HEPData Search

The polarization of the recoil proton at this energy depends on the interference of the P 33 phase shift with the P 11 and S 11 phase shifts. The measured values indicate the existence of a large P 11 phase shift. The polarization was measured by scattering from carbon blocks in spark chambers using a Vidicon scanner to record the data.

1 data table

Table 1

No description provided.

pi+ proton, pi- proton and pp elastic scattering at 8.5, 12.4 and 18.4 GeV/c

Harting, D. ; Blackall, P. ; Elsner, B. ; et al.

Nuovo Cim. 38 (1965) 60, 1965.

Inspire Record 49759 DOI 10.17182/hepdata.1110

Approximately 60 000 events have been collected in a spark chamber experiment at the CERN Proton Synchrotron which studied elastic diffraction scattering of π--p and p-p at incident momenta of 8.5, 12.4 and 18.4 GeV/c and of π+-p at 8.5 and 12.4 GeV/c. Magnetic analysis of the incoming and diffraction scattered particle, together with measurement of all angles, permitted each event to be determined as elastic subject to three constraints, so that the inelastic background was rejected with. high efficiency, even at the larger momentum, transfers. Much of the data have been processed by the CERN Automatic Flying-Spot DigitizerHPD. A detailed description of the experimental technique and of the methods of analysis is given. The results, together with data from lower energies, confirm the remarkable energy-independence of the shape of the pion-proton diffraction scattering peak up to |t| = 1.5 (GeV/c)2, wheret is the square of the four-momentum transfer, over a range of pion energies from 2 to 18 GeV. Proton-proton scattering does however appear to show a shrinking diffraction peak. In general, the data agree with other experiments using both counter and bubble chamber techniques, but some differences do appear. During the experiment, data were taken which set an upper limit of 2·102 μb/(GeV/c)2 on the differential elastic cross-section dσ/dt over a range of |t| from 20.9 to 23.4 (GeV/c)2 at 13.4 GeV/c incident pion momentum.

18 data tables

Table 1

'1'. '2'. '3'. '4'.

Table 2

'1'.

Table 3

'1'.

More…

Pion production in $\pi^-$ - $p$ interactions at energies 790, 830, and 870 {MeV}

Cason, N.M. ; Derado, I. ; Lamsa, J.W. ; et al.

Phys.Rev. 150 (1966) 1134-1140, 1966.

Inspire Record 50370 DOI 10.17182/hepdata.26587

Single-pion production has been studied in the reactions π−p→π−π+n and π−p→π−π0p at 790, 830, and 870 MeV. A total of 4193 events in these two channels, divided approximately equally between the three energies, have been identified. The most interesting feature of the data is the tendency for events to concentrate at high values of mππ and low values of four-momentum transfer. These effects are discussed in terms of conventional isobar models and a model involving two-pion exchange. Partial cross sections for the reactions studied are reported for each energy.

1 data table

Table 1

No description provided.

Pion production and elastic scattering in anti-proton-proton collisions at 6.94 bev/c

Ferbel, T. ; Johnson, J.A. ; Kraybill, H.L. ; et al.

Phys.Rev. 173 (1968) 1307-1314, 1968.

Inspire Record 55957 DOI 10.17182/hepdata.26499

We have studied nonstrange p¯−p interactions observed in 7000 pictures of the 80-in. Brookhaven National Laboratory hydrogen bubble chamber exposed to an antiproton beam with a momentum of 6.94 BeVc. The total cross section was measured to be 58.7±2.8 mb, and the elastic interaction cross section 14.2±1.2 mb. The elastic differential cross section for four-momentum transfers (−t)≤0.3 (BeVc)2 is well described by the exponential form dσeldt=(dσdt)t=0ebt, where b=13.1±1.1 (BeVc)−2. The single-pion production cross section is 4.0±0.9 mb. This channel proceeds 70% through resonance formation. N*(1238) isobar and anti-isobar formation dominates pion production in four- and six-pronged events; the double-isobar formation cross section in the final state pπ+p¯π− is 1.35±0.2 mb. Isobar production was observed to be consistent with the predictions of a dominant one-particle-exchange process. The pion-annihilation process, which has a cross section of 25±5 mb, shows substantial pion resonance formation.

1 data table

Table 1

'1'. '2'.

Pi-plus-minus p elastic scattering in the 2-gev region

Busza, W. ; Duff, B.G. ; Garbutt, D.A. ; et al.

Phys.Rev. 180 (1969) 1339-1348, 1969.

Inspire Record 55449 DOI 10.17182/hepdata.6227

π±p elastic differential cross sections in the momentum range 1.72-2.80 GeV/c have been measured at the proton synchrotron "NIMROD" of the Rutherford High Energy Laboratory. The results are tabulated, and analyses of the differential cross sections employing optical models and Legendre polynomial expansions are advanced. A critical discussion of a recent interpretation of differential-cross-section structure in terms of interference between resonant and background amplitudes is presented.

