Process e^-у→ e^-H in Littlest Higgs Model

In the context of the littlest Higgs （LH） model, we estimate the production cross section of the process e^-у→ e^-H in the future high-energy linear e^＋e^- collider （ILC） with the center-of-mass （CM） energy √S = 500 GeV. Our numerical results show that the contributions of the LH model Co this process are very small in most of the parameter space allowed by the electroweak precision measurement data, and are very diffcult to be detected in the future ILC experiments.     

Correction of the Littlest Higgs Model to Higgs Production Process e-γ→veW-H in e-γ Collisions

The littlest Higgs model is the most economical one among various little Higgs models. In the context of the littlest Higgs （LH） model, we study the process e-γ → veW^-H and calculate the contributions of the LH model to the cross section of this process. The results show that in most of the parameter spaces preferred by the electroweak precision data, the value of the relative correction is larger than 10%. Such correction to the process e-γ →veW^-H is large enough to be detected via e-γ collisions in the future high energy linear e^＋ e^- collider （ILC） experiment with the c.m. energy √s = 500 GeV and a yearly integrated luminosity ￡ = 100fb^-1, which will give an idea/way to test the model.     

Effects of the littlest Higgs model on the process e~+ e~- → μ~+ μ~- at a Z~0-factory

We investigate the possibilities of finding the effects of the littlest Higgs (LH) model on the process e + e - →μ + μ - at the leadingorder at a possible Z 0-factory.We study the impacts of the LH model on the observables,such as,the total cross section,the distribution of the transverse momentum of μ-,and the forward-backward charge asymmetry of μin polarized and unpolarized electron-positron collision modes.Besides,we analyze the relations between the observables and the LH model parameters,and discuss the observables of process e + e→μ + μ-in different incoming electron-positron polarization modes.We conclude that one could observe the effects contributed by the LH model on the process e + e-→μ + μin a reasonable parameter space,or might put more stringent constraints on the LH parameters in the future experiments at the possible Z 0-factory.     

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.     

The single neutral top-higgs production at LHC and ILC in the Topcolor-Assisted Technicolor Model

In this paper, we study the single neutral top-higgs (h0t) production processes at the CERN Large Hadron Collider (LHC) and the International Linear Collider (ILC). At the LHC, the production rates of processes pp→Z(W)h0t are too small to detect h0t . However, with the reasonable parameter values, the cross sections can reach the level of 102 fb for qq→qqh0t process and 103 fb for top quark associated production process pp→th0t+X, respectively. At the ILC, we study the single top-higgs production processes e-γ→νeW-h0t and γγ→W+W-h0t in e-γ and γγ collisions. It is found that the production cross sections can reach the level of a few fb with reasonable parameter values. Furthermore, such processes with the flavor-changing decay mode h0t→tc might provide typical signatures to detected the top-higgs. Therefore, it is hopeful to find the signal of top-higgs at the LHC and ILC experiments via theses processes and test the TC2 model directly.     

Associated Production of a Photon with Dark Matter Pair at the ILC within the Littlest Higgs Model with T-parity

Within the context of the Littlest Higgs model with T -parity, the heavy photon (AH) is supposed to be an ideal dark matter (DM) candidate. One direct proof of validity of the model is to produce the heavy photon at collider. In this paper, we investigate the associated production of a photon with heavy photon pair at the planned international e+e- linear collider (ILC),i.e., e+e-→ AHAHγ and show the distributions of the transverse momenta of the photon. The numerical results indicate that the heavy photon production rate could reach several fb at the low mass parameter space and the characteristic signal is a single high energetic photon and missing energy, carried by the heavy photons. All in all, it can be a good chance to observe the heavy photon via this process with the high yearly luminosity of the ILC.     

Littlest Higgs Model and Spin Correlation of Top Quark Production at High Energy Linear e^＋e^- Colliders

Based on the littlest Higgs model, we investigate the spin correlation of the top quark pair production via the process e^＋e^- →tt at the high energy linear e^＋e^- collider （ILC） with a centre-of-mass energy √S = 800 GeV. Our numerical results show that the gauge boson ZH generates very small corrections to the spin correlation observable C in all the parameter space allowed by the electroweak data. However, with reasonable values of the free parameters, the value of the relative correction parameter RBH = （CBH-CSM）/CSM can reach 10%, which might be detected in future ILC experiments.     

