306 research outputs found

    Pseudoscalar Meson Mixing in Effective Field Theory

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    We show that for any effective field theory of colorless meson fields, the mixing schemes of particle states and decay constants are not only related but also determined exclusively by the kinetic and mass Lagrangian densities. In the general case, these are bilinear in terms of the intrinsic fields and involve non-diagonal kinetic and mass matrices. By applying three consecutive steps this Lagrangian can be reduced into the standard quadratic form in terms of the physical fields. These steps are : (i) the diagonalization of the kinetic matrix, (ii) rescaling of the fields, and (iii) the diagonalization of the mass matrix. In case, where the dimensions of the non-diagonal kinetic and mass sub-matrices are respectively, k×kk\times k and n×nn\times n, this procedure leads to mixing schemes which involve [k(k−1)/2]+[n(n−1)/2][k(k-1)/2] + [n(n-1)/2] angles and kk field rescaling parameters. This observation holds true irrespective with the type of particle interactions presumed. The commonly used mixing schemes, correspond to a proper choice of the kinetic and mass matrices, and are derived as special cases. In particular, η\eta-ηâ€Č\eta ' mixing, requires one angle, if and only if, the kinetic term with the intrinsic fields has a quadratic form.Comment: REVTeX, 6 page

    Quantum Field Theory of Meson Mixing

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    We have developed a quantum field theoretic framework for scalar and pseudoscalar meson mixing and oscillations in time. The unitary inequivalence of the Fock space of base (unmixed) eigenstates and the physical mixed eigenstates is proven and shown to lead to a rich condensate structure. This is exploited to develop formulas for two flavor boson oscillations in systems of arbitrary boson occupation number. The mixing and oscillation can be understood in terms of vacuum condensate which interacts with the bare particles to induce non-trivial effects. We apply these formulas to analyze the mixing of η\eta with ηâ€Č\eta' and comment on the KLKSK_L K_S system. In addition, we consider the mixing of boson coherent states, which may have future applications in the construction of meson lasers.Comment: 12 pages, 3 figures; Eqs.(10-12) corrected, leading to new physical insights; added paragraph under Eq.(24) explaining physical interpretation of mixing in terms of vacuum condensation; references added and minor typo correcte

    On the renormalization group for the interacting massive scalar field theory in curved space

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    The effective action for the interacting massive scalar field in curved space-time is derived using the heat-kernel method. Starting from this effective action, we establish a smooth quadratic form of the low-energy decoupling for the four-scalar coupling constant and for the nonminimal interaction parameter. The evolution of this parameter from the conformal value 1/6 at high energies down to the IR regime is investigated within the two toy models with negative and positive four-scalar coupling constants.Comment: LaTeX, 12 pages, 4 figure

    Assessment of oral overlap with antipsychotic long-acting injectables initiated in an inpatient setting

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    Introduction Long-acting injectable (LAI) antipsychotics are a promising solution to combating issues related to nonadherence to oral antipsychotics. Oral overlap is utilized when an LAI is initiated to achieve therapeutic concentrations. The place in therapy in which additional overlap is warranted is often mistaken, and providers may prescribe additional overlap based on the presentation of the patient or misunderstanding of appropriate overlap. Methods This retrospective chart review assesses patients who were initiated on an LAI while admitted to the acute inpatient psychiatric unit from January 1, 2016, to December 31, 2019. The primary outcome assesses the appropriateness of oral overlap with LAIs. Secondary outcomes include adherence to oral overlap, discontinuation of an LAI within 4 months, and reason for discontinuation of LAI. Results A total of 62 patients were included: 40 (65%) had appropriate overlap, and 22 (35%) had inappropriate overlap. The most common LAI was paliperidone (n = 50, 81%). Patients were adherent to oral overlap in 67% (n = 6) of the appropriate overlap group and 85% (n = 17) of the inappropriate overlap group. Discontinuation of an LAI in 4 months occurred in 62.5% (n = 25) of the appropriate group and 40.9% (n = 9) of the inappropriate group. There were no significant differences in secondary outcomes when comparing adherence to oral overlap (p = .26), discontinuation of LAI within 4 months (p = .62), and reason for discontinuation (p = .69). Discussion This study identified that a majority of patients had appropriate prescribing of oral antipsychotic overlap

    Neutrino oscillations from relativistic flavor currents

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    By resorting to recent results on the relativistic currents for mixed (flavor) fields, we calculate a space-time dependent neutrino oscillation formula in Quantum Field Theory. Our formulation provides an alternative to existing approaches for the derivation of space dependent oscillation formulas and it also accounts for the corrections due to the non-trivial nature of the flavor vacuum. By exploring different limits of our formula, we recover already known results. We study in detail the case of one-dimensional propagation with gaussian wavepackets both in the relativistic and in the non-relativistic regions: in the last case, numerical evaluations of our result show significant deviations from the standard formula.Comment: 16 pages, 4 figures, RevTe

