Collider signatures for the heavy lepton triplet in the type<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi mathvariant="bold">I</mml:mi><mml:mo>+</mml:mo><mml:mi>III</mml:mi></mml:math>seesaw mechanism

Arhrib, Abdesslam; Bajc, Borut; Ghosh, Dilip Kumar; Han, Tao; Huang, G. S.; Puljak, I.; Senjanović, Goran

doi:10.1103/physrevd.82.053004

Cited by 92 publications

(95 citation statements)

References 66 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Given that the LHC reach for fermion triplets discovery is around 700-800 GeV [31,32], from the previous discussion, one could be tempted to conclude that any observation of fermionic triplets at the LHC would rule out leptogenesis within this framework. This however is not entirely correct as the asymmetry might be generated by degrees of freedom at higher scales -T 2 in triplet scenario for example 6 .…”

Section: Implications For Tev Leptogenesismentioning

confidence: 99%

“…Experimentally some conclusions about whether successful high scale (due to T 2 or any other mechanism, possibly unrelated to neutrino mass generation) leptogenesis is achieved can be drawn by producing T 1 at colliders, verifying its lepton number violating interactions (typically using same sign di-lepton event signatures [31,32]) and measuring its branching ratios and the total decay width. From eq.…”

Section: Implications For Type III See-saw Models At the Lhcmentioning

confidence: 99%

See 1 more Smart Citation

Implications of flavor dynamics for fermion triplet leptogenesis

Sierra

Kamenik

Nemevšek

2010

J. High Energ. Phys.

View full text Add to dashboard Cite

We analyze the importance of flavor effects in models in which leptogenesis proceeds via the decay of Majorana electroweak triplets. We find that depending on the relative strengths of gauge and Yukawa reactions the B − L asymmetry can be sizably enhanced, exceeding in some cases an order of magnitude level. We also discuss the impact that such effects can have for TeV-scale triplets showing that as long as the B − L asymmetry is produced by the dynamics of the lightest such triplet they are negligible, but open the possibility for scenarios in which the asymmetry is generated above the TeV scale by heavier states, possibly surviving the TeV triplet related washouts. We investigate these cases and show how they can be disentangled at the LHC by using Majorana triplet collider observables and, in the case of minimal type III see-saw models even through lepton flavor violation observables.

show abstract

Section: Implications For Tev Leptogenesismentioning

confidence: 99%

Section: Implications For Type III See-saw Models At the Lhcmentioning

confidence: 99%

Implications of flavor dynamics for fermion triplet leptogenesis

Sierra

Kamenik

Nemevšek

2010

J. High Energ. Phys.

View full text Add to dashboard Cite

show abstract

“…To discern the underlying physics that is responsible for neutrino masses, it is vital to produce directly the relevant heavy particles at colliders and study their properties [11][12][13][14][15][16][17][18][19][20][21][22][23][24]. In this paper, we will study the LHC phenomenology of the type II seesaw mechanism.…”

Section: Introductionmentioning

confidence: 99%

LHC phenomenology of the type II seesaw mechanism: Nondegenerate case

2015

View full text Add to dashboard Cite

In this paper, we thoroughly investigate the LHC phenomenology of the type II seesaw mechanism for neutrino masses in the nondegenerate case where the triplet scalars of various charge (H ±± , H ± , H 0 , A 0 ) have different masses. Compared with the degenerate case, the cascade decays of scalars lead to many new, interesting signal channels. In the positive scenario where M H ±± < M H ± < M H 0 /A 0 , the four-lepton signal is still the most promising discovery channel for the doubly-charged scalars H ±± . The five-lepton signal is crucial to probe the mass spectrum of the scalars, for which, for example, a 5σ reach at 14 TeV LHC for M H ± = 430 GeV with M H ±± = 400 GeV requires an integrated luminosity of 76 fb −1 . And the six-lepton signal can be used to probe the neutral scalars H 0 /A 0 , which are usually hard to detect in the degenerate case. In the negative scenario where M H ±± > M H ± > M H 0 /A 0 , the detection of H ±± is more challenging, when the cascade decay H ±± → H ± W ± * is dominant. The most important channel is the associated H ± H 0 /A 0 production in the final state ± E T b bb b, which requires a luminosity of 109 fb −1 for a 5σ discovery, while the final state ± E T b bτ + τ − is less promising. Moreover, the associated H 0 A 0 production can give same signals as the standard model Higgs pair production. With a much larger cross section, the H 0 A 0 production in the final state b bτ + τ − could reach 3σ significance at 14 TeV LHC with a luminosity of 300 fb −1 . In summary, with an integrated luminosity ∼ O(500 fb −1 ), the triplet scalars can be fully reconstructed at 14 TeV LHC in the negative scenario.

show abstract

“…What in practice means observing events with an excess of leptons, or anti-leptons. Among the three see-saw mechanisms, the see-saw of type II gives the cleanest signal because doubly-charged scalars can decay into pairs of same-sign charged leptons, ∆ ±± → l ± l ± , which accumulate around the doubly-charged scalar mass and allow for a very efficient search [52,53]; which is not the case for heavy fermions because they decay into an odd number of light fermions (≥ 3, if we exclude decays into Higgs bosons decaying in turn into two photons) [54][55][56][57][58][59], as required by rotational invariance. As a matter of fact, CMS [60] and ATLAS [61] have already set stringent limits on this process, excluding doubly-charged scalar masses m ∆ ±± ranging from 200 to 400 GeV, depending on the assumptions on the branching ratios into same-sign dileptons; although they have not reported on the corresponding limits for LNV.…”

Section: Introductionmentioning

confidence: 99%

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

Águila

Chala

2014

J. High Energ. Phys.

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

Collider signatures for the heavy lepton triplet in the typeI+IIIseesaw mechanism

Cited by 92 publications

References 66 publications

Implications of flavor dynamics for fermion triplet leptogenesis

Implications of flavor dynamics for fermion triplet leptogenesis

LHC phenomenology of the type II seesaw mechanism: Nondegenerate case

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

Contact Info

Product

Resources

About