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Differential cross sections and recoil polarizations for the reaction gamma p -> K+ Sigma0

The CLAS collaboration Dey, B. ; Meyer, C.A. ; Bellis, M. ; et al.

Phys.Rev.C 82 (2010) 025202, 2010.

Inspire Record 857728 DOI 10.17182/hepdata.55696

High-statistics measurements of differential cross sections and recoil polarizations for the reaction $\gamma p \rightarrow K^+ \Sigma^0$ have been obtained using the CLAS detector at Jefferson Lab. We cover center-of-mass energies ($\sqrt{s}$) from 1.69 to 2.84 GeV, with an extensive coverage in the $K^+$ production angle. Independent measurements were made using the $K^{+}p\pi^{-}$($\gamma$) and $K^{+}p$($\pi^-, \gamma$) final-state topologies, and were found to exhibit good agreement. Our differential cross sections show good agreement with earlier CLAS, SAPHIR and LEPS results, while offering better statistical precision and a 300-MeV increase in $\sqrt{s}$ coverage. Above $\sqrt{s} \approx 2.5$ GeV, $t$- and $u$-channel Regge scaling behavior can be seen at forward- and backward-angles, respectively. Our recoil polarization ($P_\Sigma$) measurements represent a substantial increase in kinematic coverage and enhanced precision over previous world data. At forward angles we find that $P_\Sigma$ is of the same magnitude but opposite sign as $P_\Lambda$, in agreement with the static SU(6) quark model prediction of $P_\Sigma \approx -P_\Lambda$. This expectation is violated in some mid- and backward-angle kinematic regimes, where $P_\Sigma$ and $P_\Lambda$ are of similar magnitudes but also have the same signs. In conjunction with several other meson photoproduction results recently published by CLAS, the present data will help constrain the partial wave analyses being performed to search for missing baryon resonances.

149 data tables

Table 1

Differential cross section as a function of COS(THETA(K+,CM)) for the centre-of mass range 1.69 to 1.7 GeV.

Table 2

Differential cross section as a function of COS(THETA(K+,CM)) for the centre-of mass range 1.7 to 1.71 GeV.

Table 3

Differential cross section as a function of COS(THETA(K+,CM)) for the centre-of mass range 1.71 to 1.72 GeV.

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Differential cross section and recoil polarization measurements for the gamma p to K+ Lambda reaction using CLAS at Jefferson Lab

The CLAS collaboration McCracken, M.E. ; Bellis, M. ; Meyer, C.A. ; et al.

Phys.Rev.C 81 (2010) 025201, 2010.

Inspire Record 840934 DOI 10.17182/hepdata.54967

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.

241 data tables

Table 1

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.62-1.63 GeV.

Table 2

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.63-1.64 GeV.

Table 3

Differential cross section as a function of COS(THETA(K)) for the centre-of-mass range 1.64-1.65 GeV.

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Polarization of cumulative protons in the reaction gamma A --> p X.

Avakyan, R.O. ; Avakian, E.O. ; Avdalyan, G.A. ; et al.

Sov.J.Nucl.Phys. 51 (1990) 999-1000, 1990.

Inspire Record 306076 DOI 10.17182/hepdata.17310

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

MEASUREMENT OF THE POLARIZATION OF CUMULATIVE PROTONS IN gamma A ---> p X REACTION

Avakian, R.O. ; Avakian, E.O. ; Avetisian, A.E. ; et al.

Yad.Fiz. 42 (1985) 667-670, 1985.

Inspire Record 210380 DOI 10.17182/hepdata.17606

None

1 data table

Table 1

Axis error includes +- 7/7 contribution.

MEASUREMENT OF ASYMMETRY IN CROSS-SECTION OF GAMMA P ---> P PI0 REACTION IN THE RESONANCE REGION. (IN RUSSIAN)

Avakian, R.O. ; Avetisian, A.E. ; Bagdasaryan, A.S. ; et al.

Yad.Fiz. 38 (1983) 1196-1198, 1983.

Inspire Record 200187 DOI 10.17182/hepdata.17731

None

1 data table

Table 1

Axis error includes +- 0.0/0.0 contribution (?////DUE TO ERRORS IN PHOTON POLARIZATION).

MEASUREMENT OF THE ASYMMETRY OF THE REACTION gamma p ---> p pi0 CROSS-SECTION FOR PION PRODUCTION ANGLES IN CMS 65-degrees TO 80-degrees IN THE RESONANCE ENERGY RANGE

Avakian, R.O. ; Bagdasaryan, A.S. ; Vartapetian, G.A. ; et al.

Sov. J. Contemp. Phys. 19 ( 1984) No. 1 46-48. ( Izv. Akad. Nauk Arm. SSR 19 ( 1984) No. 1 50-53) and Erevan Phys. Inst. - EFI-674(64)-83 (83,REC.JAN.84) 13p, 1983.

Inspire Record 195991 DOI 10.17182/hepdata.18465

None

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.