0000000000077959

AUTHOR

P. Goncalves

showing 39 related works from this author

Search for composite and exotic fermions at LEP 2

1999

A search for unstable heavy fermions with the DELPHI detector at LEP is reported. Sequential and non-canonical leptons, as well as excited leptons and quarks, are considered. The data analysed correspond to an integrated luminosity of about 48~pb$^{-1}$ at an $e^+e^-$ centre-of-mass energy of 183~GeV and about 20~pb$^{-1}$ equally shared between the centre-of-mass energies of 172~GeV and 161~GeV. The search for pair-produced new leptons establishes 95\% confidence level mass limits in the region between 70~GeV/$c^2$ and 90~GeV/$c^2$, depending on the channel. The search for singly produced excited leptons and quarks establishes upper limits on the ratio of the coupling of the excited fermio…

QuarkParticle physicsPhysics and Astronomy (miscellaneous)PAIR PRODUCTIONCHARGED HEAVY-LEPTONSFOS: Physical sciences7. Clean energy01 natural sciencesPartícules (Física nuclear)CROSS-SECTIONSHigh Energy Physics - ExperimentE(+)E(-) COLLISIONSBHABHA SCATTERINGHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesMONTE-CARLO PROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONS010306 general physicsNuclear ExperimentEngineering (miscellaneous)PhysicsLuminosity (scattering theory)010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyFermionCoupling (probability)Z0 DECAYSExcited stateHigh Energy Physics::ExperimentFísica nuclearROOT-S=161 GEVEXCITED LEPTONSCHARGED HEAVY-LEPTONS; MONTE-CARLO PROGRAM; EXCITED LEPTONS; E(+)E(-) COLLISIONS; Z0 DECAYS; ROOT-S=161 GEV; RADIATIVE-CORRECTIONS; BHABHA SCATTERING; PAIR PRODUCTION; CROSS-SECTIONSParticle Physics - ExperimentLepton
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Constraints on the origin of cosmic rays above 10^18 eV from large-scale anisotropy searches in data of the Pierre Auger Observatory

2012

A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 10(18) eV at the Pierre Auger Observatory is reported. For the first time, these large-scale anisotropy searches are performed as a function of both the right ascension and the declination and expressed in terms of dipole and quadrupole moments. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Upper limits on dipole and quadrupole amplitudes are derived under the hypothesis that any cosmic ray anisotropy is dominated by such moments in this energy range. These upper limits provide constraints on the production of cosmic rays above 10(…

[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]AstronomyAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesCosmic rayAstrophysics01 natural sciencesMAGNETIC-FIELDScosmic raysObservatory0103 physical sciencesUltra-high-energy cosmic rayAnisotropyastroparticle physics – cosmic rays010303 astronomy & astrophysicsCiencias ExactasHigh Energy Astrophysical Phenomena (astro-ph.HE)Pierre Auger ObservatoryAstroparticle physicsPhysicsCOSMIC cancer database010308 nuclear & particles physicsOBSERVATÓRIOS[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Astrophysics::Instrumentation and Methods for AstrophysicsAstronomyastroparticle physicFísicaAstronomy and AstrophysicsRadiación cósmica13. Climate actionSpace and Planetary Scienceastroparticle physicsExperimental High Energy PhysicsQuadrupoleComputingMethodologies_DOCUMENTANDTEXTPROCESSINGFísica de partículasFísica nuclearAstroparticle physicsAstrophysics - High Energy Astrophysical Phenomena
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Search for neutralino pair production at root s = 189 GeV

2001

A search for pair-production of neutralinos at a LEP centre-of-mass energy of 189 GeV gave no evidence for a signal. This limits the neutralino production cross-section and excludes regions in the parameter space of the Minimal Supersymmetric Standard Model (MSSM).

GRAVITINOSParticle physicsCOLLISIONSPhysics and Astronomy (miscellaneous)LOWEST ORDER CALCULATIONSMONTE-CARLO SIMULATIONFOS: Physical sciences2-PHOTON PROCESSESParameter space01 natural sciencesSignalPartícules (Física nuclear)High Energy Physics - ExperimentPHYSICSHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesEVENT GENERATOR[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONS010306 general physicsEngineering (miscellaneous)SUPERSYMMETRYDELPHIHIGH-ENERGIESPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyLARGE ELECTRON POSITRON COLLIDERPair productionPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHINeutralinoPARTICLE PHYSICSFísica nuclearMONTE-CARLO SIMULATION; LOWEST ORDER CALCULATIONS; RADIATIVE-CORRECTIONS; 2-PHOTON PROCESSES; EVENT GENERATOR; HIGH-ENERGIES; SUPERSYMMETRY; PHYSICS; GRAVITINOS; COLLISIONSHigh Energy Physics::ExperimentEnergy (signal processing)Particle Physics - ExperimentMinimal Supersymmetric Standard ModelEUROPEAN PHYSICAL JOURNAL C
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A measurement of the Tau topological branching ratios

2001

Using data collected in the DELPHI detector at LEP-1, measurements of the inclusive tau branching ratios for decay modes containing one, three, or five charged particles have been performed, giving the following results: B_1 = B(\tau^- -> (particle)^- \geq 0pi^0 \geq 0K^0 \nu_\tau(\bar{\nu})) = (85.316 +/- 0.093 +/- 0.049)%; B_3 = B(\tau^- -> 2h^-h^+ \geq 0pi^0 \geq 0K^0 \nu_\tau) = (14.569 +/- 0.093 +/- 0.048)%; B_5 = B(\tau^- -> 3h^-2h^+ \geq 0pi^0 \geq 0K^0 \nu_\tau) = (0.115 +/- 0.013 +/- 0.006)%, where h is either a charged pi or K meson. The first quoted uncertainties are statistical and the second systematic.

Particle physicsPhysics and Astronomy (miscellaneous)MesonPAIR PRODUCTIONENERGIESFOS: Physical sciencesBranching (polymer chemistry)01 natural sciencesCROSS-SECTIONSHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)BHABHA SCATTERINGMONTE-CARLOMONTE-CARLO; RADIATIVE-CORRECTIONS; BHABHA SCATTERING; PARTICLE PHYSICS; DELPHI DETECTOR; PAIR PRODUCTION; CROSS-SECTIONS; CP-INVARIANCE; ENERGIES; DECAY0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONS010306 general physicsEngineering (miscellaneous)DELPHIPhysicshigh energy collider010308 nuclear & particles physicsLEPDELPHI DETECTORCharged particleFIS/01 - FISICA SPERIMENTALEPARTICLE PHYSICSHigh Energy Physics::ExperimentFísica nuclearCP-INVARIANCEDECAYParticle Physics - Experiment
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Measurement and interpretation of the $W$-pair cross-section in $e^+e^-$ interactions at 161 GeV

1997

In 1996 LEP ran at a centre-of-mass energy of 161~GeV, just above the threshold of W-pair production. DELPHI accumulated data corresponding to an integrated luminosity of $9.93 {\mathrm{~pb^{-1}}}$, and observed 29 events that are considered as candidates for W-pair production. From these, a cross-section for the doubly resonant $e^+e^-\to\mathrm{WW}$ process of $3.67~^{+0.97}_{-0.85} \pm 0.19{\mathrm{~pb}}$ has been measured. Within the Standard Model, this cross-section corresponds to a mass of the W-boson of ${\mathrm{80.40~\pm~0.44~(stat.)~\pm~0.09~(syst.) ~\pm 0.03~(LEP)~GeV}}/c^2$. Alternatively, if $m_{\mathrm{W}}$ is held fixed at its current value determined by other experiments, t…

COLLISIONSNuclear and High Energy PhysicsParticle physicsElectron–positron annihilation01 natural sciencesBOSON MASS; ROOT-S=1.8 TEV; COLLISIONS; COUPLINGSPartícules (Física nuclear)Standard ModelInterpretation (model theory)Nuclear physics0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsDetectors de radiacióDELPHIPhysicsLuminosity (scattering theory)010308 nuclear & particles physicsROOT-S=1.8 TEVCOUPLINGSLARGE ELECTRON POSITRON COLLIDERBOSON MASSCross section (geometry)PARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSHigh Energy Physics::ExperimentParticle Physics - ExperimentPhysics Letters B
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A search for $\eta'_c$ production in photon-photon fusion at LEP

1998

A search for the production of the $\eta'_c$ meson, the first radial excitation of the ground state of charmonium $\eta_c$(2980), in the photon-photon fusion reaction at LEP has been performed using the data collected by the DELPHI detector during 1992-1996. No evidence of $\eta'_c$ production is found in the mass region 3520--3800 MeV/c^2. An upper limit for the ratio of the two-photon widths of the $\eta'_c$ and $\eta_c$ is obtained.