25 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Evidence for dominance of pomeron like exchange in p + p ---> n + n + pi at 19 gev/c

Boggild, H. ; Hansen, K. ; Johnstad, H. ; et al.

Phys.Lett.B 30 (1969) 369-372, 1969.

Inspire Record 56657 DOI 10.17182/hepdata.28910

The reactions pp → NN π are studied at 19 GeV/ c and analysed in terms of the amplitudes with the low mass N π system in isospin states 1 2 and 3 2 respectively. The I − 1 2 cross section is compared with the corresponding one in π p→ ππ N at 8 GeV/ c .

1 data table

Table 1

'1'.

Coincidence measurements of single-pion electroproduction near the delta(1236) resonance

Mistretta, C. ; Appel, J.A. ; Budnitz, R.J. ; et al.

Phys.Rev. 184 (1969) 1487-1507, 1969.

Inspire Record 62286 DOI 10.17182/hepdata.26474

Differential cross sections for the reactions e−+p→e−+p+π0 and e−+p→e−+n+π+ have been measured near the Δ(1236) resonance at four-momentum transfers of 0.05, 0.13, 0.25, and 0.4 (GeV/c)2. A few measurements of the π+ angular distribution have been obtained at a four-momentum transfer of 0.6 (GeV/c)2. Cross sections for the π0 reaction are compared with dispersion-theory predictions at several pion-nucleon c.m. energies for each four-momentum transfer. A phenomenological analysis of the π0 results leads to the determination of the magnetic dipole and electric quadrupole partial-wave amplitudes and the γNΔ transition form factor. Evidence is found for the existence of a significant scaler-transverse interference term in the cross section, which is tentatively associated with the resonant scaler quadrupole interaction. Cross sections for π+ electroproduction are compared with dispersion theories using the pion form factor as a free parameter. The results suggest a form factor similar to that of the proton. A fit to the form-factor results, using the ρ-dominance model, requires mρ=560±80 MeV. The rms pion charge radius is estimated to be 〈r2〉12=0.86±0.14 F.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

General characteristics of the annihilation reaction p p ---> 3pi+ 3pi- (pi0) at 3.6 gev/c

Atherton, H.W. ; Blair, W.M.R. ; Celnikier, L.M. ; et al.

Nucl.Phys.B 18 (1970) 221-245, 1970.

Inspire Record 62649 DOI 10.17182/hepdata.34415

In the reaction p p → 3π + 3π − 2227 events, and in the reaction p p → 3π + 3π − π 0 6578 events have been analyzed. The general characteristics of the reactions, such as total cross sections, angular and momentum distributions, the production of ϱ, f, ω and η mesons, and angular correlations are presented.

4 data tables

Table 1

No description provided.

Table 2

THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.

Table 3

THETA being the angle between PI+ and P (or PI- and PBAR) in CMS.

More…

Anti-proton-neutron elastic scattering at 3.5 gev/c

Reynolds, B.G. ; Weaver, K.E. ; Bishop, J.M. ; et al.

Phys.Rev.D 2 (1970) 1767-1776, 1970.

Inspire Record 61323 DOI 10.17182/hepdata.4323

We have measured the p¯n differential elastic cross section for −t≥0.15 (GeV/c)2. We compare our data with existing data from p¯p and np elastic scattering experiments in this energy region. Our data show a dip in the cross section at −t≃0.45 (GeV/c)2 and a secondary maximum at −t≃0.7 (GeV/c)2. We see no evidence for backward peaking in p¯n elastic scattering at this energy. Evidence is presented for I=1, t-channel exchange in N¯N scattering.

3 data tables

Table 1

'1'. '2'. 'GLAUB'.

Table 2

No description provided.

Table 3

No description provided.

Measurement of the reaction pi- p ---> pi0 n at large momentum transfers

Brockett, W.S. ; Corlew, G.T. ; Frisken, William R. ; et al.

Phys.Rev.Lett. 26 (1971) 527-530, 1971.

Inspire Record 69039 DOI 10.17182/hepdata.21508

We present results of an experiment to measure the differential cross section of the reaction π−p→π0n between the forward and backward peaks. The measurements were made at incident π− momenta of 3.67 and 4.83 GeVc. The t range 1.7<~|t|<~4.9 (GeVc)2 was covered at the lower momentum and 1.8<~|t|<~7 (GeVc)2 at the higher momentum. At the lower momentum the cross section is essentially constant between |t|=2.4 and 4.8 (GeVc)2 while at the higher momentum the angular distribution exhibits a broad minimum centered at |t|=4.4 (GeVc)2.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Isospin invariance in the reaction n p ---> pi0 d

Wilson, S.S. ; Longo, M.J. ; Young, K.K. ; et al.

Phys.Lett.B 35 (1971) 83-86, 1971.

