标题： X650->ZZ/WW/H125H95/A450Z -- 标量、张量还是两者都有？ 显示英文标题

标题： X650->ZZ/WW/H125H95/A450Z -- scalar, tensor or both ?

摘要： 在ICHEP 2024上，CMS发表了RUN2结果，针对X650→ZZ→4轻子的情况，得出结论认为没有证据表明标量共振H650衰变为ZZ，ATLAS也通过优化用于标量粒子的MVA分析得出了同样的结论。 由于该共振在Cut Based Analysis中表现为ZZ，在其他三种模式中表现为WW、H95H125和A450Z，因此本文试图理解这些明显的矛盾。 我们的结论（需要ATLAS和CMS实验确认）是，对H650→ZZ模式的严格选择似乎不够，因为它们同样削减了信号和背景，从而降低了统计显著性。 这种行为的一种可能解释是，这些选择对于由VBF产生的张量粒子且衰变为ZZ并具有类似Drell Yan背景的角分布的情况效率较低。 如果属实，我们根据Georgi Machacek模型对各种发现的描述需要进行深入修订，这在本文中进行了尝试。 提出了一种T650作为自旋2共振的场景，它自然地容纳了WW/ZZ和H95H125衰变，同时我们认为A420Z可能来自与T650质量简并的H650共振。 我们提出了一种方案，其中标量共振被容纳在三个双态中，T650位于一个同位旋单态，T450++、T375+和T350属于一个同位旋五重态。 显示英文摘要

摘要： At ICHEP 2024 CMS has published RUN2 results for X650->ZZ->4leptons and reached the conclusion that there is no evidence for a scalar resonance H650 decaying into ZZ, as was also concluded by ATLAS using an MVA analysis optimised for a scalar particle. Since this resonance is indicated into ZZ in a Cut Based Analysis and into three other modes: WW, H95H125 and A450Z, the present paper is an attempt to understand these apparent contradictions. Our conclusion, to be confirmed by ATLAS and CMS experiments, is that strict selections for the reaction H650->ZZ mode seem inadequate, cutting as much into the signal than into the background, therefore reducing its statistical significance. A possible interpretation of this behaviour is that these selections are inefficient for a tensor particle produced by VBF and decaying into ZZ with an angular distributions similar to the Drell Yan background. If true, our description of the various findings in term of the Georgi Machacek model needs to be deeply revised, which is attempted in the present note. A scenario with T650 as a spin 2 resonance is presented which naturally accommodates WW/ZZ and H95H125 decays, while we suggest that A420Z could come from a H650 resonance degenerate in mass with T650. We propose a scheme in which scalar resonances are accommodated in three doublets, T650 in an isosinglet, T450++, T375+ and T350 belong to an isofiveplet.