arXiv subjects

Chongxing Yue

Publications and source records attributed to Chongxing Yue.

At least 19 recordsLinked to original sources

arXiv2022

Searching for the charged-current non-standard neutrino interactions at the $e^{-}p$ colliders

Considering the theoretical constraints on the charged-current (CC) non-standard neutrino interaction (NSI) parameters in a simplified $W'$ model, we study the sensitivities of the Large Hadron electron Collider (LHeC) and Future Circular Collider-hadron electron (FCC-he) to the CC NSI parameters through the subprocess $e^{-}q \to W' \to v_{e}q'$. Our results show that the LHeC with $\mathcal{L} = 100\;{\rm fb}^{-1}$ is a little more sensitive to the CC NSI parameters than that of the high-luminosity (HL) LHC, and the absolute values of the lower limits on the CC NSI parameters at the FCC-he are smaller than those of the HL-LHC about two orders of magnitude.

hep-ph↗

arXiv2005

Probing the gauge bosons $Z'$ and $B'$ from the Littlest Higgs model in the high-energy linear $e^{+}e^{-}$ colliders

The littlest Higgs (LH) model predicts the existence of the new gauge bosons $Z'$ and $B'$. We calculate the contributions of these new particles to the processes $e^{+}e^{-}\to\bar{f}f$ with $f=τ, μ, b,$ or $c$ and study the possibility of detecting these new particles via these processes in the future high-energy linear $e^{+}e^{-}$ collider (LC) experiments with $\sqrt{s}=500GeV$ and $£_{int}=340fb^{-1}$. We find that, with reasonable values of the parameter preferred by the electroweak precision data, the possible signals of these new particles might be detected. The $Z'$ mass $M_{Z'}$ can be explored up to $2.8TeV$ via the process $e^{+}e^{-}\to\bar{b}b $ for $0.3\leq c \leq 0.5 $ and the $B'$ mass $M_{B'}$ can be explored up to $1.26TeV$ via the process $e^{+}e^{-}\to\bar{l}l $ for $0.64\leq c' \leq 0.73 $.

hep-ph↗

arXiv2004

Single production of new gauge bosons from the littlest Higgs model at the $TeV$ energy $e^{-}γ$ colliders

In the context of the littlest Higgs(LH) model, we study single production of the new gauge bosons $B_{H}$, $Z_{H}$ and $W_{H}^{\pm}$ via $e^{-}γ$ collisions and discuss the possibility of detecting these new particles in the $TeV$ energy $e^{+}e^{-}$ collider($LC$). We find that these new particles can not be detected via the $e^{-}νν$ signal in all of the parameter space preferred by the electroweak precision data. However, the heavy gauge bosons $B_{H}$ and $Z_{H}$ may be observed via the decay channel $B_{H}(Z_{H})\to l^{+}l^{-}$ in wide range of the parameter space.

hep-ph↗

arXiv2004

Neutral top-pion and the rare top decays $t\to c l_{i} l_{j}$

We study the rare top decays $t\to c l_{i} l_{j}(l=τ,μ,or e)$ in the framework of topcolor-assisted technicolor($TC2$) models. We find that the neutral top-pion $π_{t}^{0}$ can produce significant contributions to these processes via the flavor changing couplings $π_{t}^{0} \bar{t} c$ and $π_{t}^{0} l_{i} l_{j}$. For the $π_{t}^{0}$ mass $m_{π_{t}}=150 GeV$ and the parameter $ε=0.08$, the branching ratio $Br$(t$\to c ττ)$ can reach $7.1\times10^{-7}$. Taking into account the constraints of the present experimental limit of the process $μ\to e γ$ on the free parameters of $TC2$ models, we find that the value of $Br$($t\to c τμ$)$\approx$$Br$($t\to c τe$) is in the range of 1.8$\times10^{-10}\sim1.7\times10^{-8}$.

hep-ph↗

arXiv2004

The neutral top-pion and the lepton flavor violating $Z$ decays $Z\to l_{i}l_{j}$