Inspire Record 69283 DOI 10.17182/hepdata.28477

A measurement of the differential cross section for the reaction n + p → d + π° has been made using a neutron beam with kinetic energies up to 720 MeV. The angle and momentum of the deuterons were measured using an analyzing magnet and wire spark chambers with a magnetostrictive readout. The photons from the decaying π° were not detected. The neutron energy was calculated from the measured deuteron angle and momentum. The cross sections are compared to those for the reaction π + + d ⇆ p + p as a test of isotopic spin invariance in strong interactions. The symmetry of the cross sections about 90° is also investigated, and an upper limit of about 1% is placed on the real part of the ratio of isospin-violating to isospin-conserving amplitudes.

1 data table

Table 1

EKIN IS 325 TO 675 MEV.

THE REACTION pi+ p ---> f0 DELTA++ AT 13.1-GeV/c

Gaidos, J.A. ; Ezell, C.R. ; Lamsa, J.W. ; et al.

Nucl.Phys.B 26 (1971) 225-230, 1971.

Inspire Record 67679 DOI 10.17182/hepdata.33719

Data for the reactionπ + p→f o Δ ++ at 13.1 GeV/ c is presented and discussed within a Reggeized pion exchange model with absorption.

3 data tables

Table 1

No description provided.

Table 2

NUMERICAL VALUES TAKEN FROM THE COMPILATION PDG2 (CHEW 73B). READ FROM GRAPH.

Table 3

No description provided.

Lambda p interactions in momentum range 300 to 1500 mev/c

Kadyk, J.A. ; Alexander, G. ; Chan, J.H. ; et al.

Nucl.Phys.B 27 (1971) 13-22, 1971.

Inspire Record 68765 DOI 10.17182/hepdata.33624

A sample of approximately 250 Λp interactions has been obtained in the Λ-hyperon momentum range of about 300 to 500 MeV/ c . An enhanced Λ-hyperon production rate was obtained by exposing an internally-mounted platinum target to the incident 1.5 GeV/ c meson beam. Cross sections and angular distributions are obtained for the reactions: Λ p → Λ p, Λ p → Σ o p and Λ p → Λ p π o . In the elastic channel, no strong evidence is seen near the Σ o p threshold for the presence of a 3 S 1 resonance, which has been reported, although there is some evidence for a small enhancement in this mass region. There is evidence for the presence of P-waves and probably also D-waves above about 800 MeV/ c , but not below this momentum.

6 data tables

Table 1

D(SIG)/DOMEGA IS ANALYSED IN TABLE 2 BY LEGENDRE POLYNOMIAL EXPANSION. ERRORS ADDED AS 1/SQRT(EVENTS).

Table 2

D(SIG)/DOMEGA IS ANALYSED IN TABLE 2 BY LEGENDRE POLYNOMIAL EXPANSION. ERRORS ADDED AS 1/SQRT(EVENTS).

Table 3

D(SIG)/DOMEGA IS ANALYSED IN TABLE 2 BY LEGENDRE POLYNOMIAL EXPANSION. ERRORS ADDED AS 1/SQRT(EVENTS).

More…

Isospin invariance in the reaction n p ---> pi0 d

Wilson, S.S. ; Longo, M.J. ; Young, K.K. ; et al.

Nucl.Phys.B 33 (1971) 253-280, 1971.

Inspire Record 68508 DOI 10.17182/hepdata.33111

A measurement of the differential cross section for the reaction np→ π 0 d has been made at the Lawrence Radiation Laboratory 184-inch cyclotron. A neutron beam with kinetic energies up to 720 MeV was incident on a liquid hydrogen target. The angle and momentum of the deuterons were measured using an analyzing magnet and wire spark chambers with a magnetostrictive readout. Deuterons were separated from protons by time-of-flight. The photons from the decaying π 0 were not detected. The neutron energy was calculated from the measured deuteron angle and momentum.

9 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

STUDY OF DELTA++ PRODUCTION IN THE REACTION pi+ p ---> pi+ pi0 p AT 13.1-GeV/c

Scharenguivel, J.H. ; Gutay, L.J. ; Gaidos, J.A. ; et al.

Nucl.Phys.B 36 (1972) 363-372, 1972.

Inspire Record 67685 DOI 10.17182/hepdata.33005

We have measured the production and decay angular distributions of the reaction π + p→ π O Δ ++ at 13.1 GeV/ c incident momentum. For − t > 0.1 (GeV/ c ) 2 the data is well described by M1 ϱ-exchange models, the best results being obtained from a weak cut model with a wrong signature nonsense zero. For − t < 0.1 (GeV/c) 2 there is evidence for the existence of other exchange mechanisms.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Polarisation in the reaction pi+ p ---> k+ sigma+ at 1.11 gev/c

Bellamy, E.H. ; Anderson, J. ; Crawford, J.F. ; et al.

Phys.Lett.B 39 (1972) 299-302, 1972.

Inspire Record 75797 DOI 10.17182/hepdata.28308

The polarisation of the recoil sigma in the reaction π + p → K + Σ + has been measured at 12 production angles at a beam momentum of 1.11 GeV /c using counters and spark chambers. The new data are compared with existing phase shift solutions of π p → K Σ channels in the low energy region.

