SwePub - search: WFRF:(Martinez R)

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1.	Schael, S, et al. (author) Precision electroweak measurements on the Z resonance 2006 In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454 Research review (peer-reviewed)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.
2.	Aamodt, K., et al. (author) The ALICE experiment at the CERN LHC 2008 In: Journal of Instrumentation. - 1748-0221. ; 3:S08002 Research review (peer-reviewed)abstract ALICE (A Large Ion Collider Experiment) is a general-purpose, heavy-ion detector at the CERN LHC which focuses on QCD, the strong-interaction sector of the Standard Model. It is designed to address the physics of strongly interacting matter and the quark-gluon plasma at extreme values of energy density and temperature in nucleus-nucleus collisions. Besides running with Pb ions, the physics programme includes collisions with lighter ions, lower energy running and dedicated proton-nucleus runs. ALICE will also take data with proton beams at the top LHC energy to collect reference data for the heavy-ion programme and to address several QCD topics for which ALICE is complementary to the other LHC detectors. The ALICE detector has been built by a collaboration including currently over 1000 physicists and engineers from 105 Institutes in 30 countries, Its overall dimensions are 16 x 16 x 26 m(3) with a total weight of approximately 10 000 t. The experiment consists of 18 different detector systems each with its own specific technology choice and design constraints, driven both by the physics requirements and the experimental conditions expected at LHC. The most stringent design constraint is to cope with the extreme particle multiplicity anticipated in central Pb-Pb collisions. The different subsystems were optimized to provide high-momentum resolution as well as excellent Particle Identification (PID) over a broad range in momentum, up to the highest multiplicities predicted for LHC. This will allow for comprehensive studies of hadrons, electrons, muons, and photons produced in the collision of heavy nuclei. Most detector systems are scheduled to be installed and ready for data taking by mid-2008 when the LHC is scheduled to start operation, with the exception of parts of the Photon Spectrometer (PHOS), Transition Radiation Detector (TRD) and Electro Magnetic Calorimeter (EMCal). These detectors will be completed for the high-luminosity ion run expected in 2010. This paper describes in detail the detector components as installed for the first data taking in the summer of 2008.
3.	Calabresi, PA, et al. (author) The incidence and significance of anti-natalizumab antibodies: results from AFFIRM and SENTINEL 2007 In: Neurology. - : Ovid Technologies (Wolters Kluwer Health). - 1526-632X .- 0028-3878. ; 69:14, s. 1391-1403 Journal article (peer-reviewed)
4.	Fox, Z, et al. (author) Predictors of CD4 count change over 8 months of follow up in HIV-1-infected patients with a CD4 count>or=300 cells/microL who were assigned to 7.5 MIU interleukin-2 2007 In: HIV medicine. - : Wiley. - 1464-2662 .- 1468-1293. ; 8:2, s. 112-123 Journal article (peer-reviewed)
5.	Abazov, V. M., et al. (author) Determination of the strong coupling constant from the inclusive jet cross section in pp collisions at s=1.96 TeV 2009 In: PHYS REV D. - 1550-7998 .- 1550-2368. ; 80, s. 111107- Journal article (peer-reviewed)abstract We determine the strong coupling constant alpha(s) and its energy dependence from the p(T) dependence of the inclusive jet cross section in pp collisions at s=1.96 TeV. The strong coupling constant is determined over the transverse momentum range 50 < p(T)< 145 GeV. Using perturbative QCD calculations to order O(alpha(3)(s)) combined with O(alpha(4)(s)) contributions from threshold corrections, we obtain alpha(s)(M-Z)=0.1161(-0.0048)(+0.0041). This is the most precise result obtained at a hadron-hadron collider.
6.	Abdesselam, A., et al. (author) Engineering for the ATLAS SemiConductor Tracker (SCT) end-cap 2008 In: Journal of Instrumentation. - 1748-0221. ; 3 Journal article (peer-reviewed)abstract The ATLAS SemiConductor Tracker (SCT) is a silicon-strip tracking detector which forms part of the ATLAS inner detector. The SCT is designed to track charged particles produced in proton-proton collisions at the Large Hadron Collider (LHC) at CERN at an energy of 14 TeV. The tracker is made up of a central barrel and two identical end-caps. The barrel contains 2112 silicon modules, while each end-cap contains 988 modules. The overall tracking performance depends not only on the intrinsic measurement precision of the modules but also on the characteristics of the whole assembly, in particular, the stability and the total material budget. This paper describes the engineering design and construction of the SCT end-caps, which are required to support mechanically the silicon modules, supply services to them and provide a suitable environment within the inner detector. Critical engineering choices are highlighted and innovative solutions are presented - these will be of interest to other builders of large-scale tracking detectors. The SCT end-caps will be fully connected at the start of 2008. Further commissioning will continue, to be ready for proton-proton collision data in 2008.
7.	Abdesselam, A., et al. (author) The barrel modules of the ATLAS semiconductor tracker 2006 In: Nuclear Instruments and Methods in Physics Research Section A. - : Elsevier BV. - 0168-9002 .- 1872-9576. ; 568:2, s. 642-671 Journal article (peer-reviewed)abstract This paper describes the silicon microstrip modules in the barrel section of the SemiConductor Tracker (SCT) of the ATLAS experiment at the CERN Large Hadron Collider (LHC). The module requirements, components and assembly techniques are given, as well as first results of the module performance on the fully assembled barrels that make up the detector being installed in the ATLAS experiment.
