Bell, Kenneth Watson
Pion-Proton Scattering
Max results
Sort by Reverse order

Showing 10 of 16 results

Date

Collaboration

Differential cross section of the pion nucleon charge-exchange reaction pi- p --> pi0 n in the momentum range from 148-MeV/c to 323-MeV/c.

The Crystal Ball collaboration Sadler, M.E. ; Kulbardis, A. ; Abaev, V. ; et al.
Phys.Rev.C 69 (2004) 055206, 2004.
Inspire Record 646714 DOI 10.17182/hepdata.31725

Measured values of the differential cross section for pion-nucleon charge exchange are presented at momenta 148, 174, 188, 212, 238, 271, 298, and 323 MeV/c, a region dominated by the Delta resonance. Complete angular distributions were obtained using the Crystal Ball detector at the Alternating Gradient Synchrotron (AGS) at Brookhaven National Laboratory (BNL). Statistical uncertainties of the differential cross sections are typically 2-6%, exceptions being the results at the lowest momentum and at the most forward measurements of the five lowest momenta. We estimate the systematic uncertainties to be 3-6%.

3 data tables
Table 1

The errors shown are statistical only.

Table 2

The errors shown are statistical only.

Table 3

The total charge-exchange reaction cross section as a function of pion momentum obtained by integrating the differential cross sections. The errors shown are the total and statistical errors.


Hard exclusive hadron nucleon scattering and color transparency

Heppelmann, S. ; Wu, J.Y. ; Appel, R. ; et al.
Nucl.Phys.A 527 (1991) 581C-583C, 1991.
Inspire Record 327578 DOI 10.17182/hepdata.36761

We present preliminary results on the measurement of a variety of exclusive hadron interactions at center of mass scattering angles of 90°. Data are also presented which show the relative transparency of nuclei to πp and pp elastic scattering in this kinematic range.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


Comparison of Exclusive Reactions at Large $T$

Baller, B.R. ; Blazey, G.C. ; Courant, H. ; et al.
Phys.Rev.Lett. 60 (1988) 1118-1121, 1988.
Inspire Record 264273 DOI 10.17182/hepdata.3063

Cross sections or upper limits are reported for 12 meson-baryon and two baryon-baryon reactions for an incident momentum of 9.9 GeV/c, near 90° c.m.: π±p→pπ±,pp±,π+°±,K+Σ±, (Λ0/Σ0)K0; K±p→pK±; p±p→pp. By studying the flavor dependence of the different reactions, we have been able to isolate the quark-interchange mechanism as dominant over gluon exchange and quark-antiquark annihilation.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


DECAY DISTRIBUTION OF HIGH TRANSVERSE MOMENTUM RHO MESONS

Heppelmann, S. ; Blazey, G.C. ; Baller, B. ; et al.
Phys.Rev.Lett. 55 (1985) 1824-1827, 1985.
Inspire Record 221964 DOI 10.17182/hepdata.20301

The exclusive process π−p→ρ−p has been measured at 90° c.m. with an incident pion momentum of 9.9 GeV/c. We present data on the angular dependence of the decay ρ−→π−π0. We observe a strong azimuthal dependence in the decay in the c.m. helicity frame of the ρ. Such an azimuthal dependence is not compatible with SU(6) valence-quark perturbation calculations.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Study of $\pi \pi$ Scattering Amplitudes in the Reaction $\pi^+ p \to \Delta^{++} \pi^0 \pi^0$ at 8.0-{GeV}

Cason, N.M. ; Cannata, P.E. ; Baumbaugh, A.E. ; et al.
Phys.Rev.D 28 (1983) 1586, 1983.
Inspire Record 13326 DOI 10.17182/hepdata.23805

An experiment studying the reaction π+p→Δ++π0π0 using the Argonne National Laboratory 1.5-m streamer chamber combined with a lead-glass hodoscope is described. The data were analyzed in terms of π+π−→π0π0 scattering, and the details of the extrapolation to the pole are discussed. An energy-independent amplitude analysis from threshold to 2.3 GeV is presented. In this analysis the f0(1270), the h0(2040), and a JP=2+ state at 1.8 GeV with a width of 0.280 GeV are observed. The amplitude ambiguity arising from analyses of π+π−→π+π− data in the 1.6-GeV region is resolved. An energy-dependent phase-shift analysis from 1.0 to 1.5 GeV is presented.

5 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Spin Rotation Measurements in $\pi^- p \to K^0 \Lambda$

Bell, Kenneth Watson ; Blissett, J.A. ; Broome, T.A. ; et al.
Nucl.Phys.B 222 (1983) 389-410, 1983.
Inspire Record 190232 DOI 10.17182/hepdata.33946

The first measurements of spin-rotation in meson-baryon scattering in the resonance region are presented. These measurements, for the reaction π − p → K 0 Λ , confirm the main predictions of a previous partial-wave analysis. Comments are made on resonant couplings in the reaction π − p → K 0 Λ .

