Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userAn initial study of mesons and baryons containing strange quarks with GlueX
85
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The primary motivation of the GlueX experiment is to search for and ultimately study the pattern of gluonic excitations in the meson spectrum produced in $gamma p$ collisions. Recent lattice QCD calculations predict a rich spectrum of hybrid mesons that have both exotic and non-exotic $J^{PC}$, corresponding to $qbar{q}$ states ($q=u,$ $d,$ or $s$) coupled with a gluonic field. A thorough study of the hybrid spectrum, including the identification of the isovector triplet, with charges 0 and $pm1$, and both isoscalar members, $|sbar{s} >$ and $|ubar{u} > + |dbar{d} >$, for each predicted hybrid combination of $J^{PC}$, may only be achieved by conducting a systematic amplitude analysis of many different hadronic final states. Detailed studies of the performance of the gx detector have indicated that identification of particular final states with kaons is possible using the baseline detector configuration. The efficiency of kaon detection coupled with the relatively lower production cross section for particles containing hidden strangeness will require a high intensity run in order for analyses of such states to be feasible. We propose to collect a total of 200 days of physics analysis data at an average intensity of $5times 10^7$ tagged photons on target per second. This data sample will provide an order of magnitude statistical improvement over the initial GlueX running, which will allow us to begin a program of studying mesons and baryons containing strange quarks. In addition, the increased intensity will permit us to study reactions that may have been statistically limited in the initial phases of GlueX. Overall, this will lead to a significant increase in the potential for gx to make key experimental advances in our knowledge of hybrid mesons and excited $Xi$ baryons.
rate research
Read More
We report the observation of two resonance-like structures in the $pi^+ chi_{c1}$ invariant mass distribution near 4.1 GeV in exclusive $Bto Kpi^+chi_{c1}$ decays. A detailed Dalitz-plot analysis demonstrates that these structures cannot be produced by reflections from any known and possibly unknown resonances in the $Kpi$ channel. If these two peaks are produced by resonances in the $pi^+chi_{c1}$ channel, their minimal quark structure would have to be a $cbar{c}ubar{d}$ tetraquark arrangement, similar to that proposed for the $Z^+(4430)$ structure reported by Belle last year in the $pi^+psi^{}$ mass distribution produced in $Bto Kpi^+psi^{}$ decays. In addition, we report some new measurements on the properties of the X(3872) meson and the $1^{--}$ $Y$ states that are produced with initial state radiation. %and also other latest XYZ results. The analyses are based on a large data sample recorded at the $Upsilon(4S)$ resonances and nearby continuum with the Belle detector at the KEKB asymmetric-energy $e^+e^-$ collider.
From only two elementary quarks ($epsilon_{u}(0) $ and $epsilon_{d}(0)) $ and the symmetries of the regular rhombic dodecahedron, using phenomenological formulae, we deduced the rest masses and the intrinsic quantum numbers (I, S, C, b and Q) of a quark spectrum. The five ground quarks of the four kinds of the deduced quarks are the five quarks of the current quark model. Then, from the quark spectrum, using sum laws and a phenomenological binding energy formula, we deduced a baryon spectrum. Finally, using the sum laws and a phenomenological binding energy formula, we deduce a meson spectrum from the quark spectrum. The intrinsic quantum numbers (I, S, C, b and Q) of the deduced baryons and the deduced mesons are the same as those of the experimental results. The rest masses of the deduced baryons and the deduced mesons are consistent with the experimental results (98%). Most of the deduced quarks in Table 11 have already been discovered by experiments. This paper infers that there are huge constant binding energies for baryons and mesons respectively. The huge binding energies provide a possible foundation for the confinement of the quarks. This paper predicts many new baryons $Lambda_{c}^{+}(6599) $, $Lambda {b}^{0}(9959) $ and $Lambda ^{0}(3369) $, ...) and new mesons (D(6231), B(9503) and $Upsilon (17868) $, ...)
We report results of a study of doubly charmed baryons and charmed strange baryons. The analysis is performed using a 980 fb^-1 data sample collected with the Belle detector at the KEKB asymmetric-energy e^+e^- collider. We search for doubly charmed baryons Xi_cc^+(+) with the Lambda_c^+K^-pi^+(pi^+) and Xi_c^0pi^+(pi^+) final states. No significant signal is observed. We also search for two excited charmed strange baryons, Xi_c(3055)^+ and Xi_c(3123)^+ with the Sigma_c^++(2455)K^- and Sigma_c^++(2520)K^- final states. The Xi_c(3055)^+ signal is observed with a significance of 6.6 standard deviations including systematic uncertainty, while no signature of the Xi_c(3123)^+ is seen. We also study properties of the Xi_c(2645)^+ and measure a width of 2.6 +- 0.2 (stat) +- 0.4 (syst) MeV/c^2, which is the first significant determination.
After some short introductory remarks on particular issues on the vector mesons in nuclei, in this paper we present a short review of recent developments concerning the interaction of vector mesons with baryons and with nuclei from a modern perspective using the local hidden gauge formalism for the interaction of vector mesons. We present results for the vector baryon interaction and in particular for the resonances which appear as composite states, dynamically generated from the interaction of vector mesons with baryons, taking also the mixing of these states with pseudoscalars and baryons into account. We then venture into the charm sector, reporting on hidden charm baryon states around 4400 MeV, generated from the interaction of vector mesons and baryons with charm, which have a strong repercussion on the properties of the $J/Psi N$ interaction. We also address the interaction of $K^*$ with nuclei and make suggestions to measure the predicted huge width in the medium by means of the transparency ratio. The formalism is extended to study the phenomenon of $J/psi$ suppression in nuclei via $J/psi$ photoproduction reactions.
We propose to create a secondary beam of neutral kaons in Hall D at Jefferson Lab to be used with the GlueX experimental setup for strange hadron spectroscopy. A flux on the order of 3 x 10^4 KL/s will allow a broad range of measurements to be made by improving the statistics of previous data obtained on hydrogen targets by three orders of magnitude. Use of a deuteron target will provide first measurements on the neutron which is {it terra incognita}. The experiment will measure both differential cross sections and self-analyzed polarizations of the produced {Lambda}, {Sigma}, {Xi}, and {Omega} hyperons using the GlueX detector at the Jefferson Lab Hall D. The measurements will span c.m. cos{theta} from -0.95 to 0.95 in the c.m. range above W = 1490 MeV and up to 3500 MeV. These new GlueX data will greatly constrain partial-wave analyses and reduce model-dependent uncertainties in the extraction of strange resonance properties (including pole positions), and provide a new benchmark for comparisons with QCD-inspired models and lattice QCD calculations. The proposed facility will also have an impact in the strange meson sector by providing measurements of the final-state K{pi} system from threshold up to 2 GeV invariant mass to establish and improve on the pole positions and widths of all K*(K{pi}) P-wave states as well as for the S-wave scalar meson {kappa}(800).
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
