We propose a new beam diagnostics method to reconstruct the phase space of charged particle bunches in 5 dimensions, which consist of the horizontal and vertical positions and divergences as well as ...the time axis. This is achieved by combining a quadrupole-based transverse phase-space tomography with the adjustable streaking angle of a polarizable X-band transverse deflection structure (PolariX TDS). We demonstrate with detailed simulations that the method is able to reconstruct various complex phase-space distributions and that the quality of the reconstruction depends on the number of input projections. This method allows for the identification and visualization of previously unnoticed detailed features in the phase-space distribution, and can thereby be used as a tool towards improving the performance of particle accelerators, or performing more accurate simulation studies.
Measurements are presented of R-b, the ratio of the b (b) over bar cross-section to the q (q) over bar cross-section in e(+)e(-) collisions, and the forward-backward asymmetry A(FB)(b) at twelve ...energy points in the range root s = 130-207 GeV. These results are found to be consistent with the Standard Model expectations. The measurements are used to set limits on new physics scenarios involving contact interactions.
Neutral triple-gauge-boson couplings ZZZ, ZZγ and Zγγ have been studied with the DELPHI detector using data at energies between 183 and 208 GeV. Limits are derived on these couplings from an analysis ...of the reactions e + e - →Zγ, using data from the final states γff̄, with f=q or ν, from e + e - →ZZ, using data from the four-fermion final states qq̄qq̄, qq̄μ + μ - , qq̄e + e - , qq̄νν̄, μ + μ - νν̄ and e + e - νν̄, and from e + e - →Zγ * , in which the final state γ is off mass-shell, using data from the four-fermion final states qq̄e + e - and qq̄μ + μ - . No evidence for the presence of such couplings is observed, in agreement with the predictions of the Standard Model.
We report on a CDF measurement of the total cross section and rapidity distribution, dσ/dy, for γ∗/Z→e+e− events in the Z boson mass region (66<Mee<116 GeV/c2) produced in pp¯ collisions at s=1.96 ...TeV with 2.1 fb−1 of integrated luminosity. The measured cross section of 257±16 pb and dσ/dy distribution are compared with Next-to-Leading-Order (NLO) and Next-to-Next-to-Leading-Order (NNLO) QCD theory predictions with CTEQ and MRST/MSTW parton distribution functions (PDFs). There is good agreement between the experimental total cross section and dσ/dy measurements with theoretical calculations with the most recent NNLO PDFs.
Searches for H Z production with the Higgs boson decaying into an invisible final state were performed using the data collected by the DELPHI experiment at centre-of-mass energies between 188 GeV and ...209 GeV. Both hadronic and leptonic final states of the Z boson were analysed. In addition to the search for a heavy Higgs boson, a dedicated search for a light Higgs boson down to 40 GeV/c2 was performed. No signal was found. Assuming the Standard Model HZ production cross-section, the mass limit for invisibly decaying Higgs bosons is 112.1 GeV/c2 at 95% confidence level. An interpretation in the Minimal Supersymmetric extension of the Standard Model (MSSM) and in a Majoron model is also given.
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