Taking into account the constraints of the present experimental limit of the process $μ\to eγ$ on the free parameters of topcolor-assisted technicolor(TC2) models, we calculate the contributions of the neutral top-pion to the lepton flavor violating(LFV) $Z$ decays $Z\to l_{i}l_{j}$. Our results show that the value of the branching ratio $Br(Z\to τl)$ is larger than that of $Br(Z\to μe)$ in all of the parameter space and there is $Br(Z\to τμ)\approx Br(Z\to τe)\simeq 2\times 10^{-14} $, which is far from the reach of present or future experiments.

hep-ph↗

arXiv2004

Neutral top-pion and $tγ(z)$ production at the HERA and THERA colliders

In the context of top-color assisted technicolor ($TC2$) models, we calculate the contributions of the neutral top-pion $ π_{t}^{0}$ to $tγ$ and $tz$ production via the processes $ ep\to γc \to tγ$ and $ ep\to γc \to tz$ at the $HERA$ and $THERA$ colliders. Our results show that the cross sections $σ_{tγ}(s)$ and $σ_{tz}(s)$ are very small at the $HERA$ collider with $\sqrt{s}=320GeV $. However, in most of the parameter space, $σ_{tγ}(s)$ or $σ_{tz}(s)$ is in the range of about $0.1pb \sim 1 pb$ at the $THERA$ collider with $\sqrt{s}=1000GeV$.

hep-ph↗

arXiv2004

Detecting the non-universal gauge boson $Z^{'}$ at high-energy $e^{+}e^{-}$ collider

In the context of topcolor-assisted techicolor($TC2$) models, we investigate the feasibility of detecting the non-universal gauge boson $Z^{'}$ in the future high-energy linear $e^{+}e^{-}$ collider($LC$) experiments by performing $χ^{2}$ analysis via studying its virtual effects on the processes $e^{+}e^{-}\to f\bar{f}$ with $f=τ$, $μ$, b, and c. We find that the non-universal gauge boson $Z^{'}$ is most sensitive to the process $e^{+}e^{-}\to τ\barτ$. Discovery limits of the $Z^{'}$ mass $M_{Z^{'}}$ can be enhanced by the suitably polarized beams. If we assume that polarization of electron beam and positron beam are 80% and 60%, the $LC$ experiment with $\sqrt{s}=500GeV$ and $£_{int}=340fb^{-1}$ can explore $M_{Z^{'}}$ up to 8$TeV$ for the coupling parameter $K_{1}\leq$0.8 at 95% $CL$.

hep-ph↗

arXiv2004

Neutral top-pion and lepton flavor violating processes

In the context of topcolor-assisted techicolor(TC2) models, we study the contributions of the neutral top-pion $π^{0}_{t}$ to the lepton flavor violating(LFV) processes $l_{i}\to l_{j}γ$ and $l_{i}\to l_{j}l_{k}l_{l}$. We find that the present experimental bound on $μ\to eγ$ gives severe constraints on the free parameters of $TC2$ models. Taking into account these constraints, we consider the processes $l_{i}\to l_{j}l_{k}l_{l}$ generated by top-pion exchange at the tree-level and the one loop level, and obtain $Br(μ\to 3e)\simeq 2.87\times 10^{-14}$, $1.1\times 10^{-15}\leq Br(τ\to 3e)\simeq Br(τ\to 2eμ)\leq 4.4 \times 10^{-15} $, $3.1\times 10^{-15} \leq Br(τ\to 2μe)\simeq Br(τ\to 3μ)\leq 1.5 \times 10^{-14}$ in most of the parameter space.

hep-ph↗

arXiv2004

The branching ratio $R_{b}$ in the littlest Higgs model

In the context of the littlest Higgs(LH) model, we study the contributions of the new particles to the branching ratio $R_{b}$. We find that the contributions mainly dependent on the free parameters $f$, $c'$ and $x_{L}$. The precision measurement value of $R_{b}$ gives severe constraints on these free parameters.

