Date

Lepton Pair Production and Search for a New Heavy Lepton in $e^+ e^-$ Annihilation

The PLUTO collaboration Berger, Christoph ; Genzel, H. ; Grigull, R. ; et al.
Phys.Lett.B 99 (1981) 489-494, 1981.
Inspire Record 164302 DOI 10.17182/hepdata.27110

We have measured the reaction ee → μμ and ee → ττ at center of mass energies from 9.4 to 31.6 GeV. The production cross sections are in agreement with the predictions of quantum electrodynamics, resulting in cutoff parameter limits of 70–100 GeV at 95% c.l. The branching ratio for τ → μν ν has been determined as [1.78 ± 2.0 (statist.) ± 1.8(syst.)]% The existence of a new sequential heavy lepton with a mass <14.5 GeV is excluded at 95% c.l.

2 data tables

No description provided.

No description provided.


DELTA (1236) PRODUCTION IN ANTI-NEUTRINO n ---> mu+ n pi- REACTION AT HIGH-ENERGIES

Efremenko, V.I. ; Fedotov, A.V. ; Gorichev, P.A. ; et al.
ITEP-83-1981, 1981.
Inspire Record 167553 DOI 10.17182/hepdata.40191

None

5 data tables

No description provided.

No description provided.

No description provided.

More…

$\Delta (\Sigma^-$l) and $\Delta$ (Sigma-t) Between 200-{MeV} and 520-{MeV}

Axen, D. ; Shypit, R. ; Comyn, M. ; et al.
J.Phys.G 7 (1981) L225-L230, 1981.
Inspire Record 171520 DOI 10.17182/hepdata.38530

New pp measurements of Delta sigma L and Delta sigma T between 200 and 520 MeV disagree with earlier Argonne data, and resolve discrepancies with inelastic data, phase-shift analysis and forward dispersion relations.

2 data tables

TOTAL CROSS SECTION DIFFERENCE FOR PURE TRANSVERSE SPIN STATES (ANTIPARALLEL MINUS PARALLEL).

TOTAL CROSS SECTION DIFFERENCE FOR PURE LONGITUDINAL SPIN STATES (ANTIPARALLEL MINUS PARALLEL).


Observation of a $K \bar{K}$ Enhancement at 1.85-{GeV} in the Reaction $K^- P \to K \bar{K} \Lambda$ at 8.25-{GeV}/c

The BIRMINGHAM-CERN-GLASGOW-MICHIGAN STATE-PARIS collaboration Al- Harran, S. ; Amirzadeh, J. ; Baubillier, M. ; et al.
Phys.Lett.B 101 (1981) 357-360, 1981.
Inspire Record 170589 DOI 10.17182/hepdata.31206

In a high statistics ( ∼150 eV μb ) bubble chamber experiment on K − p interactions at 8.25 GeV c , the study of the reaction K − p → KK Λ provides evidence for an enhancement in the KK system with a mass of (1850 ± 10) MeV and a width of (80 −30 +40 ) MeV. Its possible identification with the missing isosinglet of the 3 − nonet is discussed. A K ∗ K decay mode is also observed.

1 data table

No description provided.


THE REACTION pi+ p ---> pi+ p pi0 pi0 AT 4-GeV/c: NO EVIDENCE FOR A NARROW epsilon

Borreani, G. ; Guy, J.G. ; Marchetto, F. ; et al.
Nucl.Phys.B 187 (1981) 42-52, 1981.
Inspire Record 164408 DOI 10.17182/hepdata.34256

The Track Sensitive Target technique has been used to isolate 5000 events from the reaction π + p→ π + p π 0 π 0 at 4 GeV/ c . Channel cross sections are measured. The data agree with predictions from phase-shift analyses of π + π − data: the effect of the S ∗ is clearly seen. There is strong evidence against any narrow ϵ below 1 GeV/ c 2 .

1 data table

No description provided.


PRODUCTION OF F-prime (1520) IN 8.25-GEV/C K- P INTERACTIONS

The BIRMINGHAM-CERN-GLASGOW-MICHIGAN STATE-PARIS collaboration Al- Harran, S. ; Baubillier, M. ; Bloodworth, I.J. ; et al.
Nucl.Phys.B 191 (1981) 26-38, 1981.
Inspire Record 172450 DOI 10.17182/hepdata.34233

We present results for the hypercharge exchange reaction K − p→f' λ from a high statistics experiment at 8.25 GeV/ c using the CERN 2m HBC. The total and differential cross sections have been measured; the polarisation of the Λ hyperon and the f' density matrix elements have been calculated as functions of momentum transfer. We also present detailed information on the relative strength of the natural and unnatural parity exchange contributions to the production mechanism.