8.	Acciari, V. A., et al. (author) Radio Imaging of the Very-High-Energy gamma-Ray Emission Region in the Central Engine of a Radio Galaxy 2009 In: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 325:5939, s. 444-448 Journal article (peer-reviewed)abstract The accretion of matter onto a massive black hole is believed to feed the relativistic plasma jets found in many active galactic nuclei (AGN). Although some AGN accelerate particles to energies exceeding 10(12) electron volts and are bright sources of very-high-energy (VHE) gamma-ray emission, it is not yet known where the VHE emission originates. Here we report on radio and VHE observations of the radio galaxy Messier 87, revealing a period of extremely strong VHE gamma-ray flares accompanied by a strong increase of the radio flux from its nucleus. These results imply that charged particles are accelerated to very high energies in the immediate vicinity of the black hole.
9.	Adare, A., et al. (author) Charged hadron multiplicity fluctuations in Au plus Au and Cu plus Cu collisions from s(NN)=22.5 to 200 GeV 2008 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 78:4 Journal article (peer-reviewed)abstract A comprehensive survey of event-by-event fluctuations of charged hadron multiplicity in relativistic heavy ions is presented. The survey covers Au+Au collisions at s(NN)=62.4 and 200 GeV, and Cu+Cu collisions at s(NN)=22.5,62.4, and 200 GeV. Fluctuations are measured as a function of collision centrality, transverse momentum range, and charge sign. After correcting for nondynamical fluctuations due to fluctuations in the collision geometry within a centrality bin, the remaining dynamical fluctuations expressed as the variance normalized by the mean tend to decrease with increasing centrality. The dynamical fluctuations are consistent with or below the expectation from a superposition of participant nucleon-nucleon collisions based upon p+p data, indicating that this dataset does not exhibit evidence of critical behavior in terms of the compressibility of the system. A comparison of the data with a model where hadrons are independently emitted from a number of hadron clusters suggests that the mean number of hadrons per cluster is small in heavy ion collisions.
10.	Adare, A., et al. (author) Cold nuclear matter effects on J/psi production as constrained by deuteron-gold measurements at root S-NN=200 GeV 2008 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 77:2, s. 15-024912 Journal article (peer-reviewed)abstract We present a new analysis of J/psi production yields in deuteron-gold collisions at root s(NN) =200 GeV using data taken from the PHENIX experiment in 2003 and previously published in S. S. Adler [Phys. Rev. Lett 96, 012304 (2006)]. The high statistics proton-proton J/psi data taken in 2005 are used to improve the baseline measurement and thus construct updated cold nuclear matter modification factors (R-dAu). A suppression of J/psi in cold nuclear matter is observed as one goes forward in rapidity (in the deuteron-going direction), corresponding to a region more sensitive to initial-state low-x gluons in the gold nucleus. The measured nuclear modification factors are compared to theoretical calculations of nuclear shadowing to which a J/psi (or precursor) breakup cross section is added. Breakup cross sections of sigma(breakup)=2.8(-1.4)(+1.7) (2.2(-1.5)(+1.6)) mb are obtained by fitting these calculations to the data using two different models of nuclear shadowing. These breakup cross-section values are consistent within large uncertainties with the 4.2 +/- 0.5 mb determined at lower collision energies. Projecting this range of cold nuclear matter effects to copper-copper and gold-gold collisions reveals that the current constraints are not sufficient to firmly quantify the additional hot nuclear matter effect.
11.	Adare, A., et al. (author) System size and energy dependence of jet-induced hadron pair correlation shapes in Cu+Cu and Au+Au collisions at root S-NN 200 and 62.4 GeV 2007 In: Physical Review Letters. - 1079-7114. ; 98:23 Journal article (peer-reviewed)abstract We present azimuthal angle correlations of intermediate transverse momentum (1-4 GeV/c) hadrons from dijets in Cu+Cu and Au+Au collisions at root s(NN)=62.4 and 200 GeV. The away-side dijet induced azimuthal correlation is broadened, non-Gaussian, and peaked away from Delta phi=pi in central and semicentral collisions in all the systems. The broadening and peak location are found to depend upon the number of participants in the collision, but not on the collision energy or beam nuclei. These results are consistent with sound or shock wave models, but pose challenges to Cherenkov gluon radiation models.
12.	Abdallah, J, et al. (author) Search for eta(b) in two-photon collisions at LEP II with the DELPHI detector 2006 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 634:4, s. 340-346 Journal article (peer-reviewed)abstract The pseudoscalar meson eta(b) has been searched for in two-photon interactions at LEP II. The data sample corresponds to a total integrated luminosity of 617 pb(-1) at centre-of-mass energies ranging from 161 to 209 GeV. Upper limits at a confidence level of 95% on the product Gamma(gamma gamma) (eta(b)) x BR(eta(b)) are 190, 470 and 660 eV/c(2) for the eta(b) decaying into 4, 6 and 8 charged particles, respectively.
13.	Adler, S. S., et al. (author) High transverse momentum eta meson production in p+p, d+Au, and Au+Au collisions at root s(NN)=200 GeV 2007 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 75:2 Research review (peer-reviewed)abstract Inclusive transverse momentum spectra of eta mesons in the range p(T)approximate to 2-12 GeV/c have been measured at midrapidity (vertical bar eta vertical bar < 0.35) by the PHENIX experiment at RHIC in p+p,d+Au, and Au+Au collisions at root s(NN)=200 GeV. The eta mesons are reconstructed through their eta ->gamma gamma channel for the three colliding systems as well as through the eta ->pi(0)pi(+)pi(-) decay mode in p+p and d+Au collisions. The nuclear modification factor in d+Au collisions, R-dAu(p(T))approximate to 1.0-1.1, suggests at most only modest p(T) broadening ("Cronin enhancement"). In central Au+Au reactions, the eta yields are significantly suppressed, with R-AuAu(p(T))approximate to 0.2. The ratio of eta to pi(0) yields is approximately constant as a function of p(T) for the three colliding systems in agreement with the high-p(T) world average of R-eta/pi(0)approximate to 0.5 in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions for a wide range of center-of-mass energies (root sNN approximate to 3-1800 GeV) as well as, for high scaled momentum x(p), in e(+)e(-) annihilations at root s=91.2 GeV. These results are consistent with a scenario where high-p(T) eta production in nuclear collisions at the Relativistic Heavy Ion Collider is largely unaffected by initial-state effects but where light-quark mesons (pi(0),eta) are equally suppressed due to final-state interactions of the parent partons in the dense medium produced in Au+Au reactions.
