Date

Exclusive Proton - Anti-proton Production in Two Photon Collisions

The TASSO collaboration Brandelik, R. ; Braunschweig, W. ; Gather, K. ; et al.
Phys.Lett.B 108 (1982) 67-70, 1982.
Inspire Record 167679 DOI 10.17182/hepdata.31000

Production of proton-antiproton pairs by two-photon scattering has been observed at the electron-position storage ring PETRA. A total of eight proton-antiproton pairs have been identified using the time-of-flight technique. We have measured a total cross section of 4.5 ± 0.8 nb in the photon-photon c.m. energy range 2.0–2.6 GeV.

1 data table

No description provided.


First Measurement of the Photon Structure Function F2

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 107 (1981) 168-172, 1981.
Inspire Record 167681 DOI 10.17182/hepdata.31043

Using data taken at PETRA we present results on deep inelastic electron photon scattering at momentum transfers 1 < Q 2 < 15 GeV 2 . The results are expressed in terms of the photon structure function F 2 and are compared with QCD predictions and “hadronic” models of the photon. The pointlike component of the photon is found to be dominant.

2 data tables

Data read from graph.. Data for W < 3.5 in Berger et al. 1981, PL 99B,287 (<a href=http://durpdg.dur.ac.uk/scripts/reacsearch.csh/TESTREAC/red+1164> RED = 1164 </a>).

PHOTON STRUCTURE FUNCTION. NUMERICAL VALUES OF DATA ON FIGURE SUPPLIED BY W. WAGNER.


Measurement of Hadron Production and Three Jet Event Properties at {PETRA} {MIT}

Barber, D.P. ; Becker, U. ; Bei, G.D. ; et al.
Phys.Lett.B 108 (1982) 63-66, 1982.
Inspire Record 166369 DOI 10.17182/hepdata.31009

We have performed a high statistics measurement of the production rate and the energy flow pattern of hadron events between √ s =33 and 36.7 GeV. The data show no evidence for the production of a new quark with charge 2 3 e . Planar events in e + e − →hadrons are shown to have three well separated jets. The production rate and the shape of three-jet events are compared with many models and we find that only the QCD model can explain the data.

1 data table

ENERGY SCAN WITH 7077 HADRON EVENTS.


Inclusive $\Lambda$ and $\bar{\Lambda}$ Production in $K^+ p$ Interactions at 70-{GeV}/$c$

The Brussels-CERN-Genoa-Mons-Nijmegen-Serpukhov collaboration Barth, M. ; De Clercq, C. ; De Wolf, E.A. ; et al.
Z.Phys.C 10 (1981) 205, 1981.
Inspire Record 166163 DOI 10.17182/hepdata.2217

Inclusive and semi-inclusive production of Λ and\(\bar \Lambda\) inK+p interactions is studied at an incident momentum of 70 GeV/c. Cross sections and single particle distributions are presented and compared with data at lower energies. Scaling is observed between 32 and 70 GeV/c in the Feynmanx variable in the target and the beam fragmentation regions for Λ and\(\bar \Lambda\) inclusive production respectively. An increase of Λ (\(\bar \Lambda\)) production is observed in the beam (target) fragmentation regions, whereas the data at 70 and 32 GeV/c are reasonably close in the central region. The dependence of the Λ(\(\bar \Lambda\)) polarization as a function ofx is measured and found to be in general agreement with the results at 32 GeV/c. The (Λ\(\bar \Lambda\)) pair production cross section increases significantly from 32 to 70 GeV/c. The Λ and\(\bar \Lambda\) production associated with an identified proton is also studied.

4 data tables

No description provided.

No description provided.

No description provided.

More…

Study of the Reaction $e^+ e^- \to 3 \pi^+ 3 \pi^-$ in the Total Energy Range 1400-{MeV} to 2180-{MeV}

Bisello, D. ; Bizot, J.C. ; Buon, J. ; et al.
Phys.Lett.B 107 (1981) 145-147, 1981.
Inspire Record 166353 DOI 10.17182/hepdata.31033

The e + e − → 3 π + 3 π − cross section has been measured between 1400 and 2180 MeV with the magnetic detector DM1 at the Orsay storage rings DCI. The cross section increases continuously above 1600 MeV and reaches 2 nb at the maximum explored energy, much larger than VDM previous estimates.

1 data table

No description provided.


