Within the context of the Littlest Higgs model with T-parity, the heavy photon （AH） is supposed to be an ideM dark matter （DM） candidate. One direct proof of validity of the model is to produce the heavy photon at...Within the context of the Littlest Higgs model with T-parity, the heavy photon （AH） is supposed to be an ideM 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 a/l, it can be a good chance to observe the heavy photon via this process with the high yearly luminosity of the ILC.展开更多
In the parameter space allowed by the electroweak precision measurement data, we consider the contributions of the new particles predicted by the littlest Higga model to the Higgs hoson associated production with top ...In the parameter space allowed by the electroweak precision measurement data, we consider the contributions of the new particles predicted by the littlest Higga model to the Higgs hoson associated production with top quark pair in the future high energy linear e^＋e^- collider （ILU）. We find that the contributions mainly come from the new gauge bosons ZH and BH. For reasonable values of the free parameters, the absolute value of the relative correction parameter δσ/σ^SM can be signiticanly large, which might be observed in the future ILU experiment with √S = 800 GeV.展开更多
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...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 s1/2=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.展开更多
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 m...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.展开更多
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 exis...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.展开更多
The littlest Higgs （LH） model is the most economical one among various little Higgs models, which predicts the existence of the charged scalars Φ^±. In this paper, we study the production of the charged Higgs ...The littlest Higgs （LH） model is the most economical one among various little Higgs models, which predicts the existence of the charged scalars Φ^±. In this paper, we study the production of the charged Higgs boson Φ^- with single top quark via the process gb →tΦ^- at the CERN Large Hadron Collider （LHC）. The numerical results show that the production cross section is sma/ler than 0.2 pb in most of the parameters space, it is very difficult to observe the signatures of the charged scalars via the process pp → gb ＋ X → tΦ^- ＋ X at the LHC experiments. However, it can open a window to distinguish the top-pions in the TC2 model or charged Higgs in the MSSM from Φ^±.展开更多
In the littlest Higgs model with T-parity(LHT) the mirror quarks induce the special flavor structures and some new flavor-changing couplings,which could greatly enhance the production rates of the flavor-changing proc...In the littlest Higgs model with T-parity(LHT) the mirror quarks induce the special flavor structures and some new flavor-changing couplings,which could greatly enhance the production rates of the flavor-changing processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider(ILC),i.e.,e^+e^-→bs andγγ→bs.The results show that the production rates of these processes are sizeable for the favorable values of the parameters.Therefore,it is quite possible to test the LHT model or make some constraints on the relevant parameters of the LHT through the detection of these processes at the ILC.展开更多
The T-parity in the littlest Higgs model can be broken by the anomalous Wess-Zumin-Witten term, which leads that the lightest T-odd gauge boson AH decays into the SM particles. First, we examine some lepton flavor vio...The T-parity in the littlest Higgs model can be broken by the anomalous Wess-Zumin-Witten term, which leads that the lightest T-odd gauge boson AH decays into the SM particles. First, we examine some lepton flavor violating decays of AH, namely AH → τ±μ±, AH→ τ±e±, and AH→ τ±e±. We find that the branching ratios can reach 10-7 for AH → τ±μ±, 10-s for AH → τ±μ±, and 10-s for AH → τ±e± Then, we study the lepton flavor violating plus jets signatures of the heavy charged gauge boson and mirror quarks at the LHC, and find that it is possible to be detected for pp jets, and hardly to be detected for pp → τ±e± （μ±e±） ＋ 4 jets and p p → W H W H → τ±μ±（ τ±e±,μ±e±） ＋ 6 jets.展开更多
In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing...In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing angles c` and , and the Higgs triplet vacuum expectation value v＇ in the electroweak precision data preferring ranges. We find that the LH model can give a relatively small, but non-negligible extra weak contribution to the muon anomalous magnetic moment and can reduce the deviation of △aμ from 2.6σ for the SM to 2.5σ for the LH model.展开更多
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 contribution...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.展开更多
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 ...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.展开更多
