Max results
Sort by Reverse order

Showing 10 of 10000 results

Date

Pi0 photoproduction from complex nuclei

Meyer, W.T. ; Browman, A. ; Hanson, K. ; et al.
Phys.Rev.Lett. 28 (1972) 1344-1347, 1972.
Inspire Record 75485 DOI 10.17182/hepdata.21444

The photoproduction yields of π0 mesons from D2, Be, C, Al, Cu, Ag, and Pb targets have been measured at peak bremsstrahlung energies of 4.25, 5.6, 7.8, and 9.6 GeV. The A dependence of π0 photoproduction is found to be almost independent of energy in this range in contrast to vector-meson dominance predictions.

1 data table
Table 1

A-EFFECTIVE IS SIG(GAMMA A --> PI0 A)/SIG(GAMMA NUCLEON --> PI0 NUCLEON). IT IS NORMALIZED RELATIVE TO THE VALUE FOR DEUTERIUM WHICH IS CALCULATED WITH GLAUBER CORRECTIONS.


Measurements of the symmetries in the differential cross sections for anti-p p ---> anti-p p and anti-p p ---> pi- pi+ using polarized protons

Ehrlich, R.D. ; Etkin, A. ; Glodis, P. ; et al.
Phys.Rev.Lett. 28 (1972) 1147-1150, 1972.
Inspire Record 75507 DOI 10.17182/hepdata.21461

We report measured asymmetries as a function of polar scattering angle for the reactions p¯p→π−π+ and p¯p→p¯p, using a polarized proton target. The annihilation data, obtained at a p¯ momentum of 1.64 GeV/c, are the first asymmetry data to be collected for this channel. A fit of these data and published differential cross section data is made by a partial-wave expansion, and the results are compared with a previous analysis. The elastic scattering data, obtained at 1.64 and 2.55 GeV/c, are fitted with an eight-parameter strong-absorption model.

1 data table
Table 1

No description provided.


Dip structures in pi+ p ---> rho+ p at 1.55-1.84 gev/c

Williamson, Y. ; Fung, S.Y. ; Kernan, A. ; et al.
Phys.Rev.Lett. 29 (1972) 1353-1356, 1972.
Inspire Record 75422 DOI 10.17182/hepdata.21440

Results of a high-statistics study of π++p→ρ++p at 1.55-1.84 GeVc are consistent with dominance of π and ω exchange close to threshold. A pronounced dip in ρ00sdσdt at −t≃0.4 GeV2 may be attributed to pion exchange with strong absorption.

9 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Absence of discrete s-channel resonances in anti-p p interactions at intermediate energies

Fields, T. ; Cooper, W.A. ; Rhines, D.S. ; et al.
Phys.Rev.Lett. 27 (1971) 1749-1752, 1971.
Inspire Record 75556 DOI 10.17182/hepdata.21475

We give new experimental results on ρω interference and two-body cross sections in p¯p annihilation at 2.3GeVc. These are used, together with ρω interference results from lower energies, to argue that the annihilation process is not mediated by discrete s-channel mesonic resonances in the mass range 2.1-2.6 GeV.

1 data table
Table 1

No description provided.


Pi+- and pi0 production by polarized photons in the resonance region

Alspector, J. ; Fox, D. ; Luckey, David ; et al.
Phys.Rev.Lett. 28 (1972) 1403-1406, 1972.
Inspire Record 75484 DOI 10.17182/hepdata.21872

We have measured the cross sections at 90° c.m. for π± and π0 photoproduction with polarized photons. The photon energies ranged from 0.8 to 2.2 GeV. We compare the resonant "bumps" in the cross section with theoretical models. The measured asymmetry agrees with a quark-model calculation though the predicted cross sections are low.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Study of t(z)=3/2 delta(1238) production in p p interactions at 6.6 gev/c

