A nonzero neutrino mass may be a sign of new physics beyond the standard model(SM).To explain the small neutrino mass,we can extend the SM using right-handed Majorana neutrinos in a low-scale seesaw mechanism,and the ...A nonzero neutrino mass may be a sign of new physics beyond the standard model(SM).To explain the small neutrino mass,we can extend the SM using right-handed Majorana neutrinos in a low-scale seesaw mechanism,and the CP violation effect can be induced due to the CP phase in the interference of heavy Majorana neutrinos.The existence of heavy Majorana neutrinos may lead to lepton number violation processes,which can be used to search for the signals of heavy Majorana neutrinos.In this paper,we focus on the CP violation effect related to two generations of heavy Majorana neutrinos at 15 GeV<m_(N1)<70 GeV in the pair production of W bosons and rare decays.It is valuable to investigate Majorana neutrino production signals and the related CP violation effects in rare W boson decays at future lepton colliders.展开更多
A previous preon scenario for the standard model particles, based on unbroken supersymmetry, is applied to the problem of matter-antimatter asymmetry. Attention is paid to the fact that the asymmetric hydrogen atom—l...A previous preon scenario for the standard model particles, based on unbroken supersymmetry, is applied to the problem of matter-antimatter asymmetry. Attention is paid to the fact that the asymmetric hydrogen atom—like all atoms—can be described in terms of symmetric preons. Preons are created in the early universe. The matter-antimatter asymmetry is caused by stochastic correlations in charge density fluctuations of preons and antipreons and by the subsequent preon combinatorial mechanism to form quarks and leptons, and finally the three lightest elements. A tentative gravitino mass estimate is given based on minimal interference with nucleosynthesis. With local supersymmetry the scenario can be extended to supergravity.展开更多
We present one-loop contributions for h→ℓℓγ with ℓ=νe,μ,τ,e,μ and e−e+→hγ in the U(1)_(B−L) extension of the standard model. In the phenomenological results, the signal strengths for h→ℓℓγ at the Large Hadro...We present one-loop contributions for h→ℓℓγ with ℓ=νe,μ,τ,e,μ and e−e+→hγ in the U(1)_(B−L) extension of the standard model. In the phenomenological results, the signal strengths for h→ℓℓγ at the Large Hadron Collider and for e−e+→hγ at future lepton colliders are analyzed in the physical parameter space for both the vector and chiral B−L models. We found that the contributions from the neutral gauge boson Z′ to the signal strengths are rather small. Consequently, the effects will be difficult to probe at future colliders. However, the impacts of charged Higgs and CP-odd Higgs in the chiral B−L model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.展开更多
We constructed a gauge B-L model with D_(4)×Z_(4)×Z_(2)symmetry to explain the quark and lepton mass hierarchies and their mixings with realistic CP phases via the type-I seesaw mechanism.Six quark mases,thr...We constructed a gauge B-L model with D_(4)×Z_(4)×Z_(2)symmetry to explain the quark and lepton mass hierarchies and their mixings with realistic CP phases via the type-I seesaw mechanism.Six quark mases,three quark mixing angles,and the CP phase in the quark sector take the central values whereas Yukawa couplings in the quark sector are diluted in a range of difference of three orders of magnitude by the perturbation theory at the first order.Concerning the neutrino sector,a small neutrino mass is achieved by the type-I seesaw mechanism.Both inverted and normal neutrino mass hierarchies are consistent with the experimental data.The predicted sum of neutrino masses for normal and inverted hierarchies,the effective neutrino masses,and the Dirac CP phase are also consistent with recently reported limits.展开更多
The leptonic di-flavor violation (LFV) processes μ^(±)μ^(±)→e^(±)e^(±) and μ^(±)μ^(±)→τ^(±)τ^(±) and leptonic di-number violation (LNV) processes μ^(±)μ^(±)...The leptonic di-flavor violation (LFV) processes μ^(±)μ^(±)→e^(±)e^(±) and μ^(±)μ^(±)→τ^(±)τ^(±) and leptonic di-number violation (LNV) processes μ^(±)μ^(±)→W_(i)^(±)W_(j)^(±) (i,j=1,2) at same-sign high energy μ^(±)μ^(±) colliders are studied. The new physics (NP) factors that may play roles in these processes are highlighted by cataloging them into three types. Taking into account the experimental constraints, the processes at μ^(±)μ^(±) colliders are computed, and the results are presented properly. The results lead to the conclusion that observing the NP factors through the LFV and LNV processes at TeV-energy μ^(±)μ^(±) colliders has significant advantages that cannot be achieved elsewhere. Therefore, once the techniques for muon acceleration and collision are developed successfully, the option of building same-sign high energy muon colliders should be seriously considered.展开更多
