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.


Coherent diffractive photoproduction of $\rho^{0}$ mesons on gold nuclei at RHIC

The STAR collaboration Adamczyk, L. ; Adkins, J.K. ; Agakishiev, G. ; et al.
Phys.Rev.C 96 (2017) 054904, 2017.
Inspire Record 1515028 DOI 10.17182/hepdata.101354

The STAR Collaboration reports on the photoproduction of $\pi^+\pi^-$ pairs in gold-gold collisions at a center-of-mass energy of 200 GeV/nucleon-pair. These pion pairs are produced when a nearly-real photon emitted by one ion scatters from the other ion. We fit the $\pi^+\pi^-$ invariant mass spectrum with a combination of $\rho$ and $\omega$ resonances and a direct $\pi^+\pi^-$ continuum. This is the first observation of the $\omega$ in ultra-peripheral collisions, and the first measurement of $\rho-\omega$ interference at energies where photoproduction is dominated by Pomeron exchange. The $\omega$ amplitude is consistent with the measured $\gamma p\rightarrow \omega p$ cross section, a classical Glauber calculation and the $\omega\rightarrow\pi^+\pi^-$ branching ratio. The $\omega$ phase angle is similar to that observed at much lower energies, showing that the $\rho-\omega$ phase difference does not depend significantly on photon energy. The $\rho^0$ differential cross section $d\sigma/dt$ exhibits a clear diffraction pattern, compatible with scattering from a gold nucleus, with 2 minima visible. The positions of the diffractive minima agree better with the predictions of a quantum Glauber calculation that does not include nuclear shadowing than with a calculation that does include shadowing.

13 data tables match query

The $\pi^+\pi^-$ invariant-mass distribution for all selected $\pi\pi$ candidates with $p_T~<~100~\textrm{MeV}/c$.

The ratio $|B/A|$ of amplitudes of nonresonant $\pi^+\pi^-$ and $\rho^0$ mesons in the present STAR analysis.

The ratio $|B/A|$ of amplitudes of nonresonant $\pi^+\pi^-$ and $\rho^0$ mesons in the previous STAR analysis, Phys. Rev. C 77 034910 (2008).

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The (3 $\pi$) - Nucleon Collision in Coherent Production on Nuclei at 40-{GeV}/$c$

Bellini, G. ; Chernenko, L.P. ; Datsko, V.S. ; et al.
Nucl.Phys.B 199 (1982) 1-26, 1982.
Inspire Record 165248 DOI 10.17182/hepdata.49659

Coherent 3 π production on nine different nuclear targets has been studied using a 40 GeV/ c π − beam at the Serpukhov accelerator (CERN-Serpukhov experiment no. 5). The absorption in nuclear matter of the produced system has been measured, analysing the data on the different nuclear targets. Identica results are obtained from the differential cross sections and from the coherent nuclear cross sections. The 1 + waves show a very weak absorption, definitely smaller than 0 − and 2 − waves. No influence on the absorption comes from the spin-flip amplitudes, which have been found to be negligible in the coherent region.

24 data tables match query

Data are extracted from graph by JINR data group.

Data are extracted from graph by JINR data group.

Data are extracted from graph by JINR data group.

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Partial Wave Analysis of Coherent 3 $\pi$ Production on Nuclei at 200-{GeV}

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Phys.Rev.D 30 (1984) 1855, 1984.
Inspire Record 15136 DOI 10.17182/hepdata.23674

We have carried out a partial-wave analysis (PWA) of three-pion systems produced in the coherent dissociation of π+ mesons on nuclear targets. The data have been analyzed for copper and lead targets at an incident π+ energy of 202.5 GeV. This PWA provides further evidence for resonant contributions to JP=1+ and 0− waves at 3π masses below 1.5 GeV, which can be plausibly identified with A1 and π′ mesons. The contribution from electromagnetic production of the A2 has also been extracted, and an estimate for Coulomb production and radiative width of the A1 has been obtained.

1 data table match query

No description provided.


THREE PION PRODUCTION ON NUCLEI AT 200-GEV

Zielinski, M. ; Berg, D. ; Chandlee, C. ; et al.
Z.Phys.C 16 (1983) 197-204, 1983.
Inspire Record 190869 DOI 10.17182/hepdata.16390

We have carried out a systematic study of the coherent dissociation of pions into 3 pions using nuclear targets. The experiment was performed at Fermilab using a high resolution forward spectrometer. Data were taken with carbon, copper and lead targets at an incident momentum of 202.5 GeV/c. Results are presented on momentum transfers, 3-pion masses, and on the nuclearA-dependence of the production cross section.

