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arXiv 1707.04573hep-ph
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局域$U(1)_{L_μ-L_τ}$模型中暗物质对$b\to s μ^+ μ^-$异常的贡献

Dark matter contribution to $b\to s μ^+ μ^-$ anomaly in local $U(1)_{L_μ-L_τ}$ model

Seungwon Baek

摘要:

我们提出了一个本地$U(1)_{L_μ-L_τ}$模型来解释在LHCb和Belle实验中观察到的$b \to s μ^+ μ^-$异常。该模型也有一个自然的暗物质候选人$N$。我们引入$SU(2)_L$ -二重态色标$\widetilde{q}$在单回路水平上介导$b \to s$跃迁。$U(1)_{L_μ-L_τ}$规范对称性被标量$S$自发破缺。所有新粒子都在$U(1)_{L_μ-L_τ}$下带电。我们可以获得$C_9^{μ,{\rm NP}} \sim -1$来解决$b \to sμ^+μ^-$异常,并可以同时解释宇宙中正确的暗物质遗迹密度$Ω_{\rm DM} h^2 \approx 0.12$,同时避开来自电弱精密测试,中微子三叉戟实验和其他夸克变味循环过程(如$b \to s γ$和$B_s-\overline{B}_s$混合)的限制。我们的模型可以通过在LHC和Belle-II的$B \to K^* ν\overlineν$过程中搜索$Z'$和新的有色标量来测试。

英文摘要:

We propose a local $U(1)_{L_μ-L_τ}$ model to explain $b \to s μ^+ μ^-$ anomaly observed at the LHCb and Belle experiments. The model also has a natural dark matter candidate $N$. We introduce $SU(2)_L$-doublet colored scalar $\widetilde{q}$ to mediate $b \to s$ transition at one-loop level. The $U(1)_{L_μ-L_τ}$ gauge symmetry is broken spontaneously by the scalar $S$. All the new particles are charged under $U(1)_{L_μ-L_τ}$. We can obtain $C_9^{μ,{\rm NP}} \sim -1$ to solve the $b \to sμ^+μ^-$ anomaly and can explain the correct dark matter relic density of the universe, $Ω_{\rm DM} h^2 \approx 0.12$, simultaneously, while evading constraints from electroweak precision tests, neutrino trident experiments and other quark flavor-changing loop processes such as $b \to s γ$ and $B_s-\overline{B}_s$ mixing. Our model can be tested by searching for $Z'$ and new colored scalar at the LHC and $B \to K^* ν\overlineν$ process at Belle-II.

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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