In this study,we reanalyze the top-quark pair production at next-to-next-to-leading order(NNLO)in quantum chromodynamics(QCD)at future e^(+)e^(−)colliders using the Principle of Maximum Conformality(PMC)method.The PMC...In this study,we reanalyze the top-quark pair production at next-to-next-to-leading order(NNLO)in quantum chromodynamics(QCD)at future e^(+)e^(−)colliders using the Principle of Maximum Conformality(PMC)method.The PMC renormalization scales inαs are determined by absorbing the non-conformalβterms by recursively using the Renormalization Group Equation(RGE).Unlike the conventional scale-setting method of fixing the scale at the center-of-mass energyμ_(r)=√s,the determined PMC scale Q_(⋆)is far smaller than the √sand increases with the √s,yielding the correct physical behavior for the top-quark pair production process.Moreover,the convergence of the pQCD series for the top-quark pair production is greatly improved owing to the elimination of the renormalon divergence.For a typical collision energy of √s=500 GeV,the PMC scale is Q_(⋆)=107 GeV;the QCD correction factor K for conventional results is K∼1+0.1244+0.0102+0.0012−0.0087−0.0011+0.0184−0.0086+0.0002+0.0061−0.0003,where the first error is caused by varying the scaleμr∈[√s/2,2√s]and the second error is from the top-quark massΔm_(t)=±0.7 GeV.After applying the PMC,the renormalization scale uncertainty is eliminated,and the QCD correction factor K is improved to K∼1+0.1507_(−0.0015)^(+0.0015)−0.0057_(−0.0000)^(+0.0001),where the error is from the top-quark massΔm_(t)=±0.7 GeV.The PMC improved predictions for the top-quark pair production are helpful for detailed studies of the properties of the top-quark at future e^(+)e^(−)colliders.展开更多
QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this...QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this type are the e^(+)e^(-)and μ^(+)e^(-)atoms,which were discovered 64 years ago and remain the sole examples found thus far.We demonstrate that the J_(τ)(τ^(+)τ^(-) atom with J^(PC)=1^(--))atom signal can be observed with a significance larger than 5o including both statistical and systematic uncertainties,via.the process e^(+)e^(-)→X^(+)Y^(-)E(X,Y=e,μ,π,K,or ρ,and E is the missing energy due to unobserved neutri-nos)with 1.5 ab^(-1)data taken around the τ pair production threshold.The τ lepton mass can be measured with a precision of 1 keV with the same data sample.This is within one year's running time of the pro-posed super tau-charm facility in China or super charm-tau factory in Russia.展开更多
In this paper,we discuss the mathematical relation determined by the basic physical constant between three types of quarks and the masses of leptons with charges in detail.First,by further theoretical analysis,we wond...In this paper,we discuss the mathematical relation determined by the basic physical constant between three types of quarks and the masses of leptons with charges in detail.First,by further theoretical analysis,we wonderfully see that the result got from the mass empirical formula of quark and charged lepton is identical with the data received by theoretical estimating from the gauge field theory.Second,we also gladly see that the result got from quark and lepton(with charges)mass empirical formula is completely accordant with experiment data.These mass formulas reveal the essential relation between me,mμ,mτ and mq.At the same time,the empirical formula may also derive the mass formula of neu-trinos.As to the mass of neutrinos,at present we only know the square difference of its mass,and so this is meaningful to theoretically estimating the mass.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
We propose a simple set of hypotheses governing the deviations of the leptonic mapping matrix from the Harrison-Perkins-Scott （HPS） form. These deviations are supposed to arise entirely from a perturbation of the ma...We propose a simple set of hypotheses governing the deviations of the leptonic mapping matrix from the Harrison-Perkins-Scott （HPS） form. These deviations are supposed to arise entirely from a perturbation of the mass matrix in the charged lepton sector. The perturbing matrix is assumed to be purely imaginary （thus maximally T-violating） and to have a strength in energy scale no greater （but perhaps smaller） than the muon mass. As we shall show, it then follows that the absolute value of the mapping matrix elements pertaining to the tau lepton deviate by no more than O（（mμ/mτ）^2） ≈ 3.5 ×10^-3 from their HPS values. Assuming that （mμ/mτ）^2 can be neglected, we derive two simple constraints on the four parameters θ12,θ23, θ31, and δ of the mapping matrix. These constraints are independent of the details of the imaginary T-violating perturbation of the charged lepton mass matrix. We also show that the e and μ parts of the mapping matrix have a definite form governed by two parameters α and β; any deviation of order mμ/mτ can be accommodated by adjusting these two parameters.展开更多
