scispace - formally typeset

Journal ArticleDOI

The K L -K S mass difference in left-right symmetric models and the right-handed Kobayashi-Maskawa matrix

01 Dec 1983-European Physical Journal C (Springer Science and Business Media LLC)-Vol. 20, Iss: 4, pp 305-312

AbstractKL-KS mass difference is computed in a left-right symmetric model with three generations of quarks. Under the assumption of “manifest” left-right symmetry the mass of the right-handed charged gauge boson consistent withKL-KS constraint appears to be rather high. A low mass right-handed gauge boson can be accommodated in models with broken “manifest” left-right symmetry. The latter scenario has many non-trivial predictions for the decay of heavy (c, t, b) quarks.

...read more


Citations
More filters
Journal ArticleDOI
Abstract: In minimal left–right symmetric models, the mass of the neutral Higgs field mediating tree-level flavor changing effects (FCNH) is directly related to the parity breaking scale. Specifically, the lower bound on the Higgs mass coming from Higgs-induced tree-level effects, and exceeding about 15 TeV, would tend to imply a W R mass bound much higher than that required by gauge exchange loop effects – the latter allowing W R masses as low as 2.5 TeV. Since a W R mass below 4 TeV is accessible at the LHC, it is important to investigate ways to decouple the FCNH effects from the W R mass. In this Letter, we present a model where this happens, providing new motivation for LHC searches for W R in the 1–4 TeV mass range.

56 citations

Journal ArticleDOI
Abstract: Using the left-right symmetric model as an illustrative example, we suggest a simple and straightforward way of constraining the W′ mass directly from the decay of the Higgs boson to two photons. The proposed method is generic and applicable to a diverse range of models with a W′-boson that couples to the Standard Model-like Higgs boson. Our analysis exemplifies how the precision measurement of the Higgs to diphoton signal strength can have a pivotal role in probing the scale of new physics.

4 citations

Journal ArticleDOI
Abstract: TheKL-KS mass difference in a dynamically broken gauge theory based on aSU(2)L⊗SU(2)R⊗U(1)B-L electroweak sector with manifest left-right symmetry and low right handed mass scale is analysed. We find that consistency with the observedKL-KS mass difference requires a smaller suppression factor than the corresponding quantity in a similar theory based on the standard electroweak sector. The required suppression may be accommodated in this model by reasonable choices of the adjustable parameters of the theory.
Journal ArticleDOI
01 Aug 2012
Abstract: I discuss the possibility of probing neutrino mass physics at the CERN Large Hadron Collider.
Journal ArticleDOI
01 Aug 2011
Abstract: This talk is a brief overview of some of the ideas behind our current understanding neutrino masses and mixings with special emphasis on what we can learn possibly about the scale of new physics responsible for neutrino masses from the Large Hadron Collider.

References
More filters
Journal ArticleDOI
Abstract: In a framework of the renormalizable theory of weak interaction, problems of CP-violation are studied. It is concluded that no realistic models of CP-violation exist in the quartet scheme without introducing any other new fields. Some possible models of CP-violation are also discussed. When we apply the renormalizable theory of weak interaction1l to the hadron system, we have some limitations on the hadron model. It is well known that there exists, in the case of the triplet model, a difficulty of the strangeness chang­ ing neutral current and that the quartet model is free from this difficulty. Fur­ thermore, Maki and one of the present authors (T.M.) have shown2l that, in the latter case, the strong interaction must be chiral SU ( 4) X SU ( 4) invariant as precisely as the conservation of the third component of the iso-spin 13 • In addi­ tion to these arguments, for the theory to be realistic, CP-violating interactions should be incorporated in a gauge invariant way. This requirement will impose further limitations on the hadron model and the CP-violating interaction itself. The purpose of the present paper is to investigate this problem. In the following, it will be shown that in the case of the above-mentioned quartet model, we cannot make a CP-violating interaction without introducing any other new fields when we require the following conditions: a) The mass of the fourth member of the quartet, which we will call (, is sufficiently large, b) the model should be con­ sistent with our well-established knowledge of the semi-leptonic processes. After that some possible ways of bringing CP-violation into the theory will be discussed. We consider the quartet model with a charge assignment of Q, Q -1, Q -1 and Q for p, n, A. and (, respectively, and we take the same underlying gauge group SUweak (2) X SU(1) and the scalar doublet field cp as those of Weinberg's original model.1l Then, hadronic parts of the Lagrangian can be devided in the following way:

5,101 citations

Journal ArticleDOI
Abstract: Weak and electromagnetic interactions of the leptons are examined under the hypothesis that the weak interactions are mediated by vector bosons. With only an isotopic triplet of leptons coupled to a triplet of vector bosons (two charged decay-intermediaries and the photon) the theory possesses no partial-symmetries. Such symmetries may be established if additional vector bosons or additional leptons are introduced. Since the latter possibility yields a theory disagreeing with experiment, the simplest partially-symmetric model reproducing the observed electromagnetic and weak interactions of leptons requires the existence of at least four vector-boson fields (including the photon). Corresponding partially-conserved quantities suggest leptonic analogues to the conserved quantities associated with strong interactions: strangeness and isobaric spin.

4,202 citations

Journal ArticleDOI
Abstract: Universal strong, weak, and electromagnetic interactions of leptons and hadrons are generated by gauging a non-Abelian renormalizable anomaly-free subgroup of the fundamental symmetry structure $\mathrm{SU}{(4)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}{(4)}_{R}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}({4}^{\ensuremath{'}})$, which unites three quartets of "colored" baryonic quarks and the quartet of known leptons into 16-folds of chiral fermionic multiplets, with lepton number treated as the fourth "color" quantum number. Experimental consequences of this scheme are discussed. These include (1) the emergence and effects of exotic gauge mesons carrying both baryonic as well as leptonic quantum numbers, particularly in semileptonic processes, (2) the manifestation of anomalous strong interactions among leptonic and semileptonic processes at high energies, (3) the independent possibility of baryon-lepton number violation in quark and proton decays, and (4) the occurrence of ($V+A$) weak-current effects.

2,733 citations

Journal ArticleDOI
Abstract: Unified electroweak gauge theories based on the gauge group $\mathrm{SU}{(2)}_{L}\ifmmode\times\else\texttimes\fi{}\mathrm{SU}{(2)}_{R}\ifmmode\times\else\texttimes\fi{}\mathrm{U}{(1)}_{B\ensuremath{-}L}$, in which the breakdown of parity invariance is spontaneous, lead most naturally to a massive neutrino. Assuming the neutrino to be a Majorana particle, we show that smallness of its mass can be understood as a result of the observed maximality of parity violation in low-energy weak interactions. This result is shown to be independent of the number of generations and unaffected by renormalization effects. Phenomenological consequences of this model at low energies are studied. Observation of neutrinoless double-$\ensuremath{\beta}$ decay will provide a crucial test of this class of models. Implications for rare decays such as $\ensuremath{\mu}\ensuremath{\rightarrow}e\ensuremath{\gamma}$, $\ensuremath{\mu}\ensuremath{\rightarrow}\mathrm{ee}\overline{e}$, etc. are also noted. It is pointed out that in the realm of neutral-current phenomena, departure from the predictions of the standard model for polarized-electron-hadron scattering, forward-backward asymmetry in ${e}^{+}{e}^{\ensuremath{-}}\ensuremath{\rightarrow}{\ensuremath{\mu}}^{+}{\ensuremath{\mu}}^{\ensuremath{-}}$, and neutrino interactions has a universal character and may be therefore used as a test of the model.

1,794 citations

Journal ArticleDOI

1,180 citations