An Amplitude Analysis for the Reaction pi+ p ---> pi+ pi- pi0 Delta++ at 7-GeV/c

Wagner, F. ; Tabak, M. ; Chew, D.M. ;
Phys.Lett.B 58 (1975) 201, 1975.
Inspire Record 91398 DOI 10.17182/hepdata.27792

An amplitude analysis for the reaction π + p → π + π − π 0 Δ ++ at 7 GeV/ c has been performed using the isobar model for the 3 π system. The 3 π -mass covers the range from 0.82 to 1.90 GeV. We observe strong A 2 production. The spin parity of the ω ∗ (1700) is determined to be 3 − . No significant A 1 production can be seen.

2 data tables

No description provided.

FROM INTEGRATING BREIT-WIGNER FITS TO THE JP=3- AMPLITUDE FOR -T < 0.8 GEV**2.


Photoproduction of the psi (3100) Meson at 11-GeV

Gittelman, B. ; Hanson, K.M. ; Larson, D. ; et al.
Phys.Rev.Lett. 35 (1975) 1616, 1975.
Inspire Record 99727 DOI 10.17182/hepdata.21158

The photoproduction of the ψ(3100) meson from a beryllium target has been measured using an 11.8-GeV bremsstrahlung beam. The energy and angular dependence of the measured spectra may be obtained from an elastic nucleon cross section of the form dσdt=(1.01±0.20)exp[(1.25±0.20)t] nb/GeV2. This cross section is exceedingly small in comparison with those of the other vector mesons.

1 data table

ELECTRON PAIR PRODUCTION FROM BERYLLIUM TARGET. ELASTIC CROSS SECTION VALUE ALLOWS FOR SYSTEMATIC UNCERTAINTIES AND POSSIBLE INELASTIC CONTRIBUTIONS. -TMIN = 0.41 GEV**2.


Evidence for Two Narrow p anti-p Resonances at 2020-MeV and 2200-MeV

The CERN-College de France-Ecole Poly-Orsay collaboration Benkheiri, P. ; Boucrot, J. ; Bouquet, B. ; et al.
Phys.Lett.B 68 (1977) 483, 1977.
Inspire Record 119491 DOI 10.17182/hepdata.27541

From the study of the reaction π − p→p F p p π − using a fast proton (p F ) trigger device in the CERN Omega spectrometer, we find evidence for two narrow p p states produced mainly in association with a Δ° (1232) and a N° (1520). The statistical significance of each peak is greater than 6 standard deviations. Masses and natural widths of these resonances are respectively M = 2020 ± 3 MeV , Λ 1 = 24 ± 12 MeV and M 2 = 2204 ± 5 MeV, Λ 2 = 16 −16 +20 MeV. Our data are consistent with a small production of the narrow ∼ 1935 MeV resonance already reported. Production cross sections for these new p p resonances are given.

1 data table

ERRORS TAKE INTO ACCOUNT STATISTICAL ERRORS AND BACKGROUND SUBTRACTION UNCERTAINTY BUT NOT ACCEPTANCE CORRECTIONS UNCERTAINTY OF 15 PCT.


Production and Decay of xi* (1820) in K- p Reactions at 4.2-GeV/c

The Amsterdam-CERN-Nijmegen-Oxford collaboration Gay, J.B. ; Armenteros, R. ; Berge, J.P. ; et al.
Phys.Lett.B 62 (1976) 477-480, 1976.
Inspire Record 108822 DOI 10.17182/hepdata.27651

Using a high statistics sample of K − p interactions at 4.2 GeV/ c , the production and decay properties of the Ξ ∗ (1820) are discussed. The mass and width are found to be M = (1823 ± 2) MeV and Γ = (21 ± 7) MeV. Evidence is found for Ξ ∗ (2030) in the Σ K ̄ channel and for a new Ξ ∗ at a mass of 2120 MeV in the ΛK − channel.

2 data tables

XI(1820)- PRODUCTION CROSS SECTIONS ARE FOR -UP < 3 GEV**2 AND ARE CORRECTED FOR ISOSPIN AND UNSEEN DECAY MODES.

