Many studies have been made on extensions of the standard model with B−L gauge symmetry. The addition of three singlet (right-handed) neutrinos renders it anomaly-free. It has always been assumed ...that the spontaneous breaking of B−L is accomplished by a singlet scalar field carrying two units of B−L charge. This results in a very natural implementation of the Majorana seesaw mechanism for neutrinos. However, there exists in fact another simple anomaly-free solution which allows Dirac or inverse seesaw neutrino masses. We show for the first time these new possibilities and discuss an application to neutrino mixing with S3 flavor symmetry.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In the present letter, a Dirac neutrino mass model is presented in the view of the new result on W boson mass of mWCDF−II=80.4335±0.0094 GeV, recently reported by the CDF-II experimental ...collaboration. The newly measured value of the W mass anomaly shows a 7-σ deviation from that predicted by the standard model. The model explains the CDF-II W boson mass anomaly by extending the standard model with hypercharge zero vector-like fermion triplet. Symmetry is amended with a global U(1)B−L which is broken with an hypercharge zero electroweak triplet. It is demonstrated that the model can successfully explain CDF-II result, Dirac neutrino mass origin, while satisfying standard model precision constraints and collider constraints with scalar and fermion triplet masses in the ranger 1.4 TeV−5.2 TeV and 100 TeV −1013 GeV, respectively.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
We study a gauge B–L extension of the standard model of quarks and leptons with unconventional charges for the singlet right-handed neutrinos, and extra singlet scalars, such that a residual Z3 ...symmetry remains after the spontaneous breaking of B–L. We discuss the phenomenological consequences of this scenario, including the possibility of long-lived self-interacting dark matter and Z′ collider signatures.
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Edward Snowden's disclosures of the United States's surveillance programs produced an international outcry from citizens, human rights groups, and foreign governments. Beyond creating embarrassing ...conversations for American diplomats around the world, the disclosures had real-world consequences. Germany cancelled an intelligence collection agreement from 1968 with the United States and United Kingdom. The termination was directly a result of the disclosures and need to protect individual privacy. More significantly, the Obama administration enacted Presidential Policy Directive-28 (PPD-28), making the United States the first country to give foreigners privacy protections from mass surveillance. Despite the change in American policy, both adversaries and allies of the US continue to conduct unrestrained mass surveillance of foreigners. In the digital age, governments around the world pursue these policies to meet their national security needs. This note aims to balance the national security imperative that warrants extraterritorial surveillance against the privacy rights included in the international human rights bundle. Furthermore, this note proposes creating a two-tiered code of privacy protections for foreign individuals during extraterritorial surveillance. Part I explains what extraterritorial surveillance is, how it's different from conventional espionage, and how the practice fares under international law. Notably, Part I explains that although extraterritorial surveillance implicates international privacy agreements, the agreements are inadequate tools to restrain surveillance. Part II discusses various solutions and why they do not adequately address the clash between surveillance and privacy. Part III introduces the Tiered Code, articulates Tier I's provisions, and defends potential drawbacks that would impact the Code
or any multilateral agreement.
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5.
The inverse seesaw family: Dirac and Majorana Chuliá, Salvador Centelles; Srivastava, Rahul; Vicente, Avelino
The journal of high energy physics,
03/2021, Volume:
2021, Issue:
3
Journal Article
Peer reviewed
Open access
A
bstract
After developing a general criterion for deciding which neutrino mass models belong to the category of inverse seesaw models, we apply it to obtain the Dirac analogue of the canonical ...Majorana inverse seesaw model. We then generalize the inverse seesaw model and obtain a class of inverse seesaw mechanisms both for Majorana and Dirac neutrinos. We further show that many of the models have double or multiple suppressions coming from tiny symmetry breaking “
μ
-parameters”. These models can be tested both in colliders and with the observation of lepton flavour violating processes.
We describe the many pathways to generate Majorana and Dirac neutrino mass through generalized dimension-5 operators a la Weinberg. The presence of new scalars beyond the Standard Model Higgs doublet ...implies new possible field contractions, which are required in the case of Dirac neutrinos. We also notice that, in the Dirac neutrino case, the extra symmetries needed to ensure the Dirac nature of neutrinos can also be made responsible for stability of dark matter.
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We propose a new interpretation of Peccei–Quinn symmetry within the Standard Model, identifying it with the axial B+L symmetry i.e. U(1)PQ≡U(1)γ5(B+L). This new interpretation retains all the ...attractive features of Peccei–Quinn solution to strong CP problem but in addition also leads to several other new and interesting consequences. Owing to the identification U(1)PQ≡U(1)γ5(B+L) the axion also behaves like Majoron inducing small seesaw masses for neutrinos after spontaneous symmetry breaking. Another novel feature of this identification is the phenomenon of spontaneous (and also chiral) proton decay with its decay rate associated with the axion decay constant. Low energy processes which can be used to test this interpretation are pointed out.
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We propose to relate dark matter stability to the possible Dirac nature of neutrinos. The idea is illustrated in a simple scheme where small Dirac neutrino masses arise from a type-I seesaw mechanism ...as a result of a Z4 discrete lepton number symmetry. The latter implies the existence of a viable WIMP dark matter candidate, whose stability arises from the same symmetry which ensures the Diracness of neutrinos.
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We analyze the consistency of electroweak breaking, neutrino and dark matter phenomenology within the simplest scoto-seesaw model. By adding the minimal dark sector to the simplest “missing partner” ...type-I seesaw one has a physical picture for the neutrino oscillation lengths: the “atmospheric” mass scale arises from the tree-level seesaw, while the “solar” scale is induced radiatively, mediated by the dark sector. We identify parameter regions consistent with theoretical constraints, as well as dark matter relic abundance and direct detection searches. Using two-loop renormalization group equations we explore the stability of the vacuum and the consistency of the underlying dark parity symmetry. One also has a lower bound for the neutrinoless double beta decay amplitude.
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By combining the simplest (3,1) version of the seesaw mechanism containing a single heavy “right-handed” neutrino with the minimal scotogenic approach to dark matter, we propose a theory for neutrino ...oscillations. The “atmospheric” mass scale arises at tree level from the seesaw, while the “solar” oscillation scale emerges radiatively, through a loop involving the “dark sector” exchange. Such simple setup gives a clear interpretation of the neutrino oscillation lengths, has a viable WIMP dark matter candidate, and implies a lower bound on the neutrinoless double beta decay rate.
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