Studying Kaon-pion S-wave scattering in K-matrix formalism

We generalize our previous work on \pi\pi scattering to K\pi scattering, and re-analyze the experiment data of K\pi scattering below 1.6 GeV. Without any free parameter, we explain K\pi I=3/2 S-wave phase shift very well by using t-channel rho and u-channel K^* meson exchange. With the t-channel and u-channel meson exchange fixed as the background term, we fit the K\pi I=1/2 S-wave data of the LASS experiment quite well by introducing one or two s-channel resonances. It is found that there is only one s-channel resonance between K\pi threshold and 1.6 GeV, i.e., K_0^*(1430) with a mass around 1438~1486 MeV and a width about 346 MeV, while the t-channel rho exchange gives a pole at (450-480i) MeV for the amplitude.Comment: REVTeX4 file, 11 pages and 3 figure

Measuring the Relative Strong Phase in D0→K∗+K−D^0 \to K^{*+} K^- and D0→K∗−K+D^0 \to K^{*-} K^+ Decays

In a recently suggested method for measuring the weak phase $\gamma$ in $B^\pm \to K^\pm (KK^*)_D$ decays, the relative strong phase $\delta_D$ in $D^0 \to K^{*+} K^-$ and $D^0 \to K^{*-} K^+$ decays (equivalently, in $D^0 \to K^{*+} K^-$ and \od \to K^{*+} K^-) plays a role. It is shown how a study of the Dalitz plot in $D^0 \to K^+ K^- \pi^0$ can yield information on this phase, and the size of the data sample which would give a useful measurement is estimated.Comment: 13 pages, latex, 5 figures, submitted to Phys. Rev. D. Appendix and some text on additional resonant contributions adde

The K^*_0(800) scalar resonance from Roy-Steiner representations of pi K scattering

We discuss the existence of the light scalar meson K^*_0(800) (also called kappa) in a rigorous way, by showing the presence of a pole in the pi K --> pi K amplitude on the second Riemann sheet. For this purpose, we study the domain of validity of two classes of Roy-Steiner representations in the complex energy plane. We prove that one of them is valid in a region sufficiently broad in the imaginary direction. From this representation, we compute the l=0 partial wave in the complex plane with neither additional approximation nor model dependence, relying only on experimental data. A scalar resonance with strangeness S=1 is found with the following mass and width: E_kappa = 658 \pm 13 MeV and Gamma_kappa = 557 \pm 24 MeV.Comment: 16 pages, 8 figures. Domain of validity of a Roy-Steiner representation corrected and enlarged, and features of the K^*_0(800) pole discussed in more details. Conclusions unchange

Corrosion Inhibitors for Sour Oilfield Environment (H2S Corrosion)

Lower-grade steel materials are the most commonly used construction materials for oil and gas wells due to their low cost and high performance. However, they are susceptible to corrosion when they come in contact with corrosive environments that are highly acidic. In oil wells, particularly deep oil wells, hydrogen sulfide (H2S) is commonly found. The dissolution of H2S gas in produced water makes the fluid corrosive. The use of corrosion inhibitors is perhaps the most practical and costeffective means of controlling corrosion of low carbon steels in the sour environment. In this chapter, typical corrosion inhibitors used in oil and gas fields to control the internal corrosion of oilfield equipment caused by H2S are being examined. The inhibitors found to be effective are polar functional compounds, with many being based on nitrogen-containing compounds, such as amines, imidazolines, and quaternary ammonium salts. Drawbacks of these compounds in practical applications and potentials of future developments are discussed

There is no /κ(900)

In the I=0 sector there are more scalar mesons than can fit in one nonet. Consequently, many have claimed that there is in fact more than one multiplet, perhaps both and . Such proposals require the existence of at least two strange isodoublets (and their antiparticles). The current PDG tables list just one state, the K*0(1430), while fits to data with Breit–Wigner forms and variable backgrounds can accommodate a κ(900), too. Whether a state exists in the spectrum of hadrons is not a matter of ability to fit data along the real energy axis, but is completely specified by the number of poles in the complex energy plane. Here we perform as model-independent an analytic continuation of the LASS πK scattering results between 825 MeV and 2 GeV as presently possible to determine the number and position of resonance poles. We find that there is a K*0(1430), but no κ(900). The LASS data cannot rule out the possibility of a very low mass κ well below 825 MeV