Search for muon-philic new light gauge boson at Belle II
Abstract
Motivated by the long-lasting 3.5σ discrepancy in the anomalous magnetic moment of muon, we consider a new muon-specific force mediated by a light gauge boson, X, with mass mX < 2mμ and the coupling constant gX ∼ (10-4, 10-3) . We show that the Belle II experiment has a robust chance to probe such a light boson in e+e- → μ+μ- + X channel and cover the most interesting parameter space explaining the discrepancy with the planned target luminosity, ∫dt L =50 ab-1. The clean signal of muon-pair plus missing energy at Belle II can be a smoking gun for the new gauge boson. We expect that the (invisibly decaying) muon-philic light (mX ≲ 2mμ) gauge boson can be probed down to gX ≲ 1.5 × 10-4(4.6 × 10-4, 2.3 × 10-4) for 50 (1, 10) ab-1 search.
- Publication:
-
Journal of High Energy Physics
- Pub Date:
- October 2019
- DOI:
- 10.1007/JHEP10(2019)168
- arXiv:
- arXiv:1904.13053
- Bibcode:
- 2019JHEP...10..168J
- Keywords:
-
- Beyond Standard Model;
- Gauge Symmetry;
- High Energy Physics - Phenomenology
- E-Print:
- 21 pages, 12 figures, references added, version to appear in JHEP