Nuclear and High Energy PhysicsParticle physicsPhotonMesonHigh Energy Physics::LatticeWidth ratio01 natural sciencesPartícules (Física nuclear)High Energy Physics - ExperimentNuclear physics0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Nuclear fusion010306 general physicsNuclear ExperimentDELPHIPhysicsFusion010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyLARGE ELECTRON POSITRON COLLIDERLarge Electron–Positron ColliderPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentGround stateExcitationParticle Physics - Experiment
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A Precise Measurement of the $\tau$ Polarisation at LEP-1

2000

The $\tau$ polarisation has been studied with the ${\rm e^+e^-}\to \tau^+\tau^-$ data collected by the DELPHI detector at LEP in 1993, 1994 and 1995 around the Z resonance firstly through the exclusive decay channels ${\rm e}\nu\bar{\nu}$ , $\mu\nu\bar{\nu}$ , $\pi\nu$ , $\rho\nu$ and ${\rm a}_1\nu$ and secondly with an inclusive hadronic analysis which benefits from a higher efficiency and a better systematic precision. The results have been combined with those previously published on 1990 to 1992 DELPHI data, to produce results which reflect the full LEP-1 statistics. The fit of the $\tau$ polarisation dependence on the production angle yielded the polarisation parameters ${\cal A}_{_{\sc…

Particle physicsCOLLISIONSscientific informationPOLARIZATIONPhysics and Astronomy (miscellaneous)LUND MONTE-CARLOENERGIESElectron–positron annihilationHadron01 natural sciencesComputer Science::Digital LibrariesDECAYSPartícules (Física nuclear)informationPHYSICSNEUTRINO HELICITYBHABHA SCATTERINGOpen Access0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSComputer Science::Symbolic Computation010306 general physicsEngineering (miscellaneous)LUND MONTE-CARLO; NEUTRINO HELICITY; MICHEL PARAMETERS; RADIATIVE-CORRECTIONS; BHABHA SCATTERING; DECAYS; POLARIZATION; PHYSICS; COLLISIONS; ENERGIESBhabha scatteringDELPHIPhysics010308 nuclear & particles physicscommunicationPhysicsHigh Energy Physics::PhenomenologyepistemologyWeinberg angleMICHEL PARAMETERSPolarization (waves)LARGE ELECTRON POSITRON COLLIDERPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIMichel parametersPARTICLE PHYSICSAngular dependenceFísica nuclearHigh Energy Physics::ExperimentParticle Physics - ExperimentOpen Society InstituteLepton
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Identified charged particles in quark and gluon jets

2000

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.

QuarkAntiparticleParticle physicsPhysics and Astronomy (miscellaneous)High Energy Physics::LatticeHadronNuclear TheoryFOS: Physical sciences01 natural sciencesSpectral lineDECAYSPartícules (Física nuclear)High Energy Physics - ExperimentPHYSICSHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesALGORITHMMultiplicity (chemistry)010306 general physicsNuclear ExperimentEngineering (miscellaneous)DELPHIPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyMULTIPLICITYORDER QCD; MULTIPLICITY; ALGORITHM; PHYSICS; DECAYSLARGE ELECTRON POSITRON COLLIDERCharged particleGluonBaryonPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentORDER QCDParticle Physics - Experiment
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Update of the search for charginos nearly mass-degenerate with the lightest neutralino

2000

The data collected by DELPHI in 1998 at the centre-of-mass energy of 189 GeV have been used to update the search for charginos nearly mass-degenerate with the lightest supersymmetric particle, which is assumed to be the lightest neutralino. Mass differences below \Delta M = 3 GeV/c^2 are considered. No excess of events with respect to the Standard Model expectation has been observed, and exclusions in the plane of \Delta M versus chargino mass are given. The new \Delta M independent lower limit on the mass of the chargino is 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. In the approximat…

Nuclear and High Energy PhysicsParticle physicsCOLLISIONSField (physics)LOWEST ORDER CALCULATIONSENERGIESMONTE-CARLO SIMULATIONFOS: Physical sciences2-PHOTON PROCESSES01 natural sciencesLightest Supersymmetric ParticlePartícules (Física nuclear)Standard ModelHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)MONTE-CARLO SIMULATION; LOWEST ORDER CALCULATIONS; RADIATIVE-CORRECTIONS; 2-PHOTON PROCESSES; COLLISIONS; ENERGIES; PROGRAMChargino0103 physical sciencesPROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSHiggsino010306 general physicsNuclear ExperimentDELPHIPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyGauginoLEPLARGE ELECTRON POSITRON COLLIDERSfermionNeutralinoPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentParticle Physics - Experiment
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Search for signatures of magnetically-induced alignment in the arrival directions measured by the Pierre Auger Observatory

2011

We present the results of an analysis of data recorded at the Pierre Auger Observatory in which we search for groups of directionally-aligned events (or ‘multiplets’) which exhibit a correlation between arrival direc- tion and the inverse of the energy. These signatures are expected from sets of events coming from the same source after having been deflected by intervening coherent magnetic fields. The observation of several events from the same source would open the possibility to accurately reconstruct the position of the source and also measure the integral of the component of the magnetic field orthogonal to the trajectory of the cos- mic rays. We describe the largest multiplets found an…

[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Field (physics)Astronomyultra-high energy cosmic rays; Pierre Auger Observatory; arrival directionsFOS: Physical sciencesCosmic rayAstrophysics01 natural sciencesCosmic RayAugerPosition (vector)0103 physical sciencesFIELDPierre auger observatory010303 astronomy & astrophysicsUltra-high energy cosmic rayDETECTORCiencias ExactasHigh Energy Astrophysical Phenomena (astro-ph.HE)Pierre Auger ObservatoryPhysicsArrival directions010308 nuclear & particles physics[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]PhysicsIsotropyFísicaAstronomy and AstrophysicsASTROFÍSICAUltra-high energy cosmic raysMagnetic fieldExperimental High Energy PhysicsData analysisComputingMethodologies_DOCUMENTANDTEXTPROCESSINGFísica nuclearAstrophysics - High Energy Astrophysical Phenomena[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]RAIOS CÓSMICOSArrival directionUltra-High Energy Cosmic Ray
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Measurement of the Proton-Air Cross Section ats=57  TeVwith the Pierre Auger Observatory

2012

We report a measurement of the proton-air cross section for particle production at the center-of-mass energy per nucleon of 57 TeV. This is derived from the distribution of the depths of shower maxima observed with the Pierre Auger Observatory: systematic uncertainties are studied in detail. Analyzing the tail of the distribution of the shower maxima, a proton-air cross section of [505 +/- 22(stat)(-36)(+28)(syst)] mb is found.