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.     

Searching for Flavor-Changing Neutral-Current Signals via e＋e-（γγ） →tcht0 in Topcolor-Assisted Technicolor Model

In the context of the top-color-assisted technicolor （TC2） model, the flavor-changing neutral-current （FCNC） interaction induced by the top-higgs （hOt） are predicted at tree level. We study the relevant processes of e＋e-（γγ）→tcht0 at the International Linear Collider （ILC）. It is found that these rare processes production rates can be enhanced significantly in the TC2 model. Especially for the process γγ→tcht0, the total cross section will reach a few fb in the reasonable parameter space. We also calculate the distributions of transverse momenta, pseudo-rapid and invariant mass of the top-higgs. In view of the main decay modes of top-higgs for mho 〈 2mr, we find that there will be several hundreds FCNC events produced at the ILC with annually integral luminosity of 500 fb-1. Due to the clean background, such FCNC signals can possibly be detected at the ILC.     

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.     

Probing the Stau-Stau-Higgs Couplings in the MSSM at NLC

In the minimal supersymmetric standard model (MSSM) with CP violating phases, this paper discussesthe production of the lightest neutral Higgs boson in association with tau sleptons at future high-energy e e- linearcolliders. In parameter space of the constrained MSSM, the production cross section of e e- → h0τ1 τ1- can be verysubstantial at high energies. This process would provide a production mechanism for probing couplings of neutral Higgsbosons to tau sleptons as well as some soft supersymmetric breaking parameters at next linear colliders.     

Probing the Lightest New Gauge Boson BH in the Littlest Higgs Model via Processes γγ→ ff^- Bg at ILC

The neutral gauge boson BH with the mass of hundreds GeV is the lightest particle predicted by the littlest Higgs （LH） model, and such particle should be the first signal of the LH model at the planed ILC if it exists indeed. In this paper, we study some processes of the BH production associated with the fermion pair at the ILC, i.e., γγ→ ff^- BH. The studies show that the most promising processes to detect BH amongγγ→ ff^- BH are γγ→ l＇^＋l＇^-BH （l＇ = e,μ）, and they can produce the sufficient signals in most parameter space preferred by the electroweak precision data at the ILC. On the other hand, the signal produced via the certain BH decay modes is typical and such signal can be easily identified from the SM background. Therefore, BH, the lightest gauge boson in the LH model, would be detectable at the photon collider realized at the ILC.     

Probing HZγ and Hγγ anomalous couplings in the process e~+e~-→ Hγ

We propose to measure the HZγ and Hγγ anomalous couplings in the process e+e-→Hγ with the sequential decay of H→bˉb. The discovery potential of observing the anomalous couplings are explored in detail.Our study shows that future electron–positron colliders have great potential to test the HZγ and Hγγ couplings.Conservative bounds on the two anomalous couplings are also derived when no new physics signal is detected on top of the SM backgrounds.     

Origin of pit chains in the floor of lunar Copernican craters

There are small pit chains in the floor of lunar Copernican craters. They are usually so small in scale that there are few lunar spacecrafts to detect their detailed morphology. Combining camera data from Lunar Orbiter, Lunar Reconnaissance Orbiter (LRO), Kaguya and Chang’e-1 missions, 5 representative large Copernican craters on various terrains of the lunar surface are chosen to study the origin of the pit chains in the crater floor. The morphology and distribution characteristic of the pit chains are referred by the high resolution images in this research. It is suggested that it is the magma activities from the subsurface magma layer combining with the existence of fractures and faults under the crater floor that leaded the formation of the pit chains. The model is further verified and discussed using the regolith thickness data in the crater floor. Our model suggests that the pit chains are still developing in the floor of the Copernican craters and the Moon may not be totally cold. Finally, the model limitation and potential future work are discussed based on available data.     

