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北美退伍军人节(Veterans Day),12 日无更新
arXiv 1107.5769hep-ph
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重访新的色八重态轴矢量玻色子

New color-octet axial vector boson revisited

Hao Wang, You-kai Wang, Bo Xiao, Shou-hua Zhu

摘要:

在本文中,我们重新研究如何利用以前提出的色八重态轴矢量玻色子$Z_{\rm C}$来解释$Z_{\rm C}$前向后(FB)不对称$A_{\rm FB}$的$3.4σ$异常的$m_{t\bar t}> 450$ GeV的CDF观察。我们的数值计算结果表明,最好的拟合参数是$g_A^q=0.07$,$g_A^Q=3$,和$M_{\rm C}=440\text{GeV}$,这是通过拟合的质量依赖$A_{\rm FB}$和总截面数据提供的CDF测量。这里的$g_A^q (g_A^Q)$和$M_{\rm C}$分别是$Z_{\rm C}$与前两代(第三代)夸克的轴向耦合,以及$Z_{\rm C}$质量。我们还计算了LHC中顶夸克对和底夸克对产生的单侧前后向不对称性$A_{\rm OFB}$,着重于$Z_{\rm C}$的新贡献。我们的研究表明,$A_{\rm OFB}$可以用来测量新粒子$Z_{\rm C}$的性质。

英文摘要:

In this paper we re-examine how to utilize the previous proposed color-octet axial-vector boson $Z_{\rm C}$ to explain the $3.4σ$ anomaly of $t\bar t$ forward-backward (FB) asymmetry $A_{\rm FB}$ for $m_{t\bar t}> 450$GeV observed by CDF. Our numerical results indicate that the best-fit parameters are $g_A^q=0.07$, $g_A^Q=3$, and $M_{\rm C}=440\text{GeV}$, which are obtained by fitting the mass dependent $A_{\rm FB}$ and total cross section data provided by a recent CDF measurement. Here $g_A^q (g_A^Q)$ and $M_{\rm C}$ are the axial couplings among $Z_{\rm C}$ with the first two (the third) generation quarks, and $Z_{\rm C}$ mass respectively. We also calculate one-side forward-backward asymmetry $A_{\rm OFB}$ for top and bottom quark pair production at the LHC, focusing on the new contributions from $Z_{\rm C}$. Our studies show that $A_{\rm OFB}$ can be utilized to measure the properties of new particle $Z_{\rm C}$.

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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