BESⅢ Observes New Leptonic Decay Mode for D Meson

The Beijing Spectrometer(BESIII)collaboration has reported the world’s first observation of the decay D+→τ+ν,which is the second type of pure leptonic decay of the D+meson,in a newly published Physical Review Letters paper.The paper has been highlighted by the journal as an"Editors’Suggestion."

Radiative leptonic decay of heavy quarkonia

In this study,the properties of heavy quarkonia X are examined by treating them as bound states of Q and Q at the leading-order level within the non-relativistic quantum chromodynamics(NROCD)framework,where Q represents either a charm or bottom quark.The branching ratios for the radiative leptonic decays X→γl^(+)l^(-)are revisited,and the angular and energy/momentum distributions of the final state particles are analyzed in the restframe of X.Furthermore,we apply Lorentz transformations from the rest frame of X to the center-of-mass frame of l^(+)l^(-)to establish the connection between the widths Г_(x→γl^(+)l^(-))and Г_(x→l^(+)l^(-)).The comparison of the connection tothose documented in literature(divided by 2π)for various X states,such as J/Ψ,Ψ(2S),Υ(1S),and Υ(2S),shows relative differences typically around or below 10%,comparable to the next-to-leading order corrections of O(α)and 0(ν^(4)).However,we observe a significant disparity in the ratio betweenГ_(Ψ(2S)→γτ^(+)τ^(-))andГ_(Ψ(2S)→τ^(+)τ^(-)),with our prediction being four times larger than those in literature.The outcomes derived from this study have practical im.plications in describing the quantum electrodynamics radiative processes and contribute to the investigation of QCD processes associated with the decays of heavy quarkonia and searches for new physies.

Leptonic di-flavor and di-number violation processes at high energyμ^(±)μ^(±)colliders

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.

Exotic vector charmonium and its leptonic decay width

We propose a novel type of interpolating field operator, which manifests the hybrid-like configuration that the charm quark-antiquark pair recoils against gluonie degrees of freedom. A heavy vector charmonium-like state with a mass of 4.33（2） GeV is disentangled from the conventional charmonium states in the quenched approximation. This state has affinity for the hybrid-like operators but couples less to the relevant quark bilinear operator. We also try to extract its leptonic decay constant and give a tentative upper limit that it is less than one tenth of that of J/ψ, which corresponds to a leptonic decay width about dozens of eV. The connection of this state with X（4260） is also discussed.

Study of pure and semileptonic decays of D_s meson within R-parity violating supersymmetric model

We present the comaprative study of semileptonic and leptonic decays of Ds, D±and D0meson（D →M l＋-αl-β, D → l＋αlβ, D → l＋αvα;α,β=e,μ） within the framework of R-parity violating the（ Rp） Minimal Supersymmetric Standard Model（MSSM）. The comparison shows that combination and product couplings,（λβiα λ＊ ij qor λβqkλ＊αj k）contribution to the branching fractions of the said processes（under consideration） is consistent with or comparable to the experimental measurements in most of the cases. However, some cases exist where these contributions are highly suppressed. We identify such cases in our analysis and single out the important ones suitable for exploring in the future and current experiments.

Factorization of radiative leptonic D-meson decay with sub-leading power corrections

In this work,we calculate the sub-leading power contributions to radiative leptonic D→γνdecay.For the first time,we provide the analytic expressions of next-to-leading power contributions and the error estimation associated with the power expansion of O(∧_(QCD)/m_(c)).In our calculation,we adopt two different models of the D-meson distribution amplitudesφ^(+)_(D,Ⅰ)andφ^(+)_(DⅡ).Within the framework of QCD factorization as well as the dispersion relation,we evaluate the soft contribution up to the next-to-leading logarithmic accuracy and also consider the higher-twist contribution from the two-particle and three-particle distribution amplitudes.Finally,we find that all the sub-leading power contributions are significant atλd(μ0)354 MeV,and the next-to-leading power contributions lead to 143%inφ^(+)_(D,Ⅰ)and 120%inφ^(+)_(DⅡ)corrections to leading power vector form factors with Eγ=0.5 GeV.As the corrections from the higher-twist and local sub-leading power contributions are enhanced with increasing inverse moment,it is difficult to extract an appropriate inverse moment of the D-meson distribution amplitude.The predicted branching fractions are(1.88^(+0.36)_(0.29))×10^(-5)forφ^(+)_(D,Ⅰ)and(2.31^(+0.65)_(-0.54))×10^(-5)forφ^(+)_(DⅡ).

Light meson spectrum and their leptonic decay widths in the frame work of constituent quark models

The phenomenological non-relativistic quark model has been employed to obtain the ground state masses of light vector mesons and their radially excited states and their decay widths.The full hamiltonian used in the investigation has kinetic energy,the confinement potential and the one-gluon-exchange potential.A good agreement is obtained with the experimental masses and their leptonic decay widths.