14.	Abdallah, J, et al. (author) Coherent soft particle production in Z decays into three jets 2005 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 605:1-2, s. 37-48 Journal article (peer-reviewed)abstract Low-energy particle production perpendicular to the event plane in three-jet events produced in Z decays in e(+)e(-) annihilation is measured and compared to that perpendicular to the event axis in two-jet events. The topology dependence of the hadron production ratio is found to agree with a leading-order QCD prediction. This agreement and especially the need for the presence of a destructive interference term gives evidence for the coherent nature of gluon radiation. Hadron production in three-jet events is found to be directly proportional to a single topological scale function of the inter-jet angles. The slope of the dependence of the multiplicity with respect to the topological scale was measured to be 2.211 +/- 0.014(stat.) +/- 0.053(syst.) in good agreement with the expectation given by the colour-factor ratio C-A/C-F = 9/4. This result strongly supports the assumption of local parton-hadron duality, LPHD, at low hadron momentum.
15.	Abdallah, J., et al. (author) Search for a fourth generation b '-quark at LEP-II at root s=196-209GeV 2007 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 50:3, s. 507-518 Journal article (peer-reviewed)abstract A search for the pair production of fourth generation b'-quarks was performed using data taken by the DELPHI detector at LEP-II. The analysed data were collected at centre-of-mass energies ranging from 196 to 209 GeV, corresponding to an integrated luminosity of 420 pb(-1). No evidence for a signal was found. Upper limits on BR(b'-> bZ) and BR(b'-> bZ) were obtained for b' masses ranging from 96 to 103 GeV/c(2) stop. These limits, together with the theoretical branching ratios predicted by a sequential four generations model, were used to constrain the value of R-CKM=vertical bar V-cb(') /V-tb'V-tb vertical bar there V-cb', V-tb' and V-tb are elements of the extended CKM matrix.
16.	Abdallah, J., et al. (author) Study of multi-muon bundles in cosmic ray showers detected with the DELPHI detector at LEP 2007 In: Astroparticle physics. - : Elsevier BV. - 0927-6505 .- 1873-2852. ; 28:3, s. 273-286 Journal article (peer-reviewed)abstract The DELPHI detector at LEP has been used to measure multi-muon bundles originating from cosmic ray interactions with air. The cosmic events were recorded in "parasitic mode" between individual e(+)e(-) interactions and the total live time of this data taking is equivalent to 1.6 x 10(6) s. The DELPHI apparatus is located about 100 m underground and the 84 metres rock overburden imposes a cutoff of about 52 GeV/c on muon momenta. The data from the large volume Hadron Calorimeter allowed the muon multiplicity of 54,201 events to be reconstructed. The resulting muon multiplicity distribution is compared with the prediction of the Monte Carlo simulation based on CORSIKA/QGSJETOI. The model fails to describe the abundance of high multiplicity events. The impact of QGSJET internal parameters on the results is also studied.
17.	Adler, S. S., et al. (author) Dense-medium modifications to jet-induced hadron pair distributions in Au+Au collisions at root(NN)-N-S=200 GeV 2006 In: Physical Review Letters. - 1079-7114. ; 97:5 Journal article (peer-reviewed)abstract Azimuthal correlations of jet-induced high-p(T) charged hadron pairs are studied at midrapidity in Au+Au collisions at root s(NN)=200 GeV. The distribution of jet-associated partner hadrons (1.0 < p(T)< 2.5 GeV/c) per trigger hadron (2.5 < p(T)< 4.0 GeV/c) is found to vary with collision centrality, in both shape and yield, indicating a significant effect of the nuclear collision medium on the jet fragmentation process.
18.	Adler, S. S., et al. (author) Detailed study of high-p(T) neutral pion suppression and azimuthal anisotropy in Au plus Au collisions at root s(NN) =200 GeV 2007 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 76:3 Journal article (peer-reviewed)abstract Measurements of neutral pion (pi(0)) production at midrapidity in root s(NN)=200 GeV Au+Au collisions as a function of transverse momentum, p(T), collision centrality, and angle with respect to reaction plane are presented. The data represent the final pi(0) results from the PHENIX experiment for the first RHIC Au+Au run at design center-of-mass energy. They include additional data obtained using the PHENIX Level-2 trigger with more than a factor of 3 increase in statistics over previously published results for p(T)>6 GeV/c. We evaluate the suppression in the yield of high-p(T) pi(0)'s relative to pointlike scaling expectations using the nuclear modification factor R-AA. We present the p(T) dependence of R-AA for nine bins in collision centrality. We separately integrate R-AA over larger p(T) bins to show more precisely the centrality dependence of the high-p(T) suppression. We then evaluate the dependence of the high-p(T) suppression on the emission angle Delta phi of the pions with respect to event reaction plane for seven bins in collision centrality. We show that the yields of high-p(T) pi(0)'s vary strongly with Delta phi, consistent with prior measurements 1,2. We show that this variation persists in the most peripheral bin accessible in this analysis. For the peripheral bins we observe no suppression for neutral pions produced aligned with the reaction plane, whereas the yield of pi(0)'s produced perpendicular to the reaction plane is suppressed by a factor of similar to 2. We analyze the combined centrality and Delta phi dependence of the pi(0) suppression in different p(T) bins using different possible descriptions of parton energy loss dependence on jet path-length averages to determine whether a single geometric picture can explain the observed suppression pattern.