Pierre Auger ObservatoryPhysicsProton010308 nuclear & particles physicsAstrophysics::High Energy Astrophysical PhenomenaHadronAstrophysics::Instrumentation and Methods for AstrophysicsGeneral Physics and Astronomy01 natural scienceslaw.inventionAugerNuclear physicsCross section (physics)law0103 physical sciencesHigh Energy Physics::ExperimentFermilabNuclear Experiment010306 general physicsNucleonColliderPhysical Review Letters
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Search for the sgoldstino at √s = 189 to 202 GeV.

2000

A search for the supersymmetric partner of the goldstino, the sgoldstino S, at LEP2 is presented. 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. No evidence for the S production was found and limits on the S mass corresponding to different theory parameters are given.

PhysicsNuclear and High Energy PhysicsParticle physicsPhoton010308 nuclear & particles physicsHigh Energy Physics::Phenomenology01 natural sciencesPartícules (Física nuclear)GluonSgoldstino0103 physical sciencesHigh Energy Physics::ExperimentFísica nuclearGoldstino010306 general physics
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Search for neutral and charged Higgs bosons in $e^+ e^-$ collisions at $\sqrt{s}$= 161 GeV and 172 GeV

1998

A search for neutral and charged Higgs bosons has been performed in the data collected by the {\sc DELPHI} detector at centre-of-mass energies of 161~GeV and 172~GeV. The analysis assumes either the pair-production of charged Higgs bosons, ${\mathrm H}^{\pm}$, or the production of the lightest neutral Higgs boson, h, with either a Z or a neutral pseudoscalar Higgs boson, A. All final state topologies expected from the decay of h and A %neutral Higgs particles into hadrons or a pair of $\tau$ leptons, and from the decay of ${\mathrm H}^{\pm}$ %charged Higgs bosons into a pair of quarks or a $\tau \nu_{\tau}$ pair have been considered. %In the case of the associated production with a Z boson,…

QuarkParticle physicsPhysics and Astronomy (miscellaneous)LOWEST ORDER CALCULATIONSElectron–positron annihilationHigh Energy Physics::LatticeHadronMONTE-CARLO SIMULATIONSTANDARD MODEL2-PHOTON PROCESSES01 natural sciencesPartícules (Física nuclear)Nuclear physicsPHYSICS0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSNuclear Experiment010306 general physicsEngineering (miscellaneous)SUPERSYMMETRYDELPHIBosonPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologySupersymmetryE+E-ANNIHILATIONLARGE ELECTRON POSITRON COLLIDERMONTE-CARLO SIMULATION; LOWEST ORDER CALCULATIONS; E+E-ANNIHILATION; RADIATIVE-CORRECTIONS; 2-PHOTON PROCESSES; STANDARD MODEL; Z(0) DECAYS; PHYSICS; SUPERSYMMETRYZ(0) DECAYSPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHILarge Electron–Positron ColliderHiggs bosonPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentParticle Physics - ExperimentLepton
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Search for point-like sources of ultra-high energy neutrinos at the pierre auger observatory and improved limit on the diffuse flux of tau neutrinos

2012

The surface detector array of the Pierre Auger Observatory can detect neutrinos with energy Eν between 1017 eV and 1020 eV from point-like sources across the sky south of +55º and north of −65º declinations. A search has been performed for highly inclined extensive air showers produced by the interaction of neutrinos of all flavors in the atmosphere (downward-going neutrinos), and by the decay of tau leptons originating from tau neutrino interactions in Earth’s crust (Earth-skimming neutrinos). No candidate neutrinos have been found in data up to 2010 May 31. This corresponds to an equivalent exposure of ∼3.5 years of a full surface detector array for the Earth-skimming channel and ∼2 years…

Physics::Instrumentation and DetectorsSolar neutrinoAstronomyAstrophysics01 natural sciences7. Clean energyneutrinoTelescopiosTau neutrinoastroparticle physics; cosmic rays; neutrinos; telescopes010303 astronomy & astrophysicsGeneralLiterature_REFERENCE(e.g.dictionariesencyclopediasglossaries)cosmic rayPhysics[PHYS]Physics [physics]High Energy Astrophysical Phenomena (astro-ph.HE)[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]neutrinosCOSMIC-RAYSCosmic neutrino backgroundastroparticle physicsMeasurements of neutrino speedFísica nuclearNeutrinoAstrophysics - High Energy Astrophysical Phenomena[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Radiación CósmicaAstrophysics::High Energy Astrophysical PhenomenaTELESCÓPIOSFOS: Physical sciencesAstroparticle physiccosmic rays0103 physical sciencesDETECTORCiencias ExactasPierre Auger Observatory010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyFísicaAstronomy and AstrophysicstelescopesSolar neutrino problem13. Climate actionSpace and Planetary ScienceExperimental High Energy PhysicsHigh Energy Physics::ExperimentAstroparticle physics[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]Lepton
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Measurement of trilinear gauge boson couplings WWV, (V Z,gamma) in e(+)e(-) collisions at 189 GeV

2001

Measurements of the trilinear gauge boson couplings WWgamma and WWZ are presented using the data taken by DELPHI in 1998 at a centre-of-mass energy of 189 GeV and combined with DELPHI data at 183 GeV. Values are determined for Delta(g_1^Z) and Delta(kappa_gamma), the differences of the WWZ charge coupling and of the WWgamma dipole coupling from their Standard Model values, and for lambda_gamma, the WWgamma quadrupole coupling. A measurement of the magnetic dipole and electric quadrupole moment of the W is extracted from the results for Delta(kappa_gamma) and lambda_gamma. The study uses data from the final states jjlv, jjjj, lX, jjX and gammaX, where j represents a quark jet, l an identifie…

QuarkNuclear and High Energy PhysicsParticle physicsENERGIESAstrophysics::High Energy Astrophysical Phenomenastandard modelLEP-IIFOS: Physical sciencesLambda7. Clean energy01 natural sciencesPartícules (Física nuclear)High Energy Physics - ExperimentStandard ModelEVENTSHigh Energy Physics - Experiment (hep-ex)BHABHA SCATTERINGMONTE-CARLO0103 physical sciencesOPTIMAL OBSERVABLES[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]W-MASSgauge couplings010306 general physicsDETECTORQCDELPHIPhysicsGauge boson010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyCharge (physics)LARGE ELECTRON POSITRON COLLIDERFIS/01 - FISICA SPERIMENTALECol·lisions (Física nuclear)QuadrupolePARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIOPTIMAL OBSERVABLES; BHABHA SCATTERING; MONTE-CARLO; W-MASS; LEP-II; EVENTS; DETECTOR; DELPHI; E+E-->W+W; ENERGIESelectron-positron collisionPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentE+E-->W+WMagnetic dipoleLepton
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A search for invisible Higgs bosons produced in e+e- interactions at LEP 2 energies

1999

Searches for HZ production with the Higgs boson decaying into an invisible final state have been performed with the data collected by the DELPHI experiment up to the centre-of-mass energy of 183 GeV. The hadronic and muon pair final states of the Z boson were analysed. From the absence of signal, upper limits on the cross-section and the corresponding Higgs boson mass limits were set at 95% confidence level. The results are interpreted as excluded parameter regions in the framework of the minimal supersymmetric standard model and in the simplest Majoron model with one Higgs doublet and one Higgs singlet field. (C) 1999 Elsevier Science B.V. All rights reserved.

