Saved in:
| Main Author: | |
|---|---|
| Format: | Preprint |
| Published: |
2025
|
| Subjects: | |
| Online Access: | https://arxiv.org/abs/2511.00172 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866917053510713344 |
|---|---|
| author | Bibi, Maryam |
| author_facet | Bibi, Maryam |
| contents | Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks (VLQs). VLQs, which do not require electroweak symmetry breaking for mass generation, can mix with SM quarks and induce flavor-changing neutral currents (FCNCs). We investigate the impact of down-type iso-singlet VLQs on the rare decay $B^+ \to K^+ ν\barν$, a theoretically clean channel sensitive to new physics. The Belle-II collaboration recently reported a branching ratio of $[2.3 \pm 0.5] \times 10^{-5}$, significantly higher than the SM prediction of $[0.45 \pm 0.07] \times 10^{-5}$, suggesting possible new contributions. To constrain the relevant mixing parameter $U_{sb}$, we also analyze related decays such as $B_s \to μ^+ μ^-$ and $B \to X_s μ^+ μ^-$. Incorporating VLQ effects into the effective field theory framework, we compute modified Wilson coefficients ($C_7$, $C_9$, $C_{10}$, $C_L$) and predict enhanced branching ratios for $B \to X_s ν\barν$ and $B \to K ν\barν$. $χ^2$ contour analyses indicate that VLQs can account for observed anomalies, providing a viable and testable extension to the SM. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2511_00172 |
| institution | arXiv |
| publishDate | 2025 |
| record_format | arxiv |
| spellingShingle | One Loop Calculations of Rare B-decays Beyond the Standard Model Bibi, Maryam High Energy Physics - Phenomenology Rare $B$-meson decays, suppressed in the Standard Model (SM) by the GIM mechanism, are sensitive probes of new physics. In particular, loop-level $b \to s$ transitions can reveal effects of heavy virtual particles such as vector-like quarks (VLQs). VLQs, which do not require electroweak symmetry breaking for mass generation, can mix with SM quarks and induce flavor-changing neutral currents (FCNCs). We investigate the impact of down-type iso-singlet VLQs on the rare decay $B^+ \to K^+ ν\barν$, a theoretically clean channel sensitive to new physics. The Belle-II collaboration recently reported a branching ratio of $[2.3 \pm 0.5] \times 10^{-5}$, significantly higher than the SM prediction of $[0.45 \pm 0.07] \times 10^{-5}$, suggesting possible new contributions. To constrain the relevant mixing parameter $U_{sb}$, we also analyze related decays such as $B_s \to μ^+ μ^-$ and $B \to X_s μ^+ μ^-$. Incorporating VLQ effects into the effective field theory framework, we compute modified Wilson coefficients ($C_7$, $C_9$, $C_{10}$, $C_L$) and predict enhanced branching ratios for $B \to X_s ν\barν$ and $B \to K ν\barν$. $χ^2$ contour analyses indicate that VLQs can account for observed anomalies, providing a viable and testable extension to the SM. |
| title | One Loop Calculations of Rare B-decays Beyond the Standard Model |
| topic | High Energy Physics - Phenomenology |
| url | https://arxiv.org/abs/2511.00172 |