Searching for the neutrinoless double beta decay(NLDBD)is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments.Panda X-II...Searching for the neutrinoless double beta decay(NLDBD)is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments.Panda X-III(particle and astrophysical xenon experiment III)will search for the NLDBD of136Xe at the China Jin Ping Underground Laboratory(CJPL).In the first phase of the experiment,a high pressure gas Time Projection Chamber(TPC)will contain 200 kg,90%136Xe enriched gas operated at10 bar.Fine pitch micro-pattern gas detector(Microbulk Micromegas)will be used at both ends of the TPC for the charge readout with a cathode in the middle.Charge signals can be used to reconstruct the electron tracks of the NLDBD events and provide good energy and spatial resolution.The detector will be immersed in a large water tank to ensure～5 m of water shielding in all directions.The second phase,a ton-scale experiment,will consist of five TPCs in the same water tank,with improved energy resolution and better control over backgrounds.展开更多
A feasibility study is performed on the search for vector-like leptons(VLLs)at a muon collider in the context of the"4321 model",an ultraviolet-complete model with rich collider phenomenology and the potenti...A feasibility study is performed on the search for vector-like leptons(VLLs)at a muon collider in the context of the"4321 model",an ultraviolet-complete model with rich collider phenomenology and the potential to explain several recent existing B physics measurements or anomalies.Pair production and decays of VLLs lead to an interesting final state topology with multi-jets and multi-tau leptons.In this study,we perform a Monte Carlo investigation with various machine learning techniques and examine the projected sensitivity on VLLs over a wide mass range at a TeV-scale muon collider.We find that a 3 TeV muon collider with only 10 fb^(−1) of data can be sensitive over the mass range of a VLL up to 1450 GeV in the"4321 model."展开更多
In this study,we analyze the rare decays of the neutral vector mesons J/ψ and Υ(nS)in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method.The predicted branchi...In this study,we analyze the rare decays of the neutral vector mesons J/ψ and Υ(nS)in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method.The predicted branching ratios are dominated by the mass insertion parameters δ^(ij),i.e.,the off-diagonal inputs,and the contributions of different parts are comparable.Taking into account the experimental constraints on the mass insertion parameters,the predicted branching ratios for the most promising processes Υ(nS)→lτ are ten orders of magnitude smaller than the present experimental bounds.展开更多
We discuss recent results on τ lepton physics obtained at the BABAR, Belle and KEDR detectors They include tests of lepton universality using new measurements of T lepton mass and some branching fractions Also descri...We discuss recent results on τ lepton physics obtained at the BABAR, Belle and KEDR detectors They include tests of lepton universality using new measurements of T lepton mass and some branching fractions Also described are selected results on τ lepton hadronic decays coming from BABAR and Belle.展开更多
Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the r...Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the rare decays B → K （＊） l ＋ l￣ in two di-lepton mass bins above and below the J/ψ resonance.For the B → K＊ l ＋ l￣ decay,we also measure the K＊ longitudinal polarization fraction and the di-lepton forwardbackward asymmetry.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
Recently, the LHCb experiment announced 3.5σ evidence for direct CP violation in D0 decay by looking at the difference between A CP （D0 → K＋ K- ） and A CP （D0 →π＋ π- ）. This is the first evidence of CP viol...Recently, the LHCb experiment announced 3.5σ evidence for direct CP violation in D0 decay by looking at the difference between A CP （D0 → K＋ K- ） and A CP （D0 →π＋ π- ）. This is the first evidence of CP violation in a charm system, which may indicate new physics beyond the Standard Model. Motivated by this measurement, we review rare processes in charmonium decay, especially, the weak decay, C or P violated decay, and lepton flavor violated decays. In case the new physics appears in charm sector, these rare decays of charmonium states will provide an opportunity to search for significant contributions from physics beyond the Standard Model. With huge J/ψ and ψ（2S） samples in BES experiment, the rare decays may be feasible.展开更多
基金Supported in part by the National Natural Science Foundation of China(12235008,11875179)the Natural Science Foundation of Shandong Province,China(ZR2021QA040)。
文摘A nonzero neutrino mass may be a sign of new physics beyond the standard model(SM).To explain the small neutrino mass,we can extend the SM using right-handed Majorana neutrinos in a low-scale seesaw mechanism,and the CP violation effect can be induced due to the CP phase in the interference of heavy Majorana neutrinos.The existence of heavy Majorana neutrinos may lead to lepton number violation processes,which can be used to search for the signals of heavy Majorana neutrinos.In this paper,we focus on the CP violation effect related to two generations of heavy Majorana neutrinos at 15 GeV<m_(N1)<70 GeV in the pair production of W bosons and rare decays.It is valuable to investigate Majorana neutrino production signals and the related CP violation effects in rare W boson decays at future lepton colliders.