Nuclear and High Energy PhysicsParticle physicsCOLLISIONSVIOLATIONSTANDARD MODELMASS01 natural sciencesDECAYSPartícules (Física nuclear)Standard ModelNuclear physicsPHYSICSsymbols.namesakeMONTE-CARLO0103 physical sciencesPROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]STANDARD MODEL; MONTE-CARLO; PHYSICS; DECAYS; PROGRAM; SUPERSYMMETRY; COLLISIONS; VIOLATION; PARTICLE; MASS010306 general physicsSUPERSYMMETRYBosonMajoronDELPHIPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologySupersymmetryLARGE ELECTRON POSITRON COLLIDERHiggs fieldPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIsymbolsHiggs bosonPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentPARTICLEHiggs mechanismParticle Physics - ExperimentMinimal Supersymmetric Standard Model
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Large-scale distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory

2012

A thorough search for large-scale anisotropies in the distribution of arrival directions of cosmic rays detected above 1018 eV at the Pierre Auger Observatory is presented. This search is performed as a function of both declination and right ascension in several energy ranges above 1018 eV, and reported in terms of dipolar and quadrupolar coefficients. Within the systematic uncertainties, no significant deviation from isotropy is revealed. Assuming that any cosmic-ray anisotropy is dominated by dipole and quadrupole moments in this energy range, upper limits on their amplitudes are derived. These upper limits allow us to test the origin of cosmic rays above 1018 eV from stationary Galactic …

[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]Radiación CósmicaAstronomyMilky WayAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesCosmic rayAstrophysicsEXTENSIVE AIR-SHOWERSSURFACE DETECTOR01 natural sciencesGALACTIC MAGNETIC-FIELDSAuger[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]cosmic raysObservatory0103 physical sciencesastroparticle physics; cosmic raysAnisotropy010303 astronomy & astrophysicsGeneralLiterature_REFERENCE(e.g.dictionariesencyclopediasglossaries)Ciencias ExactasHigh Energy Astrophysical Phenomena (astro-ph.HE)Astroparticle physicsPhysicsPierre Auger ObservatoryANISOTROPY010308 nuclear & particles physicsAstrophysics::Instrumentation and Methods for AstrophysicsAstronomyFísicaAstronomy and AstrophysicsENERGY-SPECTRUMUltra-High Energy Cosmic Rays Pierre Auger Observatory Large Scale AnisotropiesSpace and Planetary Scienceastroparticle physicsExperimental High Energy PhysicsROTATIONARRAYFísica nuclearAstroparticle physicsRight ascensionAstrophysics - High Energy Astrophysical Phenomena
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Masses, lifetimes and production rates of Ξ− and Ξ¯+ at LEP 1

2006

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.

PhysicsNuclear physicsNuclear and High Energy Physics010308 nuclear & particles physicsElectron–positron annihilation0103 physical sciencesProduction (computer science)010306 general physics01 natural sciencesBar (unit)Xi baryonPhysics Letters B
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Measurement of the Λb0 decay form factor

2004

The form factor of Λb0 baryons is estimated using 3.46×106 hadronic Z decays collected by the DELPHI experiment between 1992 and 1995. Charmed Λc+ baryons fully reconstructed in the pK-π+, pK S0, and Λπ+π+π - modes, are associated to a lepton with opposite charge in order to select Λb0→Λc+l-ν̄l decays. From a combined likelihood and event rate fit to the distribution of the Isgur-Wise variable w, and using the Heavy Quark Effective Theory (HQET), the slope of the b-baryon form factor is measured to be ρ̂2=2.03±0.46(stat) -1.00+0.72(syst). The exclusive semileptonic branching fraction Br(Λb0→Λc+l-ν̄l) can be derived from ρ̂2 and is found to be (5.0-0.8+1.1(stat)-1.2+1.6(syst))%. Limits on ot…

Semileptonic decayPhysicsParticle physicsNuclear and High Energy Physics010308 nuclear & particles physicsBranching fractionElectron–positron annihilationHadronLambdaLambda baryon01 natural sciencesNuclear physicsBaryon0103 physical sciences010306 general physicsLepton
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Search for supersymmetric particles in scenarios with a gravitino LSP and stau NLSP

2000

Sleptons, neutralinos and charginos were searched for in the context of scenarios where the lightest supersymmetric particle is the gravitino. It was assumed that the stau is the next-to-lightest supersymmetric particle. Data collected with the DELPHI detector at a centre-of-mass energy near 189 GeV were analysed combining the methods developed in previous searches at lower energies. No evidence for the production of these supersymmetric particles was found. Hence, limits were derived at 95% confidence level.

NEUTRALINOSParticle physicsPhysics and Astronomy (miscellaneous)LOWEST ORDER CALCULATIONSPAIR PRODUCTIONENERGIESMONTE-CARLO SIMULATIONpluridisciplinarityFOS: Physical sciences2-PHOTON PROCESSESContext (language use)01 natural sciencesLightest Supersymmetric ParticlePartícules (Física nuclear)High Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)E(+)E(-) COLLISIONS0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSontology010306 general physicsEngineering (miscellaneous)DELPHIPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyreflexivityLEPscience studiesepistemologieLARGE ELECTRON POSITRON COLLIDERhistory of sciencePARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIMONTE-CARLO SIMULATION; LOWEST ORDER CALCULATIONS; RADIATIVE-CORRECTIONS; PAIR PRODUCTION; E(+)E(-) COLLISIONS; 2-PHOTON PROCESSES; ENERGIES; BREAKING; LEP; NEUTRALINOSParticlePARTICLE PHYSICSGravitinoFísica nuclearHigh Energy Physics::ExperimentcomplexityParticle Physics - ExperimentBREAKING
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Search for First Harmonic Modulation in the Right Ascension Distribution of Cosmic Rays Detected at the Pierre Auger Observatory

2011

We present the results of searches for dipolar-type anisotropies in different energy ranges above 2.5 × 1017 eV with the surface detector array of the Pierre Auger Observatory, reporting on both the phase and the amplitude measurements of the first harmonic modulation in the right-ascension distribution. Upper limits on the amplitudes are obtained, which provide the most stringent bounds at present, being below 2% at 99% C.L. for EeV energies. We also compare our results to those of previous experiments as well as with some theoretical expectations.

Large scale anisotripies[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Auger ExperimentAstronomyAstrophysics::High Energy Astrophysical PhenomenaPhase (waves)FOS: Physical sciencesCosmic rayAstrophysicsanisotropySURFACE DETECTOR01 natural sciencesCosmic RayAugerLarge scale anisotropiesObservatoryLarge scale anisotropie0103 physical sciences010303 astronomy & astrophysicsUltra-high energy cosmic rayCiencias ExactasHigh Energy Astrophysical Phenomena (astro-ph.HE)PhysicsPierre Auger ObservatoryFÍSICA DE PARTÍCULASUltra High Energy Cosmic Rays.010308 nuclear & particles physicsORIGINPhysics[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]Astrophysics::Instrumentation and Methods for AstrophysicsFísicaAstronomy and AstrophysicsPierre Auger ObservatoryUltra-high energy cosmic raysENERGY-SPECTRUMRadiación cósmicaAnisotropíaAmplitudeHarmonicsUltra-high energy cosmic rays; Large scale anisotropies; Pierre Auger ObservatoryExperimental High Energy PhysicsComputingMethodologies_DOCUMENTANDTEXTPROCESSINGARRAYFísica nuclearRight ascensionAstrophysics - High Energy Astrophysical Phenomena
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Study of dimuon production in photon-photon collisions and measurement of QED photon structure functions at LEP