1 data table

Table 1

THE ASYMMETRY PARAMETER, ALPHA, FOR SIGMA+ --> P PI0 IS CLOSE TO -1. THE LAST DATA VALUE IS DEDUCED FROM ALL THE EXPERIMENTAL EVENTS.

K+ p elastic scattering between 2.11 and 2.72 gev/c

Danysz, J.A. ; Penney, B.K. ; Stewart, B.C. ; et al.

Nucl.Phys.B 42 (1972) 29-43, 1972.

Inspire Record 75131 DOI 10.17182/hepdata.32928

Final results are presented of the analysis of the elastic channel in an exposure of 40 000 pictures at each of the four incident K + momenta 2.11, 2.31, 2.5 and 2.72 GeV/ c taken in the 1.5 m British National Hydrogen Bubble Chamber at the 8 GeV/ c proton synchrotron at the Rutherford High Energy Laboratory. Differential cross sections are presented and the results are compared with other published data. A Legendre polynomial analysis requires partial waves up to G wave at all momenta. For the backward peak, visible at each momentum, the slope and the intercept are calculated. A comparison of the forward peak is made with extrapolations from Regge models fitted at higher momenta.

12 data tables

Table 1

RESULTS DIFFER SLIGHTLY FROM THOSE PREVIOUSLY REPORTED IN J. M. BRUNET ET AL., NP B36, 45 (1972).

Table 2

No description provided.

Table 3

No description provided.

More…

K+ p cross-sections between 2.1 and 2.7 gev/c

Brunet, J.M. ; Narjoux, J.L. ; Danysz, J.A. ; et al.

Nucl.Phys.B 36 (1972) 45-57, 1972.

Inspire Record 75386 DOI 10.17182/hepdata.33006

Cross sections are presented for the K + p interacttions with 2, 3, 4 and 5 particles in the final state for incident momenta between 2.1 and 2.7 GeV/c. The results are compared with those from other experiments at nearby momenta.

1 data table

Table 1

Axis error includes +- 0.0/0.0 contribution (?////).

Polarization measurement of the anti-p p ---> anti-n n charge exchange at 8 gev/c

Le Du, P. ; Guisan, O. ; Beusch, W. ; et al.

Phys.Lett.B 44 (1973) 390-392, 1973.

Inspire Record 84827 DOI 10.17182/hepdata.28100

The p p → n n polarization has been measured at 8 GeV/ c and for − t values ranging from 0 up to 0.8 (GeV/ c ) 2 . A small and negative polarization has been found.

1 data table

Table 1

ERRORS INCLUDE STATISTICAL AS WELL AS RELATIVELY SMALL SYSTEMATIC EFFECTS.

Measurements of the polarization parameter in pi+- p elastic scattering between 2.50 and 5.15 gev/c

Scheid, J.A. ; Booth, N.E. ; Conforto, G. ; et al.

Phys.Rev.D 8 (1973) 1263-1277, 1973.

Inspire Record 81836 DOI 10.17182/hepdata.3516

The polarization parameter in π±p elastic scattering has been measured at several momenta in the range 2.50-5.15 GeV/c pion laboratory momentum and covering the range in t approximately from -0.2 to -2.0(GeV/c)2. The data show positive polarization for π±p scattering, having a dip near t=−0.6 (GeV/c)2 and becoming relatively large at greater values of −t. The results for π+ and π− scattering are approximately equal in magnitude but of opposite sign. The data have been analyzed to separate the components, which are symmetric and antisymmetric with respect to pion charge, and to show both the t and s dependence of each part.

29 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Production of $\rho^0$ and $F^0$ in 4 GeV $\pi+D$ interactions

Charlesworth, J.A. ; Sekulin, R.L. ; Emms, M.J. ; et al.

AIP Conf.Proc. 13 (1973) 317-321, 1973.

Inspire Record 83445 DOI 10.17182/hepdata.32392

We have applied the Estabrooks and Martin analysis to a sample of 5279 events produced in the reactionπ+n ⇒ pρ0, and have made a density matrix study, including a positivity analysis, of theJ = 0, 1, 2density matrix in the f0 region, using a sample of 2385 events.

4 data tables

Table 1

S-CHANNEL MOMENTS.

Table 2

T-CHANNEL MOMENTS.

Table 3

S-CHANNEL FRAME.

More…

Elastic anti-p d scattering at 5.55 gev/c incident momentum

Braun, Henri ; Fridman, A. ; Jegham, E. ; et al.

Nucl.Phys.B 54 (1973) 61-77, 1973.

