arXiv subjects

Wu-Jun Huo

Publications and source records attributed to Wu-Jun Huo.

4 recordsLinked to original sources

arXiv2002

Lepton flavor violation decays with the fourth generation neutrino

We investigate the lepton flavor violation decays, $τ\to μγ$, $τ\to eγ$ and $μ\to eγ$, in the framwork of a squential fourth generation model with a heavy fourth neutrino, $ν'$. Using the recent experimental bounds, we can obtain the constraints of the $4\times 4$ leptonic mixing matrix element factors, $V_{1ν'},V_{2ν'}$ and $V_{3ν'}$. We find that LFV decays can give strigent costraints on the parameter space of the 4th neutrino mass $m_{ν'}$.

hep-ph↗

arXiv2002

Effects of the Fourth Generation on $ΔM_{B_{d,s}}$ in $B^0-\bar B^0$ Mixing

We investigate the mass differences $ΔM_{B_{d,s}}$ in the mixing $B^0_{d,s}-\bar B^0_{d,s}$ with a new up-like quark $t^{\prime}$ in the sequential fourth generation model. We give the basic formulae for $ΔM_{B_{d,s}}$ in this model and obtain two kinds of numerical results of $ΔM_{B_{s}}$ which is the function of $m_{t^{\prime}}$. We find that one of our results can satisfy the present experimental low bound of $ΔM_{B_s}$. We also get the constraints of the fourth generation CKM factor $V^{*}_{t^{'}b}V_{t^{'}d}$, which is the function of $t^{'}$, from the experimental measurements of $ΔM_{B_d}$. Thus, $ΔM_{B_{d,s}}$ provide a possible test of the fourth generation and give a signal of the new physics.

hep-ph↗

arXiv2000

Constraints on the Mass and Mixing of the 4th Generation Quark From Direct CP Violation$ε^{\prime}/ε$ and Rare K Decays

We investigate the $ε^{\prime} /ε$ for $K\to ππ$ in a sequential fourth generation model. By giving the basic formulae for $ε^{\prime}/ε$ in this model, we analyze the numerical results which are dependent of $m_{t^{\prime}}$ and imaginary part of the fourth CKM factor, ${Im}V^{*}_{t^{'}s}V_{t^{'}d}$ (or $V^{*}_{t^{'}s}V_{t^{'}d}$ and the fourth generation CKM matrix phase $θ$). We find that, unlike the SM, when taking the central values of all parameters for $ε^{\prime}/ε$, the values of $ε^{\prime}/ ε$ can easily fit to the current experimental data for all values of hadronic matrix elements estimated from various approaches. Also, we show that the experimental values of $ε^{\prime}/ε$ and rare K decays can provide a strong constraint on both mass and mixing of the fourth generation quark. When taking the values of hadronic matrix elements from the lattice or 1/N expansion calculations, a large region of the up-type quark mass $m_{t^{\prime}}$ is excluded.

hep-ph↗

arXiv1999

The $B\to X_sl^+l^-$ and $B\to X_s γ$ decays with the fourth generation

If the fourth generation fermions exist, the new quarks could influence the branching ratios of the decays of $B\to X_s γ$ and $B\to X_sl^+l^-$. We obtain two solutions of the fourth generation CKM factor $V^{*}_{t^{'}s}V_{t^{'}b}$ from the decay of $B\to X_s γ$. We use these two solutions to calculate the new contributions of the fourth generation quark to Wilson coefficients of the decay of $B\to X_sl^+l^-$. The branching ratio and the forward-backward asymmetry of the decay of $B\to X_sl^+l^-$ in the two cases are calculated. Our results are quite different from that of SM in one case, almost same in another case. If Nature chooses the formmer, the $B$ meson decays could provide a possible test of the forth generation existence.

hep-ph↗