19.	Adler, S. S., et al. (author) Evidence for a long-range component in the pion emission source in Au plus Au collisions at root s(NN)=200 GeV 2007 In: Physical Review Letters. - 1079-7114. ; 98:13 Journal article (peer-reviewed)abstract Emission source functions are extracted from correlation functions constructed from charged pions produced at midrapidity in Au+Au collisions at s(NN)=200 GeV. The source parameters extracted from these functions at low k(T) give first indications of a long tail for the pion emission source. The source extension cannot be explained solely by simple kinematic considerations. The possible role of a halo of secondary pions from resonance emissions is explored.
20.	Adler, S. S., et al. (author) Measurement of single muons at forward rapidity in p+p collisions at root s=200 GeV and implications for charm production 2007 In: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 1550-2368. ; 76:9 Journal article (peer-reviewed)abstract Muon production at forward rapidity (1.5 <=\|eta\|<= 1.8) has been measured by the PHENIX experiment over the transverse momentum range 1 <= p(T)<= 3 GeV/c in root s=200 GeV p+p collisions at the Relativistic Heavy Ion Collider. After statistically subtracting contributions from light hadron decays an excess remains which is attributed to the semileptonic decays of hadrons carrying heavy flavor, i.e. charm quarks or, at high p(T), bottom quarks. The resulting muon spectrum from heavy flavor decays is compared to PYTHIA and a next-to-leading-order perturbative QCD calculation. PYTHIA is used to determine the charm quark spectrum that would produce the observed muon excess. The corresponding differential cross section for charm quark production at forward rapidity is determined to be d sigma(c (c) over bar)/dy\|(y=1.6)=0.243 +/- 0.013(stat.)+/- 0.105(data syst.)(-0.087)(+0.049)(PYTHIA syst.) mb.
21.	Abdallah, J, et al. (author) Bose-Einstein correlations in W+W- events at LEP2 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 44:2, s. 161-174 Journal article (peer-reviewed)abstract Bose-Einstein correlations (BEC) between final state particles in the reaction e(+)e(-) -> W+ W- -> q(1)(q(2)) over barq(3)(q(4)over bar>) over bar) have been studied. Data corresponding to a total integrated luminosity of 550 pb(-1), recorded by the DELPHI detector at centre-of-mass energies ranging from 189 to 209 GeV, were analysed. An indication for inter-W BEC between like-sign particles has been found at the level of 2.4 standard deviations of the combined statistical and systematic uncertainties.
22.	Abdallah, J, et al. (author) Correlations between polarisation states of W particles in the reaction e(-)e(+)-> W-W+ at LEP2 energies 189-209 GeV 2009 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 63:4, s. 611-623 Journal article (peer-reviewed)abstract In a study of the reaction e(-)e(+)-> W-W+ with the DELPHI detector, the probabilities of the two W particles occurring in the joint polarisation states transverse-transverse (T T), longitudinal-transverse plus transverse-longitudinal (LT) and longitudinal-longitudinal (LL) have been determined using the final states WW -> lvq (q) over bar (l = e, mu). The two-particle joint polarisation probabilities, i.e. the spin density matrix elements rho T T, rho LT, rho LL, are measured as functions of the W- production angle, theta(W-), at an average reaction energy of 198.2 GeV. Averaged over all cos.W-, the following joint probabilities are obtained: (rho) over barT T = (67 +/- 8)%, (rho) over barL T = (30 +/- 8)%, (rho) over barL T = (3 +/- 7)%. These results are in agreement with the Standard Model predictions of 63.0%, 28.9% and 8.1%, respectively. The related polarisation cross-sections sigma(TT), sigma(LT) and sigma(LL) are also presented.
23.	Abdallah, J, et al. (author) Determination of A(FB)(b) at the Z pole using inclusive charge reconstruction and lifetime tagging 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 40:1, s. 1-25 Journal article (peer-reviewed)abstract A novel high precision method measures the b-quark forward-backward asymmetry at the Z pole on a sample of 3,560,890 hadronic events collected with the DELPHI detector in 1992 to 2000. An enhanced impact parameter tag provides a high purity b sample. For event hemispheres with a reconstructed secondary vertex the charge of the corresponding quark or anti-quark is determined using a neural network which combines in an optimal way the full available charge information from the vertex charge, the jet charge and from identified leptons and hadrons. The probability of correctly identifying b-quarks and anti-quarks is measured on the data themselves comparing the rates of double hemisphere tagged like-sign and unlike-sign events. The b-quark forward-backward asymmetry is determined from the differential asymmetry, taking small corrections due to hemisphere correlations and background contributions into account. The results for different centre-of-mass energies are: A(FB)(b) ( 89.449 GeV) = 0.0637 +/- 0.0143( stat.) +/- 0.0017( syst.), A(FB)(b) ( 91.231 GeV) = 0.0958 +/- 0.0032( stat.) +/- 0.0014( syst.), A(FB)(b) ( 92.990 GeV) = 0.1041 +/- 0.0115( stat.) +/- 0.0024( syst.). Combining these results yields the b-quark pole asymmetry A(FB)(b0) = 0.0972 +/- 0.0030( stat.) +/- 0.0014( syst.).
24.	Abdallah, J., et al. (author) Di-jet production in gamma gamma collisions at LEP2 2008 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:58, s. 531-541 Journal article (peer-reviewed)
25.	Abdallah, J, et al. (author) Flavour independent searchesfor hadronically decaying neutral Higgs bosons 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 44:2, s. 147-159 Journal article (peer-reviewed)abstract This paper describes flavour independent searches for hadronically decaying neutral Higgs bosons in the data collected by the DELPHI experiment at LEP, at centre-of-mass energies between 189 and 209 GeV. The collected data-set corresponds to an integrated luminosity of around 610 pb(-1). The e(+)e(-) -> hA and e(+)e(-) -> hZand processes are considered, with direct Higgs boson decays into hadrons. No evidence for Higgs boson production is found, and cross-section limits are set as a function of the Higgs boson masses. No explicit assumptions are made on the underlying physics beyond the Standard Model, allowing interpretation of the data in a large class of models.
