Date

Observation of the K* (1780) in the Reaction K+ p --> K0(s) pi+ p at 10-GeV/c

Baldi, R. ; Bohringer, T. ; Dorsaz, P.A. ; et al.
Phys.Lett.B 63 (1976) 344-348, 1976.
Inspire Record 115724 DOI 10.17182/hepdata.27636

An analysis of the Kπ-system in the mass region of the K ∗ (1780), based on a sample of 46000 K s o π + final states, is presented. Evidence for a relatively narrow width, τ ≈ 100 MeV, and for the spin parity assignment J P = 3 − is found.

1 data table

SLOPE DETERMINED WITHIN 0.2 < -T < 0.8 GEV**2 AND USED TO ESTIMATE TOTAL CROSS SECTION.


Angular Distribution of the Target Asymmetry on Polarized Protons for the Reaction gamma p (Polarized) --> pi+ n at a Photon Energy of 700-MeV

Althoff, K.H. ; Conrad, R. ; Gies, M. ; et al.
Phys.Lett.B 63 (1976) 107-110, 1976.
Inspire Record 114330 DOI 10.17182/hepdata.27654

At the Bonn 2.5 GeV electron synchrotron the angular distribution of the target asymmetry T = (σ↑ − σ↓) (σ↑ + σ↓) for the reaction γp↑ → π + n was measured at a mean photon energy of 700 MeV and pion CM-angles from 50° to 155°. The combination of a 3 He-cryostat, polarizing the free protons in the target up to 65%, with a large acceptance magnet for pion detection led to statistical errors of the target asymmetry comparable with those of cross section measurements.

1 data table

No description provided.


Observation of a DIP-Bump Structure in Differential Cross-Section for anti-p + p --> anti-N + n in the 700-MeV/c to 760-MeV/c Momentum Range

Bogdanski, M. ; Emura, T. ; Ganguli, S.N. ; et al.
Phys.Lett.B 62 (1976) 117-120, 1976.
Inspire Record 109019 DOI 10.17182/hepdata.27664

Based on a sample of about 3500 events, we have measured the total and differential cross sections of p p → n n in the 700–760 MeV/ c incident momentum region. It is found that σ CE = 10.7 ± 0.2 mb at the average momentum of 730 MeV/ c . The differential angular distribution is characterised by a sharp peak and a dip in the forward direction followed by a secondary maximum. The position of the dip corresponds to | t | ≈ m π 2 . These results are compared with the predictions of the model of Bryan-Phillips. On the other hand, this dip-bump structure can be well understood on a simple picture involving a π exchange and a constant background (for | t | ≲ 3 m π 2 ).

3 data tables

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K+ p Elastic Scattering at 32-GeV/c

The FRENCH-SOVIET-CERN collaboration Granet, P. ; Loret, M. ; Mosca, L. ; et al.
Phys.Lett.B 62 (1976) 350-352, 1976.
Inspire Record 114035 DOI 10.17182/hepdata.27668

Elastic scattering of 32.1 GeV/ c K + on protons has been measured in a bubble chamber experiment. Results are presented in the momentum transfer interval 0.06–1.40 GeV 2 and compared with data at different energies. An effective Regge trajectory is calculated using K + p elastic data from 10 to 175 GeV/ c .

1 data table

No description provided.


The Applicability of Zweig's Rule to anti-p p Annihilations at 3.6-GeV/c

Donald, R.A. ; Edwards, D.N. ; Houlden, M. ; et al.
Phys.Lett.B 61 (1976) 210-212, 1976.
Inspire Record 113109 DOI 10.17182/hepdata.27692

The final states øππ and øKK̄ arising from p̄p annihilations at 3.6 GeV/ c have been studied. The results are in agreement with Zweig's rule contrary to what is observed in high energy pp collisions.

1 data table

No description provided.


New Determination of the Upper Limit for the Muon Neutrino Mass

Daum, M. ; Dubal, L. ; Eaton, G.H. ; et al.
Phys.Lett.B 60 (1976) 380-384, 1976.
Inspire Record 112895 DOI 10.17182/hepdata.27715

We have measured the muon momentum in pion decay at rest using a magnetic spectrometer. From the result, p μ + = (29.787±0.005) MeV/ c , we deduce a squared muon neutrino mass of (0.23±0.54) MeV 2 / c 4 .

1 data table

No description provided.