    Renormalization-Scale-Invariant PQCD Predictions for R_e+e- and the Bjorken Sum Rule at Next-to-Leading Order

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    We discuss application of the physical QCD effective charge αV\alpha_V, defined via the heavy-quark potential, in perturbative calculations at next-to-leading order. When coupled with the Brodsky-Lepage-Mackenzie prescription for fixing the renormalization scales, the resulting series are automatically and naturally scale and scheme independent, and represent unambiguous predictions of perturbative QCD. We consider in detail such commensurate scale relations for the e+e−e^+e^- annihilation ratio Re+e−R_{e^+e^-} and the Bjorken sum rule. In both cases the improved predictions are in excellent agreement with experiment.Comment: 13 Latex pages with 5 figures; to be published in Physical Review

    Higgs Boson Mass in Low Scale Gauge Mediation Models

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    We consider low scale gauge mediation models with a very light gravitino m_{3/2}~16 eV, in the light of recent experimental hints on the Higgs boson mass. The light gravitino is very interesting since there is no gravitino over-production problem, but it seems difficult to explain the Higgs boson mass of ~125 GeV. This is because of the conflict between the light gravitino mass and heavy SUSY particle masses needed for producing the relatively heavy Higgs boson mass. We consider two possible extensions in this paper: a singlet extension of the Higgs sector, and strongly coupled gauge mediation. We show that there is a large parameter space, in both scenarios, where the Higgs boson mass of ~125 GeV is explained without any conflict with such a very light gravitino.Comment: 23 pages, 5 figure

    Yukawa Unification and the Superpartner Mass Scale

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    Naturalness in supersymmetry (SUSY) is under siege by increasingly stringent LHC constraints, but natural electroweak symmetry breaking still remains the most powerful motivation for superpartner masses within experimental reach. If naturalness is the wrong criterion then what determines the mass scale of the superpartners? We motivate supersymmetry by (1) gauge coupling unification, (2) dark matter, and (3) precision b-tau Yukawa unification. We show that for an LSP that is a bino-Higgsino admixture, these three requirements lead to an upper-bound on the stop and sbottom masses in the several TeV regime because the threshold correction to the bottom mass at the superpartner scale is required to have a particular size. For tan beta about 50, which is needed for t-b-tau unification, the stops must be lighter than 2.8 TeV when A_t has the opposite sign of the gluino mass, as is favored by renormalization group scaling. For lower values of tan beta, the top and bottom squarks must be even lighter. Yukawa unification plus dark matter implies that superpartners are likely in reach of the LHC, after the upgrade to 14 (or 13) TeV, independent of any considerations of naturalness. We present a model-independent, bottom-up analysis of the SUSY parameter space that is simultaneously consistent with Yukawa unification and the hint for m_h = 125 GeV. We study the flavor and dark matter phenomenology that accompanies this Yukawa unification. A large portion of the parameter space predicts that the branching fraction for B_s to mu^+ mu^- will be observed to be significantly lower than the SM value.Comment: 34 pages plus appendices, 20 figure

    Electroweak pinch technique to all orders

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    The generalization of the pinch technique to all orders in the electroweak sector of the Standard Model within the class of the renormalizable 't Hooft gauges, is presented. In particular, both the all-order PT gauge-boson-- and scalar--fermions vertices, as well as the diagonal and mixed gauge-boson and scalar self-energies are explicitly constructed. This is achieved through the generalization to the Standard Model of the procedure recently applied to the QCD case, which consist of two steps: (i) the identification of special Green's functions, which serve as a common kernel to all self-energy and vertex diagrams, and (ii) the study of the (on-shell) Slavnov-Taylor identities they satisfy. It is then shown that the ghost, scalar and scalar--gauge-boson Green's functions appearing in these identities capture precisely the result of the pinching action at arbitrary order. It turns out that the aforementioned Green's functions play a crucial role, their net effect being the non-trivial modification of the ghost, scalar and scalar--gauge-boson diagrams of the gauge-boson-- or scalar--fermions vertex we have started from, in such a way as to dynamically generate the characteristic ghost and scalar sector of the background field method. The pinch technique gauge-boson and scalar self-energies are also explicitly constructed by resorting to the method of the background-quantum identities.Comment: 48 pages, 8 figures; v2: typos correcte

    Can we distinguish between h^{SM} and h^0 in split supersymmetry?

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    We investigate the possibility to distinguish between the Standard Model Higgs boson and the lightest Higgs boson in Split Supersymmetry. We point out that the best way to distinguish between these two Higgs bosons is through the decay into two photons. It is shown that there are large differences of several percent between the predictions for \Gamma(h\to\gamma\gamma) in the two models, making possible the discrimination at future photon-photon colliders. Once the charginos are discovered at the next generation of collider experiments, the well defined predictions for the Higgs decay into two photons will become a cross check to identify the light Higgs boson in Split Supersymmetry.Comment: 8 pages, 3 Figures, typos fixed, version published in J.Phys. G31 (2005) 563-56
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