Max results
Sort by Reverse order

Showing 10 of 10000 results

Date

Search for Narrow States by Detection of Monochromatic $\gamma$ Rays in $\bar{p} p$ Annihilation at Rest

The Fukui-Tokyo-KEK-Kyoto Sangyo-Osaka-Tokyo Metropolitan collaboration Chiba, M. ; Doi, K. ; Fujitani, T. ; et al.
Phys.Lett.B 177 (1986) 217-222, 1986.
Inspire Record 229794 DOI 10.17182/hepdata.30244

An inclusive γ ray spectrum in p̄p annihilation at rest has been measured with modularized NaI(Tℓ) detectors with statistics several times higher than before. The aim of the experiment was to search for baryonium B in p̄p → γB by detection of narrow lines in the γ ray spectrum. We have not observed any narrow state B with yield greater than 1.5 × 10 −3 per annihilation and with statistical significance higher than 2σ.

1 data table
Table 1

No description provided.


Direct Photon Production at the {CERN} $\bar{p} p$ Collider

The UA2 collaboration Appel, J.A. ; Bagnaia, P. ; Banner, M. ; et al.
Phys.Lett.B 176 (1986) 239, 1986.
Inspire Record 229895 DOI 10.17182/hepdata.30247

Using the UA2 apparatus, the inclusive cross section has been measured for production of high- p T direct photons in p̄p collisions at s =546 GeV and s =630 GeV . The results are in good agreement with QCD predictions.

2 data tables
Table 1

No description provided.

Table 2

No description provided.


Analysis of the Fragmentation Properties of Quark and Gluon Jets at the CERN SPS $p \bar{p}$ Collider

The UA1 collaboration Arnison, G. ; Albrow, M.G. ; Allkofer, O.C. ; et al.
Nucl.Phys.B 276 (1986) 253-271, 1986.
Inspire Record 229898 DOI 10.17182/hepdata.33618

A sample of two-jet events from the UA1 experiment at the CERN $p \bar{p}$ Collider has been used to study the fragmentation of high-energy quark and gluon jets into charged hadrons. Compared with lower-energy jets observed in $e^+ e^−$ and $pp$ collisions, the fragmentation function measured in the present experiment is softer (i.e. peaked to smaller values of z) and the mean internal transverse momentum is larger, mainly because of the effects of the QCD scaling violations. Using our knowledge of the quark and gluon structure functions in the proton, together with the QCD matrix elements, a statistical separation of quark and gluon jets is achieved within the present experiment. The fragmentation function for the gluon jets is found to be softer, and the angular spread of the fragmentation products larger, than is the case for quark jets.

1 data table
Table 1

No description provided.


A SEARCH FOR ANOMALOUSLY INTERACTING STABLE PARTICLES IN THE MASS RANGE FROM 1.0-GeV/c**2 TO 1.8-GeV/c**2

Abramov, V.V. ; Arbuzov, B.A. ; Baldin, B.Yu. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 452, 1987.
Inspire Record 233158 DOI 10.17182/hepdata.40869

None

1 data table
Table 1

FOR PARTICLES WITH ABSORPTION CROSS SECTION OF 1.E-23 CM**2 NAME EXOTIC IS USED.


STUDY OF INCLUSIVE CHARACTERISTICS OF rho0 AND K*0 (890) MESONS IN ANTI-NEUTRINO CHARGED CURRENT INDUCED QUARK JET

Ammosov, V.V. ; Burtovoy, V.S. ; Gapienko, V.A. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 833, 1987.
Inspire Record 234597 DOI 10.17182/hepdata.40836

None

8 data tables
More…

COHERENT pi MESON PRODUCTION IN NEUTRINO AND ANTI-NEUTRINO INTERACTIONS ON FREON NUCLEI

Grabosch, H.J. ; Kaufmann, H.H. ; Krecker, U. ; et al.
IFVE-86-117, 1986.
Inspire Record 234599 DOI 10.17182/hepdata.40875

None

1 data table
Table 1

No description provided.