Inspire Record 84177 DOI 10.17182/hepdata.32581

Based on 150 000 photographs taken at the ZGS with the 30 inch deuterium-filled chamber we present an analysis of the elastic p d scattering reaction. Due to unrecoreded small deuteron recoils we were only able to measure the elastic cross section in the four-momentum region | t | > 0.03 (GeV/ c ) 2 . Extrapolation towards small | t | by two different methods gave us two compatible estimates of the total elastic cross section. The differential cross section was analyzed by means of the Glauber formalism both with and without the effects due to the D-wave part of the deuteron wave function. The differential cross sections of np at 5.4 GeV/ c and pn deduced from our data were compared and exhibit a crossover phenomenon.

2 data tables

Table 1

CALCULATED USING TOTAL ELASTIC SIG(-T > 0.03 GEV**2) = 7.2 +- 0.4. THE SMALL ANGLE SCATTERING APPROXIMATION HOLDS: D(SIG)/DOMEGA(RF=LAB) = (P**2/PI)*D(SIG)/DT.

Table 2

INTEGRATED CROSS SECTION USING EITHER EXPONENTIAL EXTRAPOLATION OR GLAUBER MODEL FIT FOR -T < 0.03 GEV**2.

$\pi^- p$ Interactions at 205-GeV/c: Cross-Sections and Charged Particle Multiplicity.

Bogert, D. ; Hanft, R. ; Huson, F.R. ; et al.

Phys.Rev.Lett. 31 (1973) 1271-1274, 1973.

Inspire Record 81730 DOI 10.17182/hepdata.21380

Results are reported based on a study of 3114 π−p events at 205 GeV/c in the National Accelerator Laboratory 30-in. bubble chamber. The measured π−p total and elastic cross sections are 24.0 ± 0.5 and 3.0 ± 0.3 mb, respectively. The elastic differential cross section has a slope of 9.0 ± 0.7 GeV−2 for 0.03≤−t≤0.6 GeV2. The average charged-particle multiplicity for the inelastic events is 8.02 ± 0.12.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Measurement of Neutron-Deuteron Polarization at 35 MeV

Zamudio-Cristi, J. ; Bonner, B.E. ; Brady, F.P. ; et al.

Phys.Rev.Lett. 31 (1973) 1009-1012, 1973.

Inspire Record 945160 DOI 10.17182/hepdata.21394

The neutron polarization asymmetry in neutron-deuteron scattering has been measured from 44.5° to 160° (c.m.) neutron angle. The results display quantitatively the same structure as proton-deuteron polarization data, but discrepancies appear for angles corresponding to those near the minimum of the differential cross section. In this region the polarization is considerably more negative than in the proton-deuteron case, and both are more negative than current theoretical predictions.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

The Energy Dependence of Backward $\pi^+ p$ Elastic Scattering from 2 GeV/c to 6 GeV/c

Baker, W.F. ; Eartly, David P. ; Pretzl, K. ; et al.

Phys.Rev.Lett. 32 (1974) 251, 1974.

Inspire Record 80709 DOI 10.17182/hepdata.21310

The energy dependence of backward π+p elastic scattering has been measured for incident π momenta 2.0-6.0 GeV/c in steps of typically 100 MeV/c. Values are presented for both the differential cross section extrapolated to 180° and the slope of the backward peak as a function of momentum. In the s channel we see the effects of the established Δ++ resonances and evidence for the Δ(3230). Also, the data show the existence of a negative-parity Δ resonance with mass ∼2200 MeV/c2.

1 data table

Table 1

No description provided.

The n n scattering amplitude at 845 mev/c

Dutton, L.M.C. ; Howells, R.J.W. ; Jafar, J.D. ; et al.

Nucl.Phys.B 78 (1974) 484-492, 1974.

Inspire Record 94570 DOI 10.17182/hepdata.32243

Experimental data on dd small-angle elastic scattering in the Coulomb interference region are analysed to yield the dd scattering amplitude. This amplitude is then expressed in terms of the nucleon-nucleon scattering amplitudes and the Glauber correction. The value for the nn scattering amplitude found is shown to be in good agreement with the pp amplitude.

1 data table

Table 1

No description provided.

A study of neutral final states in k- p interactions in the range from 690 to 934 mev/c

Baxter, D.F. ; Buckingham, I.D. ; Corbett, I.F. ; et al.

Nucl.Phys.B 67 (1973) 125-156, 1973.

Inspire Record 94876 DOI 10.17182/hepdata.32387

The K − p reactions with final states Λπ 0 , Σ 0 π 0 , Λπ 0 π 0 , Λη and Σ 0 η have been studied at 14 momenta between 685 and 934 MeV/ c using optical spark chambers. The charged decay products of the Λ are detected by low mass spark chambers while γ-rays from π 0 and Σ 0 decays are detected in high mass chambers. Approximately 250 000 photographs were analysed from which partial and differential cross sections were determined. These results are presented with an energy dependent, single channel partial-wave analysis.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Measurement of the polarization in k- p ---> anti-k0 n charge exchange at 8 gev/c

Beusch, W. ; Borghini, M. ; Misuri, G. ; et al.

Phys.Lett.B 46 (1973) 477-480, 1973.

