Armstrong, C
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Total hadronic cross-section of gamma rays in hydrogen in the energy range 0.265-GeV to 4.215-GeV

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Phys.Rev.D 5 (1972) 1640-1652, 1972.
Inspire Record 67298 DOI 10.17182/hepdata.22462

The total cross section of γ rays in hydrogen resulting in hadron production, σT, has been measured over the energy range 265-4215 MeV. A tagging system with narrow energy bins was employed. Structure in the resonance region followed by a steady fall with energy has been observed and the results are analyzed. The forward amplitude of γ-proton scattering is evaluated, and its behavior in the Argand diagram studied as a function of energy. The relationships of the measurements to Regge-pole theory and the vector-dominance model are detailed.

2 data tables
Table 1

No description provided.

Table 2

SPIN AVERAGED FORWARD COMPTON SCATTERING AMPLITUDE. IM(AMP) WAS CALCULATED VIA THE OPTICAL THEOREM FROM A SMOOTH FIT TO THE DATA, AND USED IN THE DISPERSION RELATION TO CALCULATE RE(AMP). AT THRESHOLD THE THOMSON AMPLITUDE IS -3.0 MUB*GEV.


Total hadronic photoabsorption cross-sections of nuclei for photons in the gev energy range

Brookes, G.R. ; Clough, A.S. ; Freeland, J.H. ; et al.
Phys.Rev.D 8 (1973) 2826-2836, 1973.
Inspire Record 93332 DOI 10.17182/hepdata.22018

The total hadronic photoabsorption cross sections of a number of nuclei (C, Al, Cu, Nb, Sn, Ta, Pb) have been studied in detail using a tagged photon beam over the energy range 1.7-4 GeV. The results are described, and compared with models of photoabsorption.

3 data tables
Table 1

STATISTICAL ERRORS. MEAN CROSS SECTIONS FOR EACH OF THE TWO ELECTRON BEAM ENERGIES OF 3.5 AND 4.6 GEV ARE ALSO GIVEN.

Table 2

A-EFFECTIVE/A, USING SIG(GAMMA P) = 137 MUB AND SIG(GAMMA N) = 126 MUB. STATISTICAL ERRORS.

Table 3

A-EFFECTIVE/A, USING SIG(GAMMA P) = 129 MUB AND SIG(GAMMA N) = 123 MUB. STATISTICAL ERRORS.


Observation of Double $\phi$ Meson Production in the Central Region for the Reaction $p p \to p$(f) ($K^+ K^- K^+ K^-$) $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.
Phys.Lett.B 221 (1989) 221-226, 1989.
Inspire Record 276743 DOI 10.17182/hepdata.29825

The reaction pp→p f (K + K − K + K − )p s in which the K + K − K + K − system is centrally produced has been studied at 300 GeV/ c . φφ production has been observed and the ratio σ (φK + K − )/ σ ( φφ ) is 1.0±0.3. The cross section for central production of φφ is found to be the same at 300 GeV/ c and 85 GeV/ c . An angular analysis of the φφ system favours J P =2 + over 0 − .

1 data table
Table 1

No description provided.


A Spin Parity Analysis of the F(1) (1285) and F(1) (1420) Mesons Centrally Produced in the Reaction $p p \to p$(f) ($K^0_S K^\pm \pi^\mp$) at $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.
Phys.Lett.B 221 (1989) 216-220, 1989.
Inspire Record 276742 DOI 10.17182/hepdata.29828

Results are presented of an analysis of the reaction pp→p f (K S 0 K ± π ∓ )p s at 300 GeV/ c . Clear f 1 (1285) and f 1 (1420) signals are seen. A spin-parity analysis shows that both are consistent with being 1 ++ states. The f 1 (1420) is found to decay only to K ∗ K and no 0 −+ or 1 +− waves are required to describe the data. The production of the f 1 (1285) as a function of energy is not the same as that for the f 1 (1420) whose cross section is found to be constant with energy.

1 data table
Table 1

No description provided.


Evidence for New States Produced in the Central Region in the Reaction $p p \to p$(f) ($\pi^+ \pi^- \pi^+ \pi^-$) $p(s$) at 300-{GeV}/$c$

The WA76 collaboration Armstrong, T.A. ; Benayoun, Maurice ; Beusch, W. ; et al.
Phys.Lett.B 228 (1989) 536-542, 1989.
Inspire Record 280165 DOI 10.17182/hepdata.29783

The reaction pp→p f ( π + π − π + π − )p s , where the π + π − π + π − system is centrally produced, has been studied at 300 GeV/ c in an experiment designed to search for gluonic states. The π + π − π + π − mass spectrum shows evidence for the f 1 (1285) with a mass of 1281±1 MeV and a width of 31±5 MeV. In addition there is evidence for two new enhancements at masses of 1449±4 and 1901±13 MeV with widths of 78±18 and 312±61 MeV respectively. An analysis of the state at 1.45 GeV indicates that it is not a π + π − π + π − decay mode of the f 1 (1420) or ι η(1440) .