2001

Muon pair production in the process e+e- -> e+e-mu+mu- is studied using the data taken at LEP1 (sqrt(s) \simeq m_Z) with the DELPHI detector during the years 1992-1995. The corresponding integrated luminosity is 138.5 pb^{-1}. The QED predictions have been tested over the whole Q^2 range accessible at LEP1 (from several GeV^2/c^4 to several hundred GeV^2/c^4) by comparing experimental distributions with distributions resulting from Monte Carlo simulations using various generators. Selected events are used to extract the leptonic photon structure function F_2^\gamma. Azimuthal correlations are used to obtain information on additional structure functions, F_A^\gamma and F_B^\gamma, which orig…

Particle physicsE+E ANNIHILATIONPhotonPhysics and Astronomy (miscellaneous)PAIR PRODUCTIONAstrophysics::High Energy Astrophysical Phenomena4-LEPTON FINAL-STATES; GAMMA-GAMMA-COLLISIONS; MONTE-CARLO SIMULATION; PAIR PRODUCTION; AZIMUTHAL CORRELATIONS; RADIATIVE-CORRECTIONS; E+E ANNIHILATION; MUON PAIRS; 4TH ORDER; SCATTERINGMONTE-CARLO SIMULATIONMonte Carlo methodFOS: Physical sciences01 natural sciences7. Clean energyPartícules (Física nuclear)High Energy Physics - ExperimentAZIMUTHAL CORRELATIONSHigh Energy Physics - Experiment (hep-ex)4TH ORDER0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSSCATTERING010306 general physicsEngineering (miscellaneous)DELPHIPhysicsMuonLuminosity (scattering theory)010308 nuclear & particles physicsMUON PAIRSHigh Energy Physics::PhenomenologyGAMMA-GAMMA-COLLISIONSLARGE ELECTRON POSITRON COLLIDERPhoton structure function3. Good healthScattering amplitude4-LEPTON FINAL-STATESPair productionPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSProduction (computer science)Física nuclearHigh Energy Physics::ExperimentParticle Physics - Experiment
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Single intermediate vector boson production in e(+)e(-) collisions at root s=183 and 189 GeV

2001

The cross sections for the production of single charged and neutral intermediate vector bosons were measured using integrated luminosities of 52 pb-1 and 154 pb-1 collected by the experiment at centre-of-mass energies of 182.6 GeV and 188.6 GeV, respectively. The cross sections for the reactions were determined in limited kinematic regions. The results found are in agreement with the Standard Model predictions for these channels. © 2001 Elsevier Science B.V.

Nuclear and High Energy PhysicsParticle physicsLOWEST ORDER CALCULATIONSMONTE-CARLO SIMULATIONFOS: Physical sciences2-PHOTON PROCESSESKinematics01 natural sciencesPartícules (Física nuclear)Standard ModelVector bosonHigh Energy Physics - ExperimentPHYSICSHigh Energy Physics - Experiment (hep-ex)BHABHA SCATTERINGLEP20103 physical sciencesPROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]DELPHIPhysics010304 chemical physics010308 nuclear & particles physicsCOUPLINGSLARGE ELECTRON POSITRON COLLIDERPhysique atomique et nucléaire3. Good healthMONTE-CARLO SIMULATION; LOWEST ORDER CALCULATIONS; 2-PHOTON PROCESSES; BHABHA SCATTERING; PROGRAM; DELPHI; COUPLINGS; COLLIDERS; PHYSICS; LEP2COLLIDERSPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSProduction (computer science)High Energy Physics::ExperimentParticle Physics - Experiment
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Measurement of the transverse spin correlation in Z → τ+ τ- decays

1997

The measurement of the correlation between the transverse spin components of tau(+)tau(-) pairs collected during 1992 to 1994 with the DELPHI detector at LEP1 is presented. A value C-TT = 0.87 +/- 0.20 (stat.)(-0.12)(+0.10) (syst.) was obtained for the correlation parameter, in agreement with the Standard Model expectation. (C) 1997 Published by Elsevier Science B.V.

QuarkNuclear and High Energy PhysicsParticle physicsLUND MONTE-CARLOElectron–positron annihilationLEP-SLC ENERGIES01 natural sciencesPartícules (Física nuclear)JET FRAGMENTATIONStandard ModelNuclear physicsPHYSICS0103 physical sciencesRADIATIVE-CORRECTIONS010306 general physicsNuclear ExperimentDetectors de radiacióLUND MONTE-CARLO; LEP-SLC ENERGIES; RADIATIVE-CORRECTIONS; JET FRAGMENTATION; TAU-POLARIZATION; SIMULATION; PHYSICS; QUARKSpin-½DELPHIPhysics010308 nuclear & particles physicsTAU-POLARIZATIONQUARKCenter (category theory)LARGE ELECTRON POSITRON COLLIDERTransverse planePARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHISIMULATIONPARTICLE PHYSICSHigh Energy Physics::ExperimentAstrophysics::Earth and Planetary Astrophysics
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Measurement of the spin density matrix for the rho(0), K*(0)(892) and phi produced in Z(0) decays

1997

The spin density matrix elements for the rho(0), K-*0(892) and phi produced in hadronic Z(0) decays are measured in the DELPHI detector. There is no evidence for spin alignment of the K-*0(892) and phi, in the region x(p) less than or equal to 0.3 (x(p) = p/p(beam)), where rho(00) = 0.33 +/- 0.05 and rho(00) = 0.30 +/- 0.04, respectively. In the fragmentation region, x(p) greater than or equal to 0.4, there is some indication for spin alignment of the rho(0) and K-*0(892), since rho(00) = 0.43 +/- 0.05 and rho(00) = 0.46 +/- 0.08, respectively. These values are compared with those found in meson-induced hadronic reactions. For the phi, rho(00) = 0.30 +/- 0.04 for x(p) greater than or equal …

Nuclear and High Energy PhysicsMesonElectron–positron annihilationD-STARHadronANNIHILATIONSPartícules (Física nuclear)QUARK FRAGMENTATION; D-STAR; ANNIHILATIONS; HADRONS; MESONSNuclear physicsAngular distribution[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Matrix elementSpin densityDetectors de radiacióDELPHIPhysicsHADRONSD-STARQUARK FRAGMENTATIONLARGE ELECTRON POSITRON COLLIDERMESONSPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIMass spectrumPARTICLE PHYSICSAtomic physicsParticle Physics - ExperimentPHYSICS LETTERS B
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A search for anisotropy in the arrival directions of ultra high energy cosmic rays recorded at the Pierre Auger Observatory

2012

Observations of cosmic ray arrival directions made with the Pierre Auger Observatory have previously provided evidence of anisotropy at the 99% CL using the correlation of ultra high energy cosmic rays (UHECRs) with objects drawn from the Véron-Cetty Véron catalog. In this paper we report on the use of three catalog independent methods to search for anisotropy. The 2pt–L, 2pt+ and 3pt methods, each giving a different measure of selfclustering in arrival directions, were tested on mock cosmic ray data sets to study the impacts of sample size and magnetic smearing on their results, accounting for both angular and energy resolutions. If the sources of UHECRs follow the same large scale structu…

HIRES STEREO[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]AstronomySMALL-SCALE ANISOTROPYAstrophysics01 natural sciencesAltas energíasCosmic Rays ShowerCosmologyUltra-high-energy cosmic rayAnisotropy010303 astronomy & astrophysicsmedia_commonPhysicsHigh Energy Astrophysical Phenomena (astro-ph.HE)[PHYS]Physics [physics]BL-LACERTAEAstrophysics::Instrumentation and Methods for AstrophysicsPierre Auger ObservatoryRadiación cósmicaFísica nuclearOBJECTSAstrophysics - High Energy Astrophysical Phenomenacosmic ray experiments; ultra high energy cosmic raysACTIVE GALACTIC NUCLEIActive galactic nucleusmedia_common.quotation_subjectAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesCosmic raysearch for anisotropyultra high energy cosmic raysCosmic Ray[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]0103 physical sciences010306 general physicsCiencias ExactasPierre Auger ObservatorySPECTRUMAstronomyFísicaAstronomy and AstrophysicsASTROFÍSICAUniverseGalaxyExperimental High Energy Physicsanisotrpycosmic ray experiments[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]cosmologyJournal of Cosmology and Astroparticle Physics
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A study of the Lorentz structure in tau decays

