Top Quark Chromomagnetic Dipole Moment in the Littlest Higgs Model with T-Parity

The littlest Higgs model with T-parity, which is called LHT model, predicts the existence of the new particles, such as heavy top quarks, heavy gauge bosons, and mirror fermions. We calculate the one-loop contributions of these new particles to the top quark ehromomagnetic dipole moment （CMDM） AK. We find that the contribution of the LHT model is one order of magnitude smaller than the standard model prediction value.     

Photoinduced Polaron-Splitting in Polymer

We simulate a relaxation process of a polaron in polymer after photo excitation, and a new state is realized by means of proper excitation. The original lattice configuration of the polaron splits into two symmetrical peaks, and consequently a double-well potential is formed, where the wavefunctions of electron localized in these two wells are entangled. Thus, this process provides a method to generate the Schroedinger cat state. According to the dynamical process of the lattice configuration, the relaxation time of splitting is about 150fs.     

Probing magnetic moment operators in H_γ production and H→τ~+τ~-γ rare decay

The magnetic moment(a_γ) and weak magnetic moment(a_W) of charged leptons and quarks are sensitive to quantum effects of new physics heavy resonances.In effective field theory,a_γ and a_W are induced by two independent operators.Therefore,one has to measure both ay and aw to shed light on new physics.The aw's of the SM fermions are measured at the LEP.In this work,we analyze the contributions from magnetic and weak magnetic moment operators in the processes of pp→H_γ and gg→H→τ~+τ~-γ at the High-Luminosity Large Hadron Collider.We demonstrate that the two processes can cover most of the parameter space that cannot be probed at the LEP.     

Associated Production of Scalars and New Gauge Bosons from a Little Higgs Model at the LHC

The littlest Higgs model with T-parity （LHT model） predicts the existence of the T-odd scalars （Φ^±, Φ^0, and Φ^P）. We consider the production of these new particles associated with T-odd gauge bosons at the Large Hadron Collider （LHC）. It is found that the partonic process qq^1 →Φ^＋ BH can generate a number of the characteristic signal events with a charged lepton and large missing energy at the LHC.     

Implications of the RK and R_(K*) anomalies

We discuss the implications of the recently reported R_K and R_(K*) anomalies, the lepton flavor nonuniversality in the B → Kl~+l~-and B → K~*l~+~l- decay channels. Using two sets of hadronic inputs of form factors, we perform a fit of new physics to the R_K and R_(K*) data, and significant new physics contributions are found. We suggest the study of lepton flavor universality in a number of related rare B,Bs,Bc and Λb decay channels, and in particular we give predictions for the μ-to-e ratios of decay widths with different polarizations of the final state particles, and of the b → dl~+l~- processes, which are presumably more sensitive to the structure of the underlying new physics. With the new physics contributions embedded in the Wilson coefficients, we present theoretical predictions for lepton flavor non-universality in these processes.     

Production of Charged Higgs Bosons from Left-Right Twin Higgs Model at TeV Energy e-γ Colliders

The left-right twin Higgs （LRTH） model predicts the existence of three additional Higgs bosons： one neutral Higgs φo and a pair of charged Higgs bosons φ±. In this paper, we study two pair production processes of these new particles at the next generation eγ colliders, i.e., e-γ → e-φ＋φ- , and e-γ→vRφ-φ0. We find that the production cross section of the process e-γ → e-φ＋φ- are at the level of several tens fb, the production cross section of the process e-γ→vRφ-φ0 can reach 0.35 fb with the reasonable parameter values. As long as the charged Higgs bosons are not too heavy, we conclude that these processes might be used to test for the left-right twin Higgs model in future high-energy linear collider experiments.     

Rare Decay Process K→πvv^- in Three-Site Higgsless Model]

Rare decay processes K→πvv^- and KL→π^0vv^- are considered in the framework of three-site Higgsless model. The contributions of this new physics model to these two decay processes come from the new heavy gauge bosons and the correction terms for the couplings of the ordinary gauge bosons with fermions. Our numerical results show that the branching ratios of these two decay processes can be enhanced by 40% and 50% relative to those predicted by the standard model.     