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Study of the A-dependence of Inclusive $p$, $\bar{p}$, $\Lambda$ and $\bar{\Lambda}$ Production in $\pi^\pm$ Nucleus Interactions at 30-{GeV}/$c$

The CERN-Lisbon-Neuchatel-Paris-Warsaw collaboration Abreu, M.G. ; Armstrong, T. ; Baubillier, M. ; et al.
Z.Phys.C 25 (1984) 115, 1984.
Inspire Record 200776 DOI 10.17182/hepdata.16301

We present the first results on the production of fast (p>10 GeV/c)p,\(\bar p\), Λ and\(\bar \Lambda \) from π± hydrogen and nucleus interactions at 30 GeV/c using the CERN Ω′ spectrometer. We have used five nuclear targets (C, Al, Cu, Sn, Pb) to study theA-dependence of the inclusive particle distributions in the region 0.3<xF<0.6. The high statistical level of our experiment allows us to demonstrate the differentA-behaviour of baryon and antibaryon inclusive reactions. We relate this difference to the final state interaction inside a nucleus using the formation-zone model.

1 data table
Table 1

No description provided.


Measurement of the imaginary part of the I=1 $\bar{N} N$ S‐wave scattering length

Mutchler, G.S. ; Clement, J. ; Kruk, J. ; et al.
Phys.Rev.D 38 (1988) 742-753, 1988.
Inspire Record 268866 DOI 10.17182/hepdata.23244

The survival time spectrum of slow antineutrons produced in a LH2 target has been measured. From these data the imaginary part of the I=1 spin averaged S‐wave antineutron proton scattering length has been deduced to be Im a1= −0.83±0.07 fm. The result lies within the range of values calculated from current potential models.

1 data table
Table 1

THE VALUE AT PLAB = 0. HAVE BEEN OBTAINED BY EXTRAPOLATION.


The total photon-proton cross-section for hadron production

Armstrong, T.A. ; Hogg, W.R. ; Lewis, G.M. ; et al.
Phys.Lett.B 34 (1971) 535-538, 1971.
Inspire Record 69289 DOI 10.17182/hepdata.28520

The total hadronic cross section, σ T has been measured for tagged γ -rays, using electron beams in the GeV range, and narrow energy bins. Preliminary data are given covering the γ -energy region 275 MeV-1850 MeV, where interesting structure characteristics are observed.

1 data table
Table 1

No description provided.


A Partial Wave Analysis of the ($K^+ K^- \pi^-$) System Produced in $\pi^- p \to K^+ K^- \pi^- p$ at 16-{GeV}/$c$

The Aachen-Bari-Bonn-CERN-Glasgow-Liverpool-Milan collaboration Armstrong, T.A. ; Baccari, B. ; Bonesini, M. ; et al.
Nucl.Phys.B 202 (1982) 1-20, 1982.
Inspire Record 169445 DOI 10.17182/hepdata.44589

The reaction π − p → K + K − π − p at 16 GeV/ c was studied in the CERN OMEGA spectrometer and a partial-wave analysis (PWA) of the low-mass (K + K − π − ) system (1.3–2.0 GeV) was performed. Only states in the unnatural spin-parity series produced by natural parity exchange are important and they approximately conserve t -channel helicity. The 1 + S K ∗ K wave dominates the low-mass (K + K − π − ) region. We observe an enhancement in 2 − P K ∗ K wave at a mass of 1.7 GeV, consistent with the decay of the A 3 resonance.

3 data tables
Table 1

TOTAL ACCEPTANCE CORRECTED CROSS SECTION.

Table 2

ACCEPTANCE CORRECTED.

Table 3

MOST IMPORTANT CONTRIBUTING STATES CORRECTED FOR ACCEPTANCE.


SEARCH FOR NONSTRANGE BARYONIUM STATES IN THE BARYON EXCHANGE REACTION K- P ---> Y0 ANTI-P P AT 18.5-GeV/c

The BARI-BIRMINGHAM-CERN-MILAN-PARIS-PAVIA collaboration Armstrong, T. ; Baubillier, M. ; Beusch, W. ; et al.
Nucl.Phys.B 206 (1982) 185-192, 1982.
Inspire Record 184140 DOI 10.17182/hepdata.34058

Narrow baryonium production in the baryon exchange reactions K − p → Λ p p and K − p → pK − p p at 18.5 GeV/ c is investigated in a 12 events/nb experiment performed at the CERN Ω′ spectrometer. No narrow structure is observed in the p p mass spectra. Upper limits for production of baryonium states are given as a function of p p mass.

2 data tables
Table 1

'1'. (AP P) SYSTEM PRODUCED IN BACKWARD DIRECTION IN THE CMS.

Table 2

'1'. (AP P) SYSTEM PRODUCED IN BACKWARD DIRECTION IN THE CMS.