Backward Production in $\pi^- p \to p_f \pi^+ \pi^- \pi^-$ Reaction at 9-{GeV}/$c$ and 12-{GeV}/$c$

Ferrer, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Nucl.Phys.B 142 (1978) 77-107, 1978.
Inspire Record 130740 DOI 10.17182/hepdata.34939

We have analyzed backward meson production in the reaction π − p → p f π + π − π − at 9 GeV/ c and 12 GeV/ c incident π − momenta, from an experiment performed at the CERN Ω Spectrometer using a fast proton (p f ) trigger device. We find strong production of quasi-two-body processes N ∗ ϱ and N ∗ f with a production mechanism consistent with u -channel nucleon exchange. At a lower level, we observe N ∗ π processes with a 3-body baryon decay through Δ(1232)π. In the (3π) − system, we find evidence for A 1 − and clear A 2 − backward production with similar cross sections (≈0.5 μb).

3 data tables

No description provided.

U-HELICITY JACKSON FRAME.

U-HELICITY JACKSON FRAME.


Total Cross-section for Hadron Production by $e^+ e^-$ Annihilation at Center-of-mass Energies Between 3.6-{GeV} and 5.2-{GeV}

The DASP collaboration Brandelik, R. ; Braunschweig, W. ; Martyn, H.U. ; et al.
Phys.Lett.B 76 (1978) 361, 1978.
Inspire Record 129715 DOI 10.17182/hepdata.27431

The total cross section for e + e − annihilation into hadronic final states between 3.6 and 5.2 GeV was measured by the nonmagnetic inner detector of DASP, which has similar trigger and detection efficiencies for photons and charged particles. The measured difference in R = σ had / σμμ between 3.6 GeV and 5.2 GeV is ΔR = 2.1 ± 0.3. We observe three peaks at cm energies of 4.04, 4.16 and 4.417 GeV, the parameters of which, when interpreted as resonances, are given.

2 data tables

EXCLUDING CONTRIBUTION OF TAU HEAVY LEPTON.

INCLUDING CONTRIBUTION OF TAU HEAVY LEPTON.


Evidence for Spin Effects in $p p$ Elastic Scattering at 150-{GeV}/$c$

Fidecaro, G. ; Fidecaro, M. ; Nurushev, S. ; et al.
Phys.Lett.B 76 (1978) 369-373, 1978.
Inspire Record 130230 DOI 10.17182/hepdata.27444

Proton elastic scattering off a polarized proton target has been measured at 150 GeV/ c , in the |; t |-range 0.2–3.0 GeV 2 . The results on polarization and differential cross section are presented.

2 data tables

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A Measurement of the Energy Dependence of Elastic $\pi p$ and $p p$ Scattering at Large Angles

Jenkins, K.A. ; Price, L.E. ; Klem, R. ; et al.
Phys.Rev.Lett. 40 (1978) 425, 1978.
Inspire Record 6233 DOI 10.17182/hepdata.3359

We have measured π±p and pp elastic differential cross sections in the range |cosθc.m.|<0.35 for incident momenta from 2 to 9.7 GeV/c for π−p and pp and from 2 to 6.3 GeV/c for π+p. We find that the fixed-c.m.-angle πp differential cross sections cannot be described as simple functions of s. The data are compared to the energy and angular dependence predicted by the constituent model of Gunion, Brodsky, and Blankenbecler.

56 data tables

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INVARIANT CROSS-SECTIONS FOR THE INCLUSIVE REACTIONS anti-p p ---> pi+ X AND anti-p p ---> p X AT 22.4-GeV/c

The Alma Ata-Dubna-Helsinki-Moscow-Prague collaboration Boos, E.G. ; Ermilova, D.I. ; Samoilov, V.V. ; et al.
Nuovo Cim.A 47 (1978) 377, 1978.
Inspire Record 130221 DOI 10.17182/hepdata.37561

Invariant inclusive cross-sections for π+-mesons and protons from\(\bar pp\) reactions at 22.4 GeV/c are presented. The average multiplicity for the production of π+-mesons is 1.92±0.02 and for protons 0.41±0.02. Annihilation spectra have been approximated by using the difference between\(\bar pp\) and pp data. The resulting distributions have similar gross features as the total\(\bar pp\) data.

1 data table

No description provided.


Fluctuations in Large Angle $\pi^\pm p$ Elastic Scattering

Jenkins, K.A. ; Price, L.E. ; Klem, R. ; et al.
Phys.Rev.Lett. 40 (1978) 429, 1978.
Inspire Record 6210 DOI 10.17182/hepdata.76245

Large-angle π±p elastic-scattering cross sections, measured between 2 and 9 GeV/c in fine intervals of incident momentum and scattering angle, are used to search for cross-section fluctuations occurring for small changes in the center-of-mass energy as suggested by Ericson and Mayer-Kuckuck and by Frautschi. Significant fluctuations are observed.

