96 research outputs found
Hadro-Production of Quarkonia in Fixed Target Experiments
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 and , 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 to
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
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
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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