The present article develops a model initially published in ref. [1]. It is a quasi-classical quantum model of composite particles with ultra-relativistic (UR) constituents (leptons and quarks). The model is used to c...The present article develops a model initially published in ref. [1]. It is a quasi-classical quantum model of composite particles with ultra-relativistic (UR) constituents (leptons and quarks). The model is used to calculate the mass energy of three composite particles: a UR tauonium, a UR bottomonium and a UR leptoquarkonium. The result is that these three hypothetic particles have masses close to 125 GeV: the Higgs boson mass energy. These results are recalled in the present article. Then the model is extended to calculate the mass energy of <i>pi</i>-mesons, <i>W</i> and <i>Z</i> bosons. Finally, the model provides a hypothesis on dark matter.展开更多
The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants including particles and bosons are associated with specific quantum integers, n. These integers define partial har...The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants including particles and bosons are associated with specific quantum integers, n. These integers define partial harmonic fractional exponents, 1 ± (1/n), of a fundamental frequency, Vf. The goal is to evaluate the prime and composite factors associated with the neutron n0, the quarks, the kinetic energy of neutron beta decay, the Rydberg constant, R, e, a0, H0, h, α, W, Z, the muon, and the neutron gluon. Their pure number characteristics correspond and explain the hierarchy of the particles and bosons. The elements and black body radiation represent consecutive integer series. The relative scale of the constants cluster in a partial harmonic fraction pattern around the neutron. The global numerical organization is related to the only possible prime factor partial fractions of 2/3, or 3/2, as pairs of 3 physical entities with a total of 6 in each group. Many other progressively resonant prime number factor patterns are identified with increasing numbers of smaller factors, higher primes, or larger partial fractions associated with higher order particles or bosons.展开更多
为了研究LHCb 7 TeV W+、W-和Z实验数据对CT14HERA2部分子分布函数(Parton Distribution Functions,PDFs)的影响,首先将收集到的数据进行了理论预测并将其和实验测量结果进行了比较,在误差允许的范围内理论和实验符合的很好。其次,用误...为了研究LHCb 7 TeV W+、W-和Z实验数据对CT14HERA2部分子分布函数(Parton Distribution Functions,PDFs)的影响,首先将收集到的数据进行了理论预测并将其和实验测量结果进行了比较,在误差允许的范围内理论和实验符合的很好。其次,用误差PDFs更新软件包(Error PDFs Updated Method Package,EPUMP)更新了CT14HERA2 PDFs,并和全局拟合的PDFs进行了比较。最后,加入协方差矩阵后的实验数据可以在较大和较小的x区域减少d(x,Q)/u(x,Q)误差,同时也对CT14HERA2 PDFs进行了优化。验证结果表明,LHCb 7 TeV W+、W-和Z产生的实验数据在较大的x区域对g(x,Q)、d(x,Q)、d(x,Q)/u(x,Q)、d(x,Q)/u(x,Q)、u(x,Q)、d(x,Q)和u(x,Q)PDFs的中心值约束较大,可以用前4个误差PDFs代替原来全局拟合或优化后得到的56个误差集。展开更多
Heavy neutral gauge boson Z' is proposed in many new physics models.It has rich phenomena at the future muon collider.We study the properties of Z' boson with the process of μ^(+)μ^(-)→qq,μ^(+)μ^(-)→l^(+...Heavy neutral gauge boson Z' is proposed in many new physics models.It has rich phenomena at the future muon collider.We study the properties of Z' boson with the process of μ^(+)μ^(-)→qq,μ^(+)μ^(-)→l^(+)l^(-),μ^(+)μ^(-)→ ZH and μ^(+)μ^(-)→ W^(+)W^(-).The discrepancy of Z' coupling to different types of particles can be shown in the cross section distributions around the resonance peak of various decay modes.Angular distributions of the final quark or lepton in μ^(+)μ^(-)→qq/l^(+)l^(-)process are sensitive to the parameters such as mass of Z' and the Z-Z' mixing angle.The interaction of new gauge boson coupling to the standard model gauge particles and Higgs boson are also studied through μ^(+)μ^(-)→ ZH→l^(+)l^(-)bb and μ^(+)u^(-)→ W^(+)W^(-)→l^(+)l^(-)v_(l)v_(l).The cross section and the final particles' angular distributions with the contribution of Z' boson differ from those processes with only standard model particles.A forward-backward asymmetry defined by the angular distribution is provided to show the potential of searching for new physics at the muon collider.Especially,the beam polarization with certain value can effectively enlarge the forward-backward asymmetry.展开更多
A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity...A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit.展开更多
