215 research outputs found

    Gluon Fragmentation into Spin-Triplet S-Wave Quarkonium

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    The leading color-singlet contribution to the fragmentation function for a gluon to split into spin-triplet S-wave quarkonium is presented. In the case of charmonium, we find that this color-singlet term is always negligible compared to the leading color-octet contribution.Comment: 7 Latex page

    Dark Matter Production Associated With a Heavy Quarkonium at B Factories

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    We investigate light dark matter production associated with a heavy quarkonium at B factories in a model-independent way by adopting the effective field theory approach for the interaction of dark matter with standard model particles. We consider the effective operators for the dark matter-heavy quark interaction, which are relevant to the production of dark matter associated with a heavy quarkonium. We calculate the cross sections for dark matter production associated with a J/psi or eta_c to compare with the standard model backgrounds. We set bounds on the energy scale of new physics for various effective operators and also obtain the corresponding limits for the dark matter-nucleon scattering cross sections for light dark matter with mass of the order of a few GeV.Comment: 13 pages, 5 figures, references adde

    Partially Strong WW Scattering

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    What if only a light Higgs boson is discovered at the CERN LHC? Conventional wisdom tells us that the scattering of longitudinal weak gauge bosons would not grow strong at high energies. We show that this is not always true. In some composite models, two-Higgs-doublet models, or even supersymmetric models, the presence of a light Higgs boson does not guarantee the complete unitarization of the WWWW scattering. After the partial unitarization by the light Higgs boson, the WWWW scattering becomes strongly interacting until it hits one or more heavier Higgs bosons or other strong dynamics. We analyze how the LHC experiments can reveal this interesting possibility of partially strong WWWW scattering.Comment: 4 pages, 3 figures; updated reference information and added a referenc

    Glueball Production via Gluonic Penguin B Decays

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    We study glueball GG production in gluonic penguin decay Bβ†’G+XsB\to G + X_s, using the next-to-leading order bβ†’sgβˆ—b\to s g^* gluonic penguin interaction and effective couplings of a glueball to two perturbative gluons. Subsequent decays of a scalar glueball are described by using techniques of effective chiral Lagrangian to incorporate the interaction between a glueball and pseudoscalar mesons. Mixing effects between the pure glueball with other mesons are considered. Identifying the f0(1710)f_0(1710) to be a scalar glueball, we find that both the top and charm penguin to be important and obtain a sizable branching ratio for Bβ†’f0(1710)+XsB\to f_0(1710) + X_s of order 1.3\times 10^{-4} (f/0.07\mbox{GeV}^{-1})^2, where the effective coupling strength ff is estimated to be 0.070.07 GeVβˆ’1^{-1} using experimental data for the branching ratio of f0(1710)β†’KKβ€Ύf_0(1710) \to K \overline K based on chiral Lagrangian estimate. An alternative perturbative QCD based estimation of ff is a factor of 20 larger, which would imply a much enhanced branching ratio. Glueball production from this rare semi-inclusive BB decay can be probed at the LHCb and Belle II to narrow down the allowed parameter space. Similar branching ratio is expected for the pseudoscalar glueball. We also briefly comment on the case of vector and tensor glueballs.Comment: Latex 14 pages with 2 figures. Significant update from the older version of arXiv:hep-ph/0612108. Version to appear in Eur. Phys. J.
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