151 research outputs found

    Parity violation correlations in light muonic atoms

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    The 2 S -1 S transition in light muonic atoms is very sensitive to parity violation correlations induced via neutral currents. Observables depending on these transitions such as the photon polarization and the angular correlation between the emitted radiation and the atom polarization are a clear signal of weak neutral currents in atoms. We find the relation between the lepton and quark couplings and these observables emphasizing the effect of the nuclear spin. The results expected in muonic, atoms μ- 4 He and μ- 3 He are given.This work has been supported in part by CICYT, under grant AE-0021. Two of us (J.B. and J.V.) are indebted to Ministerio de Educación y Ciencia and to C.S.I.C., respectively for the research fellowships.Peer reviewe

    Witten's cubic vertex in the comma theory (I)

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    It is shown that Witten's interaction 3-vertex is a solution to the comma overlap equations; hence establishing the equivalence between the conventional and the 'comma' formulation of interacting string theory at the level of vertices

    On the Corner Elements of the CKM and PMNS Matrices

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    Recent experiments show that the top-right corner element (Ue3U_{e3}) of the PMNS, like that (VubV_{ub}) of the CKM, matrix is small but nonzero, and suggest further via unitarity that it is smaller than the bottom-left corner element (Uτ1U_{\tau 1}), again as in the CKM case (Vub<VtdV_{ub} < V_{td}). An attempt in explaining these facts would seem an excellent test for any model of the mixing phenomenon. Here, it is shown that if to the assumption of a universal rank-one mass matrix, long favoured by phenomenologists, one adds that this matrix rotates with scale, then it follows that (A) by inputting the mass ratios mc/mt,ms/mb,mμ/mτm_c/m_t, m_s/m_b, m_\mu/m_\tau, and m2/m3m_2/m_3, (i) the corner elements are small but nonzero, (ii) Vub<VtdV_{ub} < V_{td}, Ue3<Uτ1U_{e 3} < U_{\tau 1}, (iii) estimates result for the ratios Vub/VtdV_{ub}/V_{td} and Ue3/Uτ1U_{e 3}/U_{\tau 1}, and (B) by inputting further the experimental values of Vus,VtbV_{us}, V_{tb} and Ue2,Uμ3U_{e2},U_{\mu 3}, (iv) estimates result for the values of the corner elements themselves. All the inequalities and estimates obtained are consistent with present data to within expectation for the approximations made.Comment: 9 pages, 2 figures, updated with new experimental data and more detail

    A Solution of the Strong CP Problem Transforming the theta-angle to the KM CP-violating Phase

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    It is shown that in the scheme with a rotating fermion mass matrix (i.e. one with a scale-dependent orientation in generation space) suggested earlier for explaining fermion mixing and mass hierarchy, the theta-angle term in the QCD action of topological origin can be eliminated by chiral transformations, while giving still nonzero masses to all quarks. Instead, the effects of such transformations get transmitted by the rotation to the CKM matrix as the KM phase giving, for θ\theta of order unity, a Jarlskog invariant typically of order 10−510^{-5} as experimentally observed. Strong and weak CP violations appear then as just two facets of the same phenomenon.Comment: 14 pages, 2 figure

    Bottom quark mass and QCD duality

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    The mass of the bottom quark is analyzed in the context of QCD finite energy sum rules. In contrast to the conventional approach, we use a large momentum expansion of the QCD correlator including terms to order alpha(S)(2)(m(b)(2)/q(2))(6) with the upsilon resonances from e(+)c(-) annihilation data as main input. A stable result m(b)(m(b)) = (4.19 +/- 0.05) GeV for the bottom quark mass is obtained. This result agrees with the independent calculations based on the inverse moment analysis

    Search for new physics in semileptonic decays of K and B as implied by the g-2 anomaly in FSM

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    The framed standard model (FSM), constructed to explain, with some success, why there should be 3 and apparently only 3 generations of quarks and leptons in nature falling into a hierarchical mass and mixing pattern, suggests also, among other things, a scalar boson U, with mass around 17 MeV and small couplings to quarks and leptons, which might explain the g-2 anomaly reported in experiment. The U arises in FSM initially as a state in the predicted `hidden sector' with mass around 17 MeV, which mixes with the standard model (SM) Higgs hWh_W, acquiring thereby a coupling to quarks and leptons and a mass just below 17 MeV. The initial purpose of the present paper is to check whether this proposal is compatible with experiment on semileptonic decays of Ks and Bs where the U can also appear. The answer to this we find is affirmative, in that the contribution of U to new physics as calculated in the FSM remains within the experimental bounds, but only if mUm_U lies within a narrow range just below the unmixed mass. As a result from this, one has an estimate mU∼15−17m_U \sim 15 - 17 MeV for the mass of UU, and from some further considerations the estimate ΓU∼0.02\Gamma_U \sim 0.02 eV for its width, both of which may be useful for an eventual search for it in experiment. And, if found, it will be, for the FSM, not just the discovery of a predicted new particle, but the opening of a window into a whole ``hidden sector" containing at least some, perhaps ven the bulk, of the dark matter in the universe

    New Angle on the Strong CP and Chiral Symmetry Problems from a Rotating Mass Matrix

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    It is shown that when the mass matrix changes in orientation (rotates) in generation space for changing energy scale, then the masses of the lower generations are not given just by its eigenvalues. In particular, these masses need not be zero even when the eigenvalues are zero. In that case, the strong CP problem can be avoided by removing the unwanted θ\theta term by a chiral transformation in no contradiction with the nonvanishing quark masses experimentally observed. Similarly, a rotating mass matrix may shed new light on the problem of chiral symmetry breaking. That the fermion mass matrix may so rotate with scale has been suggested before as a possible explanation for up-down fermion mixing and fermion mass hierarchy, giving results in good agreement with experiment.Comment: 14 page
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