Leptonic Decays of Heavy Vector and Pseudoscalar Mesons

Pure leptonic decays of D~*0)(B_^(*s),B_d~*)→l^+l^- and D^(±*)(D_s~*,B^(*+),B_c~*)→lν_l are investigated.The hadronic contributions such as D^0→D^(*0)γ→μ^+μ^- are also explored.We then obtain the updated branching fractions of the pseudoscalar mesons to lepton pairs are modified by a factor of few percentages.Specifically,the Br(B+→e^+ν_e)is reduced by a factor 13%.

Broken S_(3L)×S_(3R) flavor symmetry and leptonic CP violation

In the framework of the canonical seesaw model,we present a simple but viable scenario to explicitly break an S3L×S3R flavor symmetry in the leptonic sector.It turns out that the leptonic flavor mixing matrix is completely determined by the mass ratios of the charged leptons（i.e.,me/mμand mμ/mτ） and those of light neutrinos（i.e.,m1/m2 and m2/m3）.The latest global-fit results of the three neutrino mixing angles {θ12,θ13,θ23}and two neutrino mass-squared differences {？m212,？m312} at the 3σ level are used to constrain the parameter space of {m1/m2,m2/m3}.The predictions for the mass spectrum and flavor mixing are highlighted：（1） the neutrino mass spectrum shows a hierarchical pattern and a normal ordering,e.g.,m1≈2.2meV,m2≈8.8 meV and m3≈52.7 meV;（2） only the first octant of θ23 is allowed,namely,41.8？ θ23 43.3？;（3） the Dirac C P-violating phase δ ≈-22？deviates significantly from the maximal value-90？.All these predictions are ready to be tested in ongoing and forthcoming neutrino oscillation experiments.Moreover,we demonstrate that the cosmological matter-antimatter asymmetry can be explained via resonant leptogenesis,including the individual lepton-flavor effects.In our scenario,leptonic C P violation at low-and high-energy scales is closely connected.

Study on the Effects of the Light CP-odd Higgs via the Leptonic Decays of Pseudoscalar Mesons

To explain the anomALously large decay rate of ∑＋→p＋μ＋μ-, it was proposed that a new mechanism where a light CP-odd pseudoscaJar boson of mAo = 214.3 MeV makes a crucial contribution. Later, some authors have studied the transition π0→e＋e- and γ→γA10 in terms of the same mechanism and their result indicates that with the suggested mass one cannot fit the data. This discrepancy might be caused by experimental error of ∑＋→p＋μ＋μ- because there were only a few events. Whether the mechanism is a reasonable one motivates us to investigate the transitions π0→e＋e-;η（η′）→μ＋μ-;ηc→μ＋μ-;ηb→τ＋τ- within the same framework. It is noted that for π0→ e＋ e-, the standard model （SM） prediction is smaller than the data, whereas the experimental central value of η→μ＋μ- is also above the SM prediction. It means that there should be extra contributions from other mechanisms and the contribution of A may be a possible one. Theoretically calculating the branching ratios of the concerned modes, we would cheek if we can obtain a univers mass for A10 which reconcile the theoretical predictions and data for all the modes. Unfortunately, we find that it is impossible conclude that the phenomenology does not favor such a to have such a mass with the same coupling｜gt｜. Therefore we light A10, even though a small window is still open.

Revisiting the heavy vector quarkonium leptonic widths

We revisit the heavy quarkonium leptonic decays ψ(nS)→■^+■^- and Υ(nS)→■^+■^- using the Bethe-Salpeter method.The emphasis is on the relativistic corrections.For the ψ(1S-5S)decays,the relativistic effects are 22-2^+3%,34-2^+5%,41-6^+6%,52-13^+11% and 62-12^+14%,respectively.For the Υ(1S-5S) decays,the relativistic effects are 14-2^+1%,23-3^+0%,20-2^+8%,21-7^+6% and 28-7^+2%,respectively.Thus,the relativistic corrections are large and important in heavy quarkonium leptonic decays,especially for the highly excited charmonium.Our results forΥ(nS)→■^+■^- are consistent with the experimental data.

Anomalies in(semi)-leptonic B decays B~±→τ~±ν,B~±→Dτ~±ν and B~±→D~*τ~±ν,and possible resolution with sterile neutrino

The universality of the weak interactions can be tested in semileptonic b→c transitions,and in particular in the ratios R（D＊） ≡ Γ（B → D（＊）τν）/Γ（B → D＊lν）（where 1 = μ or e）.Due to the recent differences between the experimental measurements of these observables by Ba Bar,Belle and LHCb on the one hand and the Standard Model predicted values on the other hand,we study the predicted ratios R（D＊）=Γ（B→D＊τ＋＂missing＂）/Γ（B→D（＊）lν）in scenarios with an additional sterile heavy neutrino of mass ～1 Ge V.Further,we evaluate the newly defined ratio R（0）≡Γ（B→τ＋＂missing＂）/Γ（B→μν） in such scenarios,in view of the future possibilities of measuring the quantity at Belle-Ⅱ.

