$\bar{p} p$ Annihilation Into $\pi^+ \pi^-$ and $K^+ K^-$ From Atomic $p$ States

The ASTERIX collaboration Doser, M. ; Botlo, M. ; Ahmad, S. ; et al.
Nucl.Phys.A 486 (1988) 493-511, 1988.
Inspire Record 261310 DOI 10.17182/hepdata.37012

We have obtained the branching ratios for p p annihilation at rest into π + π − and K + K − in a pure p p initial angular momentum state L = 1. A gaseous hydrogen target at normal pressure and temperature was used and events associated with transitions of the antiprotonic atom to the 2p level were selected by detecting the Balmer X-ray series. The branching ratios for p p annihilation into π + π − and K + K − from the 2p state are (4.81 ± 0.49) × 10 −3 and (2.87 ± 0.51) × 10 −4 , respect The pion yield is slightly larger than in liquid hydrogen, where L = 0 annihilation dominates, while the kaon yield is suppressed by a factor of four. Using these and previous data, we derive the branching ratios for pp annihilation into all ππ and K K modes from S and P states. A measurement in gaseous hydrogen, without X-ray requirement, yields the branching ratios (4.30 ± 0.14) × 10 −3 and (6.92 ± 0.41) × 10 −4 . With the known branching ratios of (3.33 ± 0.17) × 10 −3 and (1.01 ± 0.05) × 10 −3 in liquid hydrogen, we find that (50.3 ± 6.4)% of all annihilations in gas at NTP occur in the initial angular momentum state L = 1.

2 data tables

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

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


ASYMMETRY OF THE REACTION CROSS-SECTION FOR PI+ MESON PHOTOPRODUCTION ON HYDROGEN INDUCED BY POLARIZED PHOTONS IN THE RESONANCE ENERGY REGION. (IN RUSSIAN)

Abramian, L.O. ; Aganyants, Aleksandr O. ; Adamian, F.V. ; et al.
Yad.Fiz. 32 (1980) 128-132, 1980.
Inspire Record 159785 DOI 10.17182/hepdata.18977

None

2 data tables

Axis error includes +- 10/10 contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).

Axis error includes +- 10/10 contribution (DUE TO BEAM POLARIZATION UNCERTAINTY).


Asymmetry measurements for elastic scattering of k+ mesons by polarized protons

Ehrlich, R.D. ; Etkin, A. ; Glodis, P. ; et al.
Phys.Rev.Lett. 26 (1971) 925-928, 1971.
Inspire Record 69016 DOI 10.17182/hepdata.21466

We report measured values of the asymmetry in the elastic scattering of K+ mesons from polarized protons. The data were obtained at fourteen incident K+ momenta from 1.33 to 2.58 GeVc; the approximate angular range covered was −0.85<cosθKc.m.<0.9. We compare our results with other available measurements and note several significant differences.

14 data tables

No description provided.

No description provided.

No description provided.

More…

Asymmetry of the cross section of the reaction $\gamma$P $\rightarrow$ P$\pi^{0}$ in the energy interval 0.9-1.65 GeV at $\theta _{\pi}^{0 cms}$ = 110°

Abramyan, L.O. ; Avakyan, R.O. ; Akopov, N.Z. ; et al.
JETP Lett. 23 (1976) 375-378, 1976.
Inspire Record 1393126 DOI 10.17182/hepdata.39803

None

2 data tables

THE ERRORS INCLUDE THE 10 PCT ERROR IN THE EFFECTIVE PHOTON POLARIZATION.

No description provided.


CROSS-SECTION ASYMMETRY OF THE gamma n ---> pi- p REACTION BY POLARIZED PHOTONS IN THE THIRD AND FOURTH RESONANCE REGIONS

Adamian, F.V. ; Akopian, G.G. ; Galumian, P.I. ; et al.
EFI-722-37-84-YEREVAN, 1984.
Inspire Record 206944 DOI 10.17182/hepdata.18433

None

5 data tables

No description provided.

