Energy-dependent Partial-wave Analysis Research Articles

The reaction K −p → ωΛ in the c.m. energy range 1915–2168 MeV

A bubble chamber study has been made of the reaction K −p → ωΛ at 13 momenta in the c.m. energy range 1915 to 2168 MeV. Differential cross sections are presented together with Legendre polynomial expansions of these and of the single and joint density matrices. An energy dependent partial wave analysis is carried out yielding evidence for resonance formation. The G 07Λ(2100) is found to have a small ωΛ branching ratio.

K o°D ++(1236) production in K +p scattering between 0.9 and 1.5 GeV/ c

This paper presents data on the quasi two-body reaction K +p → K o Δ ++(1236) → K o p π + in the momentum range 0.9 to 1.5 GeV/ c. The data has been used in an energy-dependent partial wave analysis of the above reaction. The solutions obtained in this analysis do not require the formation of an exotic resonance (Z 1 ∗) in the s-channel.

An improved partial wave analysis of [formula omitted] from 800 to 1200 MeV/ c

An extensive search for resonant states has been performed through an energy dependent partial wave analysis of K N data in the momentum region 777 – 1226 MeV/ c. The K −p → K −p, K On differential cross sections, polarization angular distributions and total K −p cross sections were included in the fit. In addition to the well established hyperons, evidence is reported for a resonant state Σ(1760) of J P= 1 2 − and for the assignment J P= 3 2 + for a Λ(1870) state previously assigned to J P= 7 2 + . From the K −p differential and total cross sections between 436 and 1226 MeV/ c the ratio of the real to the imaginary part of the forward scattering amplitude has been derived as a function of K − incident momentum. These results are found to be consistent with the predictions of several dispersion relation calculations.

K −p elastic and charge-exchange scattering in the c.m. energy range 1915–2168 MeV

Total and differential cross sections are presented for the reactions K −p → K −p and K − p → K o n at 13 points in the c.m. energy range 1915–2168 MeV. An energy-dependent partial-wave analysis is carried out on these data together with the polarisation measurements of Daum et al. [1] and the total cross section measurements [2] within this energy range. The well known Σ(1915), Σ(2030) and Λ(2100) are observed and their resonance parameters measured. Structure is also found in the D 05 and F 07 waves. An SU(3) analysis of the 5 2 + octet, 7 2 + decuplet and 7 2 − singlet gives generally good agreement between theory and experiment except that the elasticity of the Σ(1915) is experimentally rather larger than predicted.

New experimental results on the reactions [formula omitted] and a partial-wave analysis between 430 and 800 MeV/c

The reactions K − p → K − p, K 0 n and K − p → Σ +π −, Σ 0π 0, Σ −π + have been studied in the c.m. energy range 1530 – 1700 MeV; new experimental data are presented and results of an energy-dependent partial-wave analysis are discussed.

Energy-dependent partial-wave analysis of the π−p → K0Λ reaction up to 1.5 GeV/c

Energy-dependent partial-wave analysis of the π−p → K0Λ reaction up to 1.5 GeV/c

Polarization ofΣ−in the Reactionπ−+p→Σ−+K+at 1130MeVc

We have measured the polarization ${P}_{{\ensuremath{\Sigma}}^{\ensuremath{-}}}$ of the ${\ensuremath{\Sigma}}^{\ensuremath{-}}$ in the production reaction ${\ensuremath{\pi}}^{\ensuremath{-}}+p\ensuremath{\rightarrow}{\ensuremath{\Sigma}}^{\ensuremath{-}}+{K}^{+}$ due to a ${\ensuremath{\pi}}^{\ensuremath{-}}$ beam of momentum 1130 $\frac{\mathrm{MeV}}{c}$ striking a polarized proton target. We find ${P}_{{\ensuremath{\Sigma}}^{\ensuremath{-}}}$ to lie between -0.1 and -0.5 in each of seven angular bins in the range $\ensuremath{-}1.0lcos{{\ensuremath{\theta}}_{\ensuremath{\Sigma}}}^{*}l0.3$. Combining this and other measurements, we have performed an energy-dependent partial-wave analysis of the associated production reactions $\ensuremath{\pi}p\ensuremath{\rightarrow}\ensuremath{\Sigma}K$ between threshold and 1170 $\frac{\mathrm{MeV}}{c}$, using only $S$ and $P$ waves below 1130 $\frac{\mathrm{MeV}}{c}$ but including $D$ waves at higher momenta. Using a momentum-dependent form for the amplitudes first proposed by Lee et al., we find the $I=\frac{3}{2}$ amplitudes to be uniquely determined over the whole energy range, but the $I=\frac{1}{2}$ amplitudes to have several solutions of similar, but low, likelihood. Thus, this particular parametrization does not appear to hold for the $I=\frac{1}{2}$ channels near threshold. A possible reason is the presence of a highly inelastic ${P}_{11}$ resonance in the direct channel.