K- p --> Lambda0 Or Sigma0 Vector Meson at 3.1-GeV/c-3.6-GeV/c

Lyons, L. ; Cooper-Sarkar, Amanda M. ; Clark, A.G. ;
Nucl.Phys.B 125 (1977) 207-242, 1977.
Inspire Record 125082 DOI 10.17182/hepdata.35373

We present data on the five final states Λω, Λφ, Λϱ 0 , Σ 0 ⊘ and Σ 0 ϱ 0 produced in 3.1–3.6 GeV/ c K − p interactions. These data are from a bubble chamber experiment with 18 events/μb. For all reactions the data consist of the overall and differetial cross sections, and the hyperon polarisation and the vector meson's density matrix elements as a function of momentum transfer. For Λω and Λ⊘, an almost complete amplitude analysis is performed in several regions of momentum transfer. The data are examined from the point of view of various exchange models.

15 data tables

CORRECTED FOR UNSEEN DECAY MODES OF LAMBDA, OMEGA AND PHI.

No description provided.

NO BACKWARD PHI PRODUCTION.

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A Measurement of the Polarization Parameter in Large Angle Proton Proton Elastic Scattering at 7.9-GeV/c

Aschman, D.G. ; Crabb, D.G. ; Green, K. ; et al.
Nucl.Phys.B 125 (1977) 349-368, 1977.
Inspire Record 125075 DOI 10.17182/hepdata.35322

The polarization parameter in proton-proton elastic scattering has been measured at an incident momentum of 7.9 GeV/ c and four-momentum transfers in the range 0.9 < | t | < 6.5 (GeV/ c ) 2 using a high intensity unpolarized proton beam incident on a polarized proton target. The angle and momentum of the forward scattered protons were measured with a magnet spectrometer and scintillation counter hodoscopes and the angle of the recoil proton was measured using similar hodoscopes. A clean separation between the elastic scattering from free hydrogen and that coming from inelastic interactions and from interactions with complex nuclei in the target was obtained. The polarization shows substantial structure rising from zero at | t | = 1.0 (GeV/ c ) 2 to a maximum at | t | = 1.7 (GeV/ c ) 2 and then falling to zero at | t | = 2.0 (GeV/ c ) 2 . There is evidence of a further peak at | t | = 2.8 (GeV/ c ) 2 . Above | t | = 3.25 (GeV/ c ) 2 the polarization is small and consistent with zero. A comparison of these data with data obtained at other beam momenta shows that the polarization parameter has a strong momentum dependence.

1 data table

No description provided.


Measurement of Differential Cross-Section and Polarization in the Backward Peak of the Reactions pi- p --> Lambda K0 and pi- p --> Lambda K* (890) at 8-GeV/c

Brundiers, H. ; Hartung, R. ; Runge, K. ; et al.
Nucl.Phys.B 119 (1977) 349-361, 1977.
Inspire Record 123952 DOI 10.17182/hepdata.35527

Differential cross sections and polarizations have been measured for the backward peaks in the reactions π − p →Λ K 0 and π − p →Λ K ∗ (890) at 8 GeV/c. The experiment was performed with a liquid hydrogen target at the ω spectrometer. The cross sections for u′>−2 ( GeV /c) 2 are 0.27 ± 0.03 μ b for π − p →Λ+ K 0 and 0.55±0.07 μ b for π − p →Λ K ∗0 . Large positive Λ polarization was observed in both reactions for u ′>−0.5 (GeV/ c ) 2 . The dominant production mechanism was found to be unnatural baryon exchange.

3 data tables

Axis error includes +- 0.0/0.0 contribution (?////).

Axis error includes +- 0.0/0.0 contribution (?////).

No description provided.


Study of the Reaction pi+ p --> K+ Sigma+ Between 1.721-GeV-1.954-GeV Center-Of-Mass Energy

Winik, M. ; Toaff, S. ; Revel, D. ; et al.
Nucl.Phys.B 128 (1977) 66-74, 1977.
Inspire Record 126060 DOI 10.17182/hepdata.35247

Cross-section, angular distribution and polarization measurements are presented at six incident π + energies for the reaction π + p → K + Σ + . Results at already studied energies are compatible with existing data and roughly agree with predictions of partial-waves analyses. However, new results around 1.920 GeV are in disagreement with such predictions, casting some doubt on the determination of decay branching ratios of the T = 3 2 isobars around this mass into K + Σ + .

8 data tables

No description provided.

No description provided.

No description provided.

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Measurement of the Polarization Parameter in 24-GeV/c Proton Proton Elastic Scattering at Small Momentum Transfers

Crabb, D.G. ; Green, K. ; Kyberd, P. ; et al.
Nucl.Phys.B 121 (1977) 231-236, 1977.
Inspire Record 124254 DOI 10.17182/hepdata.35517

A measurement of the polarization parameter P 0 in pp elastic scattering has been made at 24 GeV/ c over the range | t | = 0.1 to 0.9 (GeV/ c ) 2 , positive, falling to zero around | t | = 0.8 (GeV/ c ) 2 . For the range 0.1 ⪕ |t| ⪕ 0.4 GeV /c) 2 , P 0 is constant at about 0.03.

1 data table

Axis error includes +- 5/5 contribution (SYS-ERR DUE MAINLY TO UNCERTAINTY IN KNOWLEDGE OF ABSOLUTE VALUE OF TARGET POLARIZATION).