hep-ph↗

arXiv2003

Littlest Higgs model and associated ZH production at high energy $e^{+}e^{-}$ collider

In the context of the littlest Higgs (LH) model, we consider the Higgs strahlung process $e^{+}e^{-}\to ZH $. We find that the correction effects on this process mainly come from the heavy photon $B'$. If we take the mixing angle parameter $c$ in the range of 0.75 - 1, the contributions of the heavy gauge boson $W_{3}'$ is larger than 6%. In most of the parameter space, the deviation of the total production cross section $σ^{tot}$ from its SM value is larger than 5%, which may be detected in the future high energy $e^{+}e^{-}$ collider (LC) experiments. The future LC experiments could test the LH model by measuring the cross section of the process $e^{+}e^{-}\to ZH $.

hep-ph↗

arXiv2003

Non-universal gauge bosons $Z^{\prime}$ and rare top decays

We study a new method for detecting non-universal gauge bosons $Z'$ via considering their effects on rare top decays. We calculate the contributions of the non-universal gauge bosons $Z'$ predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models on the rare top decays $t\longrightarrow cV(V=g,γ,Z)$ and $t\longrightarrow cl_{i}l_{j}(l_{i}, l_{j}=τ, μ$, or $e)$. We show that the branching ratios of these processes can be significantly enhanced. Over a sizable region of the parameter space, we have $Br(t\longrightarrow cg)\sim10^{-5}$ and $Br(t\longrightarrow cττ)\sim10^{-7}$, which may approach the observable threshold of near future experiments. Non-universal gauge bosons $Z'$ may be detected via the rare top decay processes at the top-quark factories such as the CERN LHC.

hep-ph↗

arXiv2003

Production of the top-pions at the THERA collider based $γp$ collisions

In the framework of the topcolor-assisted technicolor (TC2) models, we study the production of the top-pions $π^{0}_{t}$, $π_{t}^{\pm}$ via the processes $ep\toγc\toπ^{0}_{t}c$ and $ep\toγc\toπ^{\pm}_{t}b$ mediated by the anomalous top coupling $tcγ$. We find that the production cross section of the process $ep\toγc\toπ^{0}_{t}c$ is very small. With reasonable values of the parameters in TC2 models, the production cross section of the process $ep\toγc\toπ^{\pm}_{t}b$ can reach $ 1.2pb$. The charged top-pions $π^{\pm}_{t}$ might be directly observed via this process at the THERA collider based $γp$ collisions.

hep-ph↗

arXiv2003

Detecting the neutral top-pion at future muon colliders

The signals of the neutral top-pion $π^{0}_{t}$ at the first muon collider (FMC) are discussed by calculating its contributions to the processes $μ^{+}μ^{-}\longrightarrow b\bar{b}$ and $μ^{+}μ^{-}\longrightarrow \bar{t}c$. We find that the contributions to the process $μ^{+}μ^{-}\longrightarrow b\bar{b}$ are very small and the ratio of signal over square root of the background ($S/\sqrt{B})$ is smaller than 0.2. However, in most of the parameter space, the $π^{0}_{t}$ can generate 36 and up to 649 observable $\bar{t}c$ events at the FMC. The signals of the neutral top-pion $π^{0}_{t}$ may be detected via the process $μ^{+}μ^{-}\longrightarrow \bar{t}c$ at the FMC.

hep-ph↗

arXiv2003

The process $e^{+}e^{-}\toν\barνγ$ in topcolor-assisted technicolor models

In the context of topcolor-assisted technicolor (TC2) models, we consider the process $e^{+}e^{-}\to ν\barνγ$ and calculate the cross section of this process at leading order.It is shown that the extra U(1) gauge boson $Z^{\prime}$ predicted by TC2 models can give significant contributions to the process $e^{+}e^{-}\to ν_τ\barν_τγ$, which may be detected in the future high energy linear $e^{+}e^{-}$ collider(LC) experiments.