Observation of a New Isoscalar Vector Meson in $e^+ e^- \to \omega \pi^+ \pi^-$ Annihilation at 1.65-{GeV}

Cordier, A. ; Bisello, D. ; Bizot, J.C. ; et al.
Phys.Lett.B 106 (1981) 155-158, 1981.
Inspire Record 166964 DOI 10.17182/hepdata.31042

The e + e − → ωπ + π − → π + π − π + π − π 0 cross section has been measured at DCI by the DMI experiment in the 1.4–2.2 GeV energy range. A bump in this cross section appears at 1.65 GeV above a small background, with 6.2 s.d. statistical significance. It can be interpreted as a new isoscalar vector meson: ω ′ or ø ′.

1 data table

THE INDIVIDUAL SYSTEMATIC ERRORS ARISE FROM THE UNCERTAINTY IN SUBTRACTING THE FIVE-PION (NON-OMEGA) BACKGROUND. THESE ERRORS ARE CORRELATED WITH THE STATISTICAL ERRORS.


Baryon Production in e+ e- Annihilation at PETRA

The JADE collaboration Bartel, W. ; Cords, D. ; Dittmann, P. ; et al.
Phys.Lett.B 104 (1981) 325-329, 1981.
Inspire Record 166363 DOI 10.17182/hepdata.31062

Data on p and Λ production by e + e − -annihilation at CM energies between 30 and 36 GeV are presented. Indication for an angular anticorrelation in events with baryon-antibaryon pairs is seen.

3 data tables

No description provided.

No description provided.

AVERAGE NUMBER OF ANTIBARYONS PER HADRONIC EVENT. AN EXPONENTIAL SLOPE OF 2.5 GEV*-1 IN E WAS ASSUMED IN EXTRAPOLATING E*D3(SIG)/DP**3 TO ALL MOMENTA.


Test of Nuclear Effects in Hadronic Dimuon Production

The NA3 collaboration Badier, J. ; Boucrot, J. ; Bourotte, J. ; et al.
Phys.Lett.B 104 (1981) 335, 1981.
Inspire Record 166153 DOI 10.17182/hepdata.31167

We present the final analysis of the nuclear effects on the cross section of dimuon production, using simultaneously a hydrogen and a platinum target in a 150, 200 and 280 GeV pion beam. For the dimuon mass interval 4.1 to 8.5 GeV, the ratio of the cross sections is in agreement with the Drell-Yan model within a 10% error, mainly due to systematics. The variation of this ratio with the dimuon mass, x 1 and x 2 is also in good agreement, and no variation with the transverse momentum is observed.

5 data tables

No description provided.

No description provided.

No description provided.

More…

RESONANCE PRODUCTION BY TWO PHOTON INTERACTIONS AT SPEAR

Jenni, P. ; Burke, D.L. ; Telnov, Valery I. ; et al.
Phys.Rev.D 27 (1983) 1031, 1983.
Inspire Record 173430 DOI 10.17182/hepdata.23843

Two-photon interactions have been studied with the SLAC-LBL Mark II magnetic detector at SPEAR. The cross section for η′ production by the reaction e+e−→e+e−η′ has been measured at beam energies from 2.0 to 3.7 GeV. The radiative width Γγγ(η′) has been determined to be 5.8±1.1 keV (±20% systematic uncertainty). Upper limits on the radiative widths of the f(1270), A2(1310), and f′(1515) tensor mesons have been determined. A search has been made for production of the E(1420) by γγ collisions, but no signal is observed.

2 data tables

No description provided.

NO SIGNAL ABOVE BACKGROUND SEEN. UPPER LIMITS AT 95 PCT CL GIVEN.


SEARCH FOR NARROW QUARKONIUM STATES AND PAIR PRODUCTION OF NEW HEAVY QUARKS AT c.m. ENERGIES FROM 33-GeV TO 36.7-GeV

The CELLO collaboration Behrend, H.J. ; Chen, Ch. ; Field, J.H. ; et al.
DESY-81-029, 1981.
Inspire Record 166365 DOI 10.17182/hepdata.45222

None

1 data table

CONTINUOUS COVERAGE OF THREE ENERGY RANGES (33.00 TO 33.80, 34.00 TO 35.26 AND 36.08 TO 36.72 GEV PLUS SEVEN ADDITIONAL DATA POINTS AROUND 35.7 GEV).