In the littlest Higgs Model with T-parity,we discuss the Higgs production in association with bottom quarks at the LHC and future electron-positron collider.We calculate the cross sections of production channels pp→b...In the littlest Higgs Model with T-parity,we discuss the Higgs production in association with bottom quarks at the LHC and future electron-positron collider.We calculate the cross sections of production channels pp→bb H,bb→H and bg→b H at 14 Te V LHC and the cross sections of production channel e^+e^-→bb H in(un)polarized beams at the lowest order.In order to investigate the observability,we display some typical final state distributions in the Higgs to diphoton channel.展开更多
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.T...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.展开更多
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 accele...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.展开更多
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 obs...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.展开更多
In the framework of the littlest Higgs model with T-parity, we study the top pair production at the next generation colliders like LHC and ILC. We find that the order O（αs） corrections to the standard model top pai...In the framework of the littlest Higgs model with T-parity, we study the top pair production at the next generation colliders like LHC and ILC. We find that the order O（αs） corrections to the standard model top pair production cross section at LHC can be very small and the magnitude is below 1%. However, the magnitude of corrections to the standard model top pair production rate at ILC may be over 5% for reasonable values＇of the parameters. Besides this, the corrections to the asymmetry ALR（tt） may be more sizable. Therefore, the top pair production at ILC may serve as a probe of the littlest Higgs model with T-parity, especially the asymmetry ALR（tt）.展开更多
The lightest new gauge boson BH with mass of hundreds GeV is predicted in the littlest Higgs model. BH should be accessible in the planned ILC and the observation of such particle can strongly support the littlest Hig...The lightest new gauge boson BH with mass of hundreds GeV is predicted in the littlest Higgs model. BH should be accessible in the planned ILC and the observation of such particle can strongly support the littlest Higgs model. The realization of 7Y and e^-γ collisions would open a wider window to probe BH. In this paper, we study the new gauge boson BH production processes e^-γ→e^-BH and e^-γ→e^-BH at the ILC. Our results show that the production cross section of the process e^-γ→e^-BH is less than 0.1 fb in most parameter spaces allowed by the electroweak precision data while the cross section of the process e^-γ→e^-BH can be over one fb in the favorable parameter spaces. With the high luminosity, the enough typical signals could be produced via e^-γ→e^-BH. Because the final electron and photon beams can be easily identified and the signal can be easily distinguished from the backgrounds produced by Z and H decaying, e^-γ→e^-BH is a promising process to probe BH.展开更多
Motivated by the search for flavor-changing neutral current（FCNC） top quark decays at the LHC,we calculate the rare Higgs three body decay H→Wbc induced by top-Higgs FCNC coupling in the littlest Higgs model with T...Motivated by the search for flavor-changing neutral current（FCNC） top quark decays at the LHC,we calculate the rare Higgs three body decay H→Wbc induced by top-Higgs FCNC coupling in the littlest Higgs model with T-parity（LHT）.We find that the branching ratio of H→Wbc in the LHT model can reach O（10^-7） in the allowed parameter space.展开更多
With the high energy and luminosity, the planned ILC has the considerable capability to probe the new heavy particles predicted by the new physics models. In this paper, we study the potential to discover the lightest...With the high energy and luminosity, the planned ILC has the considerable capability to probe the new heavy particles predicted by the new physics models. In this paper, we study the potential to discover the lightest new gauge boson BH of the Littlest Higgs model via the processes e^＋e^- →γ（Z）BH at the ILC. The results show that the production rates of these two processes are large enough to detect BH in a wide range of the parameter spaces, specially for the process e^＋e^- →γ TBH. Furthermore, there exist some decay modes for BH which can provide the typical signal and clean backgrounds. Therefore, the new gauge boson BH should be observable via these production processes with the running of the ILC if it exist.展开更多
The littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson BH, which can be seen as an attractive dark matter candidate. We study production of the new gauge boso...The littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson BH, which can be seen as an attractive dark matter candidate. We study production of the new gauge boson BH via ey and ep collisions. We find that BH can be abundantly produced via the subprocesses e^-T→ L^-BH and γq→BHQ, which might give rise to characteristic signals. Some discussions about the SM backgrounds for this kind of signals are also given.展开更多
基金Supported by the National Natural Science Foundation of China under Grant No.11075045the Natural Science Foundation of Education Department of Henan Province under Grant No.2011A140005
文摘Within the context of the Littlest Higgs model with T-parity, the heavy photon （AH） is supposed to be an ideM 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 a/l, it can be a good chance to observe the heavy photon via this process with the high yearly luminosity of the ILC.
