Search results for "Física de partícules"

showing 10 items of 63 documents

Study of J/ψ Production in Jets

2017

The production of $J/\psi$ mesons in jets is studied in the forward region of proton-proton collisions using data collected with the LHCb detector at a center-of-mass energy of 13 TeV. The fraction of the jet transverse momentum carried by the $J/\psi$ meson, $z \equiv p_{\rm T}(J/\psi)/p_{\rm T}({\rm jet})$, is measured using jets with $p_{\rm T}({\rm jet}) > 20$ GeV in the pseudorapidity range $2.5 < \eta({\rm jet}) < 4.0$. The observed $z$ distribution for $J/\psi$ mesons produced in $b$-hadron decays is consistent with expectations. However, the results for prompt $J/\psi$ production do not agree with predictions based on fixed-order non-relativistic QCD. This is the first measurement o…

13000 GeV-cmsQuantum chromodynamics: Experimental testNuclear TheoryGeneral Physics and Astronomy01 natural sciences7. Clean energytransverse momentum [jet]Settore FIS/04 - Fisica Nucleare e SubnucleareHigh Energy Physics - ExperimentParticle production Quantum chromodynamicsddc:550scattering [p p][PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]LHCb - Abteilung HintonParticle productionNuclear ExperimentQuantum chromodynamicsPhysicsJet (fluid)Large Hadron Collider02 Physical SciencesHadron-induced high- and super-high-energy interactions (energy > 10 GeV): Inclusive production with identified hadronParticle physicsQuarkoniumPROMPTJ/psi mesonLeptonic semileptonic and radiative decays of J/ψ Υ and other quarkoniaCERN LHC Collhadroproduction [J/psi(3100)]Pseudorapidityrapidity [jet]root S=7 TEVPhysical SciencesLHCcolliding beams [p p]Particle Physics - ExperimentParticle physicsGeneral PhysicsMesonPSI(2S)Astrophysics::High Energy Astrophysical PhenomenaPhysics Multidisciplinarynonrelativistic [quantum chromodynamics]OCTET QUARKONIA PRODUCTIONNOJets in large-Q2 scatteringNuclear physicsOctet quarkonia production PP collision root S=7 TEV PSI(2S) physics prompt decayPHYSICSPhysics and Astronomy (all)OCTET QUARKONIA PRODUCTION; PP COLLISIONS; ROOT-S=7 TEV; PSI(2S); PHYSICS; PROMPT; DECAY0103 physical sciencesRapiditySDG 7 - Affordable and Clean Energy010306 general physics/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyScience & TechnologyPP COLLISIONSROOT-S=7 TEV010308 nuclear & particles physicsPP collisionhep-exHigh Energy Physics::PhenomenologyLHC-BHEPLHCbHigh Energy Physics::ExperimentHeavy quarkoniaFísica de partículesExperimentsDECAYQuantum chromodynamicsexperimental results
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Observation of $Z$ production in proton-lead collisions at LHCb

2014

The first observation of $Z$ boson production in proton-lead collisions at a centre-of-mass energy per proton-nucleon pair of $\sqrt{s_{NN}}=5~\text{TeV}$ is presented. The data sample corresponds to an integrated luminosity of $1.6~\text{nb}^{-1}$ collected with the LHCb detector. The $Z$ candidates are reconstructed from pairs of oppositely charged muons with pseudorapidities between 2.0 and 4.5 and transverse momenta above $20~\text{GeV}/c$. The invariant dimuon mass is restricted to the range $60-120~\text{GeV}/c^2$. The $Z$ production cross-section is measured to be \begin{eqnarray*} ��_{Z\to��^+��^-}(\text{fwd})&amp;=&amp;13.5^{+5.4}_{-4.0}\text{(stat.)}\pm1.2\text{(syst.)}~\text{nb} …