The hitherto unconstrained lepton flavor mixings,induced by the new gauge boson Z ,which are the prediction of many new physics models,such as topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models...The hitherto unconstrained lepton flavor mixings,induced by the new gauge boson Z ,which are the prediction of many new physics models,such as topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models,may lead to the lepton flavor violating productions of τμˉ,τeˉ and μeˉ in photon-photon collision at the proposed International Linear Collider (ILC).Through a comparative analysis of these processes,we find that the better channel to probe the new physics models is the production of τμˉ or τeˉ which occurs at a much higher rate than μeˉ production due to the large mixing angle and the large flavor changing coupling,and may reach the detectable level of the ILC for a large part of the parameter space.Since the rates predicted by the Standard Model are far below the detectable level,these processes may serve as a sensitive probe for such new physics models.展开更多
The production of the three normal neutrinos via e-e+ collision at Z-boson peak(neutrino production in a Z-factory) is investigated thoroughly. The differences of νe-pair production from νμ-pair and ντ-pair produ...The production of the three normal neutrinos via e-e+ collision at Z-boson peak(neutrino production in a Z-factory) is investigated thoroughly. The differences of νe-pair production from νμ-pair and ντ-pair production are presented in various aspects. Namely the total cross sections, relevant differential cross sections and the forwardbackward asymmetry etc. for these neutrinos are presented in terms of figures as well as numerical tables. The restriction on the room for the mixing of the three species of light neutrinos with possible externals(heavy neutral leptons and/or sterile neutrinos) from refined measurements of the invisible width of Z-boson is discussed.展开更多
At the designed circular electron-positron collider(CEPC), similar to the hadron collider, the angular distribution coefficients of the decay lepton pair from the produced Z(W) boson in e^+e^- collisions are predicted...At the designed circular electron-positron collider(CEPC), similar to the hadron collider, the angular distribution coefficients of the decay lepton pair from the produced Z(W) boson in e^+e^- collisions are predicted. Their dependence on cosθZ(cosθW) are presented in four different polarization frames. Furthermore, the value of the angular distribution coefficients in different bins of cosθZ are presented in the C-S frame. In comparison with the case at the hadron collider, better accurate measurement for Z(W) is expected because there is less background, and W could be reconstructed from its leptonic decay channel. This works provides a method to precisely test the electroweak production mechanism or some effect induced from new physics in the future measurements at the CEPC.展开更多
A new general parameterization with eight mixing parameters among Z, γ and an extra neutral gauge boson Z is proposed and subjected to phenomenological analysis. We show that in addition to the conventional Weinberg ...A new general parameterization with eight mixing parameters among Z, γ and an extra neutral gauge boson Z is proposed and subjected to phenomenological analysis. We show that in addition to the conventional Weinberg angle θW , there are seven other phenomenological parameters, G , ξ, η, θl, θr, r and l, for the most general Z-γ-Z mixings, in which parameter G arises due to the presence of an extra Stueckelberg- type mass coupling. Combined with the conventional Z-Z mass mixing angle θ , the remaining six parameters, ξ, η, θl θ , θr θ , r and l, are caused by general kinetic mixing. In all eight phenomenological parameters, θW , G , ξ, η, θl, θr , r and l, we can determine the Z-Z mass mixing angle θ and the mass ratio MZ/MZ . The Z-γ-Z mixing that we discuss are based on the model-independent description of the extended electroweak chiral Lagrangian （EWCL） previously proposed by us. In addition, we show that there are eight corresponding independent theoretical coefficients in our EWCL, which are fully fixed by our eight phenomenological mixing parameters. We further find that the experimental measurability of these eight parameters does not rely on the extended neutral current for Z , but depends on the Z-Z mass ratio.展开更多