基金The project supported in part by the Program for New Century Excellent Talents in Universities under Grant No, NCET-04-0290, Nations/Natural Science Foundation of China under Grant Nos. 90203005 and 1047S037, and the Natural Science Foundation of Lisoning Science Committee under Grant No. 20032101
文摘In the parameter space allowed by the electroweak precision measurement data, we consider the contributions of the new particles predicted by the littlest Higga model to the Higgs hoson associated production with top quark pair in the future high energy linear e^＋e^- collider （ILU）. We find that the contributions mainly come from the new gauge bosons ZH and BH. For reasonable values of the free parameters, the absolute value of the relative correction parameter δσ/σ^SM can be signiticanly large, which might be observed in the future ILU experiment with √S = 800 GeV.
基金supported by the National Natural Science Foundation of China(NNSFC)under grant No.11405047。
文摘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 s1/2=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.
基金The project supported in part by National Natural Science Foundation of China under Grant Nos. 10375017 and 10575029
文摘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.
基金National Natural Science Foundation of China under Grant Nos.10375017 and 10575029
文摘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.
文摘The littlest Higgs （LH） model is the most economical one among various little Higgs models, which predicts the existence of the charged scalars Φ^±. In this paper, we study the production of the charged Higgs boson Φ^- with single top quark via the process gb →tΦ^- at the CERN Large Hadron Collider （LHC）. The numerical results show that the production cross section is sma/ler than 0.2 pb in most of the parameters space, it is very difficult to observe the signatures of the charged scalars via the process pp → gb ＋ X → tΦ^- ＋ X at the LHC experiments. However, it can open a window to distinguish the top-pions in the TC2 model or charged Higgs in the MSSM from Φ^±.
基金Supported by the National Natural Science Foundation of China under Grant Nos.10775039,11075045by Specialized Research Fund for the Doctoral Program of Higher Education under Grant Nos.20094104110001,20104104110001by the Programme for Youth's Talents of Xinyang Normal University under Grant No.200950
文摘In the littlest Higgs model with T-parity(LHT) the mirror quarks induce the special flavor structures and some new flavor-changing couplings,which could greatly enhance the production rates of the flavor-changing processes. We in this paper study some bottom and anti-strange production processes in the LHT model at the International Linear Collider(ILC),i.e.,e^+e^-→bs andγγ→bs.The results show that the production rates of these processes are sizeable for the favorable values of the parameters.Therefore,it is quite possible to test the LHT model or make some constraints on the relevant parameters of the LHT through the detection of these processes at the ILC.
基金Supported in part by the National Natural Science Foundation of China under Grant Nos.11005089 and 11105116by the Foundation of Yantai University under Grant Nos.WL10B24 and WL09B31
文摘The T-parity in the littlest Higgs model can be broken by the anomalous Wess-Zumin-Witten term, which leads that the lightest T-odd gauge boson AH decays into the SM particles. First, we examine some lepton flavor violating decays of AH, namely AH → τ±μ±, AH→ τ±e±, and AH→ τ±e±. We find that the branching ratios can reach 10-7 for AH → τ±μ±, 10-s for AH → τ±μ±, and 10-s for AH → τ±e± Then, we study the lepton flavor violating plus jets signatures of the heavy charged gauge boson and mirror quarks at the LHC, and find that it is possible to be detected for pp jets, and hardly to be detected for pp → τ±e± （μ±e±） ＋ 4 jets and p p → W H W H → τ±μ±（ τ±e±,μ±e±） ＋ 6 jets.
基金The project supported in part by National Natural Science Foundation of China and Special Fund sponsored by the Chinese Academy of Sciences
文摘In this paper the anomalous magnetic dipole moment ofmuon in the littlest Higgs （LH） model is studied at one-loop level. We discuss the dependence of the contributions on the global symmetry breaking scale f, mizing angles c` and , and the Higgs triplet vacuum expectation value v＇ in the electroweak precision data preferring ranges. We find that the LH model can give a relatively small, but non-negligible extra weak contribution to the muon anomalous magnetic moment and can reduce the deviation of △aμ from 2.6σ for the SM to 2.5σ for the LH model.
基金supported in part by the Program for New Century Excellent Talents in Universities under Grant No.NCET-04-0290National Natural Science Foundation of China under Grant No.10675057
文摘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.
基金The project supported in part by the Program for New Century Excellent Talents in Universities NCET-04-0290 and National Natural Science Foundation of China under Grant No, 10475037
文摘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.