Inspire Record 95156 DOI 10.17182/hepdata.28055

The K − p → K 0 n polarization has been measured at 8 GeV/ c and for − t values ranging from 0 up tp 1.2 (GeV/ c ) 2 . A negative polarization has been found.

1 data table

Table 1

No description provided.

The Discovery of a Second Narrow Resonance in e+ e- Annihilation

Abrams, G.S. ; Briggs, D. ; Chinowsky, William ; et al.

Phys.Rev.Lett. 33 (1974) 1453-1455, 1976.

Inspire Record 91611 DOI 10.17182/hepdata.21287

We have observed a second sharp peak in the cross section for e+e−→hadrons at a center-of-mass energy of 3.695±0.004 GeV. The upper limit of the full width at half-maximum is 2.7 MeV.

1 data table

Table 1

No description provided.

Evidence for the omega pi pi decay modes of the a2 and omega(1675)

Diaz, J. ; Dibianca, F.A. ; Fickinger, W.J. ; et al.

Phys.Rev.Lett. 32 (1974) 260-264, 1974.

Inspire Record 94695 DOI 10.17182/hepdata.21339

We present evidence for the decay A20→ωπ+π0 with a branching ratio Γ(A2→ωππ)Γ(A2→ρπ)=0.28±0.09 and for the decay ω(1675)→ωπ+π− with a branching ratio Γ(ω(1975)→ωπ+π−)Γ(ω(1675)→ρπ)=0.47±0.18. Evidence is given for an intermediate B(1235)π state in the ω(1675) decay.

2 data tables

Table 1

FITTED WITH BREIT-WIGNER RESONANCES PLUS BACKGROUND.

Table 2

BACKGROUND SUBTRACTED TP DISTRIBUTIONS.

Strange-particle production in n p interactions at 4-8 gev/c

Ansorge, R.E. ; Carter, J.R. ; Charlesworth, J.A. ; et al.

Phys.Rev.D 10 (1974) 32-44, 1974.

Inspire Record 95568 DOI 10.17182/hepdata.25044

Results of a survey of strange-particle production in np interactions in the momentum range 4-8 GeV/c are presented. As details of 3-body events have already been published, the results for the most part concern 4- and 5-body events with no missing neutrals. Cross sections for production of the most prominent resonances are given, and the properties of certain quasi-3-body channels discussed and compared with the corresponding states produced in pp interactions. It is found that the Σ−(1385) resonance is produced very strongly in unfitted topologies and certain statistical tensors for its production are shown to be in agreement with the predictions of the quark model.

1 data table

Table 1

No description provided.

A Study of the Reactions pi+ p --> (rho0, omega) Delta++ at 13-GeV/c

Gaidos, J.A. ; Hirata, A.A. ; DeBonte, R.J. ; et al.

Nucl.Phys.B 72 (1974) 253-282, 1974.

Inspire Record 763 DOI 10.17182/hepdata.32316

Cross sections, differential cross sections, density matrix elements and statistical tensors are given for the reactions π + p → ( ϱ 0 , ω ) Δ ++ at 13.2 GeV/ c . A discussion of the results in terms of particle exchanges, quark model or dipole coupling constraints, and the equal phase hypothesis is presented in some detail for the high statistics ϱ 0 Δ ++ channel.

10 data tables

Table 1

BREIT-WIGNER FITS WHICH CORRECT FOR RESONANCE TAILS AND BACKGROUNDS.

Table 2

No description provided.

Table 3

JACKSON FRAME DENSITY MATRIX ELEMENTS.

More…

Partial Wave Analysis of the (pi+ pi+ pi-) System Through the Region of the A3 Meson

Thompson, G. ; Badewitz, R.C. ; Gaidos, J.A. ; et al.

Nucl.Phys.B 69 (1974) 381-398, 1974.

Inspire Record 760 DOI 10.17182/hepdata.32348

A recent spin-parity analysis of the π + π + π − system formed opposite a proton and a coherent deuteron by incident 13 GeV/ c 2 π + mesons, is extended to a three-pion mass of 1.9 GeV/ c . Relative proportions of the contributing partial waves are presented, from threshold, and the A 3 region is discussed in detail. Contrary to results with the (3 π ) − system, a change in phase is noted for the 2 − amplitude decaying to f 0 π + via am S-wave.

7 data tables

Table 1

FOR A3+ DEFINED AS 2+ S-WAVE WITH 1.5 < M(3PI) < 1.8 GEV).

Table 2

CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.

Table 3

CONSTRAINT IMPLIES RHO(11) + RHO(1-1) = 0.

More…

Study of the R Meson Produced in 13-GeV/c pi+ p Interactions

Thompson, G. ; Gaidos, J.A. ; McIlwain, R.L. ; et al.

Nucl.Phys.B 69 (1974) 220-236, 1974.

Inspire Record 759 DOI 10.17182/hepdata.32359

The missing mass spectrum opposite the proton in a 750 000 picture exposure, 13 GeV/ c π + p bubble chamber experiment, is investigated in two and four pion channels for structures observed or denied by boson spectrometers at the same energy in the reaction π − p→X − p.

