تقرير
The SM expected branching ratio for $h \to \gamma \gamma$ and an excess for $h \to Z \gamma$
| العنوان: | The SM expected branching ratio for $h \to \gamma \gamma$ and an excess for $h \to Z \gamma$ |
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| المؤلفون: | He, Xiao-Gang, Huang, Zhong-Lv, Li, Ming-Wei, Liu, Chia-Wei |
| سنة النشر: | 2024 |
| المجموعة: | High Energy Physics - Experiment High Energy Physics - Phenomenology |
| مصطلحات موضوعية: | High Energy Physics - Phenomenology, High Energy Physics - Experiment |
| الوصف: | Combination of recent measurements for $h \to Z \gamma$ from ALTLAS and CMS shows an excess that the ratio of the observed and standard model (SM) predicted branching ratios $\mu = (\sigma\cdot{\cal B})_{\mathrm{obs}}/(\sigma\cdot{\cal B})_{\mathrm{SM}}$ is $2.2\pm 0.7$. If confirmed, it is a signal of new physics (NP) beyond SM. We study NP explanation for this excess. In general, for a given model it also affects the process $h \to \gamma \gamma$. Since measured branching ratio for this process agrees with SM prediction well, the model is constrained severely. We find that a minimally fermion singlets and doublet extended NP model can explain simultaneously the current data for $h \to Z \gamma$ and $h\to \gamma\gamma$. There are two solutions. One is the SM amplitude $c_Z^{\text{SM}}$ is enhanced by $\delta c_Z$ for $h \to Z \gamma$ to the observed value, but the $h \to \gamma \gamma$ amplitude $c_\gamma^{\text{SM}} +\delta c_\gamma$ is decreased to $-c_\gamma^{\text{SM}}$ to give the observed branching ratio. This seems to be a contrived solution that although cannot be ruled out simply using branching ratio measurements. We, however, find another solution which naturally enhances the $h \to Z \gamma$ to the measured value, but keeps the $h \to \gamma\gamma$ close to its SM prediction. We also comment on some phenomenology of these new fermions. Comment: 8 pages, 7 figures |
| نوع الوثيقة: | Working Paper |
| URL الوصول: | http://arxiv.org/abs/2402.08190 |
| رقم الأكسشن: | edsarx.2402.08190 |
| قاعدة البيانات: | arXiv |
| الوصف غير متاح. |