2000

This paper describes a measurement of the Michel parameters, \eta, \rho, \xi, \xi\delta, and the average \nu_{\tau} helicity, h_{\nu_{\tau}}, in tau lepton decays together with the first measurement of the tensor coupling in the weak charged current. The tau+tau- pairs were produced at the LEP e+e- collider at CERN from 1992 through 1995 in the DELPHI detector. Assuming lepton universality in the decays of the tau the measured values of the parameters were: \eta = -0.005 +/- 0.036 +/- 0.037, \rho = 0.775 +/- 0.023 +/- 0.020, \xi = 0.929 +/- 0.070 +/- 0.030, \xi\delta = 0.779 +/- 0.070 +/- 0.028, h_{\nu_{\tau}} = -0.997 +/- 0.027 +/- 0.011. The strength of the tensor coupling was measured to…

Particle physicsPhysics and Astronomy (miscellaneous)CHARGED WEAK-INTERACTIONSLUND MONTE-CARLOENERGIESLorentz transformationFOS: Physical sciences01 natural sciencesJET FRAGMENTATIONPartícules (Física nuclear)law.inventionHigh Energy Physics - Experimentsymbols.namesakeHigh Energy Physics - Experiment (hep-ex)NEUTRINO HELICITYLUND MONTE-CARLO; CHARGED WEAK-INTERACTIONS; RIGHT-SYMMETRICAL MODEL; MICHEL PARAMETERS; NEUTRINO HELICITY; RADIATIVE-CORRECTIONS; JET FRAGMENTATION; ENERGIES; LEPTON; PARTICLESlaw0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSPARTICLESTensor010306 general physicsColliderLEPTONEngineering (miscellaneous)Charged currentDELPHIPhysics010308 nuclear & particles physicsMICHEL PARAMETERSCoupling (probability)HelicityLARGE ELECTRON POSITRON COLLIDERRIGHT-SYMMETRICAL MODELPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIsymbolsMichel parametersPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentAstrophysics::Earth and Planetary AstrophysicsParticle Physics - ExperimentLeptonEuropean physical journal : C : particles and fields
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Search for a fermiophobic Higgs at LEP 2

2001

Higgs bosons predicted by the fermiophobic scenario within Two Higgs Doublets Models were searched for in the data collected by the DELPHI detector at centre-of-mass energies between 189 GeV and 202 GeV, corresponding to a total integrated luminosity of 380 pb^{-1}. No signal was found and confidence limits were derived in the framework of possible extensions of the Standard Model Higgs sector.

BOSONSNuclear and High Energy PhysicsParticle physicsENERGIESQUARK PAIR PRODUCTION; CARLO PROGRAM KORALZ; MONTE-CARLO; BHABHA SCATTERING; SUPERSYMMETRY; PHOTONS; PHYSICS; BOSONS; ANNIHILATION; ENERGIESFOS: Physical sciencesPHOTONS01 natural sciencesPartícules (Física nuclear)High Energy Physics - ExperimentHiggs sectorStandard ModelPHYSICSHigh Energy Physics - Experiment (hep-ex)BHABHA SCATTERINGCARLO PROGRAM KORALZMONTE-CARLO0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsANNIHILATIONSUPERSYMMETRYBosonDELPHIPhysicsLuminosity (scattering theory)010308 nuclear & particles physicsDetectorHigh Energy Physics::PhenomenologyQUARK PAIR PRODUCTIONLARGE ELECTRON POSITRON COLLIDERPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIHiggs bosonPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentParticle Physics - Experiment
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Determination of |Vub|/|Vcb| with DELPHI at LEP

2001

The ratio of the CKM quark-mixing matrix elements |Vub|/|Vcb| has been measured using B hadron semileptonic decays. The analysis uses the reconstructed mass M_X of the secondary hadronic system produced in association with an identified lepton. Since B -> X_u lepton anti-nu transitions are characterised by hadronic masses below those of the D mesons produced in B -> X_c lepton anti-nu transitions, events with a reconstructed value of M_X significantly below the D mass are selected. Further signal enrichments are obtained using the topology of reconstructed decays and hadron identification. A fit to the numbers of decays in the b -> u enriched and depleted samples with M_X above and…

Nuclear and High Energy PhysicsParticle physicsMesonHadronFOS: Physical sciences01 natural sciencesPartícules (Física nuclear)High Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesNuclear Experiment010306 general physicsDELPHIPhysicsEnergy distribution010308 nuclear & particles physicsBranching fractionHigh Energy Physics::PhenomenologyRest frameLARGE ELECTRON POSITRON COLLIDERPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentParticle Physics - ExperimentLeptonPhysics Letters B
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A Search for Heavy Stable and Long-Lived Squarks and Sleptons in $e^+ e^-$ Collisions at Energies from 130 to 183 GeV

1998

A search for stable and long-lived heavy charged particles used the data taken by the DELPHI experiment at energies from 130 to 183 GeV. The Cherenkov light detected in the Ring Imaging Cherenkov Detector and the ionization loss measured in the Time Projection Chamber identify heavy particles from masses of 2 to nearly 89 GeV/c$^2$. Upper limits are given on the production cross-section and masses of sleptons, free squarks with a charge of $q = \pm 2/3e$ and hadronizing squarks. A search for stable and long-lived heavy charged particles used the data taken by the DELPHI experiment at energies from 130 to 183 GeV. The Cherenkov light detected in the Ring Imaging Cherenkov Detector and the io…

Nuclear and High Energy PhysicsParticle physicsPhysics::Instrumentation and DetectorsFOS: Physical sciences01 natural sciencesRing-imaging Cherenkov detectorPartícules (Física nuclear)High Energy Physics - ExperimentPHYSICSHigh Energy Physics - Experiment (hep-ex)Ionization0103 physical sciencesCHARGED-PARTICLES; SUPERSYMMETRY; PHYSICS; LEP[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsNuclear ExperimentSUPERSYMMETRYCherenkov radiationDELPHIPhysicsTime projection chamber010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyCharge (physics)LEPLARGE ELECTRON POSITRON COLLIDERCharged particleCHARGED-PARTICLESPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentParticle Physics - Experiment
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Measurement of the mass of the W boson using direct reconstruction at √s = 183 GeV

1999

From data corresponding to an integrated luminosity of 53.5 pb(-1) taken during the 183 GeV run in 1997, DELPHI has measured the W mass from direct reconstruction of WW --> lq (q) over bar and WW --> q (q) over bar q (q) over bar events. Combining these channels, a value of m(w) = 80.238 +/- 0.154(stat) +/- 0.035(syst) +/- 0.035(fsi) +/- 0.021 (LEP) GeV/c(2) is obtained, where fsi denotes final state interaction. Combined with the W mass obtained by DELPHI from the WW production cross-section and with the direct measurement at 172 GeV this leads to a measured value of m(w) = 80.270 +/- 0.137(stat) +/- 0.031(syst) +/- 0.030(fsi) +/- 0.021(LEP)GeV/c(2), in good agreement with the Standard Mod…