文摘A previous preon scenario for the standard model particles, based on unbroken supersymmetry, is applied to the problem of matter-antimatter asymmetry. Attention is paid to the fact that the asymmetric hydrogen atom—like all atoms—can be described in terms of symmetric preons. Preons are created in the early universe. The matter-antimatter asymmetry is caused by stochastic correlations in charge density fluctuations of preons and antipreons and by the subsequent preon combinatorial mechanism to form quarks and leptons, and finally the three lightest elements. A tentative gravitino mass estimate is given based on minimal interference with nucleosynthesis. With local supersymmetry the scenario can be extended to supergravity.
基金Supported by Vietnam National Foundation for Science and Technology Development(NAFOSTED,103.01-2023.16)。
文摘We present one-loop contributions for h→ℓℓγ with ℓ=νe,μ,τ,e,μ and e−e+→hγ in the U(1)_(B−L) extension of the standard model. In the phenomenological results, the signal strengths for h→ℓℓγ at the Large Hadron Collider and for e−e+→hγ at future lepton colliders are analyzed in the physical parameter space for both the vector and chiral B−L models. We found that the contributions from the neutral gauge boson Z′ to the signal strengths are rather small. Consequently, the effects will be difficult to probe at future colliders. However, the impacts of charged Higgs and CP-odd Higgs in the chiral B−L model on the signal strengths are significant and can be measured with the help of the initial polarization beams at future lepton colliders.
基金funded by Tay Nguyen University under grant number T2023-45CBTD。
文摘We constructed a gauge B-L model with D_(4)×Z_(4)×Z_(2)symmetry to explain the quark and lepton mass hierarchies and their mixings with realistic CP phases via the type-I seesaw mechanism.Six quark mases,three quark mixing angles,and the CP phase in the quark sector take the central values whereas Yukawa couplings in the quark sector are diluted in a range of difference of three orders of magnitude by the perturbation theory at the first order.Concerning the neutrino sector,a small neutrino mass is achieved by the type-I seesaw mechanism.Both inverted and normal neutrino mass hierarchies are consistent with the experimental data.The predicted sum of neutrino masses for normal and inverted hierarchies,the effective neutrino masses,and the Dirac CP phase are also consistent with recently reported limits.
基金the National Natural Science Foundation of China(NNSFC)(12047503,12075301,11821505,11705045)It was also Supported in part by the Key Research Program of Frontier Sciences,CAS(QYZDY-SSW-SYS006)。
文摘The leptonic di-flavor violation (LFV) processes μ^(±)μ^(±)→e^(±)e^(±) and μ^(±)μ^(±)→τ^(±)τ^(±) and leptonic di-number violation (LNV) processes μ^(±)μ^(±)→W_(i)^(±)W_(j)^(±) (i,j=1,2) at same-sign high energy μ^(±)μ^(±) colliders are studied. The new physics (NP) factors that may play roles in these processes are highlighted by cataloging them into three types. Taking into account the experimental constraints, the processes at μ^(±)μ^(±) colliders are computed, and the results are presented properly. The results lead to the conclusion that observing the NP factors through the LFV and LNV processes at TeV-energy μ^(±)μ^(±) colliders has significant advantages that cannot be achieved elsewhere. Therefore, once the techniques for muon acceleration and collision are developed successfully, the option of building same-sign high energy muon colliders should be seriously considered.
