96 research outputs found

    Hadro-Production of Quarkonia in Fixed Target Experiments

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    In this talk I review the recent progress made in the calculations of quarkonia production in fixed target experiments. NRQCD organizes the calculations in a systematic expansion in αs\alpha_s and vv, the relative velocity between the heavy quarks. Within this formalism there are octet contributions which are not included in the color singlet model. These contributions depend upon unknown matrix elementsof local operators which are fit to the data. Using these fits, there are several predictions which do indeed improve agreement with the data. However, the prediction for the polarization of the produced states as well as the ratio of the χ1\chi_1 to χ2\chi_2 cross sections differ substantially from the data for the case of pion beams. Possible large corrections from higher twist effects are discussed as is the issue of the the proper choice of masses.Comment: 10 pages, 2 figures included. To appear in the Proceedings of the University of Illinois, Chicago, Quarkonium Workshop, June 13-15, 199

    Extracting V_{ub} Using the Radiative Decay Data

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    In this talk I review recent progress made in extracting V_{ub} from the cut electron energy and hadronic mass spectra of inclusive B meson decays utilizing the data from radiative decays. It is shown that an extraction is possible without modeling the B meson structure function. I discuss the issues involving the assumptions of local duality in various extractions. I also comment on the recent CLEO extraction of V_{ub}.Comment: Presented at 9th International Symposium on Heavy Flavor Physics, Pasadena, California, 10-13 Sep 2001. 7 page

    Symmetry Realization via a Dynamical Inverse Higgs Mechanism

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    The Ward identities associated with spontaneously broken symmetries can be saturated by Goldstone bosons. However, when space-time symmetries are broken, the number of Goldstone bosons necessary to non-linearly realize the symmetry can be less than the number of broken generators. The loss of Goldstones may be due to a redundancy or the generation of a gap. This phenomena is called an Inverse Higgs Mechanism (IHM). However, there are cases when a Goldstone boson associated with a broken generator does not appear in the low energy theory despite the lack of the existence of an associated IHM. In this paper we will show that in such cases the relevant broken symmetry can be realized, without the aid of an associated Goldstone, if there exists a proper set of operator constraints, which we call a Dynamical Inverse Higgs Mechanism (DIHM). We consider the spontaneous breaking of boosts, rotations and conformal transformations in the context of Fermi liquids, finding three possible paths to symmetry realization: pure Goldstones, no Goldstones and DIHM, or some mixture thereof. We show that in the two dimensional degenerate electron system the DIHM route is the only consistent way to realize spontaneously broken boosts and dilatations, while in three dimensions these symmetries could just as well be realized via the inclusion of non-derivatively coupled Goldstone bosons. We have present the action, including the leading order non-linearities, for the rotational Goldstone (angulon), and discuss the constraint associated with the possible DIHM that would need to be imposed to remove it from the spectrum. Finally we discuss the conditions under which Goldstone bosons are non-derivatively coupled, a necessary condition for the existence of a Dynamical Inverse Higgs Constraint (DIHC), generalizaing the results for Vishwanath and Wantanabe.Comment: Added a new result for the beta function for the UV theory of unitary fermion
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