HEPData Search

Showing 10 of 334 results

rivet Analysis
Jet Production and Fragmentation in e+ e- Annihilation at 12-GeV to 43-GeV

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.

Z.Phys.C 22 (1984) 307-340, 1984.

Inspire Record 195333 DOI 10.17182/hepdata.16272

We present the general properties of jets produced bye+e− annihilation. Their production and fragmentation characteristics have been studied with charged particles for c.m. energies between 12 and 43 GeV. In this energy rangee+e− annihilation into hadrons is dominated by pair production of the five quarksu, d, s, c andb. In addition, hard gluon bremsstrahlung effects which are invisible at low energies become prominent at the high energies. The observed multiplicity distributions deviate from a Poisson distribution. The multiplicity distributions for the overall event as well as for each event hemisphere satisfy KNO scaling to within ∼20%. The distributions ofxp=2p/W are presented; scale breaking is observed at the level of 25%. The quantityxpdδ/dxp is compared with multigluon emission calculations which predict a Gaussian distribution in terms of ln(1/x). The observed energy dependence of the maximum of the distributions is in qualitative agreement with the calculations. Particle production is analysed with respect to the jet axis and longitudinal and transverse momentum spectra are presented. The angular distribution of the jet axis strongly supports the idea of predominant spin 1/2 quark pair production. The particle distributions with respect to the event plane show clearly the growing importance of planar events with increasing c.m. energies. They also exclude the presence of heavy quark production,e+e−→Q$\bar Q$ for quark masses up to 5

14 data tables

Table 1

R VALUES BELOW 32.5 GEV ARE IDENTICAL TO THOSE GIVEN IN BRANDELIK ET AL., PL 113B, 499 (1982).

Table 2

No description provided.

Table 3

CHARGED PARTICLE MULTIPLICITY DISTRIBUTIONS.

More…

Properties of Charm Jets Produced in $e^+ e^-$ Annihilation Near 34-{GeV}

The TASSO collaboration Althoff, M. ; Braunschweig, W. ; Kirschfink, F.J. ; et al.

Phys.Lett.B 135 (1984) 243-249, 1984.

Inspire Record 194050 DOI 10.17182/hepdata.30600

D ∗± production via e + e − → D ∗± X was studied at CM energies near 34 GeV. The charged particles produced in the hemisphere opposite to that of the D ∗ were used to investigate the fragmentation of charm jets. All spectra studied show a close similarity between the charm jet and the average jet obtained by summing over all quark flavours. The spectra of particles produced in the D ∗ hemisphere were used to study separately first rank and higher rank fragmentation.

2 data tables

Table 1

THE C-JET IS THE JET IN THE HEMISPHERE OPPOSITE TO THAT CONTAINING THE D* MESON. DIVISION IS MADE BY A PLANE PERPENDICULAR TO THE THRUST AXIS.

Table 2

No description provided.

A comparison of $p$, $\bar{p}$ and meson distributions in final states of deep inelastic muon scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Phys.Lett.B 135 (1984) 225-230, 1984.

Inspire Record 193432 DOI 10.17182/hepdata.30608

New results on the forward produced protons and antiprotons in high energy muon-nucleon scattering are presented. Their W 2 , z and p 2 T dependences are compared with those of the other charged hadrons. Significant differences are observed which can be related to the flavour content of the target and to a difference between the baryon content of quark and gluon jets.

9 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

PROPERTIES OF D* PRODUCTION IN e+ e- ANNIHILATION AT 29-GeV

The HRS collaboration Ahlen, S.P. ; Akerlof, C. ; Baranko, G. ; et al.

HRS-CP-83-3, 1983.

Inspire Record 192098 DOI 10.17182/hepdata.13343

None

2 data tables

Table 1

D* FRAGMENTATION FUNCTION.

Table 2

R VALUE IS RADIATIVELY CORRECTED (BUT NOT CROSS SECTION).

Measurement of Hadronic Azimuthal Distributions in Deep Inelastic Muon Proton Scattering

The European Muon collaboration Aubert, J.J. ; Bassompierre, G. ; Becks, K.H. ; et al.