A Measurement of the Electromagnetic Size of the Pion from Direct Elastic Pion Scattering Data at 50-GeV/c

Adylov, G.T. ; Aliev, F.K. ; Bardin, D.Yu. ; et al.
Nucl.Phys.B 128 (1977) 461-505, 1977.
Inspire Record 126055 DOI 10.17182/hepdata.35248

We report the results of a pion-electron scattering experiment to measure the charge radius of the pion. The experiment was performed in a 50 GeV/ c negative, unseparated beam at the IHEP accelerator, Serpukhov, and has been briefly reported in an earlier publication [1]. A magnetic spectrometer instrumented with wire spark chambers was used to record the incident pion trajectory and the angles and momenta of the scattered particles. Events are reconstructed by detailed trackfinding programs, and a set of kinematic and geometric cuts define the elastic sample. Electrons are identified both by kinematic criteria and pulse height information from total absorption lead glass Čerenkov counters. The final elastic sample consisted of 40 000 πe events in the region of four-momentum transfer squared 0.013 (GeV/ c ) 2 ⩽ q 2 ⩽ 0.036 (GeV/ c ) 2 . A full error matrix fit to the form factors of the pion gave the r.m.s. charge radius of the pion: 〈r π 2 〉 1 2 = (0.78 −0.10 +0.09 ) fm .

23 data tables

Axis error includes +- 0.7/0.7 contribution (DUE TO ACCIDENTAL ANTI-COINCIDENCES).

No description provided.

No description provided.

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Investigation of (K pi) Mass Enhancement Near 1870-MeV in the Reaction K- p --> K- pi+ n at 10-GeV/c and 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Grassler, H. ; Laven, H. ; Otter, G. ; et al.
Nucl.Phys.B 125 (1977) 189, 1977.
Inspire Record 119121 DOI 10.17182/hepdata.35408

An enhancement in the (K − π + ) mass distribution at 1871 ± 10 MeV with full width of 285 ± 40 MeV is observed in the charge-exchange reaction K − p → K − π + n at 10 and 16 GeV/ c . The energy dependence of its cross section, the shape of the differential cross section d σ /d t and the decay angular distributions are consistent with a production mechanism by pion exchange. No significant enhancement at the same mass is seen in the non-charge exchange reaction K − p → (K π ) − p. The experimental evidence is reviewed and it is suggested that there may be more than one K ∗ enhancement in the 1700–1900 mass region.

2 data tables

FOR ALL EVENTS WITH 1.7 < M(K- PI+) < 2 GEV. NO FORWARD DIP. 'THETA CUT'.

THE 14.3 GEV/C POINT IS FROM ANALYSING THE DATA OF M. SPIRO ET AL., PL 60B, 389 (1976) IN THE SAME WAY. 'THETA-CUT'.


Measurement of Polarization in K- p Elastic Scattering at Low-Energies

Ehrlich, R.D. ; Lovett, B. ; Mishina, M. ; et al.
Phys.Lett.B 71 (1977) 455-459, 1977.
Inspire Record 126323 DOI 10.17182/hepdata.27506

The polarization parameter has been measured in K − p elastic scattering at eight incident beam momenta between 650 MeV/ c and 1071 MeV/ c throughout a center of mass angular range of −0.75 < cos θ ∗ < 0.85 . Experimental results and coefficients of Legendre polynomial fits to the data are presented and compared with other measurements and partial wave analysis.

8 data tables

No description provided.

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Amplitudes and Exchange Mechanisms for K* Resonances Produced by the Reactions K+- p --> K*+- p at 10-GeV/c

Baldi, R. ; Bohringer, T. ; Dorsaz, P.A. ; et al.
Phys.Lett.B 70 (1977) 377-382, 1977.
Inspire Record 126179 DOI 10.17182/hepdata.27517

We compare production of the low mass K π -resonances by K + and K − beams in the non-charge-exchange reactions K ± p → K 0 s π ± p at 10 GeV/ c . High statistics data, obtained with the same apparatus, allow extraction of the K ∗ (890) and K ∗ (1420) production amplitudes corresponding to unnatural and natural parity exchange in the t -channel. The NPE-part dominates in both charge states. Its t -dependence shows a strong crossover at t ≈ −0.3 (GeV/ c ) 2 for the K ∗ (1420). For the K ∗ (890) the crossover is weaker but it occurs at the same value of t . This behaviour can be explained by pomeron, f and ω Regge exchange contributions to the NPE amplitude. The UPE amplitudes agree, both in normalisation and t -dependence, with the expectations of π and B exchange as isolated from data for the charge exchange reaction K − p → (K − π + )n.

1 data table

No description provided.


Momentum Analysis of Kaon and Pion Pairs Produced from Timelike Photons at 1.6-GeV Energy

Esposito, B. ; Felicetti, F. ; Marini, A. ; et al.
Phys.Lett.B 67 (1977) 239-242, 1977.
Inspire Record 124109 DOI 10.17182/hepdata.27574

We present results for the total cross section of e + e − annihilation into two hadrons at 1.6 GeV: σ ππ = σ KK = (1.8 ± 1.1) × 10 -33 cm 2 .From these values we obtain the time-like electromagnetic form factors these mesons: | F π | 2 = 0.24 ± 0.14 and | F K | 2 = 0.46 ± 0.26.

1 data table

No description provided.