We study the potential of the LHCb 13 TeV single W±and Z boson pseudo-data for constraining the parton distribution functions(PDFs)of the proton.As an example,we demonstrate the sensitivity of the LHCb 13 TeV dat...We study the potential of the LHCb 13 TeV single W±and Z boson pseudo-data for constraining the parton distribution functions(PDFs)of the proton.As an example,we demonstrate the sensitivity of the LHCb 13 TeV data,collected with integrated luminosities of 5fb^(-1) and 300 fb^(-1) ,to reducing the PDF uncertainty bands of the CT14HERA2 PDFs,using the error PDF updating package EPUMP.The sensitivities of various experimental observables are compared.Generally,sizable reductions in PDF uncertainties can be observed in the 300fb^(-1) data sample,particularly in the small-x region.The double-differential cross section measurement of Z boson pT and rapidity can greatly reduce the uncertainty bands of u and d quarks in almost the whole x range,as compared to various single observable measurements.展开更多
We investigate the rare baryonic Λ_b→Λl^＋l^- decays in a non-universal Z＇ model, which is one of the wellmotivated extensions of the standard model（SM）. Considering the effects of Z-mediated flavour-changing ne...We investigate the rare baryonic Λ_b→Λl^＋l^- decays in a non-universal Z＇ model, which is one of the wellmotivated extensions of the standard model（SM）. Considering the effects of Z-mediated flavour-changing neutral currents（FCNCs） we analyse the differential decay rate, forward-backward asymmetries and lepton polarisation asymmetries for the Λb→Λl^＋l^- decays. We find significant deviations from their SM predictions, which could indicate new physics arising from the Z gauge boson.展开更多
The indirect estimation of the Higgs Boson mass from electroweak radiative corrections within the Standard Model is compared with the directly measured value obtained by the ATLAS and CMS Collaborations at the CERN LH...The indirect estimation of the Higgs Boson mass from electroweak radiative corrections within the Standard Model is compared with the directly measured value obtained by the ATLAS and CMS Collaborations at the CERN LHC collider. Treating the direct measurement of m_H as input, the Standard Model indirect estimation of the top-quark mass is also obtained and compared with its directly measured value. A model-independent analysis finds an indirect value of m_H of ■70 GeV, below the directly measured value of 125.7±0.4 GeV and an indirect value：m_t = 177.3±1.0 GeV, above the directly measured value： 173.21±0.87 GeV. A goodness-of-fit test to the Standard Model using all Z-pole observables and mW has a χ~2 probability of ■2%. The reason why probability values about a factor of ten larger than this, and indirect estimates of m H about 30 GeV higher, have been obtained in recent global fits to the same data is recalled.展开更多
We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and discuss its phenomenology at colliders in the allowed parameter space.The constraints we consider come from the pre...We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and discuss its phenomenology at colliders in the allowed parameter space.The constraints we consider come from the precision electroweak data,the direct search for Higgs boson,the muon anomalous magnetic moment,as well as some theoretical consistency requirements.We find that in the allowed parameter space the CP-odd Higgs boson A is rather light (m A < 30 GeV with 95% possibility),which is composed dominantly by the leptonic Higgs and decays dominantly into τ + τ;while the SM-like Higgs boson h (responsible largely for electroweak symmetry breaking) decays dominantly in the mode h → AA → 4τ with a large decay width,which will make the Higgs discovery more difficult at the LHC.Whereas,this scenario predicts rare Z decays Z → AAA and Z →τ + τA with their branching ratios ranging from 10-8 to 10-and 10-5 to 10-4 respectively,which may be accessible at the GigaZ option of the ILC.展开更多
文摘The present article develops a model initially published in ref. [1]. It is a quasi-classical quantum model of composite particles with ultra-relativistic (UR) constituents (leptons and quarks). The model is used to calculate the mass energy of three composite particles: a UR tauonium, a UR bottomonium and a UR leptoquarkonium. The result is that these three hypothetic particles have masses close to 125 GeV: the Higgs boson mass energy. These results are recalled in the present article. Then the model is extended to calculate the mass energy of <i>pi</i>-mesons, <i>W</i> and <i>Z</i> bosons. Finally, the model provides a hypothesis on dark matter.