26.	Abdallah, J., et al. (author) Higgs boson searches in CP-conserving and CP-violating MSSM scenarios with the DELPHI detector 2008 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:54, s. 1-35 Journal article (peer-reviewed)abstract This paper presents the final interpretation of the results from DELPHI on the searches for Higgs bosons in the minimal supersymmetric extension of the Standard Model (MSSM). A few representative scenarios are considered, that include CP conservation and explicit CP violation in the Higgs sector. The experimental results encompass the searches for neutral Higgs bosons at LEP1 and LEP2 in final states as expected in the MSSM, as well as LEP2 searches for charged Higgs bosons and for neutral Higgs bosons decaying into hadrons independent of the quark flavour. The data reveal no significant excess with respect to background expectations. The results are translated into excluded regions of the parameter space in the various scenarios. In the CP-conserving case, these lead to limits on the masses of the lightest scalar and pseudoscalar Higgs bosons, h and A, and on tan beta. The dependence of these limits on the top quark mass is discussed. Allowing for CP violation reduces the experimental sensitivity to Higgs bosons. It is shown that this effect depends strongly on the values of the parameters responsible for CP violation in the Higgs sector.
27.	Abdallah, J, et al. (author) Measurement of the energy dependence of hadronic jet rates and the strong coupling alpha(s) from the four-jet rate with the DELPHI detector at LEP 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 38:4, s. 413-426 Journal article (peer-reviewed)abstract Hadronic events from the data collected with the DELPHI detector at LEP within the energy range from 89 GeV to 209 GeV are selected, their jet rates are determined and compared to predictions of four different event generators. One of them is the recently developed APACIC++ generator which performs a massive matrix element calculation matched to a parton shower followed by string fragmentation. The four-jet rate is used to measure alpha(s) in the next-to-leading-order approximation yielding alpha(s)(M-Z(2)) = 0.1175 +/- 0.0030. The running of alpha(s) determined by using four-jet events has been tested. The logarithmic energy slope is measured to be dalpha(s)(-1)/d log E-cm = 1.14 +/- 0.36. Since the analysis is based on four-jet final states it represents an alternative approach to previous DELPHI alpha(s) measurements using event shape distributions.
28.	Abdallah, J., et al. (author) Measurement of the mass and width of the W boson in e(+) e(-) collisions at root s=161-209 GeV 2008 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:55, s. 1-38 Journal article (peer-reviewed)abstract A measurement of the W boson mass and width has been performed by the DELPHI collaboration using the data collected during the full LEP2 programme (1996-2000). The data sample has an integrated luminosity of 660 pb(-1) and was collected over a range of centre-of-mass energies from 161 to 209 GeV. Results are obtained by applying the method of direct reconstruction of the mass of the W from its decay products in both the W+W- -> l (nu) over bar (l) and W+W- -> q (q) over bar'(q) over barq'channels. The W mass result for the combined data set is M-W = 80.336 +/- 0.055(Stat.) +/- 0.028(Syst.) +/- 0.025(FSI) +/- 0.009(LEP) GeV/c(2) , where FSI represents the uncertainty due to final state interaction effects in the q (q) over bar'(q) over barq' channel, and LEP represents that arising from the knowledge of the collision energy of the accelerator. The combined value for the W width is Gamma(W) = 2.404 +/- 0.140(Stat.) +/- 0.077(Syst.) +/- 0.065(FSI) GeV/c(2). These results supersede all values previously published by the DELPHI collaboration.
29.	Abdallah, J., et al. (author) Measurement of the tau lepton polarisation at LEP2 2008 In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 659:1-2, s. 65-73 Journal article (peer-reviewed)abstract A first measurement of the average polarisation P-tau of tau leptons produced in e(+)e(-) annihilation at energies significantly above the Z resonance is presented. The polarisation is determined from the kinematic spectra of tau hadronic decays. The measured value P-tau = -0.164 +/- 0.125 is consistent with the Standard Model prediction for the mean LEP energy of 197 GeV. (c) 2007 Elsevier B.V. All rights reserved.
30.	Abdallah, J, et al. (author) Observation of the muon inner bremsstrahlung at LEP1 2008 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:57, s. 499-514 Journal article (peer-reviewed)abstract Muon bremsstrahlung photons converted in front of the DELPHI main tracker (TPC) in dimuon events at LEP1 were studied in two photon kinematic ranges: 0.2< E-gamma <= 1 GeV and transverse momentum with respect to the parent muon p(T) < 40 MeV/c, and 1< E-gamma <= 10 GeV and pT < 80 MeV/c. A good agreement of the observed photon rate with predictions from QED for the muon inner bremsstrahlung was found, contrary to the anomalous soft photon excess that has been observed recently in hadronic Z(0) decays. The obtained ratios of the observed signal to the predicted level of the muon bremsstrahlung are 1.06 +/- 0.12 +/- 0.07 in the photon energy range 0.2< E-gamma <= 1 GeV and 1.04 +/- 0.09 +/- 0.12 in the photon energy range 1< E-gamma <= 10 GeV. The bremsstrahlung dead cone is observed for the first time in the direct photon production at LEP.
31.	Abdallah, J, et al. (author) Photon events with missing energy in e(+)e(-) collisions at root s=130 to 209 GeV 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044. ; 38:4, s. 395-411 Journal article (peer-reviewed)abstract The production of single- and multi-photon events has been studied in the reaction e(+) e(-) --> gamma(gamma) + invisible particles. The data collected with the DELPHI detector during the years 1999 and 2000 at centre-of-mass energies between 191 GeV and 209 GeV was combined with earlier data to search for phenomena beyond the Standard Model. The measured number of light neutrino families was consistent with three and the absence of an excess of events beyond that predicted by the Standard Model processes was used to set limits on new physics. Both model-independent searches and searches for new processes predicted by supersymmetric and extra-dimensional models have been made. Limits on new non-standard model interactions between neutrinos and electrons were also determined.
