SwePub
Sök i SwePub databas

  form:Ext_t

Träfflista för sökning "WFRF:(Silva Maria P.) ;pers:(Flagmeyer U.)"

form:Search_simp_t: WFRF:(Silva Maria P.) > Flagmeyer U.

  • navigation:Result_t 1-10 navigation:of_t 80
hitlist:Modify_result_t
   
hitlist:Enumeration_thitlist:Reference_thitlist:Reference_picture_thitlist:Find_Mark_t
1.
  • Schael, S., et al. (creator_code:aut_t)
  • Electroweak measurements in electron positron collisions at W-boson-pair energies at LEP
  • 2013
  • record:In_t: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 532:4, s. 119-244
  • swepub:Mat_researchreview_t (swepub:level_refereed_t)abstract
    • Electroweak measurements performed with data taken at the electron positron collider LEP at CERN from 1995 to 2000 are reported. The combined data set considered in this report corresponds to a total luminosity of about 3 fb(-1) collected by the four LEP experiments ALEPH, DELPHI, 13 and OPAL, at centre-of-mass energies ranging from 130 GeV to 209 GeV. Combining the published results of the four LEP experiments, the measurements include total and differential cross-sections in photon-pair, fermion-pair and four-fermion production, the latter resulting from both double-resonant WW and ZZ production as well as singly resonant production. Total and differential cross-sections are measured precisely, providing a stringent test of the Standard Model at centre-of-mass energies never explored before in electron positron collisions. Final-state interaction effects in four-fermion production, such as those arising from colour reconnection and Bose Einstein correlations between the two W decay systems arising in WW production, are searched for and upper limits on the strength of possible effects are obtained. The data are used to determine fundamental properties of the W boson and the electroweak theory. Among others, the mass and width of the W boson, m(w) and Gamma(w), the branching fraction of W decays to hadrons, B(W -> had), and the trilinear gauge-boson self-couplings g(1)(Z), K-gamma and lambda(gamma), are determined to be: m(w) = 80.376 +/- 0.033 GeV Gamma(w) = 2.195 +/- 0.083 GeV B(W -> had) = 67.41 +/- 0.27% g(1)(Z) = 0.984(-0.020)(+0.018) K-gamma - 0.982 +/- 0.042 lambda(gamma) = 0.022 +/- 0.019. (C) 2013 Elsevier B.V. All rights reserved.
  •  
2.
  • Schael, S, et al. (creator_code:aut_t)
  • Precision electroweak measurements on the Z resonance
  • 2006
  • record:In_t: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
  • swepub:Mat_researchreview_t (swepub:level_refereed_t)abstract
    • We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
  •  
3.
  • Abdallah, J., et al. (creator_code:aut_t)
  • A determination of the centre-of-mass energy at LEP2 using radiative two-fermion events
  • 2006
  • record:In_t: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:2, s. 295-305
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Using e(+)e(-) -> mu(+)mu(-)(gamma) and e(+)e(-) -> q (q) over bar(gamma) events radiative to the Z pole, DELPHI has determined the centre-of-mass energy, root s, using energy and momentum constraint methods. The results are expressed as deviations from the nominal LEP centre-of-mass energy, measured using other techniques. The results are found to be compatible with the LEP Energy Working Group estimates for a combination of the 1997 to 2000 data sets.
  •  
4.
  • Abdallah, J., et al. (creator_code:aut_t)
  • Determination of the b quark mass at the M-Z scale with the DELPHI detector at LEP
  • 2006
  • record:In_t: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:3, s. 569-583
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • An experimental study of the normalized three-jet rate of b quark events with respect to light quarks events (light = l equivalent to u, d, s) has been performed using the CAMBRIDGE and DURHAM jet algorithms. The data used were collected by the DELPHI experiment at LEP on the Z peak from 1994 to 2000. The results are found to agree with theoretical predictions treating mass corrections at next-to-leading order. Measurements of the b quark mass have also been performed for both the b pole mass: M-b and the b running mass: m(b)(M-Z). Data are found to be better described when using the running mass. The measurement yields: m(b)(M-Z) = 2.85 +/- 0.18(stat) +/- 0.13(exp) +/- 0.19(had) +/- 0.12(theo) GeV/c(2). for the CAMBRIDGE algorithm. This result is the most precise measurement of the b mass derived from a high energy process. When compared to other b mass determinations by experiments at lower energy scales, this value agrees with the prediction of quantum chromodynamics for the energy evolution of the running mass. The mass measurement is equivalent to a test of the flavour independence of the strong coupling constant with an accuracy of 7 parts per thousand.