文摘The Harmonic Neutron Hypothesis, HNH, has demonstrated that many of the fundamental physical constants including particles and bosons are associated with specific quantum integers, n. These integers define partial harmonic fractional exponents, 1 ± (1/n), of a fundamental frequency, Vf. The goal is to evaluate the prime and composite factors associated with the neutron n0, the quarks, the kinetic energy of neutron beta decay, the Rydberg constant, R, e, a0, H0, h, α, W, Z, the muon, and the neutron gluon. Their pure number characteristics correspond and explain the hierarchy of the particles and bosons. The elements and black body radiation represent consecutive integer series. The relative scale of the constants cluster in a partial harmonic fraction pattern around the neutron. The global numerical organization is related to the only possible prime factor partial fractions of 2/3, or 3/2, as pairs of 3 physical entities with a total of 6 in each group. Many other progressively resonant prime number factor patterns are identified with increasing numbers of smaller factors, higher primes, or larger partial fractions associated with higher order particles or bosons.
文摘为了研究LHCb 7 TeV W+、W-和Z实验数据对CT14HERA2部分子分布函数(Parton Distribution Functions,PDFs)的影响,首先将收集到的数据进行了理论预测并将其和实验测量结果进行了比较,在误差允许的范围内理论和实验符合的很好。其次,用误差PDFs更新软件包(Error PDFs Updated Method Package,EPUMP)更新了CT14HERA2 PDFs,并和全局拟合的PDFs进行了比较。最后,加入协方差矩阵后的实验数据可以在较大和较小的x区域减少d(x,Q)/u(x,Q)误差,同时也对CT14HERA2 PDFs进行了优化。验证结果表明,LHCb 7 TeV W+、W-和Z产生的实验数据在较大的x区域对g(x,Q)、d(x,Q)、d(x,Q)/u(x,Q)、d(x,Q)/u(x,Q)、u(x,Q)、d(x,Q)和u(x,Q)PDFs的中心值约束较大,可以用前4个误差PDFs代替原来全局拟合或优化后得到的56个误差集。
基金supported by the Natural Science Foundation of Shandong Province (Grant No. ZR2022MA065)the National Natural Science Foundation of China (Grant No. 12235008)。
文摘Heavy neutral gauge boson Z' is proposed in many new physics models.It has rich phenomena at the future muon collider.We study the properties of Z' boson with the process of μ^(+)μ^(-)→qq,μ^(+)μ^(-)→l^(+)l^(-),μ^(+)μ^(-)→ ZH and μ^(+)μ^(-)→ W^(+)W^(-).The discrepancy of Z' coupling to different types of particles can be shown in the cross section distributions around the resonance peak of various decay modes.Angular distributions of the final quark or lepton in μ^(+)μ^(-)→qq/l^(+)l^(-)process are sensitive to the parameters such as mass of Z' and the Z-Z' mixing angle.The interaction of new gauge boson coupling to the standard model gauge particles and Higgs boson are also studied through μ^(+)μ^(-)→ ZH→l^(+)l^(-)bb and μ^(+)u^(-)→ W^(+)W^(-)→l^(+)l^(-)v_(l)v_(l).The cross section and the final particles' angular distributions with the contribution of Z' boson differ from those processes with only standard model particles.A forward-backward asymmetry defined by the angular distribution is provided to show the potential of searching for new physics at the muon collider.Especially,the beam polarization with certain value can effectively enlarge the forward-backward asymmetry.