Small Angle p p Elastic Scattering at Energies Between 285-MeV and 572-MeV

Aebischer, D. ; Favier, B. ; Greeniaus, L.G. ; et al.
Phys.Rev.D 13 (1976) 2478-2498, 1976.
Inspire Record 114031 DOI 10.17182/hepdata.24779

Differential cross sections for elastic p−p scattering have been measured at 285, 348, 398, 414, 455, 497, 530, and 572 MeV kinetic energy. The experiment was performed at the CERN synchrocyclotron, using multiwire proportional chambers placed directly in a proton beam. Scattering was observed for 1.5°≲θ≲10° in the laboratory system. The ratio αp of the real and imaginary parts of the non-spin-flip nuclear forward amplitude was derived from the interference between the Coulomb and nuclear amplitudes. The values obtained are model-dependent, but in this energy range αp is positive and decreases with energy. Qualitatively good agreement with dispersion-relation predictions is observed.

8 data tables

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Study of the Reaction pi+ p --> omega Delta++ (1236) at 16-GeV/c

The Aachen-Berlin-Bonn-CERN-Cracow-Heidelberg collaboration Grassler, H. ; Honecker, R. ; Laven, H. ; et al.
Nucl.Phys.B 115 (1976) 365-384, 1976.
Inspire Record 110390 DOI 10.17182/hepdata.35656

The reaction π + p→ ωΔ ++ (1236) is studied at 16 GeV/ c . Cross section, differential cross section, single and joint spin-density matrix elements are given and the correlations between the ε and Δ ++ (1236) decay angular distributions are investigated. Natural and unnatural spin-parity exchanges contribute to this reaction in roughly equal amounts. Natural exchanges lead predominantly to Δ ++ (1236) with helicity ± 3 2 , while unnatural exchanges lead predominantly to Δ ++ (1236) with helicity ± 1 2 and to ε with helicity zero. Furthermore, unnatural exchanges are small at t ′≅0.2 GeV 2 compared to other t ′ values, which may be due to the nonsense wrong-signature-zero of the B-meson exchange. Quark model relations are found to be satisfied by the data.

6 data tables

CORRECTED FOR UNSEEN OMEGA DECAY MODES. 'SLICE METHOD' USED TO HANDLE RESONANCE TAILS AND BACKGROUND.

FROM EVENTS WITHIN MASS-CUTS FOR RESONANCES AND NORMALIZED TO TOTAL CROSS SECTION.

'ALL'.

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Measurements of $p p \to \pi^+ d$ between 398-MeV and 572-MeV

Aebischer, D. ; Favier, B. ; Greeniaus, L.G. ; et al.
Nucl.Phys.B 108 (1976) 214-238, 1976.
Inspire Record 114332 DOI 10.17182/hepdata.35777

The reaction pp→ π + d was studied at incident proton energies of 398, 455, 497, 530 and 572 MeV. Measurements of dσ/dΩ at 455 and 572 MeV show the presence of pion d-waves in the pion-deuteron system. Asymmetry measurements yield similar conclusions. Total cross-section measurements agree with recent fits to earlier data.

5 data tables

NORMALIZED TO 4.38 MB/SR AT THETA = 13.19 DEG FOR P P ELASTIC.

NORMALIZED TO 4.68 MB/SR AT THETA = 13.35 DEG FOR P P ELASTIC.

NORMALIZED (RELATIVE ERROR 2.1 PCT) TO THE DATA OF RICHARD-SERRE ET AL., NP B20, 413 (1970) (ABSOLUTE SCALE UNCERTAINTY 4.5 PCT).

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Measurement and Pion Exchange Analysis of the Inclusive Spectra n p --> p x0 Between 1.4-GeV/c and 1.9-GeV/c and Determination of the Differential Cross-Sections n p --> p Delta0 (33)

Bizard, G. ; Bonthonneau, F. ; Laville, J.L. ; et al.
Nucl.Phys.B 108 (1976) 189-213, 1976.
Inspire Record 114331 DOI 10.17182/hepdata.35799

A set of 43 momentum spectra from the inclusive reaction np→pX 0 was measured with good statistical accuracy at 1.39, 1.56, 1.73 and 1.90 GeV/ c (about 10 spectra per incident momentum), with a neutron beam obtained by stripping deuterons. The final proton was analysed in an angular region of between 0° and 20° in the laboratory by a magnetic spectrometer.

2 data tables

THE INDICATED POSSIBLE SYSTEMATIC ERROR ARISES FROM EXTRAPOLATION OF D(SIG)/DT TO THETA = 90 DEG.

No description provided.