We present measurements of the differential cross section and Lambda recoil polarization for the gamma p to K+ Lambda reaction made using the CLAS detector at Jefferson Lab. These measurements cover the center-of-mass energy range from 1.62 to 2.84 GeV and a wide range of center-of-mass K+ production angles. Independent analyses were performed using the K+ p pi- and K+ p (missing pi -) final-state topologies/ results from these analyses were found to exhibit good agreement. These differential cross section measurements show excellent agreement with previous CLAS and LEPS results and offer increased precision and a 300 MeV increase in energy coverage. The recoil polarization data agree well with previous results and offer a large increase in precision and a 500 MeV extension in energy range. The increased center-of-mass energy range that these data represent will allow for independent study of non-resonant K+ Lambda photoproduction mechanisms at all production angles.
Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.62-1.63 GeV.
Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.63-1.64 GeV.
Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.64-1.65 GeV.
The reaction gamma p --> K0 Sigma+ was measured in the photon energy range from threshold up to 2.6 GeV with the SAPHIR detector at the electron stretcher facility, ELSA, in Bonn. Results are presented on the reaction cross section and the polarization of the Sigma+ as a function of the kaon production angle in the centre-of-mass system, cos(Theta_K^{c.m.}), and the photon energy. The cross section is lower and varies less with photon energy and kaon production angle than that of gamma p --> K+ Sigma0. The Sigma+ is polarized predominantly at cos(Theta_K^{c.m.}) \approx 0. The data presented here are more precise than previous ones obtained with SAPHIR and extend the photon energy range to higher values. They are compared to isobar model calculations.
Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).
Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).
Axis error includes +- 10/10 contribution (Normalization uncertainty already included.).
The reactions gamma p --> K+ Lambda and gamma p --> K+ Sigma0 were measured in the energy range from threshold up to a photon energy of 2.6 GeV. The data were taken with the SAPHIR detector at the electron stretcher facility, ELSA. Results on cross sections and hyperon polarizations are presented as a function of kaon production angle and photon energy. The total cross section for Lambda production rises steeply with energy close to threshold, whereas the Sigma0 cross section rises slowly to a maximum at about E_gamma = 1.45 GeV. Cross sections together with their angular decompositions into Legendre polynomials suggest contributions from resonance production for both reactions. In general, the induced polarization of Lambda has negative values in the kaon forward direction and positive values in the backward direction. The magnitude varies with energy. The polarization of Sigma0 follows a similar angular and energy dependence as that of Lambda, but with opposite sign.
Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 0.9 to 1.0 GeV.
Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 1.0 to 1.2 GeV.
Differential cross sections for the reaction GAMMA P --> K+ LAMBDA in the energy region 1.2 to 1.4 GeV.
The\(e^ +e^ -\to K_s^0 K^ \pm\pi ^ \mp\) andK+K−π0 cross sections have been measured in the energy interval\(1350 \leqq \sqrt s\leqq 2400\) with the DM2 detector at DCI. The\(K_s^0 K^ \pm\pi ^ \mp\) cross section shows the contribution of an isoscalar vector meson at ≈1650 MeV/c2 in agreement with a previous experiment. The low statisticsK+K−π0 measurement is consistent with the above result.
The K0S K+- PI-+ cross section.
The K+ K- PI0 cross section.
Thee+e−→K+K− cross section has been measured from about 750 events in the energy interval\(1350 \leqq \sqrt s\leqq 2400 MeV\) with the DM2 detector at DCI. TheK± form factor |FF±| cannot be explained by the ρ, ω, ϕ and ρ′(1600). An additional resonant amplitude at 1650 MeV has to be added as suggested by a previous experiment.
No description provided.
No description provided.
None
ASSUMING ABS(GE)=ABS(GM).
No description provided.
No description provided.
The reactions e + e − → ρη , ρπ , φπ and φη have been studied with the magnetic detector DM1 at DCI in the total energy ranges between 1.4 and 2.18 GeV. The ρη signal is clearly seen. Upper limits for ρπ and φη channels as well as for the OZI forbidden φπ channel.
No description provided.
UPPER LIMIT TO SIG AS EXPLAINED IN SYSTEMATICS.
UPPER LIMIT TO CROSS SECTION AT CL=90 PCT.
The final state K − pn has been analyzed in a K − deuterium bubble chamber experiment at K − momenta between 680 and 840 MeV/ c . Differential cross sections for elastic K − p and K − n scattering in the c.m. energy range of 1.60–1.74 GeV are presented. The results for K − p→K − p agree well with existing data obtained with hydrogen targets. The results for K − n→K − n are lower but still compatible with recent measurements from a counter experiment.
No description provided.
No description provided.
PLAB IS THE EFFECTIVE KAON LAB MOMENTA CORRESPONDING TO THE GIVEN CM ENERGY ASSUMING AN ON-SHELL TARGET NUCLEON AT REST.
First measurements of the e + e − → K S 0 K ± π ∓ reaction in the 1.4–2.18 GeV energy range have been performed with the magnetic detector DM1 at the Orsay storage rings DCI. The cross section is rather large. The production is mainly K ∗0 K 0 which reveals an interference between isovector and isoscalar amplitudes. These results show again the existence of an isoscalar vector at 1.65 GeV shown to be a φ ′ meson.
No description provided.
First measurements of the e + e − → π + π − K + K − cross section have been performed by the DM1 on DCI in the total energy range 1.4–2.18 GeV. π + π − K + K − production is dominated by K ∗ Kπ dynamics. The cross section is rather large around 1.9 GeV. Comparison with K 0 S inclusive production shows an isospin interference. Upper limits on φππ production are compatible with the OZI rule.
No description provided.
UPPER LIMITS TO PHI CROSS SECTIONS WITH CL=90 PCT.
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