No description provided.

No description provided.

More…

CROSS-SECTIONS FOR PI- + P ---> N + (K) PI0 (K = 1 TO 5) AND PI- + P ---> N + ETA0 (ETA0 ---> 2 GAMMA) FOR INCIDENT PION MOMENTA BETWEEN 1.3-GEV/C AND 3.8-GEV/C

Crouch, H.R. ; Hargraves, R. ; Lanou, R.E. ; et al.
Phys.Rev.D 21 (1980) 3023-3058, 1980.
Inspire Record 158169 DOI 10.17182/hepdata.4334

This paper presents the results of a study of the dominant neutral final states from π−p interactions. The data were obtained in an experiment performed at the Brookhaven National Laboratory Alternating Gradient Synchrotron, using a set of steel-plate optical spark chambers surrounding a liquid-hydrogen target. We present differential and total cross sections for the reactions (1) π−p→n+π0 and (2) π−p→n+η0(η0→2γ) and total cross sections for the reactions (3) π−p→n+kπ0 (k=2, 3, 4, and 5) and (4) π−p→all neutrals for eighteen values of beam momentum in the interval 1.3 to 4.0 GeV/c. The angular distributions for (1) and (2) have been analyzed in terms of expansions in Legendre polynomials, the coefficients for which are also given.

41 data tables

No description provided.

SIG = 4*PI*LEG(L=0).

FORWARD DIFFERENTIAL CROSS SECTION CALCULATED FROM LEGENDRE POLYNOMIAL COEFFICIENTS AND ERROR MATRICES.

More…

Charge exchange and production of eta mesons and multiple neutral pions in pi- p reactions between 654 and 1247 mev/c

Bulos, F. ; Lanou, R.E. ; Piper, A.E. ; et al.
Phys.Rev. 187 (1969) 1827-1844, 1969.
Inspire Record 62084 DOI 10.17182/hepdata.5293

An experiment designed to study the π−p total neutral cross section and its breakdown into several channels has been performed at eleven incident pion momenta ranging from 654 to 1247 MeV/c. Angular distributions for the charge exchange π0 and for η0 production are given in terms of Legendre-polynomial expansion coefficients. Forward and backward differential cross sections are presented for the charge-exchange channel and comparisons with recent dispersion-relation predictions for the forward cross section are made.

34 data tables

No description provided.

No description provided.

No description provided.

More…

Cross-Section Asymmetry of eta Mesons Photoproduction by Polarized Photons in the Resonance Region

Abramian, L.O. ; Avakian, R.O. ; Aganyants, Aleksandr O. ; et al.
Pisma Zh.Eksp.Teor.Fiz. 25 (1977) 597-600, 1977.
Inspire Record 124683 DOI 10.17182/hepdata.39787

None

1 data table

No description provided.


Cross-section for b jet production in anti-p p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 85 (2000) 5068-5073, 2000.
Inspire Record 531669 DOI 10.17182/hepdata.42975

Bottom quark production in pbar-p collisions at sqrt(s)=1.8 TeV is studied with 5 inverse picobarns of data collected in 1995 by the DO detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region (|y(b)| < 1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, DO results are found to be higher than, but compatible with, next-to-leading-order QCD predictions.

1 data table

No description provided.


Elastic scattering of $\gamma$ rays by protons at energies above the $\pi$-meson photoproduction threshold

Baranov, P.S. ; Kuznetsova, V.A. ; Slovokhotov, L.I. ; et al.
Sov.J.Nucl.Phys. 3 (1966) 791-797, 1966.
Inspire Record 1392560 DOI 10.17182/hepdata.18996

None

4 data tables

Axis error includes +- 5/5 contribution (UNCERTAINTY IN RATED EFFICIENCY).

Axis error includes +- 5/5 contribution (UNCERTAINTY IN RATED EFFICIENCY).

No description provided.

More…