3 data tables match query

No description provided.

No description provided.

No description provided.


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.


Measurement of the t distribution in diffractive photoproduction at HERA.

The ZEUS collaboration Breitweg, J. ; Derrick, M. ; Krakauer, D. ; et al.
Eur.Phys.J.C 2 (1998) 237-246, 1998.
Inspire Record 452355 DOI 10.17182/hepdata.44323

Photon diffractive dissociation, $\gamma p \to Xp$, has been studied at HERA with the ZEUS detector using $ep$ interactions where the virtuality $Q^2$ of the exchanged photon is smaller than 0.02 GeV$^2$. The squared four-momentum $t$ exchanged at the proton vertex was determined in the range $0.073<|t|<0.40$ GeV$^2$ by measuring the scattered proton in the ZEUS Leading Proton Spectrometer. In the photon-proton centre-of-mass energy interval $176<W<225$ GeV and for masses of the dissociated photon system $4<M_X<32$ GeV, the $t$ distribution has an exponential shape, $dN/d|t| \propto \exp{(-b|t|)}$, with a slope parameter $b=6.8 \pm 0.9$~(stat.)~$ ^{+1.2}_{-1.1}$~(syst.)~GeV$^{-2}$.

2 data tables match query

T is the squared four momentum transfer at the proton vertex.

SLOPE of the DN/DT distribution.


ELASTIC SCATTERING AND PARTICLE PRODUCTION IN TWO PRONG PI- P INTERACTIONS AT 8-GEV/C

Kitagaki, T. ; Tanaka, S. ; Yuta, H. ; et al.
Phys.Rev.D 26 (1982) 1572-1587, 1982.
Inspire Record 182974 DOI 10.17182/hepdata.23945

Results of a high-statistics study of elastic scattering and meson resonances produced by π−p interactions at 8 GeV/c are presented. Large statistics and small systematic errors permit examination of the complete kinematic region. Total differential cross sections are given for ρ0,−, f0, g0,−, Δ±, Δ0, and N* resonances. Spin-density matrix elements and Legendre-polynomial moments are given for ρ, f, and Δ resonances. The results for ρ0 and f0 resonances are compared with the predictions of a Regge-pole-exchange model. Properties of the above resonances are compared and discussed. In particular, we present evidence that the ρ0 and f0 production mechanisms are similar. The similarity of the g0 t distribution to that of the ρ0 and f0 suggests a common production mechanism for all three resonances.

5 data tables match query

No description provided.

No description provided.

SLOPE REFERS TO EXPONENTIAL FIT IN U.

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A Study of $K^+ p$ Elastic Scattering and the Reaction $K^+ p \to K^+ p \pi^+ \pi^-$ at 70-{GeV}/$c$

The Brussels-Genoa-Mons-Nijmegen-Serpukhov-CERN collaboration Barth, M. ; Wolf, A.E. De ; Johnson, D.P. ; et al.
Z.Phys.C 16 (1982) 111, 1982.
Inspire Record 181354 DOI 10.17182/hepdata.41205

Results are presented onK+p elastic scattering and on the reactionK+p→K+pπ+π− at 70 GeV/c. For the

5 data tables match query

INTEGRATION OVER RANGE OF ABS(T) FROM 0 TO 1 GEV.

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Momentum Transfer Distributions of Some Diffractive Enhancements in K- p Interactions at 14.3-GeV/c

Pons, Y. ; Borg, A. ; Denegri, D. ; et al.
Nucl.Phys.B 123 (1977) 349-360, 1977.
Inspire Record 4400 DOI 10.17182/hepdata.35451

We discuss the structure of the momentum transfer distributions for the diffractive dissociation processes p → n π + , p → Δ ++ π − and K − → K 890 ∗0 π − . In the near-threshold mass region a clear break of slope is found around t ′KK ∼ 0.25 GeV 2 for the two baryonic channels, whereas no comparable structure is seen for the mesonic system. The K → K ∗ π differential cross section exhibits a nearly exponential behaviour up to t ′ pp ∼ 0.6 GeV 2 , falling over three orders of magnitude. The slope variations and breaks are strongly correlated both to the mass region considered and to the decay angle of the fragmentation system.

1 data table match query

No description provided.


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.