Phys.Lett.B 130 (1983) 118-122, 1983.

Inspire Record 191233 DOI 10.17182/hepdata.30663

Results on moments of the azimuthal angle ϕ of final state hadrons from 120 GeV and 280 GeV μp scattering are presented. A ϕ asymmetry is observed and its W 2 , Q 2 , z and p T dependences compared with model calculations which include intrinsic transverse momentum and first order QCD corrections. These studies indicate that the observed asymmetry is mainly due to intrinsic transverse momentum k T .

8 data tables

Table 1

No description provided.

Table 2

Typical phi distribution.

Table 3

No description provided.

More…

Experimental Study of Inclusive Muon Spectra at PETRA

The Aachen-DESY-Annecy(LAPP)-MIT-NIKHEF-Beijing collaboration Adeva, B. ; Barber, D.P. ; Becker, U. ; et al.

Phys.Rev.Lett. 51 (1983) 443, 1983.

Inspire Record 13422 DOI 10.17182/hepdata.20492

The results of a high-statistics study of inclusive muon spectra at PETRA are reported. Improved mass limits have been obtained for heavy quarks, heavy leptons, and charged Higgs particles. It is shown that the fragmentation properties of b quarks and c quarks are different, with the mean fragmentation variables 〈zb〉=0.75±0.03±0.06, 〈zc〉=0.46±0.02±0.05 and the average semileptonic branching ratio for the B and C hadrons R(B)=(10.5±1.5±1.3)%, R(C)=(11.5±1.0±1.7)%.

5 data tables

Table 1

No description provided.

Table 2

No description provided.

Table 3

No description provided.

More…

POSSIBLE DIBARYON STATES PRODUCED IN He-4 - PROTON INTERACTIONS

The Dubna-Kosice-Moscow-Strasbourg-Tbilisi-Warsaw collaboration Glagolev, V.V. ; Lebedev, R.M. ; Zhuravleva, L.I. ; et al.

JINR-E1-83-59, 1983.

Inspire Record 189949 DOI 10.17182/hepdata.39516

None

1 data table

Table 1

No description provided.

Charged Particle Multiplicity Distributions in Proton Anti-proton Collisions at 540-{GeV} Center-of-mass Energy

The UA1 collaboration Arnison, G. ; Astbury, A. ; Aubert, Bernard ; et al.

Phys.Lett.B 123 (1983) 108-114, 1983.

Inspire Record 182553 DOI 10.17182/hepdata.30779

Results on charged particle production in pp̄ collision at s 1 2 = 540 GeV are presented. The data were obtained at the CERN pp̄ collider using the UA1 detector, operated without magnetic field. The central particle density is 3.3 + - 0.2 per unit o pseudo-rapidity for non-diffractive events. KNO scaling of the multiplicity distributions withresults from ISR energies is observed.

6 data tables

Table 1

Pseudorapidity density distribution for all charged multiplicities corrected for acceptance and backgrounds by excluding NSD events. Data have been read from the plot.

Table 2

Table 3

More…

Production of $K \bar{K}$ Pairs in Photon-photon Collisions and the Excitation of the Tensor Meson F-prime (1515)

The TASSO collaboration Althoff, M. ; Brandelik, R. ; Braunschweig, W. ; et al.

Phys.Lett.B 121 (1983) 216-222, 1983.

Inspire Record 181468 DOI 10.17182/hepdata.30814

We have observed exclusive production of K + K − and K S O K S O pairs and the excitation of the f′(1515) tensor meson in photon-photon collisions. Assuming the f′ to be production in a helicity 2 state, we determine Λ( f ′ → γγ) B( f ′ → K K ) = 0.11 ± 0.02 ± 0.04 keV . The non-strange quark of the f′ is found to be less than 3% (95% CL). For the θ(1640) we derive an upper limit for the product Λ(θ rarr; γγ K K ) < 0.03 keV (95% CL ) .

2 data tables

Table 1

Data read from graph.. Errors are the square roots of the number of events.

Table 2

Data read from graph.. Errors are the square roots of the number of events.