Chang, C.Y.
Max results
Sort by Reverse order

Showing 10 of 2904 results

Date

The ratio of π° photoproductions from neutrons and protons in deuterium in the energy range of 700 to 1100 mev.

Chang, Tseng-Hsu ; Walker, Robert Lee ;
CIT-12, 1962.
Inspire Record 44258 DOI 10.17182/hepdata.37218

The ratio of the cross sections for photoproduction of neutral pions from neutrons to that from protons has been obtained at average photon energies of 750, 875, and 1050 mev at a pion CM angle of 60° and at average photon energies of 875 and 1050 mev at a pion CM angle of 90°. The experimental technique required simultaneous detection of both the pions and the nucleons. Pions were detected by three scintillation counters. Lead plates of 2.4 radiation lengths and 1.2 radiation lengths were placed in front of the second and third counters. Neutral pions were identified by the absence of output in the first counter and the large outputs in the second and third counters. Nucleons were detected in two scintillation counters. The second of the two counters is 11” thick and has approximately 20% efficiency of detecting neutrons. Neutrons were identified by the absence of output in the first counter. The energy of the incident photons was determined by synchrotron subtraction. Since the statistical accuracy of synchrotron subtraction is poor, a system of three fast coincidence circuits was used as a time-of-flight instrument to reduce the number of events initiated by low energy photons. The statistical errors assigned to the ratio range between 15-30%. The results of this experiment agree with the results of Bingham within statistical errors, but show a general tendency for the σ^(no)/ σ^o ratio to lower. The ratio of σ^(no)/ σ^o obtained in this experiment ranges between 0.4 and 0.8. The cross sections for neutral pion photoproduction from neutrons are derived from the σ^(no)/ σ^o ratio and the Caltech data on neutral pion photoproduction from hydrogen.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


PHOTOPRODUCTION OF ETA MESONS FROM 950-MeV TO 1100-MeV

Heusch, C.A. ; Prescott, C.Y. ; Bloom, Elliott D. ; et al.
Phys.Rev.Lett. 17 (1966) 573, 1966.
Inspire Record 50081 DOI 10.17182/hepdata.21826

None

1 data table
Table 1

No description provided.


RECOIL PROTON POLARIZATION IN pi0 PHOTOPRODUCTION

Bloom, Elliott D. ; Heusch, C.A. ; Prescott, C.Y. ; et al.
Phys.Rev.Lett. 19 (1967) 671, 1967.
Inspire Record 51327 DOI 10.17182/hepdata.21757

None

1 data table
Table 1

No description provided.


Differential Cross Sections in Eta Photoproduction from 0.8 to 1.45 GeV

Bloom, E.D. ; Heusch, C.A. ; Prescott, C.Y. ; et al.
Phys.Rev.Lett. 21 (1968) 1100-1103, 1968.
Inspire Record 54471 DOI 10.17182/hepdata.21721

The cross section for the process γp→pη was studied from 0.8- to 1.45-GeV incident photon energy at center-of-mass angles from 50 to 90°. The data cover a range of energies well beyond previous measurements. The results will aid in the study of I=12 nucleon isobars.

3 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.


RECOIL PROTON POLARIZATION IN ETA PHOTOPRODUCTION

Heusch, C.A. ; Prescott, C.Y. ; Rochester, L.S. ; et al.
Phys.Rev.Lett. 25 (1970) 1381, 1970.
Inspire Record 61494 DOI 10.17182/hepdata.21581

We measured the polarization of the recoil proton in the process γp→pη0, at 90° in the center-of-mass system, at incoming photon energies from 0.8 to 1.1 GeV. Detection of all three particles in the final state pγγ permitted observation of this process with little background. Subsequent rescattering off carbon nuclei yielded sizable polarization values for the protons, indicating considerable S−P—wave interference in the production process.

1 data table
Table 1

No description provided.


