Interpretations of the ATLAS diboson anomaly

We study a simple effective field theory incorporating six heavy vector bosons together with the standard-model field content. The new particles preserve custodial symmetry as well as an approximate left-right parity symmetry. The enhanced symmetry of the model allows it to satisfy precision electroweak constraints and bounds from Higgs physics in a regime where all the couplings are perturbative and where the amount of fine-tuning is comparable to that in the standard model itself.We find that the model could explain the recently observed excesses in di-boson processes at invariant mass close to 2 TeV from LHC Run 1 for a range of allowed parameter space. The masses of all the particles differ by no more than roughly 10%. In a portion of the allowed parameter space only one of the new particles has a production cross section large enough to be detectable with the energy and luminosity of Run 1, both via its decay to W Z and to W h, while the others have suppressed production rates. The model can be tested at the higher-energy and higher-luminosity run of the LHC even for an overall scale of the new particles higher than 3 TeV.

Section: Direct Searchesmentioning

confidence: 59%

Spectrum-doubled heavy vector bosons at the LHC

Appelquist

Bai

Ingoldby

et al. 2016

“…The largest deviation they found is 1.4 σ at ∼ 1.9 TeV [2]. Although we cannot conclude that there is a new particle with the mass around 2 TeV from this data, it is worthwhile to consider models which can explain this excess, and many papers have already appeared discussing interpretations of the excess [3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]. As discussed in these references, a simple candidate is a spin-1 particle.…”

Section: Introductionmentioning

confidence: 89%

Prospects for spin-1 resonance search at 13 TeV LHC and the ATLAS diboson excess

Abe

Kitahara

Nojiri

2016

Motivated by ATLAS diboson excess around 2 TeV, we investigate a phenomenology of spin-1 resonances in a model where electroweak sector in the SM is weakly coupled to strong dynamics. The spin-1 resonances, W and Z , are introduced as effective degrees of freedom of the dynamical sector. We explore several theoretical constraints by investigating the scalar potential of the model as well as the current bounds from the LHC and precision measurements. It is found that the main decay modes are V → V V and V → V h, and the V width is narrow enough so that the ATLAS diboson excess can be explained. In order to investigate future prospects, we also perform collider simulations at √ s = 13 TeV LHC, and obtain a model independent expected exclusion limit for σ(pp → W → W Z → JJ). We find a parameter space where the diboson excess can be explained, and are within a reach of the LHC at dtL = 10 fb −1 and √ s = 13 TeV.

“…Such consistency check in the context of the ATLAS diboson excess has been studied in refs. [8][9][10][11]. There are also studies considering bounds from the decay of the new resonance into heavy quarks or the Higgs boson, such as [12][13][14], but it should be noted that such considerations are model-dependent.…”

Section: Jhep11(2015)191mentioning

confidence: 99%

Testing ATLAS diboson excess with dark matter searches at LHC

Liew

Shirai

2015

Abstract:The ATLAS collaboration has recently reported a 2.6σ excess in the search for a heavy resonance decaying into a pair of weak gauge bosons. Only fully hadronic final states are being looked for in the analysis. If the observed excess really originates from the gauge bosons' decays, other decay modes of the gauge bosons would inevitably leave a trace on other exotic searches. In this paper, we propose the use of the Z boson decay into a pair of neutrinos to test the excess. This decay leads to a very large missing energy and can be probed with conventional dark matter searches at the LHC. We discuss the current constraints from the dark matter searches and the prospects. We find that optimizing these searches may give a very robust probe of the resonance, even with the currently available data of the 8 TeV LHC.