No description provided.


Measurement of the spin rotation parameter r in proton proton elastic scattering at 6 and 16 gev/c

Deregel, J. ; Bystricky, J. ; Cozzika, G. ; et al.
Phys.Lett.B 43 (1973) 338-340, 1973.
Inspire Record 84912 DOI 10.17182/hepdata.28132

The spin rotation parameter R in elastic proton-proton scattering has been determined at incident momenta 6 and 16 GeV/ c in the interval from t = −0.18 (GeV/ c ) 2 to −0.54 (GeV/ c ) 2 . R pp at 16 GeV/ c is close to the val obtained for R in π − p elastic scattering at the same incident momentum. Equality of R pp ( s , t ) and R π p ( s , t ) is expected if Pomeron exchange dominates and if factorization holds. The t -dependence of R at 16 GeV/ c is consistent with weak helicity flip.

2 data tables

No description provided.

No description provided.


Spin Spin Interactions in High p-Transverse**2 Elastic p p Scattering

O'Fallon, J.R. ; Ratner, L.G. ; Schultz, P.F. ; et al.
Phys.Rev.Lett. 39 (1977) 733, 1977.
Inspire Record 5637 DOI 10.17182/hepdata.20968

We measured dσdt for p+p→p+p at 11.75 GeV/c using the zero-gradient synchrotron 70% polarized-proton beam and a 65% polarized-proton target. We obtained the spin-orbit asymmetry parameter A and the spin-spin correlation parameter Cm out to P⊥2=4.2 (GeV/c)2. We found that A drops smoothly towards zero, but that Cnn increases abruptly near P⊥2=3.6 (GeV/c)2, where the exp(−1.4P⊥2) component of elastic scattering becomes dominant. This suggests that large-P⊥2 "hard" elastic scattering may occur mostly when the two proton spins are parallel.

1 data table

No description provided.


Analysis of the anti-p p --> anti-p p pi+ pi- Reaction at 5.7-GeV/c

Atherton, H.W. ; French, B.R. ; Skura, J. ; et al.
Nucl.Phys.B 103 (1976) 381-398, 1976.
Inspire Record 113033 DOI 10.17182/hepdata.36027

From 63 760 four pronged events we have selected 10 960 events of the p p π + π − final state. We have studied baryon resonances production and the associated production of Δ(1236) Δ (1236) isobars. We find (48.5 ± 2.6)% of Δ ++ Δ ++ and (4.5 ± 0.5)% of Δ 0 Δ 0 . Study of the various mass spectra shows that they are essentially described by the introduction of Δ ++ ( Δ ++ ) production. Introduction of the strong t dependence of the Δ ++ ( Δ ++ ) changes this description only slightly. A study of the interaction radius of the p π system reveals a best value of r = 1.6 ± 0.4 fm. Bumps observed in the p π + π − + c.c. system at 1450 and 1690 MeV when treated as resonances give rates of (4.0 ± 0.4)% and (4.5 ± 0.4)% respectively. We arrive at the conclusion that the reaction p p → p p π + π − at 5.7 GeV/ c proceeds almost entirely via the production of baryon resonances.

2 data tables

No description provided.

No description provided.


A Comparison of the Shapes of pi+ p and p p Diffraction Peaks from 50-GeV/c to 175-GeV/c

The Fermilab Single Arm Spectrometer Group collaboration Ayres, D.S. ; Diebold, Robert E. ; Maclay, G.J. ; et al.
Phys.Rev.Lett. 37 (1976) 548, 1976.
Inspire Record 108238 DOI 10.17182/hepdata.21073

The ratio of π+p to pp elastic scattering is found to be smoothly varying over the range −t=0.03 to 0.4 GeV2. It is well fitted by a single exponential, indicating the forward behavior must be quite similar for the two reactions.

1 data table

ACTUALLY THE DATA ARE THE EXPONENTIAL SLOPE OF THE RATIO OF D(SIG)/DT FOR THE TWO REACTIONS.