14.70.Hp - Z bosonProtonNuclear Theory01 natural sciencesPhysics Particles & FieldsHigh Energy Physics - ExperimentSettore FIS/04 - Fisica Nucleare e SubnucleareLuminosityHigh Energy Physics - Experiment (hep-ex)Heavy-ion collision[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Electroweak interaction; Forward physics; Heavy Ions; Heavy-ion collision; Particle and resonance productionElectroweak interactionHeavy IonsHeavy IonNuclear ExperimentQCBosonPhysics25.75.Dw - Relativistic heavy-ion collisions: Particle and resonance production; 14.70.Hp - Z bosons; 13.38.Dg - Decays of Z bosons; 12.15.-y - Electroweak interactionsPhysicsHIGH ENERGIES12.15.-y - Electroweak interactionsParticle physicsComputer Science::Computation and Language (Computational Linguistics and Natural Language and Speech Processing)13.38.Dg - Decays of Z bosons25.75.Dw - Relativistic heavy-ion collisions: Particle and resonance productionPhysical SciencesPARTON DISTRIBUTIONS; BOSON PRODUCTION; HIGH ENERGIES; NUCLEAR PDFS; DEUTERIUM; DECAYFísica nuclearProduction (computer science)14.70.Hp - Z bosonsParticle Physics - ExperimentNuclear and High Energy PhysicsParticle physicsNUCLEAR PDFS530 PhysicsDEUTERIUMFOS: Physical sciencesPhysics InstituteLHCb - Abteilung HofmannHadronsParticle and resonance production0103 physical sciencesElectroweak interaction; Forward physics; Heavy Ions; Heavy-ion collision; Particle and resonance production; Nuclear and High Energy PhysicsSDG 7 - Affordable and Clean Energy010306 general physicsForward physicLarge Hadron Collider (France and Switzerland)BOSON PRODUCTION/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyScience & TechnologyMuon010308 nuclear & particles physicshep-exComputer Science::Information RetrievalGran Col·lisionador d'Hadrons13.38.Dg - Decays of Z bosonPARTON DISTRIBUTIONSForward physicsHigh Energy Physics::ExperimentFísica de partículesExperimentsDECAYEnergy (signal processing)JHEP
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Física Nuclear i de Partícules

2018

La Física Nuclear i de Partícules és una assignatura de caràcter obligatori que s'imparteix en el primer quadrimestre de quart curs dels estudis de Grau en Física a la Universitat de València. Consta d'un total de 7.5 crèdits ECTS, dels quals 4.5 són teòrics, 1.5 teòric-pràctics (resolució de problemes), i 1.5 de laboratori. Aquesta assignatura forma part de la matèria Ampliació de Física, i permet al graduat/da adquirir coneixements bàsics sobre l'estructura de la matèria i les seues propietats. La Física Nuclear és la disciplina científica que estudia els nuclis atòmics, les seves propietats i les forces que actuen entre els seus constituents (protons i neutrons, denominats genèricament n…

Acceleradors de partículesUNESCO::FÍSICAFisica NuclearDetectors de radiacióFísica de Partícules
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Differential branching fractions and isospin asymmetries of B -> K ((*)) μ(+) μ(-) decays

2014

The isospin asymmetries of $B \to K\mu^+\mu^-$ and $B \to K^{*}\mu^+\mu^-$ decays and the partial branching fractions of the $B^0 \to K^0\mu^+\mu^-$, $B^+ \to K^+\mu^+\mu^-$ and $B^+ \to K^{*+}\mu^+\mu^-$ decays are measured as functions of the dimuon mass squared, $q^2$. The data used correspond to an integrated luminosity of 3$~$fb$^{-1}$ from proton-proton collisions collected with the LHCb detector at centre-of-mass energies of 7$\,$TeV and 8$\,$TeV in 2011 and 2012, respectively. The isospin asymmetries are both consistent with the Standard Model expectations. The three measured branching fractions, while individually consistent, all favour lower values than their respective Standard M…