基金Supported by the National Natural Science Foundation of China(NNSFC)under Grant No.11405047the Startup Foundation for Doctors of Henan Normal University under Grant No.qd15207
文摘In the littlest Higgs Model with T-parity,we discuss the Higgs production in association with bottom quarks at the LHC and future electron-positron collider.We calculate the cross sections of production channels pp→bb H,bb→H and bg→b H at 14 Te V LHC and the cross sections of production channel e^+e^-→bb H in(un)polarized beams at the lowest order.In order to investigate the observability,we display some typical final state distributions in the Higgs to diphoton channel.
基金supported in part by the National Natural Science Foundation of China (Grant No.10975067)Specialized Research Fund for the Doctoral Program of Higher Education (SRFDP) (Grant No.200801650002)+1 种基金the Natural Science Foundation of the Liaoning Scientific Committee (Grant No.20082148)the Foundation of Liaoning Educational Committee (Grant No.2007T086)
文摘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.
基金Supported by National Natural Science Foundation of China (11075045)Foundation of He’nan Educational Committee(2011A140005)Youth Foundation of Xinxiang University (12ZC10)
文摘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.
基金supported in part by the National Natural Science Foundation of China (Grant Nos.10875112 and 10675110)
文摘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.
文摘In the framework of the littlest Higgs model with T-parity, we study the top pair production at the next generation colliders like LHC and ILC. We find that the order O（αs） corrections to the standard model top pair production cross section at LHC can be very small and the magnitude is below 1%. However, the magnitude of corrections to the standard model top pair production rate at ILC may be over 5% for reasonable values＇of the parameters. Besides this, the corrections to the asymmetry ALR（tt） may be more sizable. Therefore, the top pair production at ILC may serve as a probe of the littlest Higgs model with T-parity, especially the asymmetry ALR（tt）.
基金Supported by National Natural Science Foundation of China(10375017,10575029)
文摘The lightest new gauge boson BH with mass of hundreds GeV is predicted in the littlest Higgs model. BH should be accessible in the planned ILC and the observation of such particle can strongly support the littlest Higgs model. The realization of 7Y and e^-γ collisions would open a wider window to probe BH. In this paper, we study the new gauge boson BH production processes e^-γ→e^-BH and e^-γ→e^-BH at the ILC. Our results show that the production cross section of the process e^-γ→e^-BH is less than 0.1 fb in most parameter spaces allowed by the electroweak precision data while the cross section of the process e^-γ→e^-BH can be over one fb in the favorable parameter spaces. With the high luminosity, the enough typical signals could be produced via e^-γ→e^-BH. Because the final electron and photon beams can be easily identified and the signal can be easily distinguished from the backgrounds produced by Z and H decaying, e^-γ→e^-BH is a promising process to probe BH.
基金Supported by National Natural Science Foundation of China(11305049,11405047)Startup Foundation for Doctors of Henan Normal University(11112,qd15207)Education Department Foundation of Henan Province(14A140010)
文摘Motivated by the search for flavor-changing neutral current（FCNC） top quark decays at the LHC,we calculate the rare Higgs three body decay H→Wbc induced by top-Higgs FCNC coupling in the littlest Higgs model with T-parity（LHT）.We find that the branching ratio of H→Wbc in the LHT model can reach O（10^-7） in the allowed parameter space.
基金Supported by National Natural Science Foundation of China(10375017,10575029)
文摘With the high energy and luminosity, the planned ILC has the considerable capability to probe the new heavy particles predicted by the new physics models. In this paper, we study the potential to discover the lightest new gauge boson BH of the Littlest Higgs model via the processes e^＋e^- →γ（Z）BH at the ILC. The results show that the production rates of these two processes are large enough to detect BH in a wide range of the parameter spaces, specially for the process e^＋e^- →γ TBH. Furthermore, there exist some decay modes for BH which can provide the typical signal and clean backgrounds. Therefore, the new gauge boson BH should be observable via these production processes with the running of the ILC if it exist.
基金Program for New Century Excellent Talents in University(NCET-04-0290)National Natural Science Foundation of China(10675057)
文摘The littlest Higgs model with T-parity predicts the existence of the neutral, weakly interacting, new gauge boson BH, which can be seen as an attractive dark matter candidate. We study production of the new gauge boson BH via ey and ep collisions. We find that BH can be abundantly produced via the subprocesses e^-T→ L^-BH and γq→BHQ, which might give rise to characteristic signals. Some discussions about the SM backgrounds for this kind of signals are also given.