5 data tables

D-WAVE RELATIVISTIC BREIT-WIGNER RESONANCE PLUS POLYNOMIAL BACKGROUND FIT.

FITTED FOR INDIVIDUAL TP BINS.

No description provided.

More…

Measurement of the Polarization Parameter in 24-{GeV}/$c P P$ Elastic Scattering at Large Momentum Transfers

Antille, J. ; Dick, L. ; Werlen, M. ; et al.
Nucl.Phys.B 185 (1981) 1-19, 1981.
Inspire Record 170364 DOI 10.17182/hepdata.34279

A measurement of the polarization parameter P 0 in pp elastic scattering has been made at 24 GeV/ c over the range of momentum transfer squared 0.7 < | t | < 5.0 (GeV/ c ) 2 . The structure of P 0 has changed compared to typical lower energy data. The second peak is suppressed and a dip has appeared at | t | = 3.6 (GeV/ c ) 2 .

1 data table

No description provided.


Diffraction Dissociation in Proton Proton Collisions at {ISR} Energies

Armitage, J.C.M. ; Benz, P. ; Bobbink, G.J. ; et al.
Nucl.Phys.B 194 (1982) 365-372, 1982.
Inspire Record 164126 DOI 10.17182/hepdata.7553

Data are presented on the reaction pp → pX in the range of four-momentum transfer squared 0.04< − t <0.80 GeV 2 and of c.m. energy squared 550 < s < 3880 GeV 2 . Invariant cross sections are given as a function of M 2 / s , where M is the mass of the missing system X, and of t . The cross sections are shown to scale in the variable M 2 / s , for M 2 / s > 0.01. The total diffractive cross section integrated over t and M 2 / s up to M 2 / s =0.05 rises by approximately 15% from σ dif =6.5±0.2 mb at 550 GeV 2 to σ dif =7.5±0.3 mb at 3880 GeV 2 .

9 data tables

No description provided.

No description provided.

No description provided.

More…

Production of Vector and Tensor Mesons in Proton Proton Collisions at $\sqrt{s}=52$.5-{GeV}

The Annecy(LAPP)-CERN-College de France-Dortmund-Heidelberg-Warsaw collaboration Drijard, D. ; Fischer, H.G. ; Geist, Walter M. ; et al.
Z.Phys.C 9 (1981) 293, 1981.
Inspire Record 164535 DOI 10.17182/hepdata.14085

Inclusive production of ϱ0,f, andg0 mesons and ofKs0,K*0 (892), ϕ andK*0(1430)mesons has been measured at ∼2.6 and ∼1.1 GeV/c in proton-proton interactions at\(\sqrt s= 52.5\) GeV. The negative particle from the two-body decays of these resonances were identified by a threshold Cerenkov counter and used for triggering. Starting from the measured differential cross section, total inclusive cross sections for the vector and tensor mesons were determined using various parametrizations for they andpT dependence of the differential cross section. The experimental results are discussed in the framework of production models based on the parton picture. The strangeness suppresion factor λ=(0.30±0.10) due toSU(3) symmetry breaking of the quark sea is derived.

1 data table

No description provided.


Inclusive Particle Production in $\pi^- N$ Interactions at High-energies

Abramowicz, H. ; Doroba, K. ; Kossakowski, R. ; et al.
Z.Phys.C 7 (1981) 199-208, 1981.
Inspire Record 166695 DOI 10.17182/hepdata.14106

Results on inclusive particle production in π−n interactions at 21, 205 and 360 GeV/c are presented. The invariant cross sections in both neutron fragmentation and central regions are found to be equal within errors to the corresponding cross sections for π−p collisions and exhibit the same energy dependence. A strong energy dependence of the invariant cross section ratios of negative and positive pions is observed. There is also an indication of transverse momentum dependence of these ratios. The η− correlations in the neutron fragmentation region show little variation with energy and are in agreement with the predictions of the naive quark recombination scheme.

1 data table

DATA ON MULTIPLICITY ARE OBTAINED BY AVERAGING OVER ALL THE TOPOLOGIES EXCEPT THE ONE-PRONG ONE.