B physic01 natural sciences7. Clean energyB physicsLuminosity/dk/atira/pure/sustainabledevelopmentgoals/clean_water_and_sanitationHigh Energy Physics - ExperimentSettore FIS/04 - Fisica Nucleare e SubnuclearePhysics Particles & Fields[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]11.30.HvNuclear ExperimentQCPhysics02 Physical SciencesB physics; Branching fraction; Flavour Changing Neutral Currents; Hadron-Hadron Scattering; Rare decayPhysicsParticle physicsNuclear & Particles PhysicsFIS/01 - FISICA SPERIMENTALEIsospinPhysical SciencesBranching fractionFísica nuclearLHCSDG 6 - Clean Water and SanitationParticle Physics - ExperimentParticle physicsNuclear and High Energy Physics14.40.NdFlavour Changing Neutral CurrentsLHCb - Abteilung HofmannHadronsBranching (polymer chemistry)Standard Model0103 physical sciencesLeptonic semileptonic and radiative decays of bottom meson010306 general physicsFlavor symmetrieLarge Hadron Collider (France and Switzerland)01 Mathematical SciencesScience & TechnologyFlavour Changing Neutral CurrentHadron-Hadron Scattering010308 nuclear & particles physicshep-exGran Col·lisionador d'HadronsLHCbRare decay13.20.HeBottom mesons (|B|>0)High Energy Physics::ExperimentFísica de partículesExperimentsRare decay; Branching fraction; B physics; Flavour Changing Neutral Currents; Hadron-Hadron ScatteringFIS/04 - FISICA NUCLEARE E SUBNUCLEARE
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Measurement of polarization amplitudes and CP asymmetries in B 0 → Φk *(892)0

2014

An angular analysis of the decay $B^0 \to \phi K^*(892)^0$ is reported based on a $pp$ collision data sample, corresponding to an integrated luminosity of 1.0 fb$^{-1}$, collected at a centre-of-mass energy of $\sqrt{s} = 7$ TeV with the LHCb detector. The P-wave amplitudes and phases are measured with a greater precision than by previous experiments, and confirm about equal amounts of longitudinal and transverse polarization. The S-wave $K^+ \pi^-$ and $K^+K^-$ contributions are taken into account and found to be significant. A comparison of the $B^0 \to \phi K^*(892)^0$ and $\bar{B}^0 \to \phi \bar{K}^*(892)^0$ results shows no evidence for direct CP violation in the rate asymmetry, in th…

B physic12.15.MmB physicsLuminosityHigh Energy Physics - ExperimentSettore FIS/04 - Fisica Nucleare e SubnucleareNeutral current13.88.+ePolarization[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]TOOLmedia_commonPhysicsPhysicsPHYSICS PARTICLES & FIELDSParticle physicsCharge conjugation parity time reversal and other discrete symmetriePolarization (waves)Transverse planeAmplitudeCP violationPhysical SciencesCP violationFísica nuclearLHCParticle Physics - ExperimentParticle physicsNuclear and High Energy Physicsmedia_common.quotation_subject14.40.NdFlavour Changing Neutral CurrentsLHCb - Abteilung HofmannHadronsAsymmetryDECAYSHadronic decays of bottom mesonDISTRIBUTIONSLarge Hadron Collider (France and Switzerland)B physics; CP violation; Flavour Changing Neutral Currents; Hadron-Hadron Scattering; Polarization; Nuclear and High Energy PhysicsScience & TechnologyFlavour Changing Neutral CurrentHadron-Hadron ScatteringB physics; CP violation; Flavour Changing Neutral Currents; Hadron-Hadron Scattering; PolarizationGran Col·lisionador d'HadronsLHCb13.25.HwBottom mesons (|B|>0)11.30.ErHigh Energy Physics::ExperimentFísica de partículesExperimentsPolarization in interactions and scatteringEnergy (signal processing)Bar (unit)
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Angular analysis of charged and neutral B → Kμ + μ − decays

2014

The angular distributions of the rare decays B → K+µ+µ- and B0 → K0 &lt;inf&gt;a&lt;/inf&gt;Sμ+μ- are studied with data corresponding to 3 fb-1 of integrated luminosity, collected in proton-proton collisions at 7 and 8TeV centre-of-mass energies with the LHCb detector. The angular distribution is described by two parameters, FH and the forward-backward asymmetry of the dimuon system AFB, which are determined in bins of the dimuon mass squared. The parameter F&lt;inf&gt;H&lt;/inf&gt; is a measure of the contribution from (pseudo)scalar and tensor amplitudes to the decay width. The measurements of A&lt;inf&gt;FB&lt;/inf&gt; and F&lt;inf&gt;H&lt;/inf&gt; reported here are the most precise to d…

