Dynamically generated hadronic states in the KˉN\bar{K}N and ηN\eta N coupled-channels interactions

We compare and review the theoretical predictions for the $\bar{K}N$ and $\eta N$ elastic amplitudes where sizable variations are found among the considered approaches, especially at subthreshold energies relevant for studies of kaonic atoms and meson-nuclear quasi-bound states. Conditions for an appearance of dynamically generated states in meson-baryon multi-channel interactions are established and discussed for the $\bar{K}N$ and $\eta N$ systems.Comment: 7 pages, 5 figures, proceedings of the EXA2017 conference, Vienna, Austria, September 11-15, 2017, published versio

Theoretical approaches to low energy KˉN\bar{K}N interactions

We provide a direct comparison of modern theoretical approaches based on the SU(3) chiral dynamics and describing the low energy $\bar{K}N$ data. The model predictions for the $\bar{K}N$ amplitudes and pole content of the models are discussed.Comment: 4 pages, to appear in Proceedings of the MESON2016 - the 14th International Workshop on Meson Production, Properties and Interaction, June 2-4, 2016, Krakow, Polan

SIDDHARTA impact on KˉN\bar{K}N amplitudes used in in-medium applications

We have performed new fits of our chirally motivated coupled--channels model for meson-baryon interactions and discussed the impact of the SIDDHARTA measurement on the $\bar{K}N$ amplitudes in the free space and in nuclear medium. The kaon--nucleon amplitudes generated by the model are fully consistent with our earlier studies that used the older kaonic hydrogen data by the DEAR collaboration. The subthreshold energy dependence of the in-medium $\bar{K}N$ amplitudes plays a crucial role in $\bar{K}$--nuclear applications.Comment: 4 pages, published in Proceedings of the MESON 2012 conference, Cracow, Poland, May 31 - June 5, 201

Beam-spin asymmetry Σ\boldsymbol{\Sigma} for Σ−\Sigma^- hyperon photoproduction off the neutron

We report a new measurement of the beam-spin asymmetry $\boldsymbol{\Sigma}$ for the $\vec{\gamma} n \rightarrow K^+\Sigma^-$ reaction using quasi-free neutrons in a liquid-deuterium target. The new dataset includes data at previously unmeasured photon energy and angular ranges, thereby providing new constraints on partial wave analyses used to extract properties of the excited nucleon states. The experimental data were obtained using the CEBAF Large Acceptance Spectrometer (CLAS), housed in Hall B of the Thomas Jefferson National Accelerator Facility (JLab). The CLAS detector measured reaction products from a liquid-deuterium target produced by an energy-tagged, linearly polarised photon beam with energies in the range 1.1 to 2.3 GeV. Predictions from an isobar model indicate strong sensitivity to $N(1720)3/2^+$, $\Delta(1900)1/2^-$, and $N(1895)1/2^-$, with the latter being a state not considered in previous photoproduction analyses. When our data are incorporated in the fits of partial-wave analyses, one observes significant changes in $\gamma$-$n$ couplings of the resonances which have small branching ratios to the $\pi N$ channel.Comment: 9 pages, 4 figures, Hadron Spectroscop

Energy and density dependence of the KˉN\bar{K}N and ηN\eta N amplitudes near threshold

Chirally motivated model is used to describe meson-baryon interactions at low energies. After fixing free parameters to available experimental data on reactions in the free space the model is extrapolated to subthreshold energies and to nonzero nuclear densities. The impact of nuclear matter on the elastic $\bar{K}N$ and $\eta N$ amplitudes is discussed

Strange Hadron Spectroscopy with Secondary KL Beam in Hall D

Final version of the KLF Proposal [C12-19-001] approved by JLab PAC48. The intermediate version of the proposal was posted in arXiv:1707.05284 [hep-ex]. 103 pages, 52 figures, 8 tables, 324 references. Several typos were fixedWe 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. The superior CEBAF electron beam will enable a flux on the order of $1\times 10^4~K_L/sec$, which exceeds the flux of that previously attained at SLAC by three orders of magnitude. The use of a deuteron target will provide first measurements ever with neutral kaons on neutrons. 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 CM $\cos\theta$ from $-0.95$ to 0.95 in the range W = 1490 MeV to 2500 MeV. The new data will significantly constrain the partial wave analyses and reduce model-dependent uncertainties in the extraction of the properties and pole positions of the strange hyperon resonances, and establish the orbitally excited multiplets in the spectra of the $\Xi$ and $\Omega$ hyperons. Comparison with the corresponding multiplets in the spectra of the charm and bottom hyperons will provide insight into he accuracy of QCD-based calculations over a large range of masses. The proposed facility will have a defining impact in the strange meson sector through measurements of the final state $K\pi$ system up to 2 GeV invariant mass. This will allow the determination of pole positions and widths of all relevant $K^\ast(K\pi)$ $S$-,$P$-,$D$-,$F$-, and $G$-wave resonances, settle the question of the existence or nonexistence of scalar meson $\kappa/K_0^\ast(700)$ and improve the constrains on their pole parameters. Subsequently improving our knowledge of the low-lying scalar nonet in general