4 data tables
Table 1

SPIN ROTATION ANGLE MEASUREMENTS.

Table 2

POLARIZATION MEASUREMENTS FROM THIS EXPERIMENT ALONE.

Table 3

COMBINED WITH DATA FROM BAKER ET AL., AND SAXON ET AL., (SEE COMMENTS).

More…

The Reaction $\pi^- p \to K^0 \Sigma^0$ Up to 2375-{MeV}/$c$

Hart, J.C. ; Baker, R.D. ; Bell, Kenneth Watson ; et al.
Nucl.Phys.B 166 (1980) 73-83, 1980.
Inspire Record 143420 DOI 10.17182/hepdata.34550

Differential cross-section and polarization measurements for the reaction π − p → K 0 Σ 0 are presented from 1395 to 2375 MeV/ c incident beam momentum. The polarization data from an earlier experiment, from thershold to 1334 MeV/ c , have been re-analysed by an improved method leading to a substantial reduction in the errors.

4 data tables
Table 1

No description provided.

Table 2

TOTAL CROSS SECTIONS DERIVED FROM LEGENDRE POLYNOMIAL FITS TO ANGULAR DISTRIBUTIONS.

Table 3

LEGENDRE POLYNOMIAL FITS TO D(SIG)/DOMEGA.

More…

The Reaction $\pi^- p \to K^0 \Lambda^0$ Up to 2375-{MeV}/$c$: New Results and Analysis

Saxon, D.H. ; Baker, R.D. ; Bell, Kenneth Watson ; et al.
Nucl.Phys.B 162 (1980) 522-546, 1980.
Inspire Record 142072 DOI 10.17182/hepdata.34549

New data are presented on the reaction π − p→K 0 Λ 0 at 13 incident momenta between 1395 and 2375 MeV/ c . A partial-wave analysis has been performed using these data and previous data at lower momenta. The resulting resonance parameters are in broad agreement with recent πN analyses and with the predictions of SU(6) W × O(3) for the couplings.

5 data tables
Table 1

No description provided.

Table 2

TOTAL CROSS SECTION FROM LEGENDRE POLYNOMIAL FIT TO D(SIG)/DOMEGA. ERRORS INCLUDE 20 PCT SYSTEMATIC NORMALIZATION ERROR.

Table 3

LAMBDA USED TO ANALYZE POLARIZATION, ASSUMING 0.642 FOR THE DECAY ASYMMETRY PARAMETER.

More…

Study of the Reaction $\pi^- p \to N K^0_S K^0_S$ at 6.0-{GeV}/$c$ and 7.0-{GeV}/$c$

Polychronakos, V.A. ; Cason, N.M. ; Bishop, J.M. ; et al.
Phys.Rev.D 19 (1979) 1317, 1979.
Inspire Record 7273 DOI 10.17182/hepdata.24309

The KS0KS0 system produced in the reaction π−p→nKS0KS0 at 6.0 and 7 0 GeV/c has been studied utilizing the ANL 1.5-m streamer-chamber facility. A 400 000-photograph exposure yielded 5096 unweighted nKS0KS0 events. The cross section for this reaction was determined to be 9.6 ± 1.3 μb at 6.0 GeV/c and 8.7 ± 1.1 μb at 7.0 GeV/c. The decay angular distributions were parametrized in terms of moments of the spherical harmonics. The 〈Y40〉 moment was fitted to interfering Breit-Wigner amplitudes for the f and f′ mesons. Using this fit, the branching ratio R=Γ(f→KK¯)Γ(f→all) was found to be (2.3 ± 0.8)%. An energy-independent production-amplitude analysis revealed an enhancement in the S-wave amplitude near 1300 MeV. The properties of the S-wave enhancement are discussed and compared with those observed in other recent experiments. Extrapolated cross sections for the reaction ππ→KS0KS0 are presented. We find a cross section considerably below the S-wave unitarity limit in the S* region.

1 data table
Table 1

FROM FIT TO D-WAVE (M=0) KS KS, CORRECTED FOR <K+ K-> AND <KL KL> DECAY MODES.


Backward Resonance Production in pi- p --> n pi+ pi- at 8-GeV/c

Eisenstein, Bob I. ; Elliott, J. ; Mollet, W. ; et al.
Phys.Rev.D 18 (1978) 1370-1381, 1978.
Inspire Record 136306 DOI 10.17182/hepdata.24374

We have studied backward meson and baryon production in π−p→nπ+π− at 8 GeV/c using a streamer chamber triggered by the detection of the interaction of the neutron in thick-plate optical spark chambers. Our data sample of 866 events is dominated by the quasi-two-body final states Δ−(1232)π+, nρ0, and nf0. We study the differential and total backward cross sections for these states and the decay angular distributions of the resonances. The results for the Δ− and ρ0 indicate that both nucleon and Δ exchange in the u channel are important in their production, while f0 production is, as expected, consistent with nucleon exchange.

5 data tables
Table 1

No description provided.

Table 2

BACKWARD DIP.

Table 3

No description provided.

More…