B physic12.15.MmB physicsSettore FIS/04 - Fisica Nucleare e SubnucleareLuminosityNeutral currentFlavor physicsMathematics::ProbabilityNuclear Experimentmedia_commonPhysicsB physics; Flavor physics; Flavour changing neutral currents; Hadron-hadron scattering; Rare decayPhysicsPHYSICS PARTICLES & FIELDSParticle physicsAmplitudePhysical SciencesFísica nuclearLHCNuclear and High Energy PhysicsParticle physicsmedia_common.quotation_subject14.40.NdScalar (mathematics)Flavour Changing Neutral CurrentsMathematics::Analysis of PDEsLHCb - Abteilung HofmannHadronsMeasure (mathematics)AsymmetryMathematics::Numerical AnalysisStandard ModelAngular distributionTheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITYLeptonic semileptonic and radiative decays of bottom mesonSDG 7 - Affordable and Clean EnergyTensorLarge Hadron Collider (France and Switzerland)Science & Technology/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyHadron-Hadron ScatteringGran Col·lisionador d'HadronsFlavour changing neutral currentLHCbRare decay13.20.HeFlavor physicBottom mesons (|B|>0)High Energy Physics::ExperimentFísica de partículesExperiments
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Measurement of CP asymmetry in Bs0 → Ds ∓K± decays

2014

Journal of high energy physics 2018(3), 59 (2018). doi:10.1007/JHEP03(2018)059

B physicCKM angle gamma01 natural sciencesB physicsLuminosityFlavor physicsHadron-Hadron scattering (experiments)TOOLLHCb - Abteilung HintonQCmedia_commonPhysicsParticle physicsCharge conjugation parity time reversal and other discrete symmetrie12.15.HhB physics; CKM angle gamma; CP violation; Flavor physics; Hadron-Hadron ScatteringJustice and Strong InstitutionsCP violationB physics; CKM angle gamma; CP violation; Flavor physics; Hadron-Hadron Scattering; Nuclear and High Energy PhysicsFísica nuclearLHCAstrophysics::Earth and Planetary AstrophysicsParticle physicsNuclear and High Energy PhysicsVIOLATIONSDG 16 - PeaceVIOLATION; GAMMA; TOOLAstrophysics::High Energy Astrophysical Phenomenamedia_common.quotation_subject14.40.NdLHCb - Abteilung HofmannAstrophysics::Cosmology and Extragalactic AstrophysicsHadrons530Determination of Cabibbo-Kobayashi & Maskawa (CKM) matrix elementAsymmetryNOHadronic decays of bottom mesonTheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY0103 physical scienceslcsh:Nuclear and particle physics. Atomic energy. Radioactivityddc:530010306 general physicsLarge Hadron Collider (France and Switzerland)Astrophysics::Galaxy AstrophysicsHadron-Hadron Scattering010308 nuclear & particles physicsSDG 16 - Peace Justice and Strong InstitutionsGran Col·lisionador d'HadronsGAMMA/dk/atira/pure/sustainabledevelopmentgoals/peace_justice_and_strong_institutionsHEPLHCbFlavor physic13.25.HwB physics; CKM angle gamma; CP violation; Flavor physics; Hadron-Hadron scattering (experiments)lcsh:QC770-798Bottom mesons (|B|>0)11.30.ErHigh Energy Physics::ExperimentB physics CKM angle gamma CP violation Flavor physics Hadron-Hadron ScatteringFísica de partículesExperiments
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Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays

2014

A search for $CP$ violation using $T$-odd correlations is performed using the four-body $D^0 \to K^+K^-\pi^+\pi^-$ decay, selected from semileptonic $B$ decays. The data sample corresponds to integrated luminosities of $1.0\,\text{fb}^{-1}$ and $2.0\,\text{fb}^{-1}$ recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The $CP$-violating asymmetry $a_{CP}^{T\text{-odd}}$ is measured to be $(0.18\pm 0.29\text{(stat)}\pm 0.04\text{(syst)})\%$. Searches for $CP$ violation in different regions of phase space of the four-body decay, and as a function of the $D^0$ decay time, are also presented. No significant deviation from the $CP$ conservation hypothesis is found.