文摘A search for the rare decays W^(+)→D_(s)^(+)γ and Z→D0γis performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV,corresponding to an integrated luminosity of 2.0fb−1.No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W^(+)→D_(s)^(+)γ and Z→μ+μ−decays as normalization channels.The upper limits are 6.5×10^(−4) and 2.1×10^(−3) at 95% confidence level for the W^(+)→D_(s)^(+)γ and Z→D^(0)γ decay modes,respectively.This is the first reported search for the Z→D^(0)γ decay,while the upper limit on the W+→D+sγbranching fraction improves upon the previous best limit.
文摘The hitherto unconstrained lepton flavor mixings,induced by the new gauge boson Z ,which are the prediction of many new physics models,such as topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models,may lead to the lepton flavor violating productions of τμˉ,τeˉ and μeˉ in photon-photon collision at the proposed International Linear Collider (ILC).Through a comparative analysis of these processes,we find that the better channel to probe the new physics models is the production of τμˉ or τeˉ which occurs at a much higher rate than μeˉ production due to the large mixing angle and the large flavor changing coupling,and may reach the detectable level of the ILC for a large part of the parameter space.Since the rates predicted by the Standard Model are far below the detectable level,these processes may serve as a sensitive probe for such new physics models.
基金Supported by the National Natural Science Foundation of China(NNSFC) under Grant Nos.11275243,11147001,11275036,11047002,11205227the open project of State Key Laboratory of Theoretical Physics under Grant No.Y3KF311CJ1+1 种基金the Natural Science Foundation of Hebei province under Grant No.A2013201277Natural Science Foundation of Hebei University under Grant Nos.2011JQ05,2012-242.1
文摘The production of the three normal neutrinos via e-e+ collision at Z-boson peak(neutrino production in a Z-factory) is investigated thoroughly. The differences of νe-pair production from νμ-pair and ντ-pair production are presented in various aspects. Namely the total cross sections, relevant differential cross sections and the forwardbackward asymmetry etc. for these neutrinos are presented in terms of figures as well as numerical tables. The restriction on the room for the mixing of the three species of light neutrinos with possible externals(heavy neutral leptons and/or sterile neutrinos) from refined measurements of the invisible width of Z-boson is discussed.
基金Supported by National Natural Science Foundation of China(11475183)the Key Research Program of Frontier Sciences,CAS,(Y7292610K1)
文摘At the designed circular electron-positron collider(CEPC), similar to the hadron collider, the angular distribution coefficients of the decay lepton pair from the produced Z(W) boson in e^+e^- collisions are predicted. Their dependence on cosθZ(cosθW) are presented in four different polarization frames. Furthermore, the value of the angular distribution coefficients in different bins of cosθZ are presented in the C-S frame. In comparison with the case at the hadron collider, better accurate measurement for Z(W) is expected because there is less background, and W could be reconstructed from its leptonic decay channel. This works provides a method to precisely test the electroweak production mechanism or some effect induced from new physics in the future measurements at the CEPC.
基金Supported by National Natural Science Foundation of China(10875065,10947152,11005084)
文摘A new general parameterization with eight mixing parameters among Z, γ and an extra neutral gauge boson Z is proposed and subjected to phenomenological analysis. We show that in addition to the conventional Weinberg angle θW , there are seven other phenomenological parameters, G , ξ, η, θl, θr, r and l, for the most general Z-γ-Z mixings, in which parameter G arises due to the presence of an extra Stueckelberg- type mass coupling. Combined with the conventional Z-Z mass mixing angle θ , the remaining six parameters, ξ, η, θl θ , θr θ , r and l, are caused by general kinetic mixing. In all eight phenomenological parameters, θW , G , ξ, η, θl, θr , r and l, we can determine the Z-Z mass mixing angle θ and the mass ratio MZ/MZ . The Z-γ-Z mixing that we discuss are based on the model-independent description of the extended electroweak chiral Lagrangian （EWCL） previously proposed by us. In addition, we show that there are eight corresponding independent theoretical coefficients in our EWCL, which are fully fixed by our eight phenomenological mixing parameters. We further find that the experimental measurability of these eight parameters does not rely on the extended neutral current for Z , but depends on the Z-Z mass ratio.
