Here is a list of experimental measurements in high-energy particle physics (HEP) with largest deviations from either the state-of-the art theory or some data-driven expectation. This list contains only measurements that include "evidence" for some new phenomena, which is defined as measurements with more than 3 "σ" (3 sigma or standard deviations) i.e. 0.3% probability of occurring by chance. The significance is defined as "local", i.e. it does not include look-elsewhere effect.
Intriguing deviations with significance >3 sigma can be signs of new physics. For example, top quarks were first hinted at in the 1994 paper by the CDF collaboration, observing an excess of events amounting to about 3-sigma, but the existence of the top quark was fully established later. However, in most cases, 3 sigma deviations can be due to statistical or some systematic effects that require clarifications by independent measurements.
Description | Year | Experiment | Excess level | Comment |
---|---|---|---|---|
Enhancement around 4.5 GeV [1] | 2022 | BESIII | 3.3 σ | Not confirmed by others |
Higgs search in bbmumu channel at 52 GeV [2] | 2022 | ATLAS | 3.3 σ | Not confirmed by CMS |
g-2 (muon anomalous magnetic moment)[3] | 2021 | Muon g−2 | 3.3 σ | No other experiments |
Excess of electronic recoil at 1-7 keV [4] | 2021 | XENON1T | 4.0 σ | No other experiments |
Excess of electron like events[5] | 2018 | MiniBooNE | 6 σ | No other experiments |
X17 particle at 17 MeV[6] | 2018 | Atomki Inst. | 7.2 σ | Not confirmed by other experiments |
W mass measurement [7] | 2022 | CDF | 7 σ | Not confirmed by other experiments |
Dijets+lepton mass at 1.3 TeV [8] | 2022 | ATLAS | 3.5 σ | No CMS measurement |
4-jet mass at 8 TeV [9] | 2022 | CMS | 3.6 σ | No ATLAS measurement |
SUSY search [10] | 2015 | ATLAS | 3.0 σ | Not confirmed by CMS |
Lepton universality in beauty-quark decays [11] | 2021 | LHCb | 3.1 σ | No other measurements |
Bump at 4.8 TeV for muon+jet invariant mass using unsupervised machine learning for anomaly detection [12] | 2023 | ATLAS | ~3 σ | No other measurements |
Diboson excess for ZW channel [13] | 2021 | ATLAS | 3.4 σ | CMS does not confirm |
Like-sign dimuon charge asymmetry [14] | 2010 | D0 | 3.2 σ | CDF does not confirm |
Faster-than-light neutrino [15] | 2011 | OPERA | 6 σ | Not confirmed |
2 b-quarks+1 photon [16] | 1986 | CDF | 4 σ | Not confirmed |
Excess for W + 2-jets at 140 GeV [17] | 2011 | CDF | 3.2 σ | D0 does not confirm |
Higgs-like excess at 114 GeV [18] | 2010 | ALEPH | 3.2 σ | No in other LEP experiments |
pK0 mass at 1.52 GeV[19] | 2004 | ZEUS | 3.9 σ | H1 does not confirm |
Charm pentaquark 3.1 GeV [20] | 2004 | H1 | 6.2 σ | ZEUS does not confirm |
nK+ mass at 1.54 GeV [21] | 2003 | SAPHIR | 4.8 σ | Not confirmed |
nK+ mass at 1.54 GeV [22] | 2003 | LEPS/SPring-8 | 4.6 σ | Not confirmed |
pK0 mass at 1.53 GeV [23] | 2003 | DIANA | 4.4 σ | Not confirmed |
Excess of deuterons in ep[24] | 2007 | ZEUS | 10 σ or more [25] | No other experiments |