CP violation Charm physics Hadron-Hadron Scattering Flavor physics14.40.Lb01 natural sciencesSettore FIS/04 - Fisica Nucleare e SubnucleareHigh Energy Physics - ExperimentFlavor physics[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]ASTRONOMY & ASTROPHYSICSQCmedia_commonCharm physicsPhysicsHadronic decays of charmed mesonCharm physics; CP violation; Flavor physics; Hadron-Hadron ScatteringPhysicsPHYSICS PARTICLES & FIELDSParticle physicsCharge conjugation parity time reversal and other discrete symmetrieDecay timeCP violationPhysical Sciences13.25.FtCP violationFísica nuclearLHCParticle Physics - ExperimentTRIPLE-PRODUCT CORRELATIONSPACS: 13.25.Ft 11.30.ErCharm physicNuclear and High Energy PhysicsParticle physicsmedia_common.quotation_subjectLHCb - Abteilung HofmannHadronsAsymmetryNONuclear physicsTheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY0103 physical sciencesPiSDG 7 - Affordable and Clean Energy010306 general physicsLarge Hadron Collider (France and Switzerland)Science & Technology/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyHadron-Hadron Scatteringhep-ex010308 nuclear & particles physicsGran Col·lisionador d'HadronsCharm physics; CP violation; Flavor physics; Hadron-Hadron Scattering; Nuclear and High Energy PhysicsBABAR detectorHEPANGULAR-CORRELATIONSLHCbFlavor physicPhase spaceBaBar11.30.ErFísica de partículesExperimentsCharmed mesons (|C|>0 B=0)
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Study of high-multiplicity three-prong and five-prong τ decays at BABAR

2012

We present measurements of the branching fractions of three-prong and five-prong tau decay modes using a sample of 430 million tau lepton pairs, corresponding to an integrated luminosity of 468 fb(-1), collected with the BABAR detector at the PEP-II asymmetric-energy e_e storage rings at SLAC National Accelerator Laboratory. The tau(-) -> (3 pi)(-) eta nu(tau), tau(-) -> (3 pi)(-) omega nu(tau), and tau(-) f(1) (1285)nu(tau) branching fractions are presented, as well as a new limit on the branching fraction of the second-class current decay tau(-) -> pi(-) eta'(958)nu(tau). We search for the decay mode tau(-) -> K- eta'(958)nu(tau) and for five-prong decay modes with kaons, and place the fi…

Decays of taus; TausNuclear and High Energy PhysicsParticle physicsElectron–positron annihilationDecays of tausPACS: 13.35.Dx 14.60.FgHigh multiplicity01 natural sciencesTausNuclear physics0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]Decays of tau010306 general physicsCurrent decayPhysics010308 nuclear & particles physicsBranching fractionLeptons (Física nuclear)Particle physicsHEPLeptons (Nuclear physics)BaBarHigh Energy Physics::ExperimentExperimentsFísica de partículesLepton
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Observation of Photon Polarization in theb→sγTransition

2014

This Letter presents a study of the flavor-changing neutral current radiative $B^{\pm} \to K^{\pm}\pi^{\mp}\pi^{\pm}\gamma$ decays performed using data collected in proton-proton collisions with the LHCb detector at $7$ and $8\,$TeV center-of-mass energies. In this sample, corresponding to an integrated luminosity of $3\,\text{fb}^{-1}$, nearly $14\,000$ signal events are reconstructed and selected, containing all possible intermediate resonances with a $K^{\pm}\pi^{\mp}\pi^{\pm}$ final state in the $[1.1, 1.9]\,$GeV/$c^{2}$ mass range. The distribution of the angle of the photon direction with respect to the plane defined by the final-state hadrons in their rest frame is studied in interva…

Final statePhotonmedia_common.quotation_subject14.40.NdHadronGeneral Physics and AstronomyLHCb - Abteilung Hofmann12.15.MmAsymmetryHigh energy physics Polarization Tellurium compounds; Center-of-mass energies Direct observations Final state Flavor-changing neutral current Integrated luminosity Photon polarization Proton proton collisions; PhotonsNeutral currentNuclear physicsTellurium compoundsCenter-of-mass energiesPhysics and Astronomy (all)Flavor-changing neutral currentPolarizationPhoton polarizationLeptonic semileptonic and radiative decays of bottom mesonRadiative transferIntermediate stateSDG 7 - Affordable and Clean EnergyHigh energy physicsQCmedia_commonPhysicsIntegrated luminosityPhotons/dk/atira/pure/sustainabledevelopmentgoals/affordable_and_clean_energyProton proton collisionsNeutral currentDirect observationsParticle physicsRest framePhoton polarizationLHCb13.20.HeBottom mesons (|B|>0)High Energy Physics::ExperimentLHCFísica de partículesExperimentsPhysical Review Letters
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