395 research outputs found
Scalar kappa meson in K* photoproduction
We propose that the scalar meson may play an important role in
photoproduction. In the reactions of and
, we consider the production mechanisms including
-channel , , exchanges, s-channel , diagrams,
and -channel , , diagrams within the tree level
approximation, and find that the -meson exchange may contribute
significantly to photoproduction, while it is rather supplementary
in photoproduction. We demonstrate how the observables of
photoproduction can be used to constrain the meson properties. In
particular, the parity asymmetry can separate the meson contribution
in photoproduction.Comment: 9 pages, 4 figures, REVTe
Flavor structure of pentaquark baryons in quark model
The flavor SU(3) group structure of pentaquark baryons which form ,
, , , , and multiplets is
investigated in quark model. The flavor wave functions of all the pentaquark
baryons are constructed in SU(3) quark model and their Yukawa interactions with
meson octet are obtained in general and in the special case of the
octet-antidecuplet ideal mixing with the OZI rule. The mass sum rules of
pentaquark baryons are also discussed.Comment: 8 pages, talk presented at International Workshop PENTAQUARK04 at
SPring-8, Japan, July 20-23, 200
Reducing Message Collisions in Sensing-based Semi-Persistent Scheduling (SPS) by Using Reselection Lookaheads in Cellular V2X
In the C-V2X sidelink Mode 4 communication, the sensing-based semi-persistent
scheduling (SPS) implements a message collision avoidance algorithm to cope
with the undesirable effects of wireless channel congestion. Still, the current
standard mechanism produces high number of packet collisions, which may hinder
the high-reliability communications required in future C-V2X applications such
as autonomous driving. In this paper, we show that by drastically reducing the
uncertainties in the choice of the resource to use for SPS, we can
significantly reduce the message collisions in the C-V2X sidelink Mode 4.
Specifically, we propose the use of the "lookahead," which contains the next
starting resource location in the time-frequency plane. By exchanging the
lookahead information piggybacked on the periodic safety message, vehicular
user equipments (UEs) can eliminate most message collisions arising from the
ignorance of other UEs' internal decisions. Although the proposed scheme would
require the inclusion of the lookahead in the control part of the packet, the
benefit may outweigh the bandwidth cost, considering the stringent reliability
requirement in future C-V2X applications.Comment: Submitted to MDPI Sensor
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