Date

Diffractive Dissociation and N* Production in pi- n --> pi- pi- p at 15-GeV/c

Harris, R. ; Lubatti, H.J. ; Moriyasu, K. ; et al.
Nucl.Phys.B 119 (1977) 189-209, 1977.
Inspire Record 110139 DOI 10.17182/hepdata.35579

Diffractive dissociation of neutrons and N ∗ production are studied in the reaction π − n → π − π − p at 15 GeV/ c . The reaction is dominated by a broad, low-mass diffractive enhancement in the pπ − mass. Evidence is presented for the production of at least one N ∗ resonance in the mass region 1.4–1.8 GeV. Comparison with ISR data suggest that this N ∗ resonance is produced by pomeron exchange. The N ∗ production occurs predominantly at t ′ > 0.1 GeV 2 which suggests a different coupling from the usual diffractive reactions. The non-resonant diffractive background is compared with a double-Regge model and the statistical dissociation model.

1 data table match query

DEPENDENCE OF SLOPE OF D(SIG)/DT ON <P PI-> MASS. DATA FITTED OUT TO -TP=0.4 GEV**2, EXCEPT TO 0.2 GEV**2 FOR M < 1.2 GEV.


THE STUDY OF THE DIFFRACTION PROCESSES IN THE anti-p p ---> anti-p p pi+ pi- pi0 REACTION AT 22.4-GeV/c

The Alma Ata-Dubna-Moscow-Prague-Sofiya-Helsinki collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.
Sov.J.Nucl.Phys. 47 (1988) 261, 1988.
Inspire Record 247861 DOI 10.17182/hepdata.38866

None

1 data table match query

No description provided.


THE MAIN PROPERTIES OF THE anti-p p ---> anti-p p pi+ pi- REACTION AT 22.4-GeV/c

The Alma Ata-Dubna-Moscow-Prague-Sofiya-Helsinki collaboration Batyunya, B.V. ; Boguslavsky, I.V. ; Bruncko, D. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 650, 1987.
Inspire Record 239399 DOI 10.17182/hepdata.39296

None

1 data table match query

No description provided.


Diffraction Dissociation at the {CERN} Pulsed Collider at {CM} Energies of 900-{GeV} and 200-{GeV}

The UA5 collaboration Ansorge, R.E. ; Åsman, B. ; Booth, C.N. ; et al.
Z.Phys.C 33 (1986) 175, 1986.
Inspire Record 232615 DOI 10.17182/hepdata.15812

Cross-sections for diffractive particle production and pseudorapidity distributions of the decay products of diffractive states are presented. The data were obtained with the UA 5 streamer chamber detector at the CERNpp Collider operated in a new pulsed mode yieldingpp interactions at c.m. energies of 900 and 200 GeV. Data recorded with a special trigger designed to select a sample of events enriched in single-diffractive interactions clearly favour apt-limited fragmentation of diffractive states. The cross-section for single-diffractive particle production ϊ was found to be 7.8±0.5±1.1 mb at 900 GeV and 4.8±0.5±0.8 mb at 200 GeV (first error statistical, second systematic). From the pseudorapidity distribution of diffractive states we deduce the average number of charged particles to be 6.5±1.0 at 900 GeV and 4.1±1.1 at 200 GeV. Furthermore we report on our estimates for the cross-section of double-diffractive particle production at both Collider energies.

1 data table match query

Single diffractive cross sections.


Spin-Parity Analysis of Diffractive n --> p pi- and the Question of a Parity-Change Rule

Ansorge, R.E. ; Carter, J.R. ; Neale, W.W. ; et al.
Phys.Rev.D 13 (1976) 1835, 1976.
Inspire Record 99426 DOI 10.17182/hepdata.24786

A spin-parity analysis is performed of the low-mass (≤ 1.75 GeV/c2) pπ− system in diffractive np→(pπ−)p using new data at 13 GeV/c and 20 GeV/c. In the context of a Deck-plus-resonances model a good fit to the pπ− angular moments is found only if the Gribov-Morrison parity-change rule does not hold and spin states up to j=52 are included. In particular the presence of a considerable fraction of spin-parity ½− state is indicated.

1 data table match query

DECK MODEL PLUS RESONANCES FIT TO DIFFRACTIVE EVENTS.


Observation of color-transparency in diffractive dissociation of pions.

