Decoding the $B \to K νν$ excess at Belle II: kinematics, operators, and masses
Fuente:
arXiv
Saved in:
| Main Authors: | , , , |
|---|---|
| Format: | Preprint |
| Published: |
2023
|
| Subjects: | |
| Online Access: | |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1866910520916836352 |
|---|---|
| author | Fridell, Kåre Ghosh, Mitrajyoti Okui, Takemichi Tobioka, Kohsaku |
| author_facet | Fridell, Kåre Ghosh, Mitrajyoti Okui, Takemichi Tobioka, Kohsaku |
| contents | An excess in the branching fraction for $B^+ \to K^+ νν$ recently measured at Belle II may be a hint of new physics. We perform thorough likelihood analyses for different new physics scenarios such as $B \to KX$ with a new invisible particle $X$, or $B\to Kχχ$ through a scalar, vector, or tensor current with $χ$ being a new invisible particle or a neutrino. We find that vector-current 3-body decay with $m_X \simeq 0.6$ GeV - which may be dark matter - is most favored, while 2-body decay with $m_X \simeq 2$ GeV is also competitive. The best-fit branching fractions for the scalar and tensor cases are a few times larger than for the 2-body and vector cases. Past BaBar measurements provide further discrimination, although the best-fit parameters stay similar. |
| format | Preprint |
| id |
arxiv_https___arxiv_org_abs_2312_12507 |
| institution | arXiv |
| publishDate | 2023 |
| record_format | arxiv |
| spellingShingle | Decoding the $B \to K νν$ excess at Belle II: kinematics, operators, and masses Fridell, Kåre Ghosh, Mitrajyoti Okui, Takemichi Tobioka, Kohsaku High Energy Physics - Phenomenology High Energy Physics - Experiment An excess in the branching fraction for $B^+ \to K^+ νν$ recently measured at Belle II may be a hint of new physics. We perform thorough likelihood analyses for different new physics scenarios such as $B \to KX$ with a new invisible particle $X$, or $B\to Kχχ$ through a scalar, vector, or tensor current with $χ$ being a new invisible particle or a neutrino. We find that vector-current 3-body decay with $m_X \simeq 0.6$ GeV - which may be dark matter - is most favored, while 2-body decay with $m_X \simeq 2$ GeV is also competitive. The best-fit branching fractions for the scalar and tensor cases are a few times larger than for the 2-body and vector cases. Past BaBar measurements provide further discrimination, although the best-fit parameters stay similar. |
| title | Decoding the $B \to K νν$ excess at Belle II: kinematics, operators, and masses |
| topic | High Energy Physics - Phenomenology High Energy Physics - Experiment |
| url | https://arxiv.org/abs/2312.12507 |