Elastic Scattering Crossovers from 50-GeV to 175-GeV

The Fermilab Single Arm Spectrometer Group collaboration Anderson, R.L. ; Anelli, E.F. ; Ayres, D.S. ; et al.
Phys.Rev.Lett. 37 (1976) 1025, 1976.
Inspire Record 108810 DOI 10.17182/hepdata.21092

A comparison of K±p and p±p elastic scattering is made for incident energy 50 to 175 GeV. Average values of 0.19±0.04 and 0.11±0.02 GeV2 were found for the invariant-momentum-transfer values of the Kp and pp crossover points, respectively.

1 data table

KP AND PP CROSSOVER POINTS AT -T = 0.19 +- 0.04 AND 0.11 +- 0.02 GEV**2 (AVERAGE VALUES) RESPECTIVELY.


Measurement of Elastic Scattering of Hadrons on Protons from 50-GeV/c to 175-GeV/c

Group, Fermilab Single Arm Spectrometer ;
Phys.Rev.Lett. 35 (1975) 1195, 1975.
Inspire Record 98699 DOI 10.17182/hepdata.21217

Differential cross sections have been measured at Fermilab with a focusing spectrometer for π±p, K±p, and p±p elastic scattering at 50-, 70-, 100-, 140-, and 175-GeV/c incident momentum over the |t| range 0.03 to 0.8 GeV2. The results are smooth in t and are parametrized by quadratic exponential fits.

1 data table

DATA PRESENTED AGAIN IN LATER PAPER.


Study of the Reaction anti-p p --> anti-Delta++ Delta++ at 9.1-GeV/c

Walck, C. ; Carlsson, R. ; Ekspong, G. ; et al.
Nucl.Phys.B 100 (1975) 61-73, 1975.
Inspire Record 104375 DOI 10.17182/hepdata.36103

Single and joint decay angular distributions in the reaction p p → Δ ++ Δ ++ at 9.13 GeV/ c are discussed in the framework of single and double statistical tensors. The t dependence of 12 double statistical tensors is presented. Cross sections for p p → p p π + π − and p p → Δ ++ Δ ++ are determined to be 2.60 ± 0.10 and 0.90 ± 0.10 mb respectively. The results obtained are compared with other experiments mainly at 5.7 and 12 GeV/ c .

4 data tables

No description provided.

No description provided.

FROM FITTING DECAY ANGULAR DISTRIBUTIONS OF BOTH ISOBARS ADDED.

More…

Delta Production in 3.1-GeV/c-3.6-GeV/c K- p Interactions

Wells, J. ; Radojicic, D. ; Roscoe, D.A. ; et al.
Nucl.Phys.B 101 (1975) 333-348, 1975.
Inspire Record 104378 DOI 10.17182/hepdata.36054

We present evidence for δ production in the reactions K − p→ Σ (1385) + δ − ; δ − → η 0 π − , and K − p → Λδ + π − ; δ + → η 0 π + , in a bubble chamber experiment with beam momentum in the range 3.1 to 3.6 GeV/ c . The η 0 from the δ decay is seen both as a missing mass effect, and in its charged decay modes. The δ − has a mass of 989 ± 4 MeV, and width a of 16 −16 +25 MeV (after allowing for experimental resolution). The cross section for Σ(1385) − δ − production is 7±3 μ b; the reaction is produced at small momentum transfers. The mass and width of the δ + are consistent with those of the δ − , and the cross section for the Λ 0 π − δ + final state is about 5 μb. Neither δ appears to be produced as a result of D 0 decay.

1 data table

No description provided.


PRISM Plot Analysis of the Reaction pi+ p --> p pi+ pi+ pi- at 16-GeV/c

The AACHEN-BERLIN-BONN-CERN-CRACOW-HEIDELBERG-WARSAW collaboration Deutschmann, M. ; Kirk, H. ; Sixel, P. ; et al.
Nucl.Phys.B 99 (1975) 397-419, 1975.
Inspire Record 104134 DOI 10.17182/hepdata.35967

We have analysed the reaction π + p → pπ + π + π − at 16 GeV/c by means of the prism plot analysis (PPA) as proposed by Pless et al. We have separated ten reaction channels contributing to the final state pπ + π + π − and present the results in terms of partial and differential cross sections, invariant mass and decay angular distributions. We show that the PPA is a self-controlling method which is demonstrated by the emergence of a broad (3π) + enhancement around 1800 MeV decaying into ρ 0 π + .