SU（3） Simple Group Model and New Z＇ Properties in Future Linear Colliders

In the SU（3） simple group model, the new neutral gauge boson Z＇ couples to pairs of SM fermions with couplings fixed in terms of the SM gauge couplings and depending only on the choice of the fermion embedding. In this paper, we calculate the contributions of this new particle to the processes e^＋e^-→l^＋l^-, bb^-, and cc^- and study the possibility of detecting this new particle via these processes in the future high-energy linear e^＋e^- collider（LC） experiments with √s= 500 GeV and ￡int= 340 fb^-1. We find that the new gauge boson Z＇ is most sensitive to the process e^＋e^-→b^＋b^-. As long as Mz,≤2 TeV , the absolute values of the relative correction parameter are larger than 5%. We calculate the forward-backward asymmetries and left-right asymmetries for the process e^＋e^-→c^＋c^-, with both the universal and anomaly-free fermion embeddings. Bounds on Z＇ masses are also estimated within 95% confidence level.     

Lepton Electric Charge Swap at the 10 TeV Energy Scale

We investigate the nature of the dark matter by proposing a mechanism for the breaking of local rotational symmetry between ordinary third family leptons and proposed non-regular leptons at energy scales below 10 TeV. This symmetry breaking mechanism involves electric charge swap between ordinary families of leptons can and produces highly massive non-regular leptons of order 0 （1 TeV） mass unobservable at energy scales below 10 TeV （the scale of LEP Ⅰ, Ⅱ and neutrino oscillation experiments）. Electric charge swap between ordinary families of leptons produces heavy neutral non-regular leptons with order 0 （1 TeV） masses, which may form cold dark matter. The existence of these proposed leptons can be tested once the Large Hadron Collider （LHC） becomes operative at 10 TeV energy-scales. This proposition may have far reaching applications in astrophysics and cosmology.     

The littlest Higgs model with T-parity and some lepton flavor violation decay processes

The new particles predicted by the littlest Higgs model with T-parity (called LHT model) can induce the lepton flavor violation (LFV) couplings at the one-loop level,which can add contributions to some LFV processes.Taking into account the constraints of the experimental data on the relevant free parameters,we calculate the branching ratios of the LFV decay processes Z → l ˉl and τ-→μ-P 1 P 2 with P 1 P 2 = π + π-,K + K-,and K0 ˉK 0 in the context of this new physics model.We find that the LHT model can indeed make significant contributions to some of these LFV decay processes.The Z factory option for the future high energy e + e-collider experiments will give severe constraints on the LHT model.     

Asymmetric dark matter abundance including non-thermal production

We investigate the relic abundance of asymmetric dark matter where the asymmetric dark matter is non–thermally produced from the decay of heavier particles in addition to the usual thermal production. We discuss the relic density of asymmetric dark matter including the decay of heavy particles in low-temperature scenarios. Here, we still assume that the Universe is radiationdominated and there is asymmetry before the decay of heavy particles. We obtain an increased abundance of asymmetric dark m...     

Lepton Polarization Asymmetry in B → e^＋e^- Decay beyond the Standard Model

The lepton polarization asymmetry in the B → e^＋e^- decay, when one of the leptons is polarized, is investigated by using the most general form of the effective Hamiltonian. We find allowed regions for the new scalar Wilson coefficients, assuming that the experimental branching ratio is measured within 10% percent uncertainty. Then using these restrictions to the new coefficients the sensitivity of the lepton polarization asymmetry to them is studied. Moreover, it is observed that there are regions of terms describing the scalar interactions, where lepton polarization asymmetry differs from zero, which can serve as a good test for searching new physics beyond the standard model.     

Axion-Like Particles and the Higgs Decays h→PZ and h→Pe~+e~-

Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searches and explaining the g-2 deviation,we consider the contributions of ALPs with mass in the range of 1.5GeVm_am_h-m_Z to the exclusive Higgs decays h→PZ and h→Pe~+e~-with P being the pseudoscalar mesonsπ~0,η,η',η_c andη_b in a model-independent approach.We find that,in most of the parameter space range,the contributions of ALP to these decay-processes are ver.y small,while in the case of the ALP mass ma approximatel.y equaling the meson mass m_P,the contributions are significantly large.     

Searching for new physics in D^0→μ^＋ μ^-,e^＋e^-,μ^±e at BES and/or the super charm-tau factory

In contrast with B0-ˉB0, Bs-ˉBs mixing where the standard model（SM） contributions overwhelm that of the new physics beyond standard model（BSM）, a measured relatively large D0-ˉD0mixing where the SM contribution is negligible, definitely implies the existence of the new physics BSM. It is natural to consider that the rare decays of D meson might be more sensitive to new physics, and the decay mode D0→μ＋μ-could be an ideal area to search for new physics because it is a flavor changing process. In this work we look for a trace of the new physics BSM in the leptonic decays of D0. Concretely we discuss the contributions of unparticle or an extra gauge boson Z while imposing the constraints set by fitting the D0-ˉD0mixing data. We find that the long-distance SM effects for D0→lˉl still exceed those contributions of the BSM under consideration, but for a double-flavor changing process such as D0→μ±e, the new physics contribution would be significant.     

