Search for a muonic dark force at BaBar

We study how nonstandard neutrino interactions (NSI) may be probed by a combination of coherent elastic neutrino-nucleus scattering, neutrino oscillation and collider data, from COHERENT, DUNE, T2HK and the high-luminosity (HL) LHC. We focus on NSI induced by a new flavored gauge boson Z in a generic anomaly-free ultraviolet-complete model. For Z masses above 10 GeV, the HL-LHC has the best sensitivity regardless of the flavor structure of the model. For masses between 0.01 GeV−10 GeV, current LHCb data and future COHERENT data have the best sensitivity unless the Z couplings to the first and second generation leptons are suppressed, in which case DUNE and T2HK have the best sensitivity. For Z masses between about 5 MeV−20 MeV, DUNE and T2HK have the best sensitivity. We also show how joint analyses of COHERENT and LHC data may constrain such models.

Section: )mentioning

confidence: 99%

Section: Cases a And B: µ Final Statesmentioning

confidence: 99%

Nonstandard neutrino interactions at COHERENT, DUNE, T2HK and LHC

Han

Liao

Liu

et al. 2019

“…with the Z decaying into µ + µ − [61]. The search constrains regions of Z parameter space with 2m µ < m Z 8 GeV.…”

Section: Jhep12(2016)106mentioning

confidence: 99%

Explaining dark matter and B decay anomalies with an L μ − L τ model

Altmannshofer

Gori

Profumo

et al. 2016

184

118

We present a dark sector model based on gauging the L µ − L τ symmetry that addresses anomalies in b → sµ + µ − decays and that features a particle dark matter candidate. The dark matter particle candidate is a vector-like Dirac fermion coupled to the Z gauge boson of the L µ − L τ symmetry. We compute the dark matter thermal relic density, its pair-annihilation cross section, and the loop-suppressed dark matter-nucleon scattering cross section, and compare our predictions with current and future experimental results. We demonstrate that after taking into account bounds from B s meson oscillations, dark matter direct detection, and the CMB, the model is highly predictive: B physics anomalies and a viable particle dark matter candidate, with a mass of ∼ (5 − 23) GeV, can be accommodated only in a tightly-constrained region of parameter space, with sharp predictions for future experimental tests. The viable region of parameter space expands if the dark matter is allowed to have L µ − L τ charges that are smaller than those of the SM leptons.

“…5, we show the preferred region of parameters (m X , g X and ) and the current experimental constraints. In model II, we have two allowed regions (120 MeV ∼ < m X ∼ < 160 MeV and 250 MeV ∼ < m X ∼ < 350 MeV) for the KOTO events, although higher mass region cannot explain (g − 2) µ simultaneously, due to the experimental constraints from 4µ search from BaBar [64] and the search of the muonic force coupled to b → sX FCNC vertex at LHCb [65]. In addition to down-type FCNC couplings (g eff dsX | B 3 , g eff sbX | B 3 and g eff dbX | B 3 ) which are proportional to g 2 16π 2 V ti V * tj F 1 (x t ), there are also tree-level up-type (left-handed) FCNC couplings due to SU (2) L gauge invariance as…”

Section: Constraintsmentioning

confidence: 99%

“…6. We also include the expected limits on the muonic force from Belle II using 4µ channel [64] and µ − µ + X(→ inv.) channel [36,67], and neutrino-trident production at DUNE [38] for a (L µ − L τ ) + (B 3 − L τ ) gauge boson X, Kaon decays (K + → µνX) at NA62 [37], M 3 (Muon Missing Momentum) based at Fermilab [39], and ATLAS detector as muon fixed-target experiment [68] for comparison.…”

Section: Expected Sensitivities In Future Experimentsmentioning

confidence: 99%

Light gauge boson interpretation for (g − 2)μ and the KL→ π0 + (invisible) anomaly at the J-PARC KOTO experiment

Jho

Lee

Park

et al. 2020

We discuss a list of possible light gauge boson interpretations for the longstanding experimental anomaly in (g − 2) µ and also recent anomalous excess in K L → π 0 + (invisible) events at the J-PARC KOTO experiment. We consider two models: i) L µ − L τ gauge boson with heavy vector-like quarks and ii) (L µ − L τ ) + (B 3 − L τ ) gauge boson in the presence of right-handed neutrinos. When the light gauge boson has mass close to the neutral pion in order to satisfy the Grossman-Nir bound, the models successfully explain the anomalies simultaneously while satisfying all known experimental constraints. We extensively provide the future prospect of suggested models.