Nuclear and High Energy PhysicsParticle physicsEINSTEIN CORRELATIONSCLUSTERING-ALGORITHMElectron–positron annihilationMathematicsofComputing_GENERALCOLOR DIPOLE MODEL01 natural sciencesComputer Science::Digital LibrariesPartícules (Física nuclear)LuminosityStandard ModelPHYSICSEVENTSNuclear physicsLEP20103 physical sciencesMONTE-CARLO PROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]ANNIHILATION010306 general physicsDELPHIPhysicsAnnihilation010308 nuclear & particles physicsE(+)E(-) INTERACTIONSTheoryofComputation_GENERALLARGE ELECTRON POSITRON COLLIDERMONTE-CARLO PROGRAM; PAIR CROSS-SECTION; COLOR DIPOLE MODEL; E(+)E(-) INTERACTIONS; EINSTEIN CORRELATIONS; CLUSTERING-ALGORITHM; ANNIHILATION; PHYSICS; EVENTS; LEP2PARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIComputer Science::Mathematical SoftwarePARTICLE PHYSICSProduction (computer science)Física nuclearPAIR CROSS-SECTIONParticle Physics - ExperimentBar (unit)
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Correlation of the highest-energy cosmic rays with nearby extragalactic objects.

2007

Using data collected at the Pierre Auger Observatory during the past 3.7 years, we demonstrated a correlation between the arrival directions of cosmic rays with energy above ~ 6x10^{19} electron volts and the positions of active galactic nuclei (AGN) lying within ~ 75 megaparsecs. We rejected the hypothesis of an isotropic distribution of these cosmic rays with at least a 99% confidence level from a prescribed a priori test. The correlation we observed is compatible with the hypothesis that the highest energy particles originate from nearby extragalactic sources whose flux has not been substantially reduced by interaction with the cosmic background radiation. AGN or objects having a similar…

Active galactic nucleus[SDU.ASTR.CO]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]AstronomyAstrophysics::High Energy Astrophysical Phenomenaparticle source [cosmic radiation]Cosmic background radiationFOS: Physical sciencesFluxOsservatorio Pierre AugerCosmic rayanisotropyAstrophysicsAstrophysics::Cosmology and Extragalactic AstrophysicsAstrophysics01 natural sciences[PHYS.ASTR.CO]Physics [physics]/Astrophysics [astro-ph]/Cosmology and Extra-Galactic Astrophysics [astro-ph.CO]Raggi cosmici0103 physical sciencesUltra-high-energy cosmic ray010303 astronomy & astrophysicsBackground radiationNuclei galattivi attiviPhysicsPierre Auger ObservatorySPECTRUMMultidisciplinary[SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph]010308 nuclear & particles physicsMedicine (all); MultidisciplinaryMedicine (all)Settore FIS/01 - Fisica SperimentaleAstrophysics (astro-ph)angular dependence [cosmic radiation]Astrophysics::Instrumentation and Methods for AstrophysicsFísicaEnergia ultra altaExperimental High Energy Physicsddc:500Energy (signal processing)experimental results
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Consistent measurements of alpha(s) from precise oriented event shape distributions

2000

An updated analysis using about 1.5 million events recorded at $\sqrt{s} = M_Z$ with the DELPHI detector in 1994 is presented. Eighteen infrared and collinear safe event shape observables are measured as a function of the polar angle of the thrust axis. The data are compared to theoretical calculations in ${\cal O} (\alpha_s^2)$ including the event orientation. A combined fit of $\alpha_s$ and of the renormalization scale $x_{\mu}$ in $\cal O(\alpha_s^2$) yields an excellent description of the high statistics data. The weighted average from 18 observables including quark mass effects and correlations is $\alpha_s(M_Z^2) = 0.1174 \pm 0.0026$. The final result, derived from the jet cone energ…

QuarkParticle physicsPhysics and Astronomy (miscellaneous)OPTIMIZED PERTURBATION-THEORY; JET CROSS-SECTIONS; E+ E ANNIHILATION; QUANTUM CHROMODYNAMICS; E(+)E(-) ANNIHILATION; QCD CALCULATIONS; Z0 RESONANCE; MONTE-CARLO; DECAYS; ALPHA(S)(M(Z)(2))QCD CALCULATIONSFOS: Physical sciencesScale (descriptive set theory)01 natural sciences7. Clean energyDECAYSPartícules (Física nuclear)High Energy Physics - ExperimentRenormalizationHigh Energy Physics - Experiment (hep-ex)MONTE-CARLO0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Engineering (miscellaneous); Physics and Astronomy (miscellaneous)010306 general physicsEngineering (miscellaneous)ALPHA(S)(M(Z)(2))DELPHIPhysicsQUANTUM CHROMODYNAMICS010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyOrder (ring theory)ObservableFunction (mathematics)E(+)E(-) ANNIHILATIONLARGE ELECTRON POSITRON COLLIDEROrientation (vector space)Experimental uncertainty analysisOPTIMIZED PERTURBATION-THEORYPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIPARTICLE PHYSICSJET CROSS-SECTIONSFísica nuclearHigh Energy Physics::ExperimentE+ E ANNIHILATIONZ0 RESONANCEParticle Physics - Experiment
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Cross-sections and leptonic forward-backward asymmetries from the Z(0) running of LEP

2000

During 1993 and 1995 LEP was run at 3 energies near the Z $^0$ peak in order to give improved measurements of the mass and width of the resonance. During 1994, LEP operated only at the Z $^0$ peak. In total DELPHI accumulated data corresponding to an integrated luminosity of approximately 116 pb $^{-1}$ . Analyses of the hadronic cross-sections and of the cross-sections and forward-backward asymmetries in the leptonic channels used the most precise evaluations of the LEP energies. In the dimuon channel, events with a photon radiated from the initial state have been used to probe the cross-sections and asymmetries down to PETRA energies. Model independent fits to all DELPHI lineshape and asy…

Particle physicsE+E ANNIHILATIONPhysics and Astronomy (miscellaneous)Electron–positron annihilationSQUARE-ROOT-S=29 GEVHadronCHARGE ASYMMETRIES01 natural sciencesResonance (particle physics)LuminosityStandard ModelNuclear physicsMONTE-CARLOSLC ENERGIES0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSANGLE BHABHA SCATTERING010306 general physicsEngineering (miscellaneous)DELPHIPhysics010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyOrder (ring theory)Weinberg angleMUON-PAIR PRODUCTIONSQUARE-ROOT-SLARGE ELECTRON POSITRON COLLIDEROF-MASS ENERGIESPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHILarge Electron–Positron ColliderPARTICLE PHYSICSHigh Energy Physics::ExperimentFísica nuclearMUON-PAIR PRODUCTION; ANGLE BHABHA SCATTERING; OF-MASS ENERGIES; SQUARE-ROOT-S; MONTE-CARLO; RADIATIVE-CORRECTIONS; SQUARE-ROOT-S=29 GEV; CHARGE ASYMMETRIES; E+E ANNIHILATION; SLC ENERGIESParticle Physics - Experiment
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Search for ultrahigh energy neutrinos in highly inclined events at the Pierre Auger Observatory

2011

Erratum: Phys. Rev. D 85, 029902(E) (2012) [http://dx.doi.org/10.1103/PhysRevD.85.029902]