1 data table

PARTIAL CROSS SECTIONS FOR THE (P PI+ PI+ PI-) FINAL STATE.


Production of the Delta (1950) by One Pion Exchange in pi+ p Interactions at 13-GeV/c

Gaidos, J.A. ; Miller, David Harry ;
Phys.Rev.D 12 (1975) 2565, 1975.
Inspire Record 2181 DOI 10.17182/hepdata.24834

We have observed the production of high-mass I=32 baryon resonances in π+p interactions at 13 GeV/c. The most prominent of these is found to be the F37 Δ(1950). It is produced by one-pion exchange and the data are well described by on-shell π+p phase shifts. Decays into pπ+ and pπ+π0 are observed and the Δ(1950) is found to have a mass 1.880 ± 0.010 GeV and width of 0.180 ± 0.030 GeV with a production cross section of 43 ± 4 μb.

1 data table

RESONANCE BACKGROUNDS SUBTRACTED.


Some Aspects of Lambda Production in the Exclusive Reactions K- p --> Lambda0 (n) Pions at 8.25-GeV/c

The ATHENS-DEMOCRITOS-LIVERPOOL-VIENNA collaboration Girtler, P. ; Markytan, M. ; Dallman, D.P. ; et al.
Nucl.Phys.B 99 (1975) 13-29, 1975.
Inspire Record 104142 DOI 10.17182/hepdata.31862

Cross sections are given for the various exclusive reactions K − p→ Λ 0 + n pions, as well as for quasi two-body final states involving ϱ 0 , ω 0 and Y 1 ∗ (1385) resonance production. The general features of Λ 0 production are presented as a function of the pion multiplicity n . Production of Y 1 ∗+ (1385) is clearly observed at all multiplicities while the Y 1 ∗− (1385) signals grow with the multiplicity, as expected in a non-exotic exchange picture. The polarisation of the Λ 0 is consistent with zero everywhere, except when it is a decay product of Y 1 ∗ (1385), when non-zero values are found for odd values of n . The reactions Λ 0 + 2π and Λ 0 + 3π are analysed in terms of the Plahte-Roberts model and good overall agreement is obtained for the various effective mass distributions and the p L ∗ , p T and cos θ distributions for the individual particles.

1 data table

No description provided.


The Reaction anti-p p --> anti-p p pi+ pi- pi0 at 5.7-GeV/c and a p Omega0 (anti-p Omega0) Enhancement at 1.81-GeV

Atherton, H.W. ; Bar-Nir, I. ; French, B. ; et al.
Nuovo Cim.A 30 (1975) 505, 1975.
Inspire Record 90795 DOI 10.17182/hepdata.37672

The final states\(\bar p\)pω and\(\Delta ^{ ++ } \bar \Delta ^{ -- } \pi ^0 \), produced in the reaction\(\bar p\)p →\(\bar p\)pπ+π−π0 (6435 events) at 5.7 GeV/c, are studied. Cross-sections are presented, and general features of the resonances produced are investigated. Spin alignment of the ω’s, reported earlier, is studied. An enhancement is observed in the ωp (ω\(\bar p\)) mass plot of mass (1810±15) MeV and width (87 ± 20) MeV.

1 data table

No description provided.


The Reactions K+ n --> (K pi pi) 0+ n+ 0 at 2-GeV/c to 3-GeV/c

Banerjee, S. ; Campbell, J.R. ; Hall, G. ; et al.
Nucl.Phys.B 97 (1975) 413-425, 1975.
Inspire Record 103797 DOI 10.17182/hepdata.31923

The reactions K + n → K + π + π − n, K + n → K 0 π + π − p and K + n → K + π − π 0 p have b investigated in a 3.8 event/μb K + d bubble chamber experiment with incident momenta of 2.2, 2.45 and 2.7 GeV/ c . Channel cross sections are given and the general characteristics of the production processes described. The isobar model is used in an attempt to determine the spin-parity structure of the final states.