Single Production of Top Quark via e-γ Collision in Left-Right Twin Higgs Model

In the context of the left-right twin Higgs （LRTH） model, we fist study single production of the standard model （SM） top quark via e-γ collisions. We find that the corrections of the LRTH model to the cross section of the process e-γ→vebt might be observed only for f ≤750 GeV and the heavy top quark mass scale M ≥500 GeV in future high energy linear e^＋e^- collider （LC） experiment with the center-of-mass （CM） energy √s = 500 GeV and a yearly integrated luminosity of ￡ = 100 fb^-1. We also consider single production of the heavy top quark T via e-γ collisions. Our numerical results show that the possible signals of the heavy top quark T might be observed via the decay channel T →Ф^＋b→tbb in future LC experiment with √s = 3 TeV and ￡ = 500 fb^-1.     

Flavor Changing Top Quark Decay and Bottom-Strange Production in the Littlest Higgs Model with T-parity

Flavor changing effects on the processes t → ch, e+e- → bs, e+e-→ bsh and pp → bs in the LHT model are investigated in this paper. We calculate the one-loop level contributions from the T-parity odd mirror fermions and gauge bosons. The results show that the top quark rare decay t → ch in the LHT model can be significantly enhanced relative to that in the SM. The bs production at linear colliders in the LHT model can enhance the SM cross section a lot and reach 0.1 fb in some parameter space allowed in the experiment. But the heavy gauge boson and mirror fermion loops have small contribution to the processes pp → bs and e+e-→ bsh. So the LHT effect on e+e-→ bs might be detected at future linear colliders, while it is too small to be seen for the e+e-→ bsh and pp → bs processes at future linear colliders and LHC.     

Reaction Limited Aggregation with Anisotropic Island—Edge Exchange in Surfactant—mediated Epitaxy

We simulate the two-dimensional pattern formation in surfactant-mediated epitaxy using a kinetic model,in which the nucleation and growth of the stable islands are controlled by the exchange process betwwen surfactant atoms and deposited atoms.Our model assumes the following.(1) The exchange barrier preventing an adatom from attaching to an existing island edge depends on the numbers of the adatoms nearest and next-nearest neighbours belonging to the island.(2) the exchange processes at the two different types of step are associated with different energy barriers.The simulations generate a series of surface morphologies ranging from fractal structures to compact triangular shapes,very similar to those observed in recent experiments.     

Two-photon exchange properties in to proton electromagnetic time-like region

The contributions of two-photon exchange in the process e＋ ＋ e-→ p ＋ p including N and △ intermediate states are estimated in a simple hadronic model. The corrections to the unpolarized cross section as well as to the polarized observables Px and Px are evaluated. The results show the corrections to unpolarized cross section are small and the angle dependence becomes weak at small s after considering the N and △（1232） contributions simultaneously, while the correction to Px is enhanced.     

Associated production of a neutral top-Higgs with a heavy-quark pair in the γγ collisions at ILC

We have studied the associated production processes of a neutral top-Higgs in the topcolor assisted technicolor model with a pair of heavy quarks in γγ collisions at the International Linear Collider (ILC). We find that the cross section for ttht in γγ collisions is at the level of a few fb with the c.m. energy √s=1000 GeV, which is consistent with the results of the cross section of ttH in the standard model and the cross section of tth in the minimal supersymmetric standard model. It should be clear that hundreds of to thousands of ht per year can be produced at the ILC. This process of γγ→ttht is really interesting in testing the standard model and searching the signs of technicolor.     

Perturbative QCD for J/ψ inclusive production via initial state radiation in e~+e~- collisions

The process e+e-→J/ψ+X with the center-of-mass(CM)energy in the range from 3.7 to 10.6 GeV is calculated up to the next-to-leading order(NLO)in quantum chromodynamics(QCD).At 10.6 GeV,the result is consistent with the experimental result from Belle.However,the predictions are much smaller than the background in the measurements at BESIII in the low CM energy range from 3.7 to 4.6 GeV.This indicates that the convergence of the QCD perturbative expansion becomes worse as the CM energy is closer to the inclusive J/ψ production threshold.For a further study of the QCD mechanism of J/ψ production in e~+e~-collisions with different CM energies,the initial state radiation effect of e~+e~-→J/ψ +gg and e~+e~-→J/ψ+cc are calculated in QCD NLO.The results are plotted and the number of events for different CM energy bins are provided for SuperKEKB.This provides a method to precisely test the validity of perturbative predictions for J/ψ production in future measurements.