The mass of the isodoublet of the 2^1S0 meson nonet revisited

In the qq quark model, the states π（1300）, η（1295） and η（1475） are assigned as the 2^1S0 meson nonet. The mass of the isodoublet remains interesting and needs further confirmation in experiments. This paper employs the phenomenological trajectory on the （N, M^2）-plot and meson meson mixing methods to calculate the mass of this state, the calculated results are 1341 MeV and 1311.58 ± 59 MeV respectively. These predictions can be compared with experiments in the future.[第一段]     

A possible explanation of the threshold enhancement in the process e~+e~-→∧■

Inspired by the recent measurement of the process e~+e~-→∧■,we calculate the mass spectrum of the 0 meson with the GI model.For the excited vector strangeonium states ?(3 S,4 S,5 S,6 S) and ?(2 D,3 D,4 D,5 D),we investigate the electronic decay width with the Van Royen-Weisskopf formula,and the partial widths of the ∧■,■,and■ decay modes with the extended quark-pair creation model.We find that the electronic decay width of the D-wave vector strangeonium is about 3～8 times larger than of the S-wave vector strangeonium.Around 2232 Me V,the partial decay width of the ∧■ mode can be up to several MeV for ?(3~3 S_1),while the partial ∧■ decay width of ?(2~3 D_1) is O(10~(-3)) keV.If the threshold enhancement reported by the BESIII collaboration arises from the strangeonium meson,this state is very likely the ?(3~3 S_1) state.We also note that the ∧■ and∑~+■partial decay widths of the states ?(3~3 D_1) and ?(4~3 S_1) are several MeV,which is sufficient to be observed in future experiments.     

Radiative leptonic decay B_c~-→τ~-_τγ in the standard model and the two-Higgs-doublet model

We analyze the radiative leptonic Bc decay Bc-→τ-νˉτγ in the Standard Model and the twoHiggs-doublet model using the non-relativistic constituent quark model.The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities.We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model,and it can be tested in future experiments.     

Radiative leptonic decay Bc^-→τ^vτ^-γ in the standard model and the two-Higgs-doublet model

We analyze the radiative leptonic Bc decay Bc^-→τ^vτ^-γ in the Standard Model and the two- Higgs-doublet model using the non-relativistic constituent quark model. The results confirm that this channel is experimentally promising in view of the large number of Bc mesons which are expected to be produced at future hadron facilities. We also find that this decay is sensitive to the parameters of the two-Higgs-doublet model, and it can be tested in future experiments.     

Structure of the Semi—decoupled π 1／2[411] Band in Odd Proton Nucleus ^169Ta

High spin states of the odd proton-nucleus ^169Ta have been populated in the reaction ^155Gd(^19F,5n) with beam energies of 97MeV,Rotational band based on d3/2 proton 1/2[411]Nilsson state has been pushed up to 39/2^ in the α=1/2 decay sequence.Its signature partner,the α=-1/2 decay sequence with four link transitions has been established and 1/2[411] band in ^169Ta was reassigned to be a semi-decoupled band.The systematics of the signature splitting in the K=1/2 bands in the rear-earth region and the accidental degeneracy conclusion given by the angular projection shell model were discussed.     

Mechanism of Pseudogap Detected by Electronic Raman Scattering： Phase Fluctuation or Hidden Order？

We study the electronic Raman scattering in the cuprates to distinguish the two possible scenarios of the pseudogap normal state. In one scenario, the pseudogap is assumed to be caused by phase fluctuations of the preformed Cooper pairs. We find that pair-breaking peaks appear in both the B1g and B2g Raman channels, and they axe smeared and tend to shift to the same energy with the increasing strength of phase fluctuations. Thus both channels reflect the same pairing energy scale, irrespectively of the doping level. In another scenario, the pseudogap is assumed to be caused by a hidden order that competes with the superconducting order. As an example, we assume that the hidden order is the d-density-wave （DDW） order. We find analytically and numerically that in the DDW normal state there is no Raman peak in the B2g channel in a tight-binding model up to the second nearest-neighbor hopping, while the Raman peak in the Big channel reflects the energy gap caused by the DDW order. This behavior is in agreement with experiments in the pseudogap normal state. To gain further insights, we also calculate the Raman spectra in the DDW＋SC state. We study the doping and temperature dependence of the peak energy in both channels and find a two-gap behavior, which is in agreement with recent Raman experiments. Therefore, our results shed light on the hidden order scenario for the pseudogap.     

Study of K（892） mass and width splitting caused by model difference

According to the new K^＊（892）^0 and K^＊（892）^- masses reported by the BELLE experiment and the K^＊（892）^0 mass reported by the FOCUS experiment, mass splitting between neutral and charged K^＊（892） becomes very small. This is significantly different from the current world average values given by the Particle Data Group 2008. We find that there are differences between models used to fit the K^＊（892） decay invariant mass spectra in different measurements and study the model dependence in the measurement of K^＊（892） parameters. We refit the K^＊（892）^0 mass spectra of the BELLE and FOCUS experiments with the formula used by BELLE in fitting K^＊（892）^- to get new mass and width. After refitting, the K^＊（892）^0 mass of the BELLE experiment becomes 1.4 MeV/c^2 larger than the initial value and that of the FOCUS experiment is 1 MeV/c^2 smaller than the initial value. We also fit the spectra of some other experiments to extract the K^＊ （892） parameters using the BELLE K^＊ （892）^- parametrization.     

