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北美退伍军人节(Veterans Day),12 日无更新
arXiv 2009.01771hep-phhep-ex
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$B$的统一框架-反常、μ子$g-2$和中微子质量

Unified Framework for $B$-Anomalies, Muon $g-2$, and Neutrino Masses

K. S. Babu, P. S. Bhupal Dev, Sudip Jana, Anil Thapa

摘要:

我们提出了一个辐射中微子质量的模型,它也解决了在$B$介子衰变,$R_{D^{(\star)}}$和$R_{K^{(\star)}}$,以及在μ子$g-2$测量,$Δa_μ$报告的异常。中微子质量出现在模型中,通过涉及TeV尺度的轻夸克(LQ)标量$R_2$和$S_3$的回路图。中微子振荡参数的拟合满足所有的味约束,这也解释了$1\, σ$中的异常$R_{D^{(\star)}}$,$R_{K^{(\star)}}$和$Δa_μ$。同位旋3/2希格斯四重态在产生中微子质量中起着至关重要的作用,我们指出,其中包含的双电荷标量可以在$S_3$ LQ的衰变中产生,这将其在$\sqrt s=14$ TeV高亮度LHC($\sqrt s=100$ TeV FCC-hh)中的能量提高到1.1(6.2)TeV。我们还提出了味道依赖的上限上的汤川耦合的LQs的前两个家庭费米子,所产生的非共振双轻子($pp \rightarrow \ell^+ \ell^-$)过程介导的$t$通道LQ交换,其中1 TeV的LQ质量,被发现是在范围$(0.15 - 0.36)$。这些限制排除了通过涉及最终状态的$ν_e$或$ν_μ$的LQ介导的$B$ -介子衰变对$R_{D^{(\star)}}$的任何解释。我们还发现,同样的Yukawa耦合负责的手征增强的贡献$Δa_μ$引起新的贡献SM希格斯衰变到μ子和τ对,与修改相应的分支比在(2-6)%的水平,这可以在未来的强子对撞机,如HL-LHC和FCC-hh进行测试。

英文摘要:

We present a model of radiative neutrino masses which also resolves anomalies reported in $B$-meson decays, $R_{D^{(\star)}}$ and $R_{K^{(\star)}}$, as well as in muon $g-2$ measurement, $Δa_μ$. Neutrino masses arise in the model through loop diagrams involving TeV-scale leptoquark (LQ) scalars $R_2$ and $S_3$. Fits to neutrino oscillation parameters are obtained satisfying all flavor constraints which also explain the anomalies in $R_{D^{(\star)}}$, $R_{K^{(\star)}}$ and $Δa_μ$ within $1\, σ$. An isospin-3/2 Higgs quadruplet plays a crucial role in generating neutrino masses; we point out that the doubly-charged scalar contained therein can be produced in the decays of the $S_3$ LQ, which enhances its reach to 1.1 (6.2) TeV at $\sqrt s=14$ TeV high-luminosity LHC ($\sqrt s=100$ TeV FCC-hh). We also present flavor-dependent upper limits on the Yukawa couplings of the LQs to the first two family fermions, arising from non-resonant dilepton ($pp \rightarrow \ell^+ \ell^-$) processes mediated by $t$-channel LQ exchange, which for 1 TeV LQ mass, are found to be in the range $(0.15 - 0.36)$. These limits preclude any explanation of $R_{D^{(\star)}}$ through LQ-mediated $B$-meson decays involving $ν_e$ or $ν_μ$ in the final state. We also find that the same Yukawa couplings responsible for the chirally-enhanced contribution to $Δa_μ$ give rise to new contributions to the SM Higgs decays to muon and tau pairs, with the modifications to the corresponding branching ratios being at (2-6)% level, which could be tested at future hadron colliders, such as HL-LHC and FCC-hh.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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