Partial Wave Analysis of the Q Region in the Reactions K- p --> K- pi+ pi- p and K- p --> anti-K0 pi- pi0 p at 14.3-GeV/c

Tovey, S.N. ; Hansen, J.D. ; Paler, K. ; et al.
Nucl.Phys.B 95 (1975) 109-129, 1975.
Inspire Record 2363 DOI 10.17182/hepdata.31975

We have studied the reactions K − p → K − π + π − p and K − p → K 0 π − π 0 p at 14.3 GeV/ c using respectively 15 992 and 3723 events. Partial-wave analysis of the region 1.0 < m (K ππ ) < 1.7 GeV have been made using a modified version of the method developed at the University of Illinois.

1 data table match query

No description provided.


Observation of Longitudinal Event Structure in Proton Diffractive Dissociation at the {ISR}

The R608 collaboration Smith, A.M. ; Meritet, L. ; Reyrolle, M. ; et al.
Phys.Lett.B 167 (1986) 248-254, 1986.
Inspire Record 219984 DOI 10.17182/hepdata.30272

We study the internal structure of a forward-going pπ + π − π + π − system, with invariant mass in the range 2.5-4 GeV, produced through diffractive dissociation of a beam proton at the ISR. The shape of the system, as seen in its center-of-mass, deviates strongly from isotropic phase space and possesses, rather, a longitudinal structure with a major axis along the incoming proton direction. The final state proton momentum is aligned in the direction of the incoming proton, an effect which becomes more pronounced with increasing diffractive mass.

2 data tables match query

Acceptance corrected distribution of momentum transfer to the diffractive (p-4pi) system. Data requested from authors.

No description provided.


OBSERVATION OF POLARIZATION IN DIFFRACTIVE DISSOCIATION p ---> LAMBDA0 K+ AT THE CERN ISR

Erhan, S. ; Hayes, K. ; Smith, A.M. ; et al.
62-65, 1984.
Inspire Record 202932 DOI 10.17182/hepdata.49652

None

1 data table match query

No description provided.


Double diffraction dissociation at the Fermilab Tevatron collider

The CDF collaboration Affolder, T. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 87 (2001) 141802, 2001.
Inspire Record 557212 DOI 10.17182/hepdata.42921

We present results from a measurement of double diffraction dissociation in $\bar pp$ collisions at the Fermilab Tevatron collider. The production cross section for events with a central pseudorapidity gap of width $\Delta\eta^0>3$ (overlapping $\eta=0$) is found to be $4.43\pm 0.02{(stat)}{\pm 1.18}{(syst) mb}$ [$3.42\pm 0.01{(stat)}{\pm 1.09}{(syst) mb}$] at $\sqrt{s}=1800$ [630] GeV. Our results are compared with previous measurements and with predictions based on Regge theory and factorization.

1 data table match query

Cross sections for double diffractive production.


Measurement of total and partial photon proton cross-sections at 180-GeV center-of-mass energy

The ZEUS collaboration Derrick, M. ; Krakauer, D. ; Magill, S. ; et al.
Z.Phys.C 63 (1994) 391-408, 1994.
Inspire Record 372260 DOI 10.17182/hepdata.45055

Photon proton cross sections for elastic light vector meson production, σelνp, inelastic diffractive production, σndνp, non-diffractive production, σdνp, as well as the total cross section, σtotνp, have been measured at an average υp center of mass energy of 180 GeV with the ZEUS detector at HERA. The resulting values are σelνp = 18 ± 7 μb, σdνp = 33 ± 8 μb, σndνp = 91 ± 11 μb, and σtotνp 143 ± 17 μb, where the errors include statistical and systematic errors added in quadrature.

1 data table match query

Errors contain both statistics and systematics.


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.


Observation of diffractive W boson production at the Tevatron

The CDF collaboration Abe, F. ; Akimoto, H. ; Akopian, A. ; et al.
Phys.Rev.Lett. 78 (1997) 2698-2703, 1997.
Inspire Record 440095 DOI 10.17182/hepdata.42230

We report the first observation of diffractively produced W bosons. In a sample of W -> e nu events produced in p-barp collisions at sqrt{s}=1.8 TeV, we find an excess of events with a forward rapidity gap, which is attributed to diffraction. The probability that this excess is consistent with non-diffractive production is 1.1 10^{-4} (3.8 sigma). The relatively low fraction of W+Jet events observed within this excess implies that mainly quarks from the pomeron, which mediates diffraction, participate in W production. The diffractive to non-diffractive W production ratio is found to be R_W=(1.15 +/- 0.55)%.

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.