Top Quark Decay t → cb-↑b in Topcolor-Assisted Technicolor Models

The topcolor-assisted technicolor （TC2） model predicts the existence of the top-pions and the CP-even top-Higgs with large flavor-changing couplings to the top quark, which at tree-level can mediate the top quark three-body decay t → cb-↑b. We study this decay, show the dependence of the decay rate on the relevant TC2 parameters and compare the results with the predictions in the minimal supersymmetric model. We find that the decay rate in the TC2 model is much larger than that in the minimal supersymmetric model if the new particles are not too heavy. However, in consideration of the ODF and the LEP experiment limits, the top-pion mass is greater than 340 GeV in a more realistic parameter space, so the decay width of the channel t → cb-↑b intermediated by top-pions will be depressed greatly and difficult to be detected at the future collider. Thus, to observe this channel at the future collider, considering the top-higgs contribution may be the possible way when the masses of the top-pions and the top-higgs are not degenerate.     

Radial excitation states of η and η′ in the chiral quark model

A chiral quark model is applied to calculate the spectra of pseudoscalar mesons η and η . By analyzing the obtained spectra, we find that the mesons η (2 1 S 0 ), η(4 1 S 0 ), η (3 1 S 0 ) and η (4 1 S 0 ) are the possible candidates of η(1760), X(1835), X(2120) and X(2370). The strong decay widths of these pseudoscalars to all the possible two-body decay channels are calculated within the framework of the 3 P 0 model. Although the total width of η (21S0 ) is compatible with the BES Collaboration’s experimental value for η(1760), the partial decay width to ωω is too small, which is not consistent with the BES result. If X(1835) is interpreted as η(4 1 S 0 ), the total decay width is compatible with the experimental data, and the main decay modes will be πa 0 (980) and πa 0 (1450), which needs to be checked experimentally. The assignment of X(2120) and X(2370) to η (31S0 ) and η (41S0 ) is disfavored in the present calculation because of the incompatibility of the decay widths.     

The Production of Pseudo Goldstone Boson in Top Quark Rare Decay

We calculate the flavor changing t → cπ0 decay in the framework of the topcolor assisted multiscaletechnicolor model. We find that (a) the branching ratio of t → cπ0 is insensitive to mπ, mπs and mπt, while it increasesquickly as ε increases; (b) for reasonable ranges of the parameters, the maximum of the branching ratio in this modelmay reach 7 × 10-6, seven orders larger compared to the one t → cH0 calculated in the standard model. This mightprovide an opportunity to detect the rare decay of the top quark in experiments.     

Abnormal Visible Luminescence Mechanism of Tb^3＋-Yb^3＋ Codoped SiOu-Al2O3-CaF2 Glass Studied by Time-Resolved Spectra

The upconversion energy transfer mechanism in Tb^3＋-Yb^3＋ co-doped SiO2-Al2O3-CaF2 glass is investigated by time-resolved spectra. The effect of donor ion Yb^3＋ is involved in the dynamic decay behavior of acceptor ion Tb^3＋, which provides direct proof for the energy transfer from Yb^3＋ to Tb^3＋. The pump power dependence curves show that the upconversion luminescence is a two-photon process. The measured decay curves of the 5D4 state （Tb^3＋） contain two parts： a slow decay process corresponding to its radiation, and a fast one with a decay parameter approximately twice the lifetime of the ^2F5/2 state （Yb^3＋ ）. The fast decay process is contradictory to the generally accepted cooperative sensitization upconversion rate equation model. Since the effect of the host environmental is excluded by comparative experiments, we believe that there should be another energy transfer mechanism in Tb^3＋-Yb^3＋ co-doped SiO2-Al2O3-CaF2 glass in addition to the cooperative sensitization process.     

ηb decay into charmonium in association with cc pair

We calculate the inclusive decay rates of ηb into charmonium via double c~ pairs for S- and P-wave states ηc, J/ψ and XcJ within the framework of non-relativistic QCD （NRQCD） factorization at leading order in αs. Besides calculating the contributions of the color-singlet channels ηb → cc[2s＋1SL^（1）]＋cc, the effects of cc pair in the color-octet configurations are also considered. We find that ηb → cc[3S1^（8）] ＋cc make a small contribution to Br（ηb →J/ψ（ηc）＋cc）. While in the ηb →XcJ ＋cc case, the color octet contributions are significant, for they are of the same a 5 order as the color-singlet processes. We predict Br（ηb →J/ψ（ηc）＋cc） = 2.99（2.75） × 10^-5 Vc for S-wave states J/ψ and ηc, and Br（ηb → XcJ ＋cc） = （4.37, 3.40, 2.83） × 10^-5 （for J = 0,1, 2） for P-wave states XcJ. In the end, we also find Br（ηb → cccc） is almost saturated by ηb decay into charmonium in association with cc pair from the point of view of duality.     

