Analyzing powers for the pi- p(pol.) --> pi0 n reaction across the Delta(1232) resonance.

Gaulard, C.V. ; Riedel, C.M. ; Comfort, Joseph R. ; et al.
Phys.Rev.C 60 (1999) 024604, 1999.
Inspire Record 483795 DOI 10.17182/hepdata.51678

High quality analyzing powers for the π−p→→π0n reaction have been obtained with a polarized proton target over a broad angular range at incident kinetic energies of 98.1, 138.8, 165.9, and 214.4 MeV. This experiment nearly doubled the existing πN single-charge-exchange database for energies ranging from 10 to 230 MeV, with 36 new analyzing powers. The Neutral Meson Spectrometer was used to detect the outgoing neutral pions. The data are well described by recent phase-shift analyses. When combined with high-precision and accurate cross section data at the same energies, the data can provide a good test of the degree of isospin breaking in the region of the Δ(1232) resonance. They will also be helpful for constraining the evaluation of the pion-nucleon σ term from the scattering amplitudes.

4 data tables

First error is total uncertainty.

First error is total uncertainty.

First error is total uncertainty.

More…

Measurement of the slope of the pi0 electromagnetic form-factor

Farzanpay, F. ; Gumplinger, P. ; Stetz, A. ; et al.
Phys.Lett.B 278 (1992) 413-418, 1992.
Inspire Record 338523 DOI 10.17182/hepdata.29240

We have measured the slope parameter of the π 0 electromagnetic form factor by measuring the partial branching ratio of the Dalitz decay π 0 → γe + e − into high-invariant-mass electron-positron pairs. We obtain a value a =0.026 with a total (statistical and systematic) error of ±0.054, in agreement with vector dominance and quark loop calculations.

1 data table

The PI0 form factor is parameterized as F(M(ee)**2) = 1 + SLOPE*(M(ee)/M(pi))**2. Two metod are used (see text for detail).


Analyzing power for pi- p charge exchange in the backward hemisphere from 301-MeV/c to 625-MeV/c and a test of pi N partial wave analyses

Kim, G.J. ; Arends, J. ; Engelage, J. ; et al.
Phys.Rev.D 41 (1990) 733-743, 1990.
Inspire Record 301242 DOI 10.17182/hepdata.22935

The analyzing power of π−p→π0n has been measured for pπ=301−625 MeV/c with a transversely polarized target, mainly in the backward hemisphere. The final-state neutron and a γ from the π0 were detected in coincidence with two counter arrays. Our results are compared with predictions of recent πN partial-wave analyses by the groups of Karlsruhe-Helsinki, Carnegie-Mellon University-Lawrence Berkeley Laboratory (CMU-LBL), and Virginia Polytechnic Institute (VPI). At the lower incident energies little difference is seen among the three analyses, and there is excellent agreement with our data. At 547 MeV/c and above, our data strongly favor the VPI phases, and disagree with Karlsruhe-Helsinki and CMU-LBL analyses, which are the source of the πN resonance parameters given in the Particle Data Group table.

7 data tables

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

Axis error includes +- 5/5 contribution (Uncertainty in background normalisation).

More…

AMPLITUDE ANALYSIS OF PION - NUCLEON SCATTERING AT 40-GeV/c

Siksin, V.V. ;
IFVE-87-64, 1987.
Inspire Record 249408 DOI 10.17182/hepdata.10164

None

2 data tables

No description provided.

No description provided.


Quasielastic Charge Exchange of Negative Pions on Carbon Into $\pi^0$, $\eta$, $\eta^\prime$ (958), $\omega(783)$ and F2 (1270) Mesons at 39.1-{GeV}/$c$

Apokin, V.D. ; Arestov, Yu.I. ; Belikov, N.I. ; et al.
Sov.J.Nucl.Phys. 46 (1987) 644, 1987.
Inspire Record 239549 DOI 10.17182/hepdata.40865

None

7 data tables

No description provided.

No description provided.

No description provided.

More…

POLARIZATION ASYMMETRY OSCILLATIONS IN REACTION pi- p ---> p0 n AT t <= 3-GeV/c**2

Apokin, V.D. ; Arestov, Yu.I. ; Belikov, N.I. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 840, 1987.
Inspire Record 234598 DOI 10.17182/hepdata.40905

None

1 data table

No description provided.


Polarization in the Reaction $\pi^-$ Polarized $p \to \pi^0 n$ at 40-{GeV}/$c$

Avvakumov, I.A. ; Apokin, V.D. ; Bagaturiya, Yu.Sh. ; et al.
Nucl.Phys.B 255 (1985) 253-272, 1985.
Inspire Record 206940 DOI 10.17182/hepdata.33791

The paper presents results on measuring the polarization in the reaction π − p→ π 0 n at 40 GeV/ c in the 4-momentum transfer range 0<| t |⩽2 (GeV/ c ) 2 . The results based on the statistics of about 2.2 million recorded events made it possible to observe a noticeable value and complex structure in the polarization behaviour up to | t |⩽2 (GeV/ c ) 2 .

2 data tables

MEASUREMENT OF POLARIZATION IN THE pi- p ---> pi0, n, pi0 ---> 2 gamma REACTION AT 40-GeV/c WITH THE REGISTRATION OF ALL REACTION PRODUCTS

Borisov, N.S. ; Kazarinov, Yu.M. ; Liburg, M.Yu. ; et al.
JINR-P1-84-311, 1984.
Inspire Record 203007 DOI 10.17182/hepdata.9904

None

2 data tables

No description provided.

No description provided.


Polarization in Charge Exchange Reaction $\pi^- p \to \pi^0 n$ at 40-{GeV}/$c$ for the Four Momentum Transfer Range $0 < T < 2$-{GeV}/$c^2$

Apokin, V.D. ; Avvakumov, I.A. ; Bagaturiya, Yu.Sh. ; et al.
Z.Phys.C 15 (1982) 293, 1982.
Inspire Record 169455 DOI 10.17182/hepdata.41256

The results on measuring polarization in charge exchange reaction π−+p→π0+n at 40 GeV/c are presented for the 4-momentum transfer range from 0 up to 2 (GeV/c)2. At |t|≦0.4 (GeV/c)2 the polarization has a positive sign. In the “crossover” region of π± elastic scattering a possible minimum in the polarization behaviour has been seen for the first time. the polarization is zero within the statistical accuracy near this point. In the “deep” region of the charge-exchange differential cross-section the polarization has a negative sign. The presented data are not in agreement with the modern theoretical models.

1 data table

$\pi^- p$ Scattering With Charge Exchange in the Region of Small T at 40-{GeV}/$c$ Momentum

The Serpukhov-Brussels-Annecy(LAPP) & Serpukhov-CERN collaborations Binon, F.G. ; Gouanere, M. ; Davydov, V.A. ; et al.
Sov.J.Nucl.Phys. 33 (1981) 663, 1981.
Inspire Record 156874 DOI 10.17182/hepdata.41613

None

2 data tables

D(SIG)/D(T) AT T=0. OBTAINED FROM MODEL EXTRAPOLATION.