Measurement of J/ψ leptonic width with the KEDR detector

We report a new precise determination of the leptonic widths of the J/psi meson performed with the KEDR detector at the VEPP-4M e^＋e^- collider. The measured values of the J/psi parameters are： Гee×Гee/P = 0.3323±0.0064 （stat.）±0.0048 （syst.） keV,Гee×Гμμ/Г = 0.3318±0.0052 （stat.） ±0.0063 （syst.） keY. Assuming eμ universality and using the table value of the branching ratios the leptonic Г11 = 5.59 ± 0.12 keV width and the total Г = 94.1±2.7 keV widths were obtained. We also discuss in detail a method to calculate radiative corrections at a narrow resonance.

Implications of the Daya Bay observation of θ_(13) on the leptonic flavor mixing structure and CP violation

The Daya Bay collaboration has recently reported its first νe → νe oscillation result which points to θ13 8.8 ± 0.8 （best-fit ±1σ range） or θ13 = 0 at the 5.2σ level. The fact that this smallest neutrino mixing angle is not strongly suppressed motivates us to look into the underlying structure of lepton flavor mixing and CP violation. Two phenomenological strategies are outlined： （1） the lepton flavor mixing matrix U consists of a constant leading term U0 and a small perturbation term U ; and （2） the mixing angles of U are associated with the lepton mass ratios. Some typical patterns of U0 are reexamined by constraining their respective perturbations with current experimental data. We illustrate a few possible ways to minimally correct U0 in order to fit the observed values of three mixing angles. We point out that the structure of U may exhibit an approximate μ-τ permutation symmetry in modulus, and reiterate the geometrical description of CP violation in terms of the leptonic unitarity triangles. The salient features of nine distinct parametrizations of U are summarized, and its Wolfenstein-like expansion is presented by taking U0 to be the democratic mixing pattern.

An Original Didactic about Standard Model: “The Particles’ Geometric Model” (Leptons and Bosons)

This work shows a didactic model representative (GPM) of the particles described in the Standard Model (SM). Particles are represented by geometric forms corresponding to geometric structures of coupled quantum oscillators. From the didactic hypotheses of the model emerges an in-depth phenomenology of particles that is fully compatible with that of SM. Thanks to this model, we can calculate “geometrically” the mass of Higgs’s Boson and the mass of the pair “muon and muonic neutrino”, and, by the geometric shapes of leptons and bosons, we can also solve crucial aspects of SM physics as the neutrinos’ oscillations and the intrinsic chirality of the neutrino and antineutrino.

The Substructure of Elementary Particles Demonstrated by the I-Theory

Present studies in physics assume that elementary particles are the building blocks of all matter, and that they are zero-dimensional objects which do not occupy space. The new I-Theory predicts that elementary particles do indeed have a substructure, three dimensions, and occupy space, being composed of fundamental particles called I-particles. In this article we identify the substructural pattern of elementary particles and define the quanta of energy that form each elementary particle. We demonstrate that the substructure comprises two classes of quanta which we call “attraction quanta” and “repulsion quanta”. We create a model that defines the rest-mass energy of each elementary particle and can predict new particles. Lastly, in order to incorporate this knowledge into the contemporary models of science, a revised periodic table is proposed.

Bound State Description of Particles from a Quantum Field Theory of Fermions and Bosons, Compatible with Relativity

Both, the dilemma to find a quantum field theory consistent with Einstein’s law of relativity and the problem to describe existing particles as bound states of matter has been solved by calculating bound state matrix elements from a dual fermion-boson Lagrangian. In this formalism, the fermion binding energies are compensated by boson energies, indicating that particles can be generated out of the vacuum. This yields quantitative solutions for various mesons ω (0.78 GeV) - Υ (9.46 GeV) and all leptons e, μ and τ, with uncertainties in the extracted properties of less than 1‰. For transparency, a Web-page with the address htpps://h2909473.stratoserver.net has been constructed, where all calculations can be run on line and also the underlying fortran source code can be inspected.

一种基于LEPTON 3.5的生猪体温监测系统

生猪养殖产业是我国最重要的畜牧产业之一,而生猪体温的测量在疫病防治中具有重要作用。针对常规的接触式生猪体温测量方法人力成本高及效率低的问题,文章基于热成像模块LEPTON 3.5设计了一种非接触式的生猪体温监测系统,在猪舍部署之后能自动对生猪对象进行连续的体温监测,可以被应用到生猪养殖的体温异常的筛选中,具有易于部署及使用,自动化程度高等优点。

Charmonium Spectrum and Their Transitions in Relativistic Quark Models

Using the phenomenological relativistic harmonic model （RHM） for quarks, we have obtained the masses of S wave charmonium states. The full Hamiltonian used in the investigation has Lorentz scalar plus vector confinement potential, along with the confined one gluon exchange potential （COGEP）. A good agreement with the experimental masses for the ground state and the radially excited states is obtained for both the triplet and singlet S wave mesons. The calculated charge radii, meson decay constants, leptonic decay width, two photon decay width, and the radiative M1 decay width are in good agreement with the experimental results.

Bottomonium Spectrum and Decays with One Gluon Exchange Potential

The phenomenological non-relativistic quark model （NRQM） has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential （OGEP）. An overall agreement is obtained with the experimental masses and decay widths.