Scalar kappa meson in K* photoproduction

We propose that the scalar $\kappa(800)$ meson may play an important role in $K^*$ photoproduction. In the reactions of $\gamma p \to K^{*+} \Lambda$ and $\gamma p \to K^{*0} \Sigma^+$, we consider the production mechanisms including $t$-channel $K^*$, $K$, $\kappa$ exchanges, s-channel $N$, $\Delta$ diagrams, and $u$-channel $\Lambda$, $\Sigma$, $\Sigma^*$ diagrams within the tree level approximation, and find that the $\kappa$-meson exchange may contribute significantly to $K^*\Sigma$ photoproduction, while it is rather supplementary in $K^*\Lambda$ photoproduction. We demonstrate how the observables of $K^*$ photoproduction can be used to constrain the $\kappa$ meson properties. In particular, the parity asymmetry can separate the $\kappa$ meson contribution in $K^*$ 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 $\bm{1}$, $\bm{8}$, $\bm{10}$, $\bar{\bm{10}}$, $\bm{27}$, and $\bm{35}$ 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