Physics::Instrumentation and DetectorsSolar neutrinoAstrophysicsUPPER LIMITPHOTON FRACTION01 natural sciences7. Clean energyneutrinoObservatoryHigh Energy Astrophysical Phenomena (astro-ph.HE)PhysicsORIGINPhysics[SDU.ASTR.HE]Sciences of the Universe [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]pionAstrophysics::Instrumentation and Methods for AstrophysicsPierre Auger ObservatoryCOSMIC-RAYScosmic ray detectorsand other elementary particle detectorsCosmic neutrino backgroundNEUTRINOSFísica nuclearNeutrinoAstrophysics - High Energy Astrophysical PhenomenaFLUXFERMI-LATNuclear and High Energy Physics[PHYS.ASTR.HE]Physics [physics]/Astrophysics [astro-ph]/High Energy Astrophysical Phenomena [astro-ph.HE]TELESCOPEAstrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencesCosmic rayEXTENSIVE AIR-SHOWERSSURFACE DETECTORCosmic RayPionmuon0103 physical sciencesNeutrino010306 general physicsCosmic raysPierre Auger ObservatoryMuon010308 nuclear & particles physicsFísicaand other elementary particlesUltra-high energy cosmic raysPERFORMANCECosmic rayneutrino flavor; air showers; surface detector; observatory; atmosphere; Auger; cosmic radiation; energy spectrum13. Climate actionHigh Energy Physics::Experiment
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The effect of the geomagnetic field on cosmic ray energy estimates and large scale anisotropy searches on data from the Pierre Auger Observatory

2011

We present a comprehensive study of the influence of the geomagnetic field on the energy estimation of extensive air showers with a zenith angle smaller than $60^\circ$, detected at the Pierre Auger Observatory. The geomagnetic field induces an azimuthal modulation of the estimated energy of cosmic rays up to the ~2% level at large zenith angles. We present a method to account for this modulation of the reconstructed energy. We analyse the effect of the modulation on large scale anisotropy searches in the arrival direction distributions of cosmic rays. At a given energy, the geomagnetic effect is shown to induce a pseudo-dipolar pattern at the percent level in the declination distribution t…

[PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]Astrophysics::High Energy Astrophysical PhenomenaFOS: Physical sciencescosmic ray experimentCosmic rayAstrophysicsultra high energy cosmic raysEXTENSIVE AIR-SHOWERS01 natural sciencesDeclinationultra high energy cosmic ray0103 physical sciencescosmic rays detectors; cosmic ray experiments; ultra high energy cosmic rayscosmic rays detectorAnisotropyInstrumentation and Methods for Astrophysics (astro-ph.IM)010303 astronomy & astrophysicsZenithParticle detectors.Pierre Auger ObservatoryPhysics010308 nuclear & particles physicsPhysicsOBSERVATÓRIOSAstrophysics::Instrumentation and Methods for AstrophysicsFísicaAstronomy and Astrophysics[SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM]AzimuthMODELEarth's magnetic fieldPhysics::Space PhysicsLarge detector systems for particle and astroparticle physicARRAYFísica nuclearcosmic rays detectorscosmic ray experimentsAstrophysics - Instrumentation and Methods for AstrophysicsEnergy (signal processing)Cherenkov detectorJournal of Cosmology and Astroparticle Physics
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Search for charged Higgs bosons in e^{+}e^{-}$ collisions at √s=172 GeV

1998

This paper presents results on charged Higgs boson production, based on LEP data collected at √s = 172 GeV, that complement the previous DELPHI results obtained at centre of mass energies up to 161 GeV. The charged Higgs bosons are assumed to be pair produced and to decay either into a quark pair or into τVτ. The three different possible final states are included in the analysis. Data from ring imaging Cherenkov and microvertex detectors are used to identify the quarks as a cs pair. The number of candidates found is compatible with the background expected from standard processes. Combining the results of the present analysis with those of the previous analysis at lower energies, a new lower…

QuarkPhysicsNuclear and High Energy PhysicsParticle physics010308 nuclear & particles physicsElectron–positron annihilationHigh Energy Physics::Phenomenology01 natural sciencesNuclear physics0103 physical sciencesLarge Electron–Positron ColliderHiggs bosonHigh Energy Physics::ExperimentLimit (mathematics)010306 general physicsCherenkov radiationComplement (set theory)BosonPhysics letters: B
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Search for neutral MSSM Higgs bosons at LEP

2006

The four LEP collaborations, ALEPH, DELPHI, L3 and OPAL, have searched for the neutral Higgs bosons which are predicted by the Minimal Supersymmetric Standard Model (MSSM). The data of the four collaborations are statistically combined and examined for their consistency with the background hypothesis and with a possible Higgs boson signal. The combined LEP data show no significant excess of events which would indicate the production of Higgs bosons. The search results are used to set upper bounds on the cross-sections of various Higgs-like event topologies. The results are interpreted within the MSSM in a number of "benchmark" models, including CP-conserving and CP-violating scenarios. Thes…

AlephPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; ALEPH; DELPHI; L3; OPALPhysics and Astronomy (miscellaneous)Parameter space01 natural sciencesOPAL DETECTORHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Event (probability theory)BosonPhysicsEXPLICIT CP VIOLATIONROOT-S=189 GEVOPALFLAVOR INDEPENDENT SEARCHParticle physics - ExperimentPhysicsSettore FIS/01 - Fisica SperimentaleHiggs particle. search forSUPERGAUGE TRANSFORMATIONSALEPHLARGE ELECTRON POSITRON COLLIDERALEPH DELPHI L3 OPALSUPERSYMMETRIC STANDARD MODELROOT-SL3Higgs bosonPARTICLE PHYSICSParticle physicselectron positron. colliding beamselectron positron. annihilationFOS: Physical sciencessupersymmetric standard model;; explicit cp violation;; electric-dipole moment;; e(+)e(-) collisions;; root-s=189 gev;; opal detector;; root-s;; z(0) decays;; supergauge transformations;; radiative-correctionsHiggs particle. electroproductionddc:500.2-SUPERSYMMETRIC STANDARD MODEL; EXPLICIT CP VIOLATION; FLAVOR INDEPENDENT SEARCH; ELECTRIC-DIPOLE MOMENT; E(+)E(-) COLLISIONS; ROOT-S; ROOT-S=189 GEV; OPAL DETECTOR; Z(0) DECAYS; SUPERGAUGE TRANSFORMATIONSHiggs particleLEP colliderNext-to-Minimal Supersymmetric Standard ModelELECTRIC-DIPOLE MOMENTE(+)E(-) COLLISIONSConsistency (statistics)0103 physical sciencesddc:530High Energy Physics010306 general physicsEngineering (miscellaneous)DELPHIelectron positron010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyHiggs BosonLEPHIGGSHiggs boson standard modelZ(0) DECAYSExperimental High Energy PhysicsHigh Energy Physics::ExperimentHiggs Boson; LEP colliderMSSMMinimal Supersymmetric Standard ModelHiggs
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Measurements of the trilinear gauge boson couplings WWV (V = $\gamma$ Z) in e$^+$e$^-$ collisions at 183 GeV

1999

Measurements of the trilinear gauge boson couplings WWγ and WWZ are presented from data taken by DELPHI in 1997 at an energy of 183 GeV. From a study of the reactions e + e − → W + W − , e + e − → Weν and e + e − → ννγ , values are obtained for Δg 1 Z and Δκ γ , the differences of the WWZ charge coupling and of the WWγ dipole couplings from their Standard Model values, and for λ γ , the WWγ quadrupole coupling. The observations are consistent with the predictions of the Standard Model. (Elsevier)

Nuclear and High Energy PhysicsParticle physicsElectron–positron annihilation7. Clean energy01 natural sciencesPartícules (Física nuclear)Standard ModelNuclear physics0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsEvent generatorDELPHICouplingPhysicsGauge boson010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyCharge (physics)LARGE ELECTRON POSITRON COLLIDERDipolePARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHIQuadrupolePARTICLE PHYSICSFísica nuclearHigh Energy Physics::Experiment
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