32.	Abdallah, J., et al. (author) Study of b-quark mass effects in multijet topologies with the DELPHI detector at LEP 2008 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:55, s. 525-538 Journal article (peer-reviewed)abstract The effect of the heavy b-quarkmass on the two, three and four-jet rates is studied using LEP data collected by the DELPHI experiment at the Z peak in 1994 and 1995. The rates of b-quark jets and light quark jets (l = uds) in events with n = 2, 3, and 4 jets, together with the ratio of two and four-jet rates of b-quarks with respect to light-quarks, R-n(bl), have been measured with a double-tag technique using the CAMBRIDGE jet-clustering algorithm. A comparison between experimental results and theory (matrix element or Monte Carlo event generators such as PYTHIA, HERWIG andARIADNE) is done after the hadronisation phase. Using the four-jet observabl R-4(bl), a measurement of the b-quark mass using massive leading-order calculations gives: m(b)(M-Z) = 3.76 +/- 0.32 (stat) +/- 0.17 (syst) +/- 0.22 (had) +/- 0.90 (theo) GeV/c(2). This result is compatible with previous three-jet determinations at the M-Z energy scale and with low energy mass measurements evolved to the M-Z scale using QCD renormalisation group equations.
33.	Abdallah, J., et al. (author) Z gamma* production in e(+) e(-) interactions at root s=183-209 GeV 2007 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 51:3, s. 503-523 Journal article (peer-reviewed)abstract Measurements of Z gamma* production are presented using data collected by the DELPHI detector at centre-of-mass energies ranging from 183 to 209 GeV, corresponding to an integrated luminosity of about 667 pb(-1). The measurements cover a wide range of the possible final state four-fermion configurations: hadronic and leptonic (e(+) e(-) q (q) over bar, mu(+) mu(-) q (q) over bar ,q (q) over barv (v) over bar), fully leptonic (l(+) l(-) l' (+) l'(-)) and fully hadronic. nal states (q (q) over barq (q) over bar, with a low mass q (q$) over bar pair). Measurements of the Z gamma* cross-section for the various. nal states have been compared with the Standard Model expectations and found to be consistent within the errors. In addition, a total cross-section measurement of the l(+) l(-) l'(+)l'(-) cross-section is reported, and found to be in agreement with the prediction of the Standard Model.
34.	Adler, S. S., et al. (author) Azimuthal angle correlations for rapidity separated hadron pairs in d+Au collisions at root s(NN)=200 GeV 2006 In: Physical Review Letters. - 1079-7114. ; 96:22 Journal article (peer-reviewed)abstract Deuteron-gold (d+Au) collisions at the Relativistic Heavy Ion Collider provide ideal platforms for testing QCD theories in dense nuclear matter at high energy. In particular, models suggesting strong saturation effects for partons carrying small nucleon momentum fraction (x) predict modifications to jet production at forward rapidity (deuteron-going direction) in d+Au collisions. We report on two-particle azimuthal angle correlations between charged hadrons at forward/backward (deuteron/gold going direction) rapidity and charged hadrons at midrapidity in d+Au and p+p collisions at root s(NN)=200 GeV. Jet structures observed in the correlations are quantified in terms of the conditional yield and angular width of away-side partners. The kinematic region studied here samples partons in the gold nucleus with x similar to 0.1 to similar to 0.01. Within this range, we find no x dependence of the jet structure in d+Au collisions.
35.	Adler, S. S., et al. (author) Centrality dependence of charged hadron production in deuteron plus gold and nucleon plus gold collisions at root S-NN=200 GeV 2008 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 77:1 Journal article (peer-reviewed)abstract We present transverse momentum (p(T)) spectra of charged hadrons measured in deuteron-gold and nucleon-gold collisions at root s(NN)=200 GeV for four centrality classes. Nucleon-gold collisions were selected by tagging events in which a spectator nucleon was observed in one of two forward rapidity detectors. The spectra and yields were investigated as a function of the number of binary nucleon-nucleon collisions, nu, suffered by deuteron nucleons. A comparison of charged particle yields to those in p+p collisions show that yield per nucleon-nucleon collision saturates with nu for high momentum particles. We also present the charged hadron to neutral pion ratios as a function of p(T).
36.	Adler, S. S., et al. (author) Centrality dependence of pi(0) and eta production at large transverse momentum in root s(NN) = 200 GeV d+Au collisions 2007 In: Physical Review Letters. - 1079-7114. ; 98:17 Journal article (peer-reviewed)abstract The dependence of transverse momentum spectra of neutral pions and eta mesons with p(T) < 16 GeV/c and p(T) < 12 GeV/c, respectively, on the centrality of the collision has been measured at midrapidity by the PHENIX experiment at the BNL Relativistic Heavy Ion Collider (RHIC) in d + Au collisions at root s(NN) = 200 GeV. The measured yields are compared to those in p + p collisions at the same root s(NN) scaled by the number of underlying nucleon-nucleon collisions in d + Au. At all centralities, the yield ratios show no suppression, in contrast to the strong suppression seen for central An + Au collisions at RHIC. Only a weak p(T) and centrality dependence can be observed.