基金the Natural Science Foundation of China(12175025,12147102,12265011)by the Projects of Guizhou Provincial Department(YQK[2023]016,ZK[2023]141,[2020]1Y027,GZMUZK[2022]PT01)。
文摘In this study,we reanalyze the top-quark pair production at next-to-next-to-leading order(NNLO)in quantum chromodynamics(QCD)at future e^(+)e^(−)colliders using the Principle of Maximum Conformality(PMC)method.The PMC renormalization scales inαs are determined by absorbing the non-conformalβterms by recursively using the Renormalization Group Equation(RGE).Unlike the conventional scale-setting method of fixing the scale at the center-of-mass energyμ_(r)=√s,the determined PMC scale Q_(⋆)is far smaller than the √sand increases with the √s,yielding the correct physical behavior for the top-quark pair production process.Moreover,the convergence of the pQCD series for the top-quark pair production is greatly improved owing to the elimination of the renormalon divergence.For a typical collision energy of √s=500 GeV,the PMC scale is Q_(⋆)=107 GeV;the QCD correction factor K for conventional results is K∼1+0.1244+0.0102+0.0012−0.0087−0.0011+0.0184−0.0086+0.0002+0.0061−0.0003,where the first error is caused by varying the scaleμr∈[√s/2,2√s]and the second error is from the top-quark massΔm_(t)=±0.7 GeV.After applying the PMC,the renormalization scale uncertainty is eliminated,and the QCD correction factor K is improved to K∼1+0.1507_(−0.0015)^(+0.0015)−0.0057_(−0.0000)^(+0.0001),where the error is from the top-quark massΔm_(t)=±0.7 GeV.The PMC improved predictions for the top-quark pair production are helpful for detailed studies of the properties of the top-quark at future e^(+)e^(−)colliders.
基金supported by National Key Research and Development Program of China(2020YFA0406300)National Natural Science Foundation of China(11975076,12161141008,12135005,12075018,12005040,and 12335004)the Fundamental Research Funds for the Central Universities(RF1028623046).
文摘QED atoms are composed of unstructured and point-like lepton pairs bound together by the electromag-netic force.The smallest and heaviest QED atom is formed by a τ^(+)τ^(-)pair.Currently,the only known atoms of this type are the e^(+)e^(-)and μ^(+)e^(-)atoms,which were discovered 64 years ago and remain the sole examples found thus far.We demonstrate that the J_(τ)(τ^(+)τ^(-) atom with J^(PC)=1^(--))atom signal can be observed with a significance larger than 5o including both statistical and systematic uncertainties,via.the process e^(+)e^(-)→X^(+)Y^(-)E(X,Y=e,μ,π,K,or ρ,and E is the missing energy due to unobserved neutri-nos)with 1.5 ab^(-1)data taken around the τ pair production threshold.The τ lepton mass can be measured with a precision of 1 keV with the same data sample.This is within one year's running time of the pro-posed super tau-charm facility in China or super charm-tau factory in Russia.
基金the State Key Basic Research Project(973Project)of China(Grant No.2006CB605102)the National Natural Science Foundation of China(Grant No.90306016)
文摘In this paper,we discuss the mathematical relation determined by the basic physical constant between three types of quarks and the masses of leptons with charges in detail.First,by further theoretical analysis,we wonderfully see that the result got from the mass empirical formula of quark and charged lepton is identical with the data received by theoretical estimating from the gauge field theory.Second,we also gladly see that the result got from quark and lepton(with charges)mass empirical formula is completely accordant with experiment data.These mass formulas reveal the essential relation between me,mμ,mτ and mq.At the same time,the empirical formula may also derive the mass formula of neu-trinos.As to the mass of neutrinos,at present we only know the square difference of its mass,and so this is meaningful to theoretically estimating the mass.
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.
文摘We propose a simple set of hypotheses governing the deviations of the leptonic mapping matrix from the Harrison-Perkins-Scott （HPS） form. These deviations are supposed to arise entirely from a perturbation of the mass matrix in the charged lepton sector. The perturbing matrix is assumed to be purely imaginary （thus maximally T-violating） and to have a strength in energy scale no greater （but perhaps smaller） than the muon mass. As we shall show, it then follows that the absolute value of the mapping matrix elements pertaining to the tau lepton deviate by no more than O（（mμ/mτ）^2） ≈ 3.5 ×10^-3 from their HPS values. Assuming that （mμ/mτ）^2 can be neglected, we derive two simple constraints on the four parameters θ12,θ23, θ31, and δ of the mapping matrix. These constraints are independent of the details of the imaginary T-violating perturbation of the charged lepton mass matrix. We also show that the e and μ parts of the mapping matrix have a definite form governed by two parameters α and β; any deviation of order mμ/mτ can be accommodated by adjusting these two parameters.