2 data tables

No description provided.

No description provided.


Study of xi- and omega- Production from K- n and K- p Interactions at 4.93-GeV/c

DiBianca, F.A. ; Endorf, R.J. ;
Nucl.Phys.B 98 (1975) 137-150, 1975.
Inspire Record 104141 DOI 10.17182/hepdata.31834

Cross sections, mass spectra, angular distributions and several other features of Ξ − and Ω − production from photons and neutrons in K − d interactions at 4.93 GeV/ c are presented. A five standard deviation peak is observed in Ξ K π mass spectra near 2.6 GeV/ c 2 . A sharp rise in the Ξ − three- and four-body cross sections from K − n interactions suggests direct-channel Σ ∗ (3.0–3.5) formation.

1 data table

No description provided.


Measurement of the anti-Lambda-Proton Total Cross-Section in the Momentum Range from 4 to 14-GeV/

Eisele, F. ; Geweniger, C. ; Kleinknecht, K. ; et al.
Phys.Lett.B 60 (1976) 297-301, 1976.
Inspire Record 112804 DOI 10.17182/hepdata.27729

The Λ p total cross section has been measured in the Λ momentum range 4–14 GeV/c. The weighted mean of the cross section over this momentum interval is σ( Λ p) = 49.3 ± 3.7 mb for an average Λ momentum of 8.3 ± 2.7 GeV/ c . This value differs from the corresponding value for σ(Λp) measured previously by 14.5 ± 3.8 mb. Assuming a variation with Λ momentum, pΛ , of the form σ( Λ p) − σ(Λp) = σ 1pΛ − 1 2 , a value of σ 1 = 47 ± 10 mb GeV − 1 2 is obtained.

1 data table

No description provided.


A20 Production by Charge Exchange in pi+ n Interactions at 4-GeV/c

Emms, M.J. ; Jones, G.T. ; Kinson, J.B. ; et al.
Phys.Lett.B 58 (1975) 117-120, 1975.
Inspire Record 98783 DOI 10.17182/hepdata.27809

A partial wave analysis of the reaction π + n → π + π − π 0 p yields an A 0 2 production cross section of 225 ± 30μb for momentum transfer squared < 1 (GeV/ c ) 2 ; the differential cross-section and density matrix are presented and compared with ω 0 production in the light of theoretical models.

2 data tables

Axis error includes +- 10/10 contribution.

ASSUMING NO POPULATION OF HELICITY 2 DENSITY MATRIX ELEMENTS IN T-CHANNEL FRAME. THIS MM = 1+, 1-, 2+, 2- NOTATION REFERS TO THAT SUM OR DIFFERENCE OF HELICITY M DENSITY MATRIX ELEMENTS CORRESPONDING ASYMPTOTICALLY TO NATURAL (+) OR UNNATURAL (-) PARITY EXCHANGE.


Results on pi- p Backward Elastic Scattering and Search for pi- p --> d anti-p at 9-GeV/c and 12-GeV/c

Jacholkowski, A. ; Bouquet, B. ; D'Almagne, B. ; et al.
Nucl.Phys.B 126 (1977) 1-10, 1977.
Inspire Record 125076 DOI 10.17182/hepdata.35368

From an experiment done with the CERN Omega spectrometer, triggered by a fast forward proton device, we present results on the differential cross section d σ d u for π − p backward elastic scattering. The d σ d u distribution agrees with an A e Bu law. The compilation of existing results shows a discrepancy between results but the ( d σ d u ) u=0 data fit perfectly an s 2 α 0 −2 dependence, as predicted by a single Δδ Regge trajectory exchange. A search for the reaction π − p → d p , with a fast forward deuteron, which can be produced by a double-baryon exchange mechanism, gives cross-section upper limits of ∼1% of the backward elastic cross section.