New physics search in the doubly weak decay ■→K~+π~(-*)

The doubly weak transition b-dd■ is highly suppressed in the Standard Model,which makes it a potential channel for exploring new physics signals.We present a study of the exclusive two-body wrong sign weak decay ■→K+π-,which belongs to this class,in the perturbative QCD framework.We perform a model independent analysis for various effective dimension-6 operators for which large effects are possible.We further analyze the considered process in the Randall-Sundrum model,including the custodially protected and the bulk-Higgs Randall-Sundrum models.Exploring the experimentally favored parameter space of these models leads to a large and significant enhancement of the decay rate compared to the Standard Model,which might be accessible in future experiments.We propose to search for the wrong sign decay ■→K+π-via flavor-tagged time-dependent analyses,which can be performed at LHCb and Belle-Ⅱ.     

Production of Charged Higgs Boson Associated with Top Partner at the Large Hadron Collider

In the context of the littlest Higgs （LH） model and the left-right twin Higgs （LRTH） model, we study the production of charged Higgs boson associated with top partner at the LHC. We find that, in the LH model, its cross section can be significantly larger for the scale parameter f = 500 GeV, while sharply decreases as f increases. In the LRTH model, this production process mainly transfers to the t？tb？bb final state at the Large Hadron Collider and its production rate can reach 167.2 fb.     

Single top partner production in the tZ channel at eγ collision in the littlest Higgs model with T-parity

Introducing the top partner is a common way to cancel the largest quadratically divergent contribution to the Higgs mass induced by the top quark. In this work, we study single top partner production in the tZ channel at eγ collision in the littlest Higgs model with T-parity(LHT). Since it is well known that polarized beams can enhance the cross section, we analyze the signal via polarized electron beams,and photon beams. we have selected two decay modes for comparison, based on the leptonic or the hadronic decays of the W and Z from the top partner. We then construct a detailed detector simulation, and choose a set of cuts to enhance signal significance. For mode A(B), the capacity for exclusion in this process at s~(1/2)=3TeV is comparable to the current experimental limits with L=1000(500) fb~(-1). If the integrated luminosity can be increased to 3000 fb~(-1), the top partner mass+mTcan be excluded up to 1350(1440) GeV at 2σ level. We also considered the initial state radiation effect, and find that this effect reduces the excluding ability of the eγ collision on the the top partner mass by approximately 10 GeV. Moreover, the ability to exclude the LHT parameter space at eγ collision complements the existing research.     

Is Kano-Nucleon Interaction Consistent with Pentaquark θ^＋

The quark-delocalization colour-screening model is employed to calculate the effective potential between nucleon and kaon. The results show that the potentials are attractive in the I = 0 channel and repulsive in the I = 1 channel. The interactions are very weak between K^＋n or K^0p due to the cancellation between I = 0 and I = 1. It is possible to have a high s-wave resonance （1615 MeV）, but the width may be too wide to be observed in the experiments.     

Towards the understanding of 11P1 meson mass spectrum

Based on the meson-meson mixing and Regge trajectory, this paper establishes the mass relations which can describe the mass spectrum of 1^1 P1 meson state. Using these mass relations, it obtains the mass of K1B, hi （1380） and hc（1P） to be 1358.5MeV, 1468 MeV and 3543.9 MeV, respectively. The results are compared with other theoretical results and should be tested by experiments in the future.     

Is there a Di-Ω State?

Resonating-group method has been applied to calculate the ΩΩ (SIJ = -6,0,0) dibaryon state in theframework of the extended quark-delocalization color-screening model. The mass of the di-Ω is predicted to be about45 MeV lower than the Ω-Ω threshold. The effect of channel coupling due to the tensor force and sensitivity to mesonexchange short-range cutoff radius, ro have also been studied.     

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.     

Approximate Teleportation of an Unknown Atomic-Entangled State with Dissipative Atom-Cavity Resonant Jaynes-Cummings Model

We propose a scheme for approximately and conditionally teleporting an unknown atomic-entangled state in dissipative cavity QED. It is the further development of the scheme of [Phys. Rev. A 69 （2004） 064302], where the cavity mode decay has not been considered and the state teleportated is an unknown atomic state. In this paper, we investigate the influence of the decay on the approximate and conditional teleportation of the unknown atomic-entangled state, which is different from that teleportated in [Phys. Rev. A 69 （2004） 064302] and then give the fidelity of the teleportation, which depends on the cavity mode decay. The scheme may be generalized to not only the teleportation of the cavity-mode-entangled-state by means of a single atom but also the teleportation of the unknown trapped-ionentangled-state in a linear ion trap.