Double diffractive cross-section measurement in the forward region at LHC

The TOTEM collaboration Antchev, G. ; Aspell, P. ; Atanassov, I. ; et al.
Phys.Rev.Lett. 111 (2013) 262001, 2013.
Inspire Record 1251897 DOI 10.17182/hepdata.64889

The first double diffractive cross-section measurement in the very forward region has been carried out by the TOTEM experiment at the LHC with center-of-mass energy of sqrt(s)=7 TeV. By utilizing the very forward TOTEM tracking detectors T1 and T2, which extend up to |eta|=6.5, a clean sample of double diffractive pp events was extracted. From these events, we measured the cross-section sigma_DD =(116 +- 25) mub for events where both diffractive systems have 4.7 <|eta|_min < 6.5 .

2 data tables match query

Visible double diffractive cross-section measurements in the forward region. See paper for details of the nomenclature.

True eta_min corrected double diffractive cross-section measurements in the forward region. See paper for details of the nomenclature.


Pion and Nucleon Dissociation in $\pi^- p \to \pi^- \pi^+ \pi^- p$ at 205 GeV/c

Bingham, H.H. ; Chew, D.M. ; Fretter, W.B. ; et al.
Phys.Lett.B 51 (1974) 397-401, 1974.
Inspire Record 90046 DOI 10.17182/hepdata.27930

In a 48 000-picture exposure of the Fermilab 30-inch hydrogen bubble chamber to a 205 GeV/ c π − beam, we have measured 169 events of the reaction, π − p → π − π + π − p, with a cross section of 635 ± 61 μ b. This reaction proceeds almost entirely via low mass π − → 3 π and p → p ππ dissociation. Factorization is satisfied for p → pππ dissociation in πp and pp interactions.

1 data table match query

No description provided.


Cross-Sections for Diffractive p p --> p x from 100-GeV to 400-GeV

Schamberger, R.Dean ; Lee-Franzini, Juliet ; Mccarthy, R. ; et al.
Phys.Rev.Lett. 34 (1975) 1121-1124, 1975.
Inspire Record 102549 DOI 10.17182/hepdata.21249

We have measured the cross section for p+p→p+X for MX2 up to a constant fraction of s. We observe no rise for 130<E<400 GeV. The inelastic cross section for 0<M2<0.06s is 2.50±0.05 mb for various values of s from 263 to 752 GeV2.

1 data table match query

No description provided.


DIFFRACTIVE PRODUCTION OF pi- pi- pi+ IN 200-GeV/c pi- N INTERACTIONS

Joyner, R.W. ; Chang, C.C. ; Davis, T.C. ; et al.
Phys.Rev.D 39 (1989) 1865, 1989.
Inspire Record 22768 DOI 10.17182/hepdata.23242

This paper analyzes π−N→π−π−π+N events from Fermilab experiment E-580, using 200-GeV/c particles on a segmented target of plastic scintillator. Starting with 48 657 triggers, data-quality cuts and a cut on missing mass squared of M2<16 GeV2 lead to a final sample of 7205 events. The xF distribution of the 3π system shows almost all events in a sharp peak at xF=1, suggesting the presence of beam diffraction into three pions. The overall t’ distribution is fit to the sum of three exponential terms corresponding to coherent diffraction from carbon nuclei, diffraction from individual nucleons, and background. Cross sections per nucleon and exponential slopes are reported for each of the three components as a function of 3π effective mass. The cross section for diffraction from the nucleons in the target is 0.34±0.04 mb/nucleon. The cross section for coherent diffraction from carbon is 1.08±0.12 mb/nucleus. The exponential slope for diffraction is observed to decrease with increasing 3π effective mass. The fraction of coherent carbon diffraction in the total cross section is observed to decrease with increasing 3π effective mass. In the π−π+ effective-mass spectrum the ρ0(770) and f0(1270) are observed and their cross sections per nucleon are calculated. In the π−π−π+ effective-mass spectrum the A1−/A2− and A3− enhancements are observed and a cross section for the A3− is calculated.

7 data tables match query

No description provided.

Diffraction from coherent carbon nucleus.

Diffraction from individual nucleon.

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Search for diffractive charm production in 800-GeV/c proton - silicon interactions

The Fermilab E653 collaboration Kodama, K. ; Ushida, N. ; Mokhtarani, A. ; et al.
Phys.Lett.B 316 (1993) 188-196, 1993.
Inspire Record 35969 DOI 10.17182/hepdata.28848

A search for charm production in the coherent diffractive dissociation reaction pSi→XSi was carried out for the modes D 0 → K − π + , D 0 → K − π + π + π − , and D + → K − π + π + . No charm signals were observed, and the 90% confidence level upper limit for coherent charm pair production was determined to be 26 μ b per silicon nucleus. The results are interpreted as an upper limit of 0.2% on the amount of intrinsic charm in the proton.

1 data table match query

90 pct CL upper limits.