2 data tables

Table 1

BREIT-WIGNER FITS.

Table 2

FOR 1.6 < M(4PI) < 1.8 GEV.

Observation of an A3 Amplitude Phase Change

Thompson, G. ; Badewitz, R.C. ; Gaidos, J.A. ; et al.

Phys.Rev.Lett. 32 (1974) 331, 1974.

Inspire Record 772 DOI 10.17182/hepdata.21334

A spin and parity decomposition is presented of the (π+π+π−) final state formed opposite a proton by incident 13-GeV/c π+ mesons. The A3 enhancement is identified as the 2− amplitude decaying to f0π+ via an S wave. A change in relative phase is noted between the 2−S amplitude and the other principal contributions; this is not incompatible with analyses of the (3π)− system. The method employs the University of Illinois three-body partialwave analysis program.

1 data table

Table 1

A3+ DEFINED AS JP=2- S-WAVE.

Measurement of the Polarization in the Forward Peak of pi- p --> K0 Lambda at 5-GeV/c

Beusch, W. ; Borghini, M. ; Lauper, S. ; et al.

Nucl.Phys.B 99 (1975) 53-60, 1975.

Inspire Record 89729 DOI 10.17182/hepdata.31783

The π − p→K 0 λ polarization has been measured at 5 GeV/ c in the range 0<− t <1.4 (GeV/ c ) 2 . The polarization is small for − t ⪅0.4 (GeV/ c ) 2 , becoming negative at the higher values of − t .

1 data table

Table 1

No description provided.

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

Table 1

No description provided.

Inclusive rho0 Production in pi- p Interactions at 205-GeV/c

Winkelmann, F.C. ; Bingham, H.H. ; Chew, D.M. ; et al.

Phys.Lett.B 56 (1975) 101-104, 1975.

Inspire Record 91206 DOI 10.17182/hepdata.27880

The inclusive ϱ ° production cross section has been measured in the reaction π − p → π + π − X at 205 GeV/ c . We find σ ( ϱ ° ) = 13.5 ± 3.4 mb, with most of the production occuring in the central region. Assuming σ ( ϱ + ) ≈ σ ( ϱ − ) ≈ σ ( ϱ ° ), it is concluded that approximately one-third of the pions at this energy come from ϱ -decay.

3 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

Measurement of e+ e- ---> e+ e- and e+ e- ---> mu+ mu- at SPEAR

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.

Phys.Rev.Lett. 34 (1975) 233, 1975.

Inspire Record 91755 DOI 10.17182/hepdata.21210

The reactions e+e−→e+e− and e+e−→μ+μ− have been measured at center-of-mass energies 3.0, 3.8, and 4.8 GeV and production angles of 50°<θ<130° over all azimuthal angles. Agreement with quantum electrodynamics is excellent. New limits for cutoff parameters in quantum-electrodynamic-breakdown models are given.

2 data tables

Table 1

No description provided.

Table 2

No description provided.

Discovery of a Narrow Resonance in $e^+ e^-$ Annihilation

The SLAC-SP-017 collaboration Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.

Phys.Rev.Lett. 33 (1974) 1406-1408, 1974.

Inspire Record 91761 DOI 10.17182/hepdata.21247

We have observed a very sharp peak in the cross section for e+e−→hadrons, e+e−, and possibly μ+μ− at a center-of-mass energy of 3.105±0.003 GeV. The upper limit to the full width at half-maximum is 1.3 MeV.

1 data table

Table 1

No description provided.

$\pi^+ p$ Backward Elastic Scattering from 2-GeV/c to 6-GeV/c

Lennox, Arlene J. ; Baker, W.F. ; Eartly, David P. ; et al.

Phys.Rev.D 11 (1975) 1777, 1975.

Inspire Record 90923 DOI 10.17182/hepdata.24918

The backward angular distributions obtained in an experiment at the Zero Gradient Synchrotron of Argonne National Laboratory were used to systematically study the energy dependence of the 180° differential cross section for π+p elastic scattering in the center-of-mass energy region from 2159 to 3487 MeV. At each of 38 incident pion momenta between 2.0 and 6.0 GeV/c, a focusing spectrometer and scintillation counter hodoscopes were used to obtain differential cross sections for typically five pion scattering angles from 141° to 173° in the laboratory. Values for dσdΩ at 180° were then obtained by extrapolation. A resonance model and an interference model were used to perform fits to the energy dependence of dσdΩ (180°). Both models led to good fits to our data and yielded values for the masses, widths, parities, and the product of spin and elasticity for the Δ(2200), Δ(2420), Δ(2850), and Δ(3230) resonances. Our data confirm the existence of the Δ(3230) and require the negative-parity Δ(2200).