Inclusive Cross-section Ratios in High $p_T$ Proton Proton Scattering at {ISR} Energies

The Ames-Bologna-CERN-Dortmund-Heidelberg-Warsaw collaboration Breakstone, A. ; Campanini, R. ; Crawley, H.B. ; et al.
Z.Phys.C 35 (1987) 159, 1987.
Inspire Record 229926 DOI 10.17182/hepdata.15764

Ratios of inclusive cross sections σ(π+)/σ(π++K++p) and\(\sigma (\pi ^ -)/\sigma (\pi ^ -+ K^ -+ \bar p)\) were measured for proton-proton interactions with a highpT hadron in the final state around c.m.s. scattering angles θ≅20°, 20° and 45° at two ISR energies\(\sqrt s= 31\) Gev and 62 GeV. Results are shown as functions of transverse and longitudinal momentum and are compared with parton model predictions. The different dependences of positive and negative pion fractions atpT≅2–3 GeV/c on longitudinal momenta is similar to that observed in soft hadronic interactions at low values ofpT where the leading proton effect (diquark fragmentation) is known to contribute. The quantitative agreement of the data with diquark model predictions indicates the presence of diquark fragmentation also in highpT jets.

4 data tables
Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

Antiproton-proton cross sections at 200 and 900 {GeV} c.m. energy

The UA5 collaboration Alner, G.J. ; Ansorge, R.E. ; Asman, B. ; et al.
Z.Phys.C 32 (1986) 153-161, 1986.
Inspire Record 229896 DOI 10.17182/hepdata.15857

Data on antiproton-proton cross sections at the c.m. energies 200 and 900 GeV are presented. The data were obtained at the CERN antiproton-proton Collider operated in a new pulsed mode in which the same beams were accelerated and decelerated between beam energies of 450 and 100 GeV. The properties of the machine determine the ratio of the luminosities at the two energies to about 1% and thus an accurate measurement of the ratioR of the inelastic cross sections could be made. We findR (=σ900/σ200)=1.20±0.01±0.02, where the first error is statistical and the second systematic. Interpolating existing data to estimateσine1(200 GeV) this measurement ofR leads toσine1(900 GeV)=50.3+0.4+1.0 mb. Using an extrapolated value ofσe1/σtot we estimate the total cross section at 900 GeV to be 65.3±0.7±1.5 mb. Both the inelastic and total cross sections are compatible with a ln2s dependence. Comparisons are made with different fits to the total cross section energy dependence.

2 data tables
Table 1

Ratio of inelastic cross sections at 900 and 200 Gev.

Table 2

Estimate of 900 Gev total cross section based on a) interpolation to obtain total cross section at sqrt(s)=200 Gev (51.6 +- 0.4mb.) b) interpolation and extrapolation to obtain the ratio of elastic to total cross sections at 200 & 900 Gev (0.19 +- 0.01 and 0.23 +- 0.01 respectively).


Evidence for Two Pseudoscalar Resonances of $\eta \pi^+ \pi^-$ System in the $D(1285)$ and $e$ / Iota Regions

Ando, A. ; Inaba, S. ; Inagaki, T. ; et al.
Phys.Rev.Lett. 57 (1986) 1296, 1986.
Inspire Record 229782 DOI 10.17182/hepdata.20226

High-statistics data on the reaction π−p→ηπ+π−n at 8.06 GeV/c were obtained. An isobarmodel partial-wave analysis was performed for the ηππ system. The η(1275) meson was confirmed as a narrow IJPC=00−+ resonance. It decays through both δπ and εη. A narrow state with IJPC=00−+ was found in an ηππ decay channel at 1.42 GeV. It has a prominent peak in a δπ decay mode. No significant E(1420) signal with IJPC=01++ was found near the mass region of 1.42 GeV.

1 data table
Table 1

No description provided.


MEASUREMENT OF THE CROSS-SECTION OF FORWARD COMPTON SCATTERING ON He-4 NUCLEI AT E (gamma) = 1.8-GeV + 3.8-GeV

Aleksanian, A.S. ; Babaian, G.E. ; Voskanian, A.V. ; et al.
Sov.J.Nucl.Phys. 45 (1987) 628, 1987.
Inspire Record 236051 DOI 10.17182/hepdata.18431

None

3 data tables
Table 1

MODEL DEPENDENT ESTIMATION.

Table 2

No description provided.

Table 3

No description provided.