Date

Studies of the Cabibbo-suppressed decays D+ --> pi0 l+ nu and D+ --> eta e+ nu/e.

The CLEO collaboration Bartelt, John E. ; Csorna, S.E. ; Jain, V. ; et al.
Phys.Lett.B 405 (1997) 373-378, 1997.
Inspire Record 441553 DOI 10.17182/hepdata.47235

Using 4.8 fb$~{-1}$ of data taken with the CLEO II detector, the branching fraction for the Cabibbo-suppressed decay $D~+\to\pi~0\ell~+\nu$ measured relative to the Cabibbo favored decay $D~+\to\bar{K~0}\ell~+\nu$ is found to be $0.046\pm 0.014\pm 0.017$. Using $V_{cs}$ and $V_{cd}$ from unitarity constraints, we determine $| f_+~{\pi}(0)/f_+~K(0)|~2=0.9\pm 0.3\pm 0.3$ We also present a 90% confidence level upper limit for the branching ratio of the decay $D~+ \to \eta e~+\nu_e$ relative to that for $D~+ \to \pi~0 e~+\nu_e$ of 1.5.

1 data table

Formfactors for the D+ (D-) decay into pseudoscalar P. Charge conjugate states are implied. LEPTON+ means E+ or MU+. VCD and VCS are the elements of the CKM matrix (See R.M.Barnett et al (PDG), PR D54, 1 (1996)).


Threshold measurements at the internal experimental facility COSY-11

Balewski, J. ; Brauksiepe, S. ; Budzanowski, A. ; et al.
Nucl.Phys.A 626 (1997) 85C-92C, 1997.
Inspire Record 463151 DOI 10.17182/hepdata.36361

The experimental setup and detection technique of the COSY-11 installation, an internal experimental facility at the cooler synchrotron and storage ring COSY Jülich, are described. The detection system has been designed for meson production studies with full geometrical acceptance close to threshold. Preliminary results of first measurements are presented, emphasis is put on strangeness production in the reactions pp → ppK + K − and pp → pK + Λ .

2 data tables

Excess energy of 6.1 MeV above threshold 3.3016 GeV.

Excess energy of 2 MeV above threshold 2.339 GeV.


First results from COSY

Grzonka, D. ; Kilian, K. ;
Nucl.Phys.A 626 (1997) 41C-54C, 1997.
Inspire Record 463146 DOI 10.17182/hepdata.36466

None

1 data table

Preliminary data.


Study of anti-neutron proton annihilation in two mesons in the momentum range between 50 to 400 MeV/c with OBELIX

The OBELIX collaboration Bertin, A. ; Bruschi, M. ; Capponi, M. ; et al.
Phys.Lett.B 410 (1997) 344-352, 1997.
Inspire Record 459313 DOI 10.17182/hepdata.28243

We measured the in flight annihilation frequencies and cross sections of reactions n p → π + π 0 ,π + η and K + K S in the antineutron momentum range between 50 and 400 MeV/c. The annihilation frequencies of these channels from the different allowed initial states were calculated and some information about the n p annihilation dynamics were obtained. The first determination of the D-wave contribution in this momentum range was also obtained.

1 data table

No description provided.


Charged particle production in S S collisions at 200-GeV/c per nucleon

The WA94 collaboration Andrighetto, A. ; Antinori, F. ; Bayes, A.C. ; et al.
Phys.Lett.B 412 (1997) 148-154, 1997.
Inspire Record 460283 DOI 10.17182/hepdata.28242

Charged particle production in central S-S collisions at 200 GeV/ c per nucleon has been studied by the WA94 experiment at the CERN-SPS. Particle identification has been provided by the Omega RICH, while a silicon telescope in the Omega spectrometer and an array of MultiWire Proportional Chambers have been used to trace particles through the RICH detector. Production ratios and transverse mass spectra for π ± , K ± and p( p ) at central rapidity and p T > 1.3 GeV/ c are presented.

3 data tables

Distributions are fitted with (1/MT**1.5)*DSIG/DMT = CONST*EXP(-MT/SLOPE).

