7,787 research outputs found
Gluon fragmentation to ^3D_J quarkonia
We present a calculation of the leading order QCD fragmentation functions for
gluons to split into spin-triplet D-wave quarkonia. We apply them to evaluate
the gluon fragmentation contributions to inclusive ^3D_J quarkonium production
at large transverse momentum processes like the Tevatron and find that the
D-wave quarkonia, especially the charmonium 2^{--} state, could be observed
through color-octet mechanism with present luminosity. Since there are
distinctively large gaps between the contributions of two different (i.e,
color-singlet and color-octet) quarkonium production mechanisms, our results
may stand as a unique test to NRQCD color-octet quarkonium production
mechanism.Comment: 15 pages in LaTex (2 figures in PS-file
D-wave heavy quarkonium production in fixed target experiments
We calculate the -wave heavy quarkonium production at fixed target
experiments under the NRQCD factorization formalism. We find that the color
octet contributions are two orders of magnitude larger than color-singlet
contributions if color-octet matrix elements are taken according to the NRQCD
velocity scaling rules. Within the theoretical uncertainties, the prediction
for the production rate of -wave charmonium state agrees with the
preliminary result of E705 and other experiments. Searching for the
-wave state is further suggested.Comment: 13pages, 4 PS figures, final vertion to appear in PR
Spectrum of Curvature Perturbation of Multi-field Inflation with Small-Field Potential
In this paper, we have studied the spectrum of curvature perturbation of
multi-field inflation with general small-field potential. We assume that the
isocurvature perturbation may be neglected, and by using the Sasaki-Stewart
formalism, we found that the spectrum may be redder or bluer than of its
corresponding single field. The result depends upon the values of fields and
their effective masses at the horizon-crossing time. We discuss the relevant
cases.Comment: 8 pages, no figure, to publish in JCA
A Crucial Test for Color-Octet Production Mechanism in Z^0 Decays
The direct production rates of -wave charmonia in the decays of is
evaluated. The color-octet production processes are shown to have distinctively large branching ratios, the same order
of magnitude as that of prodution, as compared with other -wave
charmonium production mechanisms. This may suggest a crucial channel to test
the color-octet mechanism as well as to observe the -wave charmonium states
in decays. In addition, a signal for the charmonium as strong as
or with large transverse momentum at the Tevatron should
also be observed.Comment: 14 pages in LaTex (3 figures in PS-file
Large Possible retardation effects of quark confinement on the meson spectrum II
We present the results of a study of heavy-light-quark bound states in the
context of the reduced Bethe-Salpeter equation with relativistic vector and
scalar interactions. We find that satisfactory fits may also be obtained when
the retarded effect of the quark-antiquark interaction is concerned.Comment: 11 pages, RevTex, to appear in PR
Possible retardation effects of quark confinement on the meson spectrum
The reduced Bethe-Salpeter equation with scalar confinement and vector gluon
exchange is applied to quark-antiquark bound states. The so called intrinsic
flaw of Salpeter equation with static scalar confinement is investigated. The
notorious problem of narrow level spacings is found to be remedied by taking
into consideration the retardation effect of scalar confinement. Good fit for
the mass spectrum of both heavy and light quarkomium states is then obtained.Comment: 14 pages in LaTex for
The Parametric Symmetry and Numbers of the Entangled Class of 2 \times M \times N System
We present in the work two intriguing results in the entanglement
classification of pure and true tripartite entangled state of under stochastic local operation and classical communication. (i) the
internal symmetric properties of the nonlocal parameters in the continuous
entangled class; (ii) the analytic expression for the total numbers of the true
and pure entangled class states. These properties help
people to know more of the nature of the entangled system.Comment: 12 pages, 5 figure
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