基金Supported by the National Natural Science Foundation of China(11875142,11965020)the U.S.National Science Foundation(PHY-2013791.C-P)。
文摘We study the potential of the LHCb 13 TeV single W±and Z boson pseudo-data for constraining the parton distribution functions(PDFs)of the proton.As an example,we demonstrate the sensitivity of the LHCb 13 TeV data,collected with integrated luminosities of 5fb^(-1) and 300 fb^(-1) ,to reducing the PDF uncertainty bands of the CT14HERA2 PDFs,using the error PDF updating package EPUMP.The sensitivities of various experimental observables are compared.Generally,sizable reductions in PDF uncertainties can be observed in the 300fb^(-1) data sample,particularly in the small-x region.The double-differential cross section measurement of Z boson pT and rapidity can greatly reduce the uncertainty bands of u and d quarks in almost the whole x range,as compared to various single observable measurements.
基金SERB,DST,Government of India for financial support(EMR/2015/000817)
文摘We investigate the rare baryonic Λ_b→Λl^＋l^- decays in a non-universal Z＇ model, which is one of the wellmotivated extensions of the standard model（SM）. Considering the effects of Z-mediated flavour-changing neutral currents（FCNCs） we analyse the differential decay rate, forward-backward asymmetries and lepton polarisation asymmetries for the Λb→Λl^＋l^- decays. We find significant deviations from their SM predictions, which could indicate new physics arising from the Z gauge boson.
文摘The indirect estimation of the Higgs Boson mass from electroweak radiative corrections within the Standard Model is compared with the directly measured value obtained by the ATLAS and CMS Collaborations at the CERN LHC collider. Treating the direct measurement of m_H as input, the Standard Model indirect estimation of the top-quark mass is also obtained and compared with its directly measured value. A model-independent analysis finds an indirect value of m_H of ■70 GeV, below the directly measured value of 125.7±0.4 GeV and an indirect value：m_t = 177.3±1.0 GeV, above the directly measured value： 173.21±0.87 GeV. A goodness-of-fit test to the Standard Model using all Z-pole observables and mW has a χ~2 probability of ■2%. The reason why probability values about a factor of ten larger than this, and indirect estimates of m H about 30 GeV higher, have been obtained in recent global fits to the same data is recalled.
基金supported in part by the National Natural Science Foundation of China (NNSFC) (Grant Nos.10505007,10821504,10725526 and 10635030)HASTIT (Grant No.2009HASTIT004)the Project of Knowledge Innovation Program (PKIP) of Chinese Academy of Sciences (Grant No.KJCX2.YW.W10)
文摘We examine various direct and indirect constraints on the lepton-specific two-Higgs doublet model and discuss its phenomenology at colliders in the allowed parameter space.The constraints we consider come from the precision electroweak data,the direct search for Higgs boson,the muon anomalous magnetic moment,as well as some theoretical consistency requirements.We find that in the allowed parameter space the CP-odd Higgs boson A is rather light (m A < 30 GeV with 95% possibility),which is composed dominantly by the leptonic Higgs and decays dominantly into τ + τ;while the SM-like Higgs boson h (responsible largely for electroweak symmetry breaking) decays dominantly in the mode h → AA → 4τ with a large decay width,which will make the Higgs discovery more difficult at the LHC.Whereas,this scenario predicts rare Z decays Z → AAA and Z →τ + τA with their branching ratios ranging from 10-8 to 10-and 10-5 to 10-4 respectively,which may be accessible at the GigaZ option of the ILC.
