell(or MS¯)mass can be determined without conventional renormalization scale ambiguity.Taking the top-quark MS¯mass m¯t(m¯t)=162.5+2.1−1.5 GeV as the input,we obtain Mt≃172.41+2.21−1.57 GeV.Here,the uncertainties arise from errors combined with those fromΔαs(MZ)and the approximate uncertainty resulting from the uncalculated five-loop terms predicted through the Padéapproximation approach.展开更多
The decay channel H→γγis an important channel for probing the properties of the Higgs boson.In this paper,we analyze its decay width by using the perturbative QCD corrections up to theα4s order with the help of th...The decay channel H→γγis an important channel for probing the properties of the Higgs boson.In this paper,we analyze its decay width by using the perturbative QCD corrections up to theα4s order with the help of the principle of maximum conformality(PMC).PMC has been suggested in literature for eliminating the conventional renormalization scheme-and-scale ambiguities.After applying PMC,we observe that an accurate renormalization scale independent decay widthΓ(H→γγ)up to the N4LO level can be achieved.Taking the Higgs mass,MH=125.09±0.21±0.11 GeV,given by the ATLAS and CMS collaborations,we obtainΓ(H→γγ)|LHC=9.364+0.076-0.075 KeV.展开更多
To the Editor: Smartphones have also changed the exposure of human eyes to light. As all the spectral peaks for smartphones are very similar to short-wavelength blue visible light,[1] it is not surprising that eye dam...To the Editor: Smartphones have also changed the exposure of human eyes to light. As all the spectral peaks for smartphones are very similar to short-wavelength blue visible light,[1] it is not surprising that eye damage with smartphones has raised public concerns. In this article, we describe one patient with suspected macular light damage caused by the excessive use of a smartphone.展开更多
In this study,we investigate in detail the generalized Crewther Relation(GCR)between the Adler function(D)and the Gross-Llewellyn Smith sum rules coefficient(C^(GLS))using the newly proposed single-scale approach of t...In this study,we investigate in detail the generalized Crewther Relation(GCR)between the Adler function(D)and the Gross-Llewellyn Smith sum rules coefficient(C^(GLS))using the newly proposed single-scale approach of the principle of maximum conformality(PMC).The resultant GCR is scheme-independent,with the residual scale dependence due to unknown higher-order terms highly suppressed.Thus,a precise test of QCD theory without renormalization schemes and scale ambiguities can be achieved by comparing with data.Moreover,a demonstration of the scheme independence of the commensurate scale relation up to all orders is presented.Additionally,for the first time,the Pade approximation approach has been adopted for estimating the unknown 5th-loop contributions from the known four-loop perturbative series.展开更多
We conducted a detailed study on the properties of the total decay width of the Higgs decay channel H→gg up toα_(s)^(6)-order QCD corrections by using the newly suggested infinite-order scale-setting approach,which ...We conducted a detailed study on the properties of the total decay width of the Higgs decay channel H→gg up toα_(s)^(6)-order QCD corrections by using the newly suggested infinite-order scale-setting approach,which is based on both the principle of maximum conformality and intrinsic conformality.This approach is called PMC_(∞) By using the PMC_(∞)approach,we observed that the conventional renormalization scale ambiguity in perturbative QCD calculation is eliminated,and the residual scale dependence due to unknown higher-order terms can also be highly suppressed.We then obtained an accurate perturbative QCD prediction on the total decay width,e.g.,Г(H→gg)|PMC_(∞)=336.42_(-6.92)^(+7.01)keV,where the errors are squared averages of those from all the mentioned error sources.展开更多
基金supported in part by the Chongqing Graduate Research and Innovation Foundation (Grant Nos. CYB21045 and ydstd1912)the National Natural Science Foundation of China (Grant Nos. 11905056, 12175025, and 12147102)the Fundamental Research Funds for the Central Universities (Grant No. 2020CQJQYZ003)。
文摘The quantum chromodynamics(QCD) coupling αs is the most important parameter for achieving precise QCD predictions. By using the well measured effective coupling α_(s)^(g)1)(Q) defined from the Bjorken sum rules as a basis, we suggest a novel self-consistency way to fix the αs at all scales: The QCD light-front holographic model is adopted for its infrared behavior, and the fixed-order p QCD prediction under the principle of maximum conformality(PMC) is used for its high-energy behavior. Using the PMC scheme-and-scale independent perturbative series,and by transforming it into the one under the physical V scheme, we observe that a precise αs running behavior in both the perturbative and nonperturbative domains with a smooth transition from small to large scales can be achieved.
