Showing papers by "A. Passeri published in 2000"
TL;DR: In this paper, a sample of 2.2 million hadronic Z decays, selected from the data recorded by the Delphi detector at LEP during 1994-1995 was used for an improved measurement of inclusive distributions of pi+, K+ and p and their antiparticles in gluon and quark jets.
Abstract: A sample of 2.2 million hadronic Z decays, selected from the data recorded by the Delphi detector at LEP during 1994-1995 was used for an improved measurement of inclusive distributions of pi+, K+ and p and their antiparticles in gluon and quark jets. The production spectra of the individual identified particles were found to be softer in gluon jets compared to quark jets, with a higher multiplicity in gluon jets as observed for inclusive charged particles. A significant proton enhancement in gluon jets is observed indicating that baryon production proceeds directly from colour objects. The maxima, xi^*, of the xi-distributions for kaons in gluon and quark jets are observed to be different.
47 citations
TL;DR: In this article, an analysis of the data collected in 1997 and 1998 with the DELPHI detector at e+e- collision energies close to 183 and 189 GeV was performed in order to extract the hadronic and leptonic fermion-pair cross-sections, as well as the leptononic forward-backward asymmetries and angular distributions.
45 citations
TL;DR: In this article, a study of b semileptonic decays into D, D pi+- and D* pi+ -final states is presented, where the D0, D+ and D *+ mesons are exclusively reconstructed in Z decay data recorded from 1992 to 1995 in the DELPHI experiment at LEP.
29 citations
TL;DR: In this paper, a search for stable and long-lived heavy charged particles was performed using the data taken by the DELPHI experiment at an energy of 189 GeV, where the Cherenkov light detected in the Ring Imaging Cherennikov Detector and the ionisation loss measured in the Time Projection Chamber were used to identify heavy particles passing through the detector.
27 citations
TL;DR: The longitudinal polarization of the Λb baryon was measured at the LEP e+e− collider by DELPHI as mentioned in this paper, which was determined from the charged lepton and neutrino energy spectra in 249±19 Λ b semileptonic decays reconstructed in ≈3.5 million hadronic Z0 decays using Λ0-lepton correlations.
24 citations
TL;DR: The DELPHI detector at LEP has collected 54 pb^{-1} of data at a centre-of-mass energy around 183 GeV during 1997, 158 pb-1 around 189 GeV and 187 pb−1 between 192 and 200 GeV between 1998 and 1999.
20 citations
TL;DR: In this paper, the ratio of the CKM quark-mixing matrix elements |Vub|/|Vcb| has been measured using B hadron semileptonic decays.
20 citations
TL;DR: In this article, a lower bound of 62.4 GeV/c^2 in the higgsino scenario (which includes the gaugino mass unification scenario), if all sfermions are heavier than the lightest chargino was given.
16 citations
TL;DR: In this article, the branching ratio for the leptonic decay of charged B mesons at the MathML source has been measured using selected leptonics view-the-MathML source and hadronic τ−→ντX decays recorded by DELPHI at LEP1 in 1992-1995.
16 citations
TL;DR: In this article, the supersymmetric partners of top and bottom quarks are searched using data taken by the DELPHI experiment at LEP in 1997 and 1998, which are taken at centre-of-mass energies of 183 GeV and 189 GeV, respectively, and correspond to integrated luminosities of 54 pb^{-1} and 158 pb−1.
14 citations
TL;DR: In this paper, the mass of charginos, neutralinos and sleptons at LEP2 center-of-mass energies from 130 GeV to 189 GeV have been used to set lower limits on the masses of the Lightest Supersymmetric Particle and other supersymmetric particles within the MSSM framework.
TL;DR: In this paper, a test of the QED process e+e- → γγ(γ) is reported, and the data analysed were collected with the DELPHI detector in 1998 and 1999 at the highest energies achieved at LEP, reaching 202 GeV in the centre-of-mass.
TL;DR: In this article, an update of the searches for charginos and gravitinos is presented, based on a data sample corresponding to the 158 pb^{-1} recorded by the DELPHI detector in 1998, at a centre-of-mass energy of 189 GeV.
TL;DR: In this paper, a search for the supersymmetric partner of the goldstino, the sgoldstino S, at LEP2 was presented, and the production Sgamma followed by S decay into two gluons or into two photons was studied at 189 - 202 GeV LEP centre-of-mass energies.
TL;DR: In this article, the relative occurrence of the rapidity-ordered configuration p M pbar, where M is a meson, and that of p pbar adjacent pairs is compared.
01 Jan 2000
TL;DR: In this article, the DELPHI results were combined with the results of the Hadronic and muon pair final states of the hadronic and hadronic pair of the d {\mbox{$ {\mathrm Z} $}} d boson to obtain a 95% confidence level upper bound on the cross-section and the corresponding Higgs boson mass lower limit.
Abstract: Searches for {\mbox{$ {\mathrm H} {\mathrm Z} $}} production d with the Higgs boson decaying into an invisible final state have been performedd the data collected by the DELPHI experimentd up to the centre-of-mass energy of 188.6~{\mbox{$ {\mathrm{GeV}}$}}. d The hadronic and muon pair final states of the d {\mbox{$ {\mathrm Z} $}} d boson were analysed. No signal was found. d Upper limits on the cross-section and the corresponding Higgs boson mass d limits were set d at 95\% confidence level. Combining these results with DELPHI results for the vd a 95\% confidence level Higgs mass lower limit of 92.3~{\mbox{$d {\mathrm{GeV}}$}} was obtained, independentd of the branching ratio into visible and invisible decays.