arXiv subjects

Y. Takanishi

Publications and source records attributed to Y. Takanishi.

23 records · Page 2Linked to original sources

arXiv2001

Neutrino mass matrix in Anti-GUT with see-saw mechanism

We have investigated the predictions of neutrino oscillations within extended Anti-GUT, based on a large gauge group - the Standard Model and an B-L abelian group assumed with separate gauge fields coupling to each family of quarks and leptons. We take into account corrections concerning a crude way of accounting for the number of ways the vacuum expectation values of the Higgs fields of the model can be ordered in the Feynman diagrams yielding the mass matrix elements. Performing these corrections in a balanced way between the charged fermion sector and the neutrino sector (case I) leads to the previous version of our model that was a fit to the MSW small angle solution region. The fit considered here is marginally worse that the previous fit inasmuch as it predicts a somewhat lower solar neutrino mass square difference (which might though be the only way of avoiding the day-night exclusion region). The other two versions (case II and case III) are characterised by the heaviest of the see-saw neutrino matrix elements that are composed either of ν_{Rμ} and ν_{Rτ} or two ν_{Rτ}. These cases II and III fit the small mixing angle MSW scenario very well.

hep-ph↗

arXiv2001

Baryogenesis via lepton number violation in Anti-GUT model

We study the baryogenesis via lepton number violation in the model of Anti-GUT. The origin of the baryogenesis is the existence of right-handed Majorana neutrinos which decay in a C, CP and lepton number violation way. The baryon number asymmetry is calculated in the extended Anti-GUT model which is only able to predict order of magnitude-wise. We predicted baryon number to entropy ratio, Y_B=1.46{+5.87\atop-1.17}\times10^{-11}, and this result agrees with experimental values very well.

hep-ph↗

arXiv2001

A Neutrino Mass Matrix Model with many Quantum charges and No SUSY

We present a model based on our favourite gauge group which we call Anti-GUT and which in its extended form to be applied for neutrinos in the see-saw picture consists in that we have for each family separately a set of gauge fields as in the Standard Model plus a gauged (B-L)-charge. It may function as a concrete model manifestation of the type of model suggested by some general statistical considerations as to what a mass matrix model is to be to match naturally the rough features of the spectrum and the baryon asymmetry so nicely obtained in see-saw models along the Fukugita-Yanagida scheme.

hep-ph↗

arXiv2000

Neutrino Oscillations in Extended Anti-GUT Model

What we call the Anti-GUT model is extended a bit to include also right-handed neutrinos and thus make use of the see-saw mechanism for neutrino masses. This model consists in assigning gauge quantum numbers to the known Weyl fermions and the three see-saw right-handed neutrinos. Each family (generation) is given its own Standard Model gauge fields and a gauge field coupled to the $B-L$ quantum number for that family alone. Further we assign a rather limited number of Higgs fields, so as to break these gauge groups down to the Standard Model gauge group and to fit, w.r.t. order of magnitude, the spectra and mixing angles of the quarks and leptons. We find a rather good fit, which for neutrino oscillations favours the small mixing angle MSW solution, although the mixing angle predicted is closest to the upper side of the uncertainty range for the measured solar neutrino mixing angle. An idea for making a ``finetuning''-principle to ``explain'' the large ratios found empirically in physics, and answer such questions as ``why is the weak scale low compared to the Planck scale?'', is proposed. A further very speculative extension is supposed to ``explain'' why we have three families.

hep-ph↗

arXiv2000

Neutrino mass matrix suppression by Abelian charges with see-saw mechanism

We have investigated a neutrino mass matrix model without supersymmetry including three see-saw right-handed neutrinos around order $10^{12}$ GeV masses, aiming at a picture with all small numbers explained as being due to approximately conserved gauge charges. The prediction of the solar neutrino mixing angle is given by $\sin^22θ_{\odot}= 3 {+3\atop -2}\times10^{-2}$; in fact, the solar mixing angle is, apart from detailed order unity corrections, equal to the Cabibbo angle. Furthermore the ratio of the solar neutrino mass square difference to that for the atmospheric neutrino oscillation is predicted to $6 {+11\atop -4}\times10^{-4}$ and is given by the same Cabibbo angle related parameter $ξ$ as $6 ξ^4$.

hep-ph↗