37.	Adler, S. S., et al. (author) Jet properties from dihadron correlations in p plus p collisions at root s=200 GeV 2006 In: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-2368. ; 74:7 Journal article (peer-reviewed)abstract The properties of jets produced in p+p collisions at root s=200 GeV are measured using the method of two-particle correlations. The trigger particle is a leading particle from a large transverse momentum jet while the associated particle comes from either the same jet or the away-side jet. Analysis of the angular width of the near-side peak in the correlation function determines the jet-fragmentation transverse momentum j(T). The extracted value, root < j(T)(2)>=585 +/- 6(stat)+/- 15(sys) MeV/c, is constant with respect to the trigger particle transverse momentum, and comparable to the previous lower root s measurements. The width of the away-side peak is shown to be a convolution of j(T) with the fragmentation variable, z, and the partonic transverse momentum, k(T). The < z > is determined through a combined analysis of the measured pi(0) inclusive and associated spectra using jet-fragmentation functions measured in e(+)e(-) collisions. The final extracted values of k(T) are then determined to also be independent of the trigger particle transverse momentum, over the range measured, with value of root < k(T)(2)>=2.68 +/- 0.07(stat)+/- 0.34(sys) GeV/c.
38.	Adler, S. S., et al. (author) Jet structure from dihadron correlations in d+Au collisions at root S-NN=200 GeV 2006 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 73:5 Journal article (peer-reviewed)abstract Dihadron correlations at high transverse momentum p(T) in d+Au collisions at root s(NN)=200 GeV at midrapidity are measured by the PHENIX experiment at the Relativistic Heavy Ion Collider. From these correlations, we extract several structural characteristics of jets: the root-mean-squared transverse momentum of fragmenting hadrons with respect to the jet root < j(T)(2)>, the mean sine-squared of the azimuthal angle between the jet axes < sin(2)phi(jj)>, and the number of particles produced within the dijet that are associated with a high-p(T) particle (dN/dx(E) distributions). We observe that the fragmentation characteristics of jets in d+Au collisions are very similar to those in p+p collisions and that there is little dependence on the centrality of the d+Au collision. This is consistent with the nuclear medium having little influence on the fragmentation process. Furthermore, there is no statistically significant increase in the value of < sin(2)phi(jj)> from p+p to d+Au collisions. This constrains the effect of multiple scattering that partons undergo in the cold nuclear medium before and after a hard collision.
39.	Adler, S. S., et al. (author) Measurement of direct photon production in p+p collisions at root s=200 GeV 2007 In: Physical Review Letters. - 1079-7114. ; 98:1 Journal article (peer-reviewed)abstract Cross sections for midrapidity production of direct photons in p+p collisions at the Relativistic Heavy Ion Collider (RHIC) are reported for transverse momenta of 3 < p(T)< 16 GeV/c. Next-to-leading order perturbative QCD (pQCD) describes the data well for p(T)> 5 GeV/c, where the uncertainties of the measurement and theory are comparable. We also report on the effect of requiring the photons to be isolated from parton jet energy. The observed fraction of isolated photons is well described by pQCD for p(T)> 7 GeV/c.
40.	Adler, S. S., et al. (author) Nuclear effects on hadron production in d plus Au collisions at root S-NN=200 GeV revealed by comparison with p plus p data 2006 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 74:2 Journal article (peer-reviewed)abstract PHENIX has measured the centrality dependence of midrapidity pion, kaon, and proton transverse momentum distributions in d+Au and p+p collisions at root s(NN) = 200 GeV. The p+p data provide a reference for nuclear effects in d+Au and previously measured Au+Au collisions. Hadron production is enhanced in d+Au, relative to independent nucleon-nucleon scattering, as was observed in lower energy collisions. The nuclear modification factor for (anti)protons is larger than that for pions. The difference increases with centrality but is not sufficient to account for the abundance of baryon production observed in central Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The centrality dependence in d+Au shows that the nuclear modification factor increases gradually with the number of collisions encountered by each participant nucleon. We also present comparisons with lower energy data as well as with parton recombination and other theoretical models of nuclear effects on particle production.
41.	Adler, S. S., et al. (author) Production of omega mesons at large transverse momenta in p+p and d+Au collisions at root S(NN) = 200 GeV 2007 In: Physical Review C (Nuclear Physics). - 0556-2813. ; 75:5 Journal article (peer-reviewed)abstract The PHENIX experiment at RHIC has measured the invariant cross section for omega-meson production at midrapidity in the transverse momentum range 2.5 < p(T)< 9.25 GeV/c in p+p and d+Au collisions at root s(NN) = 200 GeV. Measurements in two decay channels (omega ->pi(0)pi(+)pi(-) and omega ->pi(0)gamma) yield consistent results, and the reconstructed omega mass agrees with the accepted value within the p(T) range of the measurements. The omega/pi(0) ratio is found to be 0.85 +/- 0.05(stat)+/- 0.09(sys) in p+p and 0.94 +/- 0.08(stat)+/- 0.12(sys) in d+Au collisions, independent of p(T). The nuclear modification factor R-dA(omega) is 1.03 +/- 0.12(stat)+/- 0.21(sys) and 0.83 +/- 0.21(stat)+/- 0.17(sys) in minimum bias and central (0-20%) d+Au collisions, respectively.
42.	Coustenis, A., et al. (author) TandEM : Titan and Enceladus mission 2009 In: Experimental astronomy. - : Springer Science and Business Media LLC. - 0922-6435 .- 1572-9508. ; 23:3, s. 893-946 Journal article (peer-reviewed)abstract TandEM was proposed as an L-class (large) mission in response to ESA's Cosmic Vision 2015-2025 Call, and accepted for further studies, with the goal of exploring Titan and Enceladus. The mission concept is to perform in situ investigations of two worlds tied together by location and properties, whose remarkable natures have been partly revealed by the ongoing Cassini-Huygens mission. These bodies still hold mysteries requiring a complete exploration using a variety of vehicles and instruments. TandEM is an ambitious mission because its targets are two of the most exciting and challenging bodies in the Solar System. It is designed to build on but exceed the scientific and technological accomplishments of the Cassini-Huygens mission, exploring Titan and Enceladus in ways that are not currently possible (full close-up and in situ coverage over long periods of time). In the current mission architecture, TandEM proposes to deliver two medium-sized spacecraft to the Saturnian system. One spacecraft would be an orbiter with a large host of instruments which would perform several Enceladus flybys and deliver penetrators to its surface before going into a dedicated orbit around Titan alone, while the other spacecraft would carry the Titan in situ investigation components, i.e. a hot-air balloon (MontgolfiSre) and possibly several landing probes to be delivered through the atmosphere.