The E791 collaboration Aitala, E.M. ; Amato, S. ; Anjos, J.C. ; et al.
Phys.Rev.Lett. 86 (2001) 4773-4777, 2001.
Inspire Record 535233 DOI 10.17182/hepdata.42972

We have studied the diffractive dissociation into di-jets of 500 GeV/c pions scattering coherently from carbon and platinum targets. Extrapolating to asymptotically high energies (where t_{min} approaches 0) we find that when the per-nucleus cross-section for this process is parameterized as $ \sigma = \sigma_0 A^{\alpha} $, $ \alpha $ has values near 1.6, the exact result depending on jet transverse momentum. These values are in agreement with those predicted by theoretical calculations of color-transparency.

1 data table match query

Cross sections is fitted to A**POWER.


Diffraction dissociation in photoproduction at HERA

The H1 collaboration Adloff, C. ; Aid, S. ; Anderson, M. ; et al.
Z.Phys.C 74 (1997) 221-236, 1997.
Inspire Record 440126 DOI 10.17182/hepdata.44667

A study is presented of the process gamma p -->XY, where there is a large rapidity gap between the systems X and Y. Measurements are made of the differential cross section as a function of the invariant mass mx of the system produced at the photon vertex. Results are presented at centre of mass energies of W_gp = 187 GeV and W_gp = 231 GeV, both where the proton dominantly remains intact and, for the first time, where it dissociates. Both the centre of mass energy and the mx~2 dependence of HERA data and those from a fixed target experiment may simultaneously be described in a triple-Regge model. The low mass photon dissociation process is found to be dominated by diffraction, though a sizable subleading contribution is present at larger masses. The pomeron intercept is extracted and found to be alpha_pom(0) = 1.068 \pm 0.016 (stat.) \pm 0.022 (syst.) \pm 0.041 (model), in good agreement with values obtained from total and elastic hadronic and photoproduction cross sections. The diffractive contribution to the process gamma p --> Xp with mx~2 / W_gp~2 < 0.05 is measured to be 22.2 \pm 0.6 (stat.) \pm 2.6 (syst.) \pm 1.7 (model) % of the total gamma p cross section at W_gp = 187 GeV.

2 data tables match query

Data for proton remaining intact.

Data for proton dissociating.


Measurement of anti-p p single diffraction dissociation at s**(1/2) = 546-GeV and 1800-GeV

The CDF collaboration Abe, F. ; Albrow, Michael G. ; Amidei, Dante E. ; et al.
Phys.Rev.D 50 (1994) 5535-5549, 1994.
Inspire Record 359393 DOI 10.17182/hepdata.42542

We report a measurement of the diffraction dissociation differential cross section d2σSD/dM2dt for p¯p→p¯X at √s =546 and 1800 GeV, M2/s<0.2 and 0≤-t≤0.4 GeV2. Our results are compared to theoretical predictions and to extrapolations from experimental results at lower energies.

1 data table match query

Single diffraction dissociation cross section.


Diffraction dissociation in anti-p p collisions at s**(1/2) = 1.8-TeV

The E710 collaboration Amos, Norman A. ; Avila, C. ; Baker, W.F. ; et al.
Phys.Lett.B 301 (1993) 313-316, 1993.
Inspire Record 342944 DOI 10.17182/hepdata.28955

We have studied single diffraction dissociation ( p p→ p X ) in proton-antiproton collisions at √ s =1.8TeV, covering the ranges 3⪅ M X ⪅200 GeV and 0.05⪅| t |⪅0.11 (GeV/ c ) 2 . Parameterizing the production to be of the form dσ ( d t d M 2 X ) = (M 2 X ) −α exp (bt) , we obtain α = 1.13±0.07 and b = 10.5±1.8(GeV/ c ) −2 . The total single diffraction dissociation cross section is 2 σ SD =8.1±1.7 mb. Comparisons are made to previous lower energy data, and to an earlier measurement by us at the same energy.

1 data table match query

Total single diffraction cross section.


Test of S Channel Helicity Conservation in Inelastic $\rho^0$ Diffraction in 20-{GeV} Photoproduction

The SLAC Hybrid Facility Photon collaboration Abe, K. ; Bacon, T.C. ; Ballam, Joseph ; et al.
Phys.Rev.D 32 (1985) 2288, 1985.
Inspire Record 209692 DOI 10.17182/hepdata.23546

The reaction γp→ρfast0pπ+π− has been studied with the linearly polarized 20-GeV monochromatic photon beam at the SLAC Hybrid Facility to test the prediction of s-channel helicity conservation in inelastic diffraction for t’<0.4 (GeV/c)2. In a sample of 1934 events from this reaction, the ρ0 decay-angular distributions and spin-density-matrix elements are consistent with s-channel helicity conservation, the π+π− mass shape displays the same skewing as seen in the reaction γp→pπ+π−, and the pπ+π− mass distribution compares well and scales according to the vector dominance model with that produced in π±p→πfast±pπ+π−.

1 data table match query

No description provided.