hep-ph↗

arXiv2003

Flavor changing Z decay $Z\to b\bar{s}(\bar{b}s)$ in topcolor-assisted technicolor models

In the context of topcolor-assisted technicolor (TC2) models, we examine the flavor changing (FC) Z decay $Z\to b\bar{s}(\bar{b}s)$ and calculate the contributions of the new particles predicted by TC2 models to the branching ratio Br($Z\to b\bar{s}+\bar{b}s$). We find that the contributions mainly come from the top-pions. In most of the parameter space, the Br($Z\to b\bar{s}+\bar{b}s$) can reach $10^{-5}$, which may be detected in near future experiments such as Giga-Z version of the TESLA. Thus, the FC Z decay $Z\to b\bar{s}(\bar{b}s)$ can be used to test TC2 models.

hep-ph↗

arXiv2003

Lepton flavor violating processes $l_{i}\longrightarrow l_{j}ν_{l}\barν_{l}$ in topcolor-assisted technicolor models

We study the lepton flavor violating (LFV) processes $l_{i}\longrightarrow l_{j}ν_{l}\barν_{l}$ in the context of the topcolor-assisted technicolor (TC2) models. We find that the branching ratios $B_{r}(τ\longrightarrow l_{j}ν_τ\barν_τ)$ are larger than the branching ratios $B_{r}(τ\longrightarrow l_{j}ν_{l}\barν_{l})$ in all of the parameter space. Over a wide range of parameter space, we have $B_{r}(τ\longrightarrow l_{j}ν_τ\barν_τ)\sim 10^{-6}$ and $B_{r}(τ\longrightarrow l_{j}ν_{l}\barν_{l})\sim 10^{-9} (l=μ$ or $e)$. Taking into account the bounds given by the experimental upper limit $Br^{exp}(μ\longrightarrow3e)\leq1\times10^{-12}$ on the free parameters of TC2 models, we further give the upper limits of the LFV processes $l_{i}\longrightarrow l_{j}ν_{l}\barν_{l}$. We hope that the results may be useful to partly explain the data of the neutrino oscillations and the future neutrino experimental data might be used to test TC2 models.

hep-ph↗

arXiv2003

Lepton flavor violating signals of gauge bosons $Z^{\prime}$ at future $e^{+}e^{-}$ colliders

Many models, such as topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, predict the existence of extra U(1) gauge bosons $Z^{\prime}$, which couple preferentially to the third generation. The lepton flavor violating (LFV) signals of these new particles at the future $e^{+}e^{-}$ colliders (LCs) are discussed via calculating its contributions to the LFV process $e^{+}e^{-}\toμτ$. We calculate the cross section of this process and discuss its dependence on the beam polarization. The ratio of signal over square root of the background $(S/\sqrt{B})$ is also calculated. The results show that the LFV signals of the gauge bosons $Z^{\prime}$ may be detected at the future LC experiments.

hep-ph↗

arXiv2002

Non-universal gauge bosons $Z^{\prime}$ and lepton flavor-violation tau decays

There are many models beyond the standard model predicting the existence of non-universal gauge bosons $Z^{\prime}$, which can give rise to very rich phenomena. We calculate the contributions of the non-universal gauge bosons $Z^{\prime}$, predicted by topcolor-assisted technicolor (TC2) models and flavor-universal TC2 models, to the lepton flavor-violation tau decays $τ\to l_{i}γ$ and $τ\to l_{i}l_{j}l_{k}$. We find that the branching ratio $B_{r}(τ\longrightarrow l_{i}l_{j}l_{k})$ is larger than that of the process $τ\longrightarrow l_{i}γ$ in all of the parameter space. Over a sizable region of the parameter space, we have $B_{r}(τ\longrightarrow l_{i}l_{j}l_{k})\sim 10^{-8}$, which may be detected in the future experiments.

hep-ph↗