4 data tables

UMIN IS 0.0446 GEV**2.

UMIN IS 0.0333 GEV**2.

D(SIG)/DU FITTED FOR 0 < -U < 0.75 GEV**2 TO GIVE SLOPE/INTERCEPT.

More…

A Measurement of the Polarization Parameter in Large Angle Proton Proton Elastic Scattering at 7.9-GeV/c

Aschman, D.G. ; Crabb, D.G. ; Green, K. ; et al.
Nucl.Phys.B 125 (1977) 349-368, 1977.
Inspire Record 125075 DOI 10.17182/hepdata.35322

The polarization parameter in proton-proton elastic scattering has been measured at an incident momentum of 7.9 GeV/ c and four-momentum transfers in the range 0.9 < | t | < 6.5 (GeV/ c ) 2 using a high intensity unpolarized proton beam incident on a polarized proton target. The angle and momentum of the forward scattered protons were measured with a magnet spectrometer and scintillation counter hodoscopes and the angle of the recoil proton was measured using similar hodoscopes. A clean separation between the elastic scattering from free hydrogen and that coming from inelastic interactions and from interactions with complex nuclei in the target was obtained. The polarization shows substantial structure rising from zero at | t | = 1.0 (GeV/ c ) 2 to a maximum at | t | = 1.7 (GeV/ c ) 2 and then falling to zero at | t | = 2.0 (GeV/ c ) 2 . There is evidence of a further peak at | t | = 2.8 (GeV/ c ) 2 . Above | t | = 3.25 (GeV/ c ) 2 the polarization is small and consistent with zero. A comparison of these data with data obtained at other beam momenta shows that the polarization parameter has a strong momentum dependence.

1 data table

No description provided.


Spin Parity Analysis of the rho (1.71) Resonance Produced in 9.1-GeV/c pi- p Interactions

Armenise, N. ; Fogli Muciaccia, M.T. ; Silvestri, A. ; et al.
Lett.Nuovo Cim. 14 (1975) 177-183, 1975.
Inspire Record 103792 DOI 10.17182/hepdata.37443

None

1 data table

FOUR PION RESONANCE CALLED RHO(1.71) BY AUTHORS. DECAY IS CONSISTENT WITH 100 PCT <RHO0 RHO-> MODE.


Measurement of Differential Cross-Sections for anti-Proton-Proton Annihilation Into Charged Pion and Kaon Pairs Between 0.79-GeV/c and 2.43-GeV/c

Eisenhandler, E. ; Gibson, W.R. ; Hojvat, C. ; et al.
Nucl.Phys.B 96 (1975) 109-154, 1975.
Inspire Record 99060 DOI 10.17182/hepdata.31972

Differential cross sections have been measured for the interactions p p → π − π + and p p → K − K + over a centre of mass angular range −0.95 ⩽ cos θ ∗ ⩽ 0.95 at 20 incident momenta between 0.79 and 2.43 GeV/ c . A magnetic spectrometer with wire spark chambers was used. Typically 2000 π − π + and 300 K − K + events were obtained at each momentum. Results are compared with those from related experiments.

10 data tables

No description provided.

No description provided.

No description provided.

More…

Comparison of the Line Reversed Channels anti-p p --> pi- pi+ and pi+ p --> p pi+ at 6-GeV/c

Stein, N.A. ; Edelstein, R.M. ; Green, D.R. ; et al.
Phys.Rev.Lett. 39 (1977) 378-381, 1977.
Inspire Record 124936 DOI 10.17182/hepdata.20964

Differential cross sections have been measured for p¯p→π−π+ (1) and its line-reversed partner π+p→pπ+ (2) in the range tmin>t>−1.5 (GeV/c)2 at 6 GeV/c. Clear structure is seen in the differential cross section for Reaction (1) at t∼−0.4 (GeV/c)2. However, this feature is quite different from the striking dip seen in (2) at t∼−0.15 (GeV/c)2, indicating a failure of line reversal and disagreement with simple Regge models.

2 data tables

No description provided.

No description provided.