Date

Total cross section measurements with pi-, Sigma- and protons on nuclei and nucleons around 600-GeV/c.

The SELEX collaboration Dersch, U. ; Akchurin, N. ; Andreev, V.A. ; et al.
Nucl.Phys.B 579 (2000) 277-312, 2000.
Inspire Record 509036 DOI 10.17182/hepdata.24823

Total cross sections for Sigma- and pi- on beryllium, carbon, polyethylene and copper as well as total cross sections for protons on beryllium and carbon have been measured in a broad momentum range around 600GeV/c. These measurements were performed with a transmission technique adapted to the SELEX hyperon-beam experiment at Fermilab. We report on results obtained for hadron-nucleus cross sections and on results for sigma_tot(Sigma- N) and sigma_tot(pi- N), which were deduced from nuclear cross sections.

2 data tables

Results for nuclear total cross sections.

Average total cross sections for nucleon targets deduced from the nuclear target data, at the average beam momentum.


Search for second generation leptoquark pairs 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. 84 (2000) 2088-2093, 2000.
Inspire Record 508772 DOI 10.17182/hepdata.42087

We have searched for second generation leptoquark (LQ) pairs in the \mu\mu+jets channel using 94+-5 pb^{-1} of pbar-p collider data collected by the D0 experiment at the Fermilab Tevatron during 1993-1996. No evidence for a signal is observed. These results are combined with those from the \mu\nu+jets and \nu\nu+jets channels to obtain 95% confidence level (C.L.) upper limits on the LQ pair production cross section as a function of mass and $beta, the branching fraction of a LQ decay into a charged lepton and a quark. Lower limits of 200(180) GeV/c^2 for \beta=1(1/2) are set at the 95% C.L. on the mass of scalar LQ. Mass limits are also set on vector leptoquarks as a function of \beta.

1 data table

No description provided.


K- meson production in the proton proton reaction at 3.67-GeV/c.

The DISTO collaboration Balestra, F. ; Bedfer, Y. ; Bertini, R. ; et al.
Phys.Lett.B 468 (1999) 7-12, 1999.
Inspire Record 508438 DOI 10.17182/hepdata.28069

The total cross section of the reaction $pp\to ppK^+K^-$ has been determined for proton--proton reactions with $p_{beam}=3.67 GeV/c$. This represents the first cross section measurement of the $pp \to ppK^-K^+$ channel near threshold, and is equivalent to the inclusive $pp\to ppK^-X$ cross section at this beam momentum. The cross section determined at this beam momentum is about a factor 20 lower than that for inclusive $pp\to ppK^+X$ meson production at the same CM energy above the corresponding threshold. This large difference in the $K^+$ and $K^-$ meson inclusive production cross sections in proton-proton reactions is in strong contrast to cross sections measured in sub-threshold heavy ion collisions, which are similar in magnitude at the same energy per nucleon below the respective thresholds.

2 data tables

Total exclusive production cross section for the resonant and non-resonant channels.

Total PHI meson production cross section after correction for the corresponding partial width (C.Caso et al. EPJ C1(98)1).


The process $e^+e^-\to\pi^+\pi^-\pi^0$ in the energy range 2E_0=1.04 - 1.38 GeV

Achasov, M.N. ; Aulchenko, V.M. ; Baru, S.E. ; et al.
Phys.Lett.B 462 (1999) 365-370, 1999.
Inspire Record 508003 DOI 10.17182/hepdata.28071

In the experiment with the SND detector at VEPP-2M e^+e^- collider the process $e^+e^-\to\pi^+\pi^-\pi^0$ was studied in the energy range 2E_0 from 1.04 to 1.38 GeV. A broad peak was observed with the visible mass $M_{vis}=1220\pm 20$ MeV and cross section in the maximum $\sigma_0\simeq 4$ nb. The peak can be interpreted as a $\omega$-like resonance $\omega (1200)$.

1 data table

The total cross section for E+ E- --> PI+ PI- PI0 after correction for efficiency and radiative effects.


Study of QED processes e+ e- --> e+ e- gamma, e+ e- gamma gamma with the SND detector at VEPP-2M.

Achasov, M.N. ; Baru, S.E. ; Bozhenok, A.V. ; et al.
Eur.Phys.J.C 12 (2000) 369-374, 2000.
Inspire Record 506331 DOI 10.17182/hepdata.43393

Results of the SND experiment at the VEPP-2M e+ e- collider on the QED processes e+ e- --> e+ e- gamma and e+ e- --> e+ e- gamma gamma with production at large angles are presented. Energy and angular distributions of the final particles were studied. No deviations from QED with an accuracy of 3.8% for the first process and 10.3% for the second were found.

2 data tables

No statistical errors are given. 3.8 PCT is the total systematic error.

No statistical errors are given. 5.8 PCT is the total systematic error.