Superscattering of Underwater Sound via Deep Learning Approach

We design a multilayer cylindrical structure to realize superscattering of underwater sound. Because of the near degeneracy of resonances in multiple channels of the structure, the scattering contributions from these resonances can overlap to break the single-channel limit of subwavelength objects. However, tuning the design parameters to achieve the target response is an optimization process that is tedious and time-consuming. Here,we demonstrate that a well-trained tandem neural network can de...     

Searching for new physics in D~0→μ~+ μ~-,e~+e~-,μ~±e~■ at BES and/or the super charm-tau factory

In contrast with B0-ˉB0, Bs-ˉBs mixing where the standard model(SM) contributions overwhelm that of the new physics beyond standard model(BSM), a measured relatively large D0-ˉD0mixing where the SM contribution is negligible, definitely implies the existence of the new physics BSM. It is natural to consider that the rare decays of D meson might be more sensitive to new physics, and the decay mode D0→μ+μ-could be an ideal area to search for new physics because it is a flavor changing process. In this work we look for a trace of the new physics BSM in the leptonic decays of D0. Concretely we discuss the contributions of unparticle or an extra gauge boson Z while imposing the constraints set by fitting the D0-ˉD0mixing data. We find that the long-distance SM effects for D0→lˉl still exceed those contributions of the BSM under consideration, but for a double-flavor changing process such as D0→μ±e, the new physics contribution would be significant.     

Simulation of random mixed packing of different density particles

This paper presents the effects of density difference on the three-dimensional (3D) distribution of random mixed packing. The random mixed packing dynamics of particles of two different densities are simulated. The initial state is homogeneous, but the final packing state is inhomogeneous. The segregation phenomenon (inhomogeneous distribution) is also observed. In the final state, the top layers are composed of mostly light particles. The several layers beneath the top contain more heavy particles than light particles. At the bottom, they also contain more heavy particles than light particles. Furthermore, at both the top and the bottom, particle clustering is observed. The current study also analyses the cause of this inhomogeneity in detail. The main cause of this phenomenon is the velocity difference after collision of these two types of particles induced by the density difference. The present study reveals that even if particles were perfectly mixed, the packing process would lead to the final inhomogeneous mixture. It suggests that special treatment may be required to get the true homogeneous packing.     

γ Radiative Decays to Light Quark Jets and Color Octet Mechanism

We study radiative decays of T to light quark jets in nonrelativistic QCD by taking both the color singlet and color octet b^-b operators into consideration. The cut for quark jet energy and cut for the angle between two quark jets are introduced. The sensitivity to the soft and collinear singularities in the loop integrals are greatly reduced by these cuts. With the jet energy cut of about 1 GeV, and the jet angle cut of about 36°, the branching ratio for γ→ rq^- is found to be 8.2 × 10^-4 from color singlet contributions. The color octet contributions could be much larger than that of color singlet, depending on the estimate of the color octet matrix elements. This process may provide a new test for the color octet mechanism in nonrelativistic QCD.     

Dark-matter pair production at the ILC in the littlest Higgs model with T-parity

In the littlest Higgs model with T-parity, the heavy photon (A_H) is supposed to be a possible dark matter (DM) candidate. The direct proof of the validity of this model is to produce the heavy photon at an accelerator. In this paper, we study the production rate of e~+ e~- → AH AH at the international e~+ e~- linear collider (ILC) in the littlest Higgs model with T-parity, and show the distributions of the transverse momenta of A H . The numerical results indicate that the heavy photon production rate could reach the 10~-1 fb level at some parameter space, so this could be a good chance to observe the heavy photon via the pair production process with high luminosity at the ILC (500 fb~-1). We know that DM is composed of weakly interacting massive particles, so the interactions with standard model particles are weak. How to detect heavy photons at a collider and distinguish them from other DM candidates are discussed in the final section of the paper.     

Top—Higgs and the Process e^＋e^— → vvtt

We discuss the contributions of the top-Higgs ht^0 proedicted by topcolor-assisted technicolor (TC2) models to the process e^ e^-→vvtt.We find that the contributions are very large.For mht=400 GeV and ε=0.01,the production cross section of this process can reach 11.2fb,which may be detected in the future high energy e^ e^- collider experiments.The process e^ e^-→vvtt can be used to test experimentally the signal of TC2 models.