Colton, E. ; Kirschbaum, A.R. ;
Phys.Rev.D 6 (1972) 95-105, 1972.
Inspire Record 74040 DOI 10.17182/hepdata.22248

|Tz|=32Δ(1238) systems are studied from the standpoint of direct production utilizing experimental data on the reactions pp→pπ+n, pp→pπ+π−p, pp→pπ+π−π0p, and pp→pπ+π−π+n. Resonance-production total and differential cross sections are presented, in addition to the decay density-matrix elements. It is demonstrated that the experimentally defined Δ(1238) systems are not characterized solely by spin-parity 32+, and that corresponding elements of the density matrices of both pπ+ and π−n cases generally behave in a similar manner with increasing c.m. angle. Additional detailed studies of the t-channel moments are presented for peripherally produced πN systems as a function of both c.m. angle and πN invariant mass. Dynamical differences are observed between the pπ+ and nπ− moments for the very peripheral data. One-pion-exchange-model predictions are compared with the peripheral pπ+ moments and with several invariant-mass distributions from the pp→pπ+π−p data. Complications arising from the presence of two pπ+ combinations in the four- and five-body final-state data are discussed.

1 data table
Table 1

No description provided.


Proton-deuteron elastic scattering at 1.0 gev/c

Booth, N.E. ; Dolnick, C. ; Esterling, R.J. ; et al.
Phys.Rev.D 4 (1971) 1261-1267, 1971.
Inspire Record 74877 DOI 10.17182/hepdata.23150

The differential cross section and polarization in p−d elastic scattering have been measured at an incident laboratory momentum of 0.99 GeVc (kinetic energy 425 MeV) over most of the angular range. Elastic p−d scattering events from a CD2 target were selected by angular correlation, coplanarity, and time of flight. A significant feature of the results is the large positive polarization at backward scattering angles.

1 data table
Table 1

No description provided.


Proton-antiproton annihilation into pi+ pi- and k+ k- from 700 to 1100 mev/c

Mandelkern, M.A. ; Burns, R.R. ; Condon, P.E. ; et al.
Phys.Rev.D 4 (1971) 2658-2666, 1971.
Inspire Record 74756 DOI 10.17182/hepdata.23118

Total and differential cross sections are presented for proton-antiproton annihilation into π+π− and K+K− at six laboratory momenta between 686 and 1098 MeV/c. The two-pion final state displays moderate energy dependence in its differential cross section, but shows no evidence of any direct-channel resonances. In contrast, the two-kaon final state exhibits some behavior in the total and differential cross section suggestive of a possible direct-channel effect between 800 and 1000 MeV/c.

3 data tables
Table 1

NOTE CUT EXCLUDES LARGE FORWARD CROSS SECTION.

Table 2

LEGENDRE COEFFICIENTS NORMALIZED TO LEGN(L=0) = 0.5.

Table 3

LEGENDRE COEFFICIENTS NORMALIZED TO LEGN(L=0) = 0.5.


Search for peripheral k+ production in pi- p interactions from 2.75 to 10 gev/c

Bashian, A. ; Finocchiaro, G. ; Good, M.L. ; et al.
Phys.Rev.D 4 (1971) 2680-2683, 1971.
Inspire Record 74755 DOI 10.17182/hepdata.23181

Upper limits are presented for the differential cross section in the reactions π−p→K+Σ− and π−p→K+Y*−(1385) with small momentum transfer from π− to K+.

2 data tables
Table 1

EXTRAPOLATED TO T=0 ASSUMING SLOPE IS 5 GEV**-2.

Table 2

ISOTROPIC ANGULAR DISTRIBUTION ASSUMED IN GIVEN T-RANGE.


Photoproduction of neutral rho mesons

Mcclellan, G. ; Mistry, Nari B. ; Mostek, P. ; et al.
Phys.Rev.D 4 (1971) 2683-2693, 1971.
Inspire Record 74765 DOI 10.17182/hepdata.23152

Results are presented on a series of measurements of ρ-photoproduction from hydrogen, deuterium, and complex nuclei ranging up to lead, at photon energies ranging from 4 to 9 GeV. Detailed dipion mass-spectrum fits are presented, using a Drell-type nonresonant background and its interference with the resonant amplitude, with no other arbitrary backgrounds. For hydrogen and deuterium, the inelastic contributions have been subtracted. The A dependence of the cross sections is analyzed to yield values of γρ24π and σρN at average photon energies of 6.1, 6.5, and 8.8 GeV. The hydrogen-to-deuterium ratios indicate the presence of possible nondiffractive amplitudes at low energies which then decrease with energy.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…