Measurements of the total cross section difference Delta(sigma(L)(n p)) at 1.59-GeV, 1.79-GeV and 2.20-GeV.

Sharov, V.I. ; Zaporozhets, S.A. ; Adiasevich, B.P. ; et al.
JINR Rapid Commun. 96 (1999) 5-23, 1999.
Inspire Record 513865 DOI 10.17182/hepdata.43287

New results of the neutron-proton spin-dependent total cross section difference$\Delta\sigma_L(np)$at the neutron beam kinetic energies 1.59, 1.79 and 2.20 GeV ar

2 data tables

Final results from the np data.

Values of the cross section difference at I=0 deduced by combining these npdata with pure pp (I=1) data from other experiments.


Investigation of the $e^+e^- \to \omega \pi^0 \to \pi^0 \pi^0 \gamma$ reaction in the energy domain near the $\phi$-meson

Achasov, M.N. ; Aulchenko, V.M. ; Berdyugin, A.V. ; et al.
Nucl.Phys.B 569 (2000) 158-182, 2000.
Inspire Record 503946 DOI 10.17182/hepdata.41517

The $e^+e^- \to \omega \pi^0 \to \pi^0 \pi^0 \gamma$ process was investigated in the SND experiment at the VEPP-2M collider. A narrow energy interval near the $\phi$-meson was scanned. The observed cross-section reveals, at the level of three standard deviation, the interference effect caused by $\phi \to \pi^0\pi^0\gamma$ decay. The cross-section parameters, as well as the real and imaginary parts of the $\phi$-meson related amplitude, were measured.

2 data tables

Only statistical errors are presented. Cross section times branching ratio.

Cross section corrected for the branching ratio OMEGA --> PI0 GAMMA, at the PHI meson. In the range 984 to 1060 MeV the E+ E- --> OMEGA PI0 cross section can be approximated as (7.5 +- 0.9) + (0.06 +- 0.03) (SQRT(S)-M(PHI)) NB where M(PHI) = 1019.4 MeV and S is in MeV**2.


Small angle muon and bottom quark production in p anti-p collisions at S**(1/2) = 1.8-TeV

The D0 collaboration Abbott, B. ; Abolins, M. ; Abramov, V. ; et al.
Phys.Rev.Lett. 84 (2000) 5478-5483, 2000.
Inspire Record 503949 DOI 10.17182/hepdata.42072

This Letter describes a measurement of the muon cross section originating from b quark decay in the forward rapidity range 2.4 < y(mu) < 3.2 in pbarp collisions at sqrt(s) = 1.8 TeV. The data used in this analysis were collected by the D0 experiment at the Fermilab Tevatron. We find that NLO QCD calculations underestimate b quark production by a factor of four in the forward rapidity region. A cross section measurement using muon+jet data has been included in this version of the paper.

3 data tables

The forward muon cross section (per unit rapidity).

The cross section for muons originating from b-quark decay.

Integrated cross sections for muons originating from b-quark decay. The statistical and systematic errors are added in quadrature.


Measurement of the inclusive differential cross-section for Z bosons as a function of transverse momentum 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.D 61 (2000) 032004, 2000.
Inspire Record 503361 DOI 10.17182/hepdata.42104

We present a measurement of the differential cross section as a function of transverse momentum of the Z boson in ppbar collisions at sqrt{s}=1.8 TeV using data collected by the D0 experiment at the Fermilab Tevatron Collider during 1994--1996. We find good agreement between our data and the NNLO resummation prediction and extract values of the non-perturbative parameters for the resummed prediction from a fit to the differential cross section.

1 data table

Differential cross section in the electron channel. The errors contain both statistical and systematic error excluding the overall normalization error.


Charged track multiplicity in B meson decay

The CLEO collaboration Brandenburg, G. ; Ershov, A. ; Gao, Y.S. ; et al.
Phys.Rev.D 61 (2000) 072002, 2000.
Inspire Record 504672 DOI 10.17182/hepdata.47189

We have used the CLEO II detector to study the multiplicity of charged particles in the decays of B mesons produced at the $\Upsilon(4S)$ resonance. Using a sample of 1.5 x 10^6 B meson pairs, we find the mean inclusive charged particle multiplicity to be 10.71 +- 0.02 +0.21/-0.15 for the decay of the pair. This corresponds to a mean multiplicity of 5.36 +- 0.01 +0.11/-0.08 for a single B meson. Using the same data sample, we have also extracted the mean multiplicities in semileptonic and nonleptonic decays. We measure a mean of 7.82 +- 0.05 +0.21/-0.19 charged particles per $B\bar{B}$ decay when both mesons decay semileptonically. When neither B meson decays semileptonically, we measure a mean charged particle multiplicity of 11.62 +- 0.04 +0.24/-0.18 per $B\bar{B}$ pair.

1 data table

Charged track multiplicity (i.e. charged hadron and charged lepton) in B meson decay.