基金Supported in part by the National Natural Science Foundation of China(12247129,12175025,12347101)the Graduate Research and Innovation Foundation of Chongqing,China(ydstd1912)。
文摘The principle of maximum conformality(PMC)provides a systematic approach to solve the conventional renormalization scheme and scale ambiguities.Scale-fixed predictions of physical observables using the PMC are independent of the choice of renormalization scheme–a key requirement for renormalization group invariance.In this paper,we derive new degeneracy relations based on the renormalization group equations that involve both the usualβ-function and the quark mass anomalous dimensionγm-function.These new degeneracy relations enable improved PMC scale-setting procedures for correct magnitudes of the strong coupling constant and MS¯-running quark mass to be determined simultaneously.By using these improved PMC scale-setting procedures,the renormalization scale dependence of the MS¯-on-shell quark mass relation can be eliminated systematically.Consequently,the top-quark on-shell(or MS¯)mass can be determined without conventional renormalization scale ambiguity.Taking the top-quark MS¯mass m¯t(m¯t)=162.5+2.1−1.5 GeV as the input,we obtain Mt≃172.41+2.21−1.57 GeV.Here,the uncertainties arise from errors combined with those fromΔαs(MZ)and the approximate uncertainty resulting from the uncalculated five-loop terms predicted through the Padéapproximation approach.
基金Supported in part by Natural Science Foundation of China(11625520,11547010,11847301,11705033)the Project of Guizhou Provincial Department of Science and Technology(2016GZ42963)+2 种基金the Key Project for Innovation Research Groups of Guizhou Provincial Department of Education(KY[2016]028,KY[2017]067)the Fundamental Research Funds for the Central Universities(2019CDJDWL0005)the graduate scientific research and innovation foundation of Chongqing(CYS19021)
文摘The decay channel H→γγis an important channel for probing the properties of the Higgs boson.In this paper,we analyze its decay width by using the perturbative QCD corrections up to theα4s order with the help of the principle of maximum conformality(PMC).PMC has been suggested in literature for eliminating the conventional renormalization scheme-and-scale ambiguities.After applying PMC,we observe that an accurate renormalization scale independent decay widthΓ(H→γγ)up to the N4LO level can be achieved.Taking the Higgs mass,MH=125.09±0.21±0.11 GeV,given by the ATLAS and CMS collaborations,we obtainΓ(H→γγ)|LHC=9.364+0.076-0.075 KeV.
文摘To the Editor: Smartphones have also changed the exposure of human eyes to light. As all the spectral peaks for smartphones are very similar to short-wavelength blue visible light,[1] it is not surprising that eye damage with smartphones has raised public concerns. In this article, we describe one patient with suspected macular light damage caused by the excessive use of a smartphone.
基金Supported by the Chongqing Graduate Research and Innovation Foundation(ydstd1912,CYB21045)the National Natural Science Foundation of China(11625520,12047564)the Fundamental Research Funds for the Central Universities(2020CQJQY-Z003)。
文摘In this study,we investigate in detail the generalized Crewther Relation(GCR)between the Adler function(D)and the Gross-Llewellyn Smith sum rules coefficient(C^(GLS))using the newly proposed single-scale approach of the principle of maximum conformality(PMC).The resultant GCR is scheme-independent,with the residual scale dependence due to unknown higher-order terms highly suppressed.Thus,a precise test of QCD theory without renormalization schemes and scale ambiguities can be achieved by comparing with data.Moreover,a demonstration of the scheme independence of the commensurate scale relation up to all orders is presented.Additionally,for the first time,the Pade approximation approach has been adopted for estimating the unknown 5th-loop contributions from the known four-loop perturbative series.
基金Supported by the Chongqing Graduate Research and Innovation Foundation(CYB21045,ydstd1912)the Natural Science Foundation of China(12175025,12147102)the Fundamental Research Funds for the Central Universities(2020CQJQY-Z003,2021CDJZYJH-003)。
文摘We conducted a detailed study on the properties of the total decay width of the Higgs decay channel H→gg up toα_(s)^(6)-order QCD corrections by using the newly suggested infinite-order scale-setting approach,which is based on both the principle of maximum conformality and intrinsic conformality.This approach is called PMC_(∞) By using the PMC_(∞)approach,we observed that the conventional renormalization scale ambiguity in perturbative QCD calculation is eliminated,and the residual scale dependence due to unknown higher-order terms can also be highly suppressed.We then obtained an accurate perturbative QCD prediction on the total decay width,e.g.,Г(H→gg)|PMC_(∞)=336.42_(-6.92)^(+7.01)keV,where the errors are squared averages of those from all the mentioned error sources.
