What can a heavy U(1)_B−L Z^′ boson do to the muon (g−2)_µ anomaly and to a new Higgs boson mass?

Summary, in English

The minimal U(1)_B−L extension of the Standard Model (B-L-SM) offers an explanation for neutrino mass generation via a seesaw mechanism; it also offers two new physics states, namely an extra Higgs boson and a new Z^′ gauge boson. The emergence of a second Higgs particle as well as a new Z^′ gauge boson, both linked to the breaking of a local U(1)_B−L symmetry, makes the B-L-SM rather constrained by direct searches in Large Hadron Collider (LHC) experiments. We investigate the phenomenological status of the B-L-SM by confronting the new physics predictions with the LHC and electroweak precision data. Taking into account the current bounds from direct LHC searches, we demonstrate that the prediction for the muon (g−2)_µ anomaly in the B-L-SM yields at most a contribution of approximately 8.9×10⁻¹² , which represents a tension of 3.28 standard deviations, with the current 1σ uncertainty, by means of a Z^′ boson if its mass is in the range of 6.3 to 6.5 TeV, within the reach of future LHC runs. This means that the B-L-SM, with heavy yet allowed Z^′ boson mass range, in practice, does not resolve the tension between the observed anomaly in the muon (g−2)_µ and the theoretical prediction in the Standard Model. Such a heavy Z^′ boson also implies that the minimal value for the new Higgs mass is of the order of 400 GeV.

• Author: António P. Morais; Roman Pasechnik; J. Pedro Rodrigues
• Department/s: Theoretical Particle Physics - Has been reorganised
• Publishing year: 2021
• Language: English
• Publication/Series: Chinese Physics C
• Volume: 45
• Issue: 1
• Links: http://dx.doi.org/10.1088/1674-1137/abc16a
• Document type: Journal article
• Publisher: IOP Publishing
• Topic: Subatomic Physics
• Keywords: Beyond Standard Model; Gauge extensions of the Standard Model; Higgs physics; Z′ boson
• Status: Published
• ISBN/ISSN/Other: ISSN: 1674-1137