Double-tagged interactions of photons with virtualities Q^2 between 10GeV^2 and 200GeV^2 are studied with the data collected by DELPHI at LEP2 from 1998 to 2000, corresponding to an integrated ...luminosity of 550pb^-1. The gamma*gamma* -> mu+mu- data agree with QED predictions. The cross-section of the reaction gamma*gamma* -> hadrons is measured and compared to the LO and NLO BFKL calculations.
A search fur events with one jet and at most one isolated lepton used data taken at LEP-2 by the DELPHI detector. These data were accumulated at a center-of-mass energy of 183 GeV and correspond to ...an integrated luminosity of 47.7 pb(-1) Production of sin
The production of single charged and neutral intermediate vector bosons in e+e- collisions has been studied in the data collected by the DELPHI experiment at LEP at centre-of-mass energies between ...183 and 209 GeV, corresponding to an integrated luminosity of about 640 pb^{-1}. The measured cross-sections for the reactions, determined in limited kinematic regions, are in agreement with the Standard Model predictions.
A search for excited lepton production in e+e- collisions was performed using the data collected by the DELPHI detector at LEP at centre-of-mass energies ranging from 189 GeV to 209 GeV, ...corresponding to an integrated luminosity of approximately 600 pb^{-1}. No evidence for excited lepton production was found. In searches for pair-produced excited leptons, lower mass limits were established in the range 94 - 103 GeV/c^2, depending on the channel and model assumptions. In searches for singly-produced excited leptons, upper limits on the parameter f/Lambda were established as a function of the mass.
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. The Cherenkov light detected in the Ring Imaging ...Cherenkov Detector and the ionisation loss measured in the Tim
DELPHI results are presented on the inclusive production of two (K Kbar pi)^0 states in the mass region 1.2-1.6 GeV/c^2 in hadronic Z decays at LEP I. The measured masses (widths) are 1274+-6 MeV/c^2 ...(29+-12 MeV/c^2) and 1426+-6 MeV/c^2 (51+-14 MeV/c^2) respectively. A partial-wave analysis of the (K Kbar pi)^0 system shows that the first peak is consistent with the I^G(J^PC) = 0^+(1^++)/(O^-+) a_0(980)pi and the second with the I^G(J^PC) = 0^+(1^++) K*(892)Kbar + c.c assignments. The total hadronic production rates per hadronic Z decay are (0.165 +- 0.051) and (0.056 + 0.012) respectively.These measurements are consistent with the two states being the f_1(1285) and f_1(1420) mesons.
Final results from the DELPHI Collaboration on the lifetime of B+ and B0 mesons and the mean b-hadron lifetime, are presented using the data collected at the Z0 peak in 1994 and 1995. Elaborate, ...inclusive, secondary vertexing methods have been employed to ensure a b-hadron reconstruction with good efficiency. To separate samples of B+ and B0 mesons, high performance neural network techniques are used that achieve very high purity signals. The results obtained are: tau_B+ = 1.624 +/- 0.014 (stat) +/- 0.018 (syst) ps tau_B0 = 1.531 +/- 0.021 (stat) +/- 0.031 (syst) ps tau_B+/tau_B0 = 1.060 +/- 0.021 (stat) +/- 0.024 (syst) and for the average b-hadron lifetime: tau_b = 1.570 +/- 0.005 (stat) +/- 0.008 (syst) ps.
A search for the supersymmetric partner of the goldstino, the sgoldstino S, at LEP2 is presented. The production S gamma followed by S decay into two gluons or into two photons was studied at 189-202 ...GeV LEP centre-of-mass energies. No evidence for the S
The data collected with the DELPHI detector at centre-of-mass energies between 130 and 172~$\GeV$, during LEP operation in 1995 and 1996, have been used to determine the hadronic and leptonic ...cross-sections and leptonic forward--backward asymmetries. In addition the cross-section ratios and forward--backward asymmetries for flavour-tagged samples of light (uds), c and b quarks have been measured. The results are interpreted by performing S-matrix fits to these data and to the data collected previously at the energies near the $\Zzero$ resonance peak (88-93~$\GeV$). The results are also interpreted in terms of contact interactions, which parameterise physics beyond the Standard Model. Further interpretation of the data is made in terms of possible R-parity violating SUSY particles and of possible Z$^{'}$ bosons. No significant deviations from the Standard Model expectations are found and limits are given for the various interpretations which are made of physics beyond the Standard Model.
Oscillations of B-s(0) mesons have been studied in samples selected from about 3.5 million hadronic Z decays detected by DELPHI between 1992 and 1995. One analysis uses events in the exclusive decay ...channels: B-s(0) --> D(s)(-)pi (+) or D(s)(-)a(1)(+) and
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