1.54 GeV ratio is calculated from the fit to the MT distribution.

1.54 GeV ratio is calculated from the fit to the MT distribution.


Hyperon production in proton tungsten interactions at 200-GeV/c

The WA85 collaboration Abatzis, S. ; Andrighetto, A. ; Antinori, F. ; et al.
Phys.Lett.B 393 (1997) 210-216, 1997.
Inspire Record 456774 DOI 10.17182/hepdata.6511

The relative production yields and transverse mass spectra for Λ, Λ , Ξ − and Ξ + hyperons in proton-tungsten interactions are presented and compared with the WA85 results from central sulphur-tungsten interactions. A study of the negative particle yield has also been undertaken and the ratio of Λ hyperons to negative particles has been calculated.

9 data tables

No description provided.

No description provided.

No description provided.

More…

Evidence for Lambda/c(2593)+ production.

The ARGUS collaboration Albrecht, H. ; Hamacher, T. ; Hofmann, R.P. ; et al.
Phys.Lett.B 402 (1997) 207-212, 1997.
Inspire Record 440304 DOI 10.17182/hepdata.44624

Using the ARGUS detector at the e + e − storage ring DORIS II at DESY, we have found evidence for the production of the excited charmed baryon state Λ c (2593) + in the channel Λ c + π + π − . Its mass was determined to be (2594.6±0.9±0.4) MeV/c 2 , and the natural width measured to be Γ = (2.9 −2.1−1.4 +2.9+1.8 ) MeV. The production cross section times the branching ratios of σ ( e + e − → Λ c (2593) + X ) × Br ( Λ c (2593) + → Λ c + π + π − ) × Br ( Λ c + → pK − π + ) was measured to be (0.25 −0.13 +0.24 ±0.13) pb. The fractions of Λ c (2593) + decays proceeding through the Σ c 0 π + and Σ c ++ π − channels were determined to be 0.29±0.10±0.11 and 0.37±0.12±0.13, respectively.

1 data table

Results with and without extrapolation.


Lambda Antilambda production in two-photon interactions at CLEO.

The CLEO collaboration Anderson, S. ; Kubota, Y. ; Lattery, M. ; et al.
Phys.Rev.D 56 (1997) R2485-R2489, 1997.
Inspire Record 439745 DOI 10.17182/hepdata.47140

Using the CLEO detector at the Cornell $e~+e~-$ storage ring, CESR, we study the two-photon production of $\Lambda \overline{\Lambda}$, making the first observation of $\gamma \gamma \to \Lambda \overline{\Lambda}$. We present the cross-section for $ \gamma \gamma \to \Lambda \overline{\Lambda}$ as a function of the $\gamma \gamma$ center of mass energy and compare it to that predicted by the quark-diquark model.

3 data tables

No description provided.

No description provided.

No description provided.


Identified particles in quark and gluon jets.

The DELPHI collaboration Abreu, P. ; Adam, W. ; Adye, T. ; et al.
Phys.Lett.B 401 (1997) 118-130, 1997.
Inspire Record 428228 DOI 10.17182/hepdata.47615

A sample of about 1.4 million hadronic Z decays, selected among the data recorded by the DELPHI detector at LEP during 1994, was used to measure for the first time the momentum spectra of K + , K 0 , p , Λ and their antiparticles in gluon and quark jets. As observed for inclusive charged particles, the production spectra of identified particles were found to be softer in gluon jets than in quark jets, with a higher total multiplicity.

2 data tables

Y events.

Mercedes events.


Studies of quantum chromodynamics with the ALEPH detector

The ALEPH collaboration Barate, R. ; Buskulic, D. ; Decamp, D. ; et al.
Phys.Rept. 294 (1998) 1-165, 1998.
Inspire Record 428072 DOI 10.17182/hepdata.47582

Previously published and as yet unpublished QCD results obtained with the ALEPH detector at LEP1 are presented. The unprecedented statistics allows detailed studies of both perturbative and non-perturbative aspects of strong interactions to be carried out using hadronic Z and tau decays. The studies presented include precise determinations of the strong coupling constant, tests of its flavour independence, tests of the SU(3) gauge structure of QCD, study of coherence effects, and measurements of single-particle inclusive distributions and two-particle correlations for many identified baryons and mesons.

44 data tables

Charged particle sphericity distribution.

Charged particle aplanarity distribution.

Charged particle Thrust distribution.

More…