43.	Abdallah, J., et al. (author) A determination of the centre-of-mass energy at LEP2 using radiative two-fermion events 2006 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:2, s. 295-305 Journal article (peer-reviewed)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.
44.	Abdallah, J., et al. (author) A measurement of the tau hadronic branching ratios 2006 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:1, s. 1-26 Journal article (peer-reviewed)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.
45.	Abdallah, J., et al. (author) A study of b(b)over-bar production in e(+)e(-) collisions at root s=130-207 GeV 2009 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 60:1, s. 1-15 Journal article (peer-reviewed)abstract 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.
46.	Abdallah, J, et al. (author) Charged particle multiplicity in three-jet events and two-gluon systems 2005 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; C:44, s. 311-331 Journal article (peer-reviewed)abstract The charged particle multiplicity in hadronic three-jet events from Z decays is investigated. The topology dependence of the event multiplicity is found to be well described by a modified leading logarithmic prediction. A parameter fit of the prediction to the data yields a measurement of the colour factor ratio C-A/C-F with the result C-A/C-F = 2.261 +/- 0.014(stat). +/- 0.036(exp). +/- 0-066(theo). in agreement with the SU(3) expectation of QCD. The quark-related contribution to the event multiplicity is subtracted from the three-jet event multiplicity resulting in a measurement of the multiplicity of two-gluon colour-singlet states over a wide energy range. The ratios r = N-gg(s)/Ng (g) over bar (s) of the gluon and quark multiplicities and r((1)) = N'(gg)(s)/N'g (g) over bar (s) of their derivatives are compared with perturbative calculations. While a good agreement between calculations and data is observed for r((1)), larger deviations are found for r indicating that non-perturbative effects are more important for r than for r((1)).
47.	Abdallah, J, et al. (author) Determination of heavy quark non-perturbative parametersfrom spectral moments in semileptonic B decays 2006 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 45:1, s. 35-59 Journal article (peer-reviewed)abstract Moments of the hadronic invariant mass and of the lepton energy spectra in semileptonic B decays have been determined with the data recorded by the DELPHI detector at LEP. From measurements of the inclusive b-hadron semileptonic decays, and imposing constraints from other measurements on b- and c-quark masses, the first three moments of the lepton energy distribution and of the hadronic mass distribution, have been used to determine parameters which enter into the extraction of vertical bar V-cb vertical bar from the measurement of the inclusive b-hadron semileptonic decay width. The values obtained in the kinetic scheme are: m(b)(1 GeV) = 4.591 +/- 0.062 +/- 0.039 +/- 0.005 GeV/c(2), m(c)(1 GeV) = 1.170 +/- 0.093 +/- 0.055 +/- 0.005 GeV/c(2), m(pi)(2) (1 GeV) = 0.399 +/- 0.048 +/- 0.034 +/- 0.087 GeV2, (p) over tilde (3)(D) = 0.053 +/- 0.017 +/- 0.011 +/- 0.026 GeV3, and include corrections at order 1/m(b)(3). Using these results, and present measurements of the inclusive semileptonic decay partial width of b-hadrons at LEP, an accurate determination of vertical bar V-cb vertical bar is obtained: vertical bar V-cb vertical bar = 0.0421 x (1 +/- 0.014 (meas center dot) +/- 0.014 (fit) +/- 0.015 (th center dot)).
48.	Abdallah, J., et al. (author) Determination of the b quark mass at the M-Z scale with the DELPHI detector at LEP 2006 In: European Physical Journal C. Particles and Fields. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 46:3, s. 569-583 Journal article (peer-reviewed)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.
49.	Abdallah, J, et al. (author) Inclusive single-particle production in two-photon collisions at LEP II with the DELPHI detector 2009 In: Physics Letters B. - : Elsevier BV. - 0370-2693 .- 1873-2445. ; 678:5, s. 444-449 Journal article (peer-reviewed)abstract A study of the inclusive charged hadron production in two-photon collisions is described. The data were collected with the DELPHI detector at LEP II. Results on the inclusive single-particle p(T) distribution and the differential charged hadrons d sigma/dp(T) cross-section are presented and compared to the predictions of perturbative NLO QCD calculations and to published results. (C) 2009 Elsevier B.V. All rights reserved.
50.	Abdallah, J., et al. (author) Investigation of colour reconnection in WW events with the DELPHI detector at LEP-2 2007 In: European Physical Journal C. - : Springer Science and Business Media LLC. - 1434-6044 .- 1434-6052. ; 51:2, s. 249-269 Journal article (peer-reviewed)abstract In the reaction e(+)e(-) -> WW -> (q(1) (q) over bar (2))(q(3)(q) over bar (4)) the usual hadronization models treat the colour singlets q(1)(q) over bar (2) and q(3)(q) over bar (4) coming from two W bosons independently. However, since the. nal state partons may coexist in space and time, cross-talk between the two evolving hadronic systems may be possible during fragmentation through soft gluon exchange. This e. ect is known as colour reconnection. In this article the results of the investigation of colour reconnection e. ects in fully hadronic decays of W pairs in DELPHI at LEP are presented. Two complementary analyses were performed, studying the particle. ow between jets and W mass estimators, with negligible correlation between them, and the results were combined and compared to models. In the framework of the SK-I model, the value for its. parameter most compatible with the data was found to be: (SK)-S-kappa-I = 2.2(-1.3) (+2.5) corresponding to the probability of reconnection P-reco to be in the range 0.31 < P-reco < 0.68 at 68% confidence level with its best value at 0.52.

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