43 research outputs found

    Spin alignment of K(892)±K^*(892)^\pm mesons produced in neutron-carbon interactions

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    A new precise measurements of spin density matrix element ρ00\rho_{00} of K(892)±K^*(892)^{\pm} mesons produced inclusively in neutron-carbon interactions at \~60 GeV have been carried out in the EXCHARM experiment at the Serpukhov accelerator. The values of ρ00\rho_{00} obtained in the transversity frame are 0.424±0.011(stat)±0.018(sys)0.424\pm0.011(stat)\pm0.018(sys) for K(892)+K^*(892)^+ and 0.393±0.025(stat)±0.018(sys)0.393\pm0.025(stat)\pm0.018(sys) for K(892)K^*(892)^-. Significant PTP_T dependence of ρ00\rho_{00} has been observed in K(892)+K^*(892)^+ production.Comment: 8 pages, LaTeX, 3 eps figure

    Spontaneous Lorentz Violation via QED with Non-Exact Gauge Invariance

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    We reconsider an alternative theory of the QED with the photon as a massless vector Nambu-Goldstone boson and show that the underlying spontaneous Lorentz violation caused by the vector field vacuum expectation value, while being superficial in gauge invariant theory, becomes physically significant in the QED with a tiny gauge non-invariance. This leads, through special dispersion relations appearing for charged fermions, to a new class of phenomena which could be of distinctive observational interest in particle physics and astrophysics. They include a significant change in the GZK cutoff for UHE cosmic-ray nucleons, stability of high-energy pions and W bosons, modification of nucleon beta decays, and some others.Comment: 15 pages, to appear in Eur.Phys.J.
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