  •  
5.
  • Abdallah, J., et al. (creator_code:aut_t)
  • Evidence for an excess of soft photons in hadronic decays of Z(0)
  • 2006
  • record:In_t: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 47:2, s. 273-294
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qq disintegrations of the Z(0) were studied in the kinematic range 0.2 < E-y < I GeV and transverse momentum with respect to the closest jet direction P-T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10(-3) gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) X 10(-3) gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.
  •  
6.
  • Abdallah, J., et al. (creator_code:aut_t)
  • Search for excited leptons in e(+)e(-) collisions at root s=189-209 GeV
  • 2006
  • record:In_t: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:2, s. 277-293
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • 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.
  •  
7.
  • Abdallah, J., et al. (creator_code:aut_t)
  • Study of double-tagged gamma gamma events at LEPII
  • 2006
  • record:In_t: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:3, s. 559-568
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Double-tagged interactions of photons with virtualities Q(2) between 10 GeV2 and 200 GeV2 are studied with the data collected by DELPHI at LEPII from 1998 to 2000, corresponding to an integrated luminosity of 550 pb(-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.
  •  
8.
  • Abdallah, J., et al. (creator_code:aut_t)
  • A measurement of the tau hadronic branching ratios
  • 2006
  • record:In_t: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:1, s. 1-26
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • The exclusive and semi-exclusive branching ratios of the tau lepton hadronic decay modes (h(-)upsilon(tau), h(-)pi(0)upsilon(tau), h(-)pi(0)pi(0)upsilon(tau), h(-) >= 2 pi(0)nu(tau), 2h(-)h(+)upsilon(tau), 2h(-)h(+)>= 2 pi(0)upsilon(tau), 3h(-)2h(+)upsilon(tau) and 3h(-)2h(+) >= 1 pi(0)upsilon(tau)) were measured with data from the DELPHI detector at LEP.
  •  
9.
  • Abdallah, J., et al. (creator_code:aut_t)
  • Masses, lifetimes and production rates of Xi(-) and Xi(+) at LEP 1
  • 2006
  • record:In_t: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 639:3-4, s. 179-191
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • Measurements of the Xi(-) and (Xi) over bar (+) masses, mass differences, lifetimes and lifetime differences are presented. The (Xi) over bar (+) sample used is much larger than those used previously for such measurements. In addition, the S production rates in Z -> b (b) over bar and Z -> q (q) over bar events are compared and the position xi* of the maximum of the distribution in Z -> q (q) over bar events is measured.
  •  
10.
  • Abreu, P, et al. (creator_code:aut_t)
  • b-tagging in DELPHI at LEP
  • 2004
  • record:In_t: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 32:2, s. 185-208
  • swepub:Mat_article_t (swepub:level_refereed_t)abstract
    • The standard method used for tagging b-hadrons in the DELPHI experiment at the CERN LEP Collider is discussed in detail. The main ingredient of b-tagging is the impact parameters of tracks, which relies mostly on the vertex detector. Additional information, such as the mass of particles associated to a secondary vertex, significantly improves the selection efficiency and the background suppression. The paper describes various discriminating variables used for the tagging and the procedure of their combination. In addition, applications of b-tagging to some physics analyses, which depend crucially on the performance and reliability of b-tagging, are described briefly.
  •  
Skapa referenser, mejla, bekava och länka
  • navigation:Result_t 1-10 navigation:of_t 80

Kungliga biblioteket hanterar dina personuppgifter i enlighet med EU:s dataskyddsförordning (2018), GDPR. Läs mer om hur det funkar här.
Så här hanterar KB dina uppgifter vid användning av denna tjänst.

 
pil uppåt tools:Close_t

tools:Permalink_label_t