Discriminating between lepton number violating scalars using events with four and three charged leptons at the LHC

Águila, F. del; Chala, Mikael; Santamaría, Arcadi; Wudka, José

doi:10.1016/j.physletb.2013.07.014

Cited by 37 publications

(34 citation statements)

References 58 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the case of doublycharged scalar production under consideration one would like to determine the type of multiplet the doubly-charged scalar belongs to. This can be done sampling appropriately the events with four and three isolated leptons, as has been proposed in [82][83][84].…”

Section: Jhep03(2014)027mentioning

confidence: 99%

“…This means to classify the EW multiplets H which the corresponding doubly-charged scalars can belong to. In general, no matter what SU(2) L × U(1) Y multiplet including H ±± is considered, one can always write down gauge invariant effective operators giving rise to these decays after EWSB [82]. In fact, this can be done for any of the three lepton bilinears with non-…”

Section: Jhep03(2014)027mentioning

confidence: 99%

“…The lowest order gauge invariant operators coupling the doubly-charged component of these multiplets to a pair of same-sign charged leptons after EWSB are of dimension 4 for κ and ∆, 5 for χ and Σ, and 6 for Ω, respectively [82]:…”

Section: Jhep03(2014)027mentioning

confidence: 99%

“…The first two lines describe the s−channel exchange of gauge bosons [82]; whereas all of them enter in the calculation of the vector-boson fusion (VBF) contribution (see next section). These couplings depend on the type of multiplet, i.e., on T and Y , the doublycharged scalar belongs to, as do the corresponding cross-sections.…”

Section: Jhep03(2014)027mentioning

confidence: 99%

See 3 more Smart Citations

LHC bounds on lepton number violation mediated by doubly and singly-charged scalars

Águila

Chala

2014

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

Abstract:The only possible doubly-charged scalar decays into two Standard Model particles are into pairs of same-sign charged leptons, H ±± → l ± l ± , l = e, µ, τ , or gauge bosons, H ±± → W ± W ± ; being necessary the observation of both to assert the violation of lepton number. However, present ATLAS and CMS limits on doubly-charged scalar production are obtained under specific assumptions on its branching fractions into dileptons only. Although they can be extended to include decays into dibosons and lepton number violating processes. Moreover, the production rates also depend on the type of electroweak multiplet H ±± belongs to. We classify the possible alternatives and provide the Feynman rules and codes for generating the corresponding signals for pair and associated doubly-charged scalar production, including the leading contribution from the s-channel exchange of electroweak gauge bosons as well as the vector-boson fusion corrections. Then, using the same analysis criteria as the LHC collaborations we estimate the limits on the H ±± mass as a function of the electroweak multiplet it belongs to, and obtain the bounds on the lepton number violating processes pp → H ±± H ∓∓ → ± ± W ∓ W ∓ and pp → H ±± H ∓ → ± ± W ∓ Z, = e, µ, implied by the ATLAS and CMS doubly-charged scalar searches.

show abstract

Section: Jhep03(2014)027mentioning

confidence: 99%

Section: Jhep03(2014)027mentioning

confidence: 99%

Section: Jhep03(2014)027mentioning

confidence: 99%

Section: Jhep03(2014)027mentioning

confidence: 99%

See 2 more Smart Citations

LHC bounds on lepton number violation mediated by doubly and singly-charged scalars

Águila

Chala

2014

J. High Energ. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…It is also very important to be able to build renormalizable models which could give rise to the different operators in the effective Lagrangian at low energies. As we will stress, these models are quite interesting because some of the new particles may be accessible to LHC [33,34].…”

Section: Introductionmentioning

confidence: 99%

Neutrinoless double b decay with small neutrino masses

Águila¹,

Aparici²,

Bhattacharya³

et al. 2013

Proceedings of Proceedings of the Corfu Summer Institute 2012 — PoS(Corfu2012)

Self Cite

View full text Add to dashboard Cite

If the only contribution to neutrinoless double beta decay (0νβ β ) are neutrino masses its discovery may be very difficult, especially if neutrinos present a normal hierarchy spectrum. However, this is not the only possibility; 0νβ β can in general produce electrons of either chirality, in contrast with the neutrino induced 0νβ β which predicts two left-handed electrons. Using an effective Lagrangian approach we classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to 0νβ β . We point out that, for each of the three chirality assignments, e L e L , e L e R and e R e R , there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one (dimension 7) or two loops (dimension 9). Under the assumption that 0νβ β is dominated by the operators of dimension 7 or 9 we find that the scale of new physics should be relatively low ( 30 TeV). We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case. The phenomenology of a model giving rise to the dimension 9 operator has been analyzed with some detail: if 0νβ β is going to be seen in the next round of experiments, the doubly charged scalars of the model could be seen at the LHC and lepton flavour violating (LFV) rates could be at the reach of foreseen experiments. Moreover neutrino masses, which arise at two loops, display a very particular structure and are strongly constrained, in fact, sin 2 θ 13 0.008, when µ → eee is required to lie below its present experimental limit.

show abstract

Lepton number violating phenomenology of d = 7 neutrino mass models

Cepedello

Hirsch

Helo

2018

J. High Energ. Phys.

View full text Add to dashboard Cite

Abstract:We study the phenomenology of d = 7 1-loop neutrino mass models. All models in this particular class require the existence of several new SU(2) L multiplets, both scalar and fermionic, and thus predict a rich phenomenology at the LHC. The observed neutrino masses and mixings can easily be fitted in these models. Interestingly, despite the smallness of the observed neutrino masses, some particular lepton number violating (LNV) final states can arise with observable branching ratios. These LNV final states consists of leptons and gauge bosons with high multiplicities, such as 4l + 4W , 6l + 2W etc. We study current constraints on these models from upper bounds on charged lepton flavour violating decays, existing lepton number conserving searches at the LHC and discuss possible future LNV searches.

show abstract

Discriminating between lepton number violating scalars using events with four and three charged leptons at the LHC

Cited by 37 publications

References 58 publications

LHC bounds on lepton number violation mediated by doubly and singly-charged scalars

LHC bounds on lepton number violation mediated by doubly and singly-charged scalars

Neutrinoless double b decay with small neutrino masses

Lepton number violating phenomenology of d = 7 neutrino mass models

Contact Info

Product

Resources

About