Coherent k- d interactions at 12.6 gev/c

Denegri, D. ; Antich, P. ; Callahan, A. ; et al.
Nucl.Phys.B 28 (1971) 13-33, 1971.
Inspire Record 68705 DOI 10.17182/hepdata.33587

We report on coherent interactions in a 2.5 event/μb K − d exposure. The predominant channel studied is K − d → K − π + gp − d (415 events). We find strong Q- and L-production in the (K ππ ) system. The production mechanism determines I = 1 2 for both enhancements and a spin-parity in the series 0 − , 1 + ,2 − … . A spin-parity analysis shows the Q to be a 1 + object, while the L is 1 + or 2 − , although a higher spin cannot be excluded. The cross sections for Q and L production and other final states are presented.

1 data table
Table 1

CORRECTED FOR UNSEEN RECOIL DEUTERONS BY EXTRAPOLATION. (UNCORRECTED CROSS SECTIONS ARE THOSE OBSERVED WITH P(DEUT) > 140 MEV/C).


COHERENT REGENERATION IN HYDROGEN FROM 3-GeV/c TO 10-GeV/c

Buchanan, C.D. ; Drickey, Darrell James ; Rudnick, F.D. ; et al.
Phys.Lett.B 37 (1971) 213-216, 1971.
Inspire Record 67654 DOI 10.17182/hepdata.28377

We have studied the proper time distribution of coherent π + π − decays from a 3 – 10 GeV/ c K L o beam incident on a one meter liquid hydrogen target using a wire spark chamber spectrometer in the 3 0 neutral beam at SLAC. We find ∣(ƒ(0) − ƒ (0))/k∣ = 0.43 ± 0.11 mb , φ(ƒ(0) − ƒ (0)) = -101 0 ± 42 0 .

1 data table
Table 1

No description provided.


Study of the reaction anti-p n ---> anti-p pi- p at 7.0 gev/c

Antich, P. ; Carson, R. ; Chien, C.Y. ; et al.
Nucl.Phys.B 43 (1972) 45-61, 1972.
Inspire Record 75088 DOI 10.17182/hepdata.32868

From a 3.5 ev/μb exposure of the BNL 80 inch chamber filled with deuterium to a 7.0 GeV/ c p beam we obtained 664 events in the channel p n → p π − p . The channel cross section is (1270 ± 110 60 ) μb. The final state is dominated by Δ (1230) production. The experimental data is well described by a one-pion exchange model with off-mass shell corrections.

1 data table
Table 1

No description provided.


A STUDY OF THE STRONG INTERACTION FORM-FACTORS FOR K0(L) ---> pi mu neutrino AND K0(L) ---> pi electron neutrino

Dally, E. ; Innocenti, P. ; Seppi, E. ; et al.
Phys.Lett.B 41 (1972) 647-651, 1972.
Inspire Record 74541 DOI 10.17182/hepdata.28214

We have extracted the strong interaction form factors from K o e3 and K o μ3 data of our previously reported K o L experiment in a manner which does not assume an explicit q 2 = ( p K − p π ) 2 dependence. We present the unparameterized form factors ƒ + (q 2 ) from the K o L → πeν and K o L → πμν modes and ƒ o (q 2 ) and ξ ( q 2 ) from the K o L → πμν data. A comparison of these unparameterized results is made with the results of the Dalitz plot analyses.

1 data table
Table 1

The conventional form factor f+ is studied.


Topological and Leading Particle Cross-Sections for 147-GeV/c $\pi^- p$ Interactions.

Fong, D.G. ; Heller, M. ; Shapiro, A.M. ; et al.
Phys.Lett.B 53 (1974) 290-296, 1974.
Inspire Record 93415 DOI 10.17182/hepdata.27916

Results are reported based on a study of π − p interactions at 147 GeV/ c in the FERMILAB 30-inch Proportional Wire Hybrid Bubble Chamber System. We have measured the topological cross sections and separated two-prong elastic and inelastic channels. In addition, we have extracted leading particle cross sections using the increased momentum resolution of the downstream proportional wire chambers. We have compared our results with experiments and predictions of a simple fragmentation hyphothesis.

1 data table
Table 1

No description provided.