基金supported by the National Key Programme for Research and Development (NKPRD) (Grant No. 2016YFA0400300)Shanghai Jiao Tong University (SJTU) for their financial and technical support+1 种基金technical and administrative assistance from China Jin Ping Underground Laboratory (CJPL)the European Research Council (Grant No. ERC-2009-St G-240054)
文摘Searching for the neutrinoless double beta decay(NLDBD)is now regarded as the topmost promising technique to explore the nature of neutrinos after the discovery of neutrino masses in oscillation experiments.Panda X-III(particle and astrophysical xenon experiment III)will search for the NLDBD of136Xe at the China Jin Ping Underground Laboratory(CJPL).In the first phase of the experiment,a high pressure gas Time Projection Chamber(TPC)will contain 200 kg,90%136Xe enriched gas operated at10 bar.Fine pitch micro-pattern gas detector(Microbulk Micromegas)will be used at both ends of the TPC for the charge readout with a cathode in the middle.Charge signals can be used to reconstruct the electron tracks of the NLDBD events and provide good energy and spatial resolution.The detector will be immersed in a large water tank to ensure～5 m of water shielding in all directions.The second phase,a ton-scale experiment,will consist of five TPCs in the same water tank,with improved energy resolution and better control over backgrounds.
基金Supported in part by the National Natural Science Foundation of China (12150005, 12075004,. 12061141002)MOST (2018YFA0403900)
文摘A feasibility study is performed on the search for vector-like leptons(VLLs)at a muon collider in the context of the"4321 model",an ultraviolet-complete model with rich collider phenomenology and the potential to explain several recent existing B physics measurements or anomalies.Pair production and decays of VLLs lead to an interesting final state topology with multi-jets and multi-tau leptons.In this study,we perform a Monte Carlo investigation with various machine learning techniques and examine the projected sensitivity on VLLs over a wide mass range at a TeV-scale muon collider.We find that a 3 TeV muon collider with only 10 fb^(−1) of data can be sensitive over the mass range of a VLL up to 1450 GeV in the"4321 model."
基金Supported by the Natural Science Foundation of Hebei Province(A2022104001,A2022201017)the Shanxi Scholarship Council of China(2021-31)+1 种基金the youth top-notch talent support program of the Hebei Provincethe Foundation of Baoding University(2018Z01)
文摘In this study,we analyze the rare decays of the neutral vector mesons J/ψ and Υ(nS)in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method.The predicted branching ratios are dominated by the mass insertion parameters δ^(ij),i.e.,the off-diagonal inputs,and the contributions of different parts are comparable.Taking into account the experimental constraints on the mass insertion parameters,the predicted branching ratios for the most promising processes Υ(nS)→lτ are ten orders of magnitude smaller than the present experimental bounds.
基金Supported by grants RFBR 07-02-00816,RFBR 08-02-13516,RFBR 08-02-91969,RFBR 09-02-01143INTAS/05-1000008-8328+1 种基金PST.CLG.980342DFG GZ RUS 113/769/0-2
文摘We discuss recent results on τ lepton physics obtained at the BABAR, Belle and KEDR detectors They include tests of lepton universality using new measurements of T lepton mass and some branching fractions Also described are selected results on τ lepton hadronic decays coming from BABAR and Belle.
文摘Based on a data sample of 384 million BB pairs collected with the BABAR detector at the PEP-Ⅱ asymmetric e ＋ e ￣ storage ring,we measure branching fractions,direct CP,isospin and lepton-flavor asymmetries for the rare decays B → K （＊） l ＋ l￣ in two di-lepton mass bins above and below the J/ψ resonance.For the B → K＊ l ＋ l￣ decay,we also measure the K＊ longitudinal polarization fraction and the di-lepton forwardbackward asymmetry.
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.
基金Supported by National Natural Science Foundation of China (11125525)
文摘Recently, the LHCb experiment announced 3.5σ evidence for direct CP violation in D0 decay by looking at the difference between A CP （D0 → K＋ K- ） and A CP （D0 →π＋ π- ）. This is the first evidence of CP violation in a charm system, which may indicate new physics beyond the Standard Model. Motivated by this measurement, we review rare processes in charmonium decay, especially, the weak decay, C or P violated decay, and lepton flavor violated decays. In case the new physics appears in charm sector, these rare decays of charmonium states will provide an opportunity to search for significant contributions from physics beyond the Standard Model. With huge J/ψ and ψ（2S） samples in BES experiment, the rare decays may be feasible.