144 data tables

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Measurement of the Proton Proton Total Cross-Section and Small Angle Elastic Scattering at ISR Energies

Baksay, L. ; Baum, L. ; Böhm, A. ; et al.
Nucl.Phys.B 141 (1978) 1-28, 1978.
Inspire Record 136189 DOI 10.17182/hepdata.34829

Measurements of the total cross section have been performed at the ISR with c.m. energies between 23.5 GeV and 62.5 GeV. Two independent experimental methods have been applied, a measurement of total interaction rate and of small angle elastic scattering. Both experiments give consistent results showing that the total cross section increases by (11.8±1.5) % over the ISR energy range. This experiment has also measured the slope of the forward diffraction peak in elastic scattering at small momentum transfer. The elastic cross section shows the same relative rise as the total cross section, and the ratio λ of elastic to total cross section approaches a constant value of λ =0.178±0.003.

8 data tables

TOTAL CROSS SECTION FROM (INTERACTION RATE)/(LUMINOSITY). SYSTEMATIC ERROR <0.8 PCT.

TOTAL CROSS SECTION FROM APPLYING THE OPTICAL THEOREM TO SMALL ANGLE ELASTIC SCATTERING EXTRAPOLATED TO T=0.

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Photoproduction of K+ Lambda0 on Polarized Protons

Althoff, K.H. ; Gies, M. ; Herr, H. ; et al.
Nucl.Phys.B 137 (1978) 269-275, 1978.
Inspire Record 135345 DOI 10.17182/hepdata.35095

The target asymmetry for the reaction γ p → K + Λ 0 was measured at the Bonn 2.5 GeV synchroton. Data were taken at a fixed kaon c.m. angle of 90° and at photon energies between 1.1 and 1.3 GeV. The kaons were detected in a large aperture magnetic spectrometer.

1 data table

5 PCT TARGET POLARIZATION UNCERTAINTY INCLUDED IN QUOTED ERRORS.


A Study of Noncharge Exchange anti-K0 pi- Production in the Reaction K- p --> anti-K0 pi- p at 4.2-GeV/c

The AMSTERDAM-CERN-NIJMEGEN-OXFORD collaboration Engelen, J.J ; Holwerda, M.J. ; Kittel, E.W. ; et al.
Nucl.Phys.B 134 (1978) 14-30, 1978.
Inspire Record 134670 DOI 10.17182/hepdata.35138

The K π − system produced in the reaction K p → K 0 π − p at 4.2 GeV/ c is studied using high-statistics bubble-chamber data. The spin-parity structure is analysed as a function of the K 0 π − mass up to 1.52 GeV. Production of K ∗ (890) and K ∗ (1420) is observed in helicity-0 and helicity-1 states. Contributions of natural and unnatural parity exchange are present. Considerable S-wave production is observed over the whole mass region considered. We also study the t ′ dependence of the K ∗ (890) and K ∗ (1420) amplitudes. A comparison of our results on K ∗ (890) production with the results of an analysis of charge-exchange K ∗ (890) production, allows the separation of I = 0 and I = 1 exchange amplitudes. Some qualitative remarks are made concerning K ∗ (1420) production.

2 data tables

No description provided.

PARTIAL WAVE ANALYSIS ASSUMING SPIN-COHERENCE TO OBTAIN SPIN-PARITY STRUCTURE AND T DEPENDENCE OF P-WAVE AND D-WAVE AMPLITUDES.


LAMBDA POLARIZATION IN INCLUSIVE K- p INTERACTIONS AT 10-GeV/c AND 16-GeV/c

The Aachen-Berlin-CERN-London-Vienna collaboration Grassler, H. ; Honecker, R. ; Laven, H. ; et al.
Nucl.Phys.B 136 (1978) 386, 1978.
Inspire Record 129719 DOI 10.17182/hepdata.35096

A strong negative transverse polarization P z is found for forward produced lambdas observed in 10 and 16 GeV/ c K − p interactions. This indicates that exchanges of natural spin-parity are dominant in the production process. Using the polarization results, the d σ d u′ distributions for natural and unnatural spin-parity exchanges are derived. For unnatural exchanges, a dip is observed at u ′≅0.3 GeV 2 , which can be explained as a nonsense-wrong-signature zero of the N β trajectory. The value of P z for forward producted lambdas is constant with energy. This is in agreement with the triple-Regge model prediction, as is the fact that P z is constant as a function of M 2 s . The two non-transverse polarization components, P x and P y , have been measured and are found to be consistent with zero for all x values, unlike P z .

4 data tables

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