39 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

rivet Analysis
Total Cross-Section for Hadron Production by electron-Positron Annihilation Between 2.4-GeV and 5.0-GeV Center-Of-Mass Energy

Augustin, J.E. ; Boyarski, A. ; Breidenbach, Martin ; et al.

Phys.Rev.Lett. 34 (1975) 764, 1975.

Inspire Record 100592 DOI 10.17182/hepdata.21227

The total cross section for hadron production by e+e− annihilation has been measured at center-of-mass energies between 2.4 and 5.0 GeV. Aside from the very narrow resonances ψ(3105) and ψ(3695), the cross section varies between 32 and 17 nb over this region with structure in the vicinity of 4.1 GeV.

2 data tables

Table 1

No description provided.

Table 2

MEAN CHARGED MULTIPLICITY. ERRORS ARE STATISTICAL ONLY.

Search for Narrow Resonances in e+ e- Annihilation in the Mass Region 3.2-GeV to 5.9-GeV

Boyarski, A. ; Breidenbach, Martin ; Bulos, F. ; et al.

Phys.Rev.Lett. 34 (1975) 762, 1975.

Inspire Record 100594 DOI 10.17182/hepdata.21228

We have searched the mass region 3.2 to 5.9 GeV for evidence of narrow resonances in e+e−→hadrons. We find no evidence for any such resonances other than the ψ(3695) in this region with a sensitivity ranging from about 12 to 45% of the integrated cross section of the ψ(3695). The more stringent bounds apply to resonances of a few MeV width, while the looser bounds apply to resonances of up to 20 MeV width.

1 data table

Table 1

EXTREAMLY GOOD DATA, MUST BE ASCED FROM AUTHORS.

A Study of the Reactions pi+ p --> K+ Sigma+ and K- p --> pi- Sigma+ at 10-GeV/c

Berglund, A. ; Buran, T. ; Carlson, P.J. ; et al.

Phys.Lett.B 57 (1975) 100, 1975.

Inspire Record 99264 DOI 10.17182/hepdata.27855

For the first time, the reactions π + p →K + ∑ + and K − p→ π − ∑ + have been studied in the same apparatus. This has been done at an adequately high momentum (10.1 GeV/ c ) to allow a check of the prediction of exchange degeneracy, that the differential cross sections should be converging at high energy. We have measured the cross section for momentum transfers t between t min and t = −0.3 (GeV/ c ) 2 . We find that for both reactions the differential cross section shows an exponential fall, with no deviations right in to t = t min (where some other experiments have shown a dip in the cross section). Furthermore, we find the magnitude of the differential cross sections to be closely similar at t = 0, with a ratio R= ( d σ d t) t=0 ( K − p →π − ∑ + ) ( d σ d t) t=0 (π + p → K + ∑ + However, the slope for the positive reaction is about 19% steeper than that for the negative reaction.

1 data table

Table 1

No description provided.

Charge Asymmetry in Inelastic $\pi^-p$ Interactions at 205-GeV/c for Particles with Transverse Momentum > 1.0-GeV/c

Fretter, W.B. ; Graves, W.R. ; Bingham, H.H. ; et al.

Phys.Lett.B 57 (1975) 197-200, 1975.

Inspire Record 98702 DOI 10.17182/hepdata.27857

In 205 GeV / c π − p inelastic interactions, negative particles with transverse momentum greater than 1.0 GeV / c moving forward in the center of mass outnumber similar positive particles by a factor of 3.7 to 1, greatly in excess of the corresponding ratio for small transverse momentum. The asymmetry is reversed in the backward direction. The forward asymmetry is most prominent in 2-, 4-, and 6-prong interactions, but both forward and backward asymmetries are also substantial for higher multiplicity interactions.

6 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

The Quantum Numbers and Decay Widths of the psi (3095)

Boyarski, A. ; Breidenbach, Martin ; Bulos, F. ; et al.

Phys.Rev.Lett. 34 (1975) 1357, 1975.

Inspire Record 100657 DOI 10.17182/hepdata.21242

We present cross sections for e+e−→hadrons, e+e−, and μ+μ− near 3095 MeV. The ψ(3095) resonance is established as having an assignment JPC=1−−. The mass is 3095 ±4 MeV. The partial width to electrons is Γe=4.8±0.6 keV and the total width Γ=69±15 keV. Total rates and interference measurements for the lepton channels are in accord with μ−e universality.

1 data table

Table 1

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

Table 1

Axis error includes +- 10/10 contribution.

Table 2

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.

A Study of K+ d Elastic Scattering in the Region of 600-MeV/c to 900-MeV/c

Sakitt, M. ; Skelly, J. ; Thompson, J.A. ;

Phys.Rev.D 12 (1975) 3386, 1975.

Inspire Record 99707 DOI 10.17182/hepdata.24821

Measurements of the differential cross section for the coherent elastic scattering process K+d→K+d are presented at four momenta from 600 MeV/c to 890 MeV/c for 0.03<|t|<0.25 (GeV/c)2. Comparisons are made with previous work and with predictions from partial-wave analyses.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.