Search results for "CALCULATIONS"

showing 10 items of 468 documents

Study of the f(2)(1270) , f(2)'(1525) , f(0)(1370) and f(0)(1710) in the J/psi radiative decays

2009

In this paper we present an approach to study the radiative decay modes of the J/psi into a photon and one of the tensor mesons f (2)(1270) , f' (2)(1525) , as well as the scalar ones f (0)(1370) and f (0)(1710) . Especially, we compare predictions that emerge from a scheme where the states appear dynamically in the solution of vector meson-vector meson scattering amplitudes to those from a (admittedly naive) quark model. We provide evidence that it might be possible to distinguish amongst the two scenarios, once improved data are available.

Nuclear and High Energy PhysicsParticle physicsPhotonMesonScalar (mathematics)Radiative decayhadronic decay [J/psi(3100)]01 natural sciencesf0(1710)bound state [vector meson]radiative decay [J/psi(3100)]0103 physical sciencesRadiative transferddc:530f0(1370)Tensor010306 general physicsnumerical calculationsdecay modes [J/psi(3100)]Physicsquark modelf2(1525)ratio [width]010308 nuclear & particles physicsHigh Energy Physics::PhenomenologyQuark modelFísicascalar meson3. Good healthScattering amplitudef2(1270)tensor mesonHigh Energy Physics - Phenomenologywidth [J/psi(3100)]High Energy Physics::Experiment
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The radiative decay of the Lambda(1405) and its two-pole structure

2007

We evaluate theoretically the radiative decay widths into $\gamma\Lambda$ and $\gamma\Sigma^0$ of the two poles of the $\Lambda(1405)$ found in chiral unitary theories and we find quite different results for each of the two poles. We show that, depending on which reaction is used to measure the $\Lambda(1405)$ radiative decays, one gives more weight to one or the other pole, resulting in quite different shapes in the $\gamma\Lambda(\Sigma^0)$ invariant mass distributions. Our results for the high-energy pole agree with those of the empirical determination of the $\gamma\Lambda$ and $\gamma\Sigma^0$ radiative widths (based on an isobar model fitting of the $K^-p$ atom data), which are someti…

Nuclear and High Energy PhysicsParticle physicsRadiative decayStructure (category theory)radiative decay [Lambda(1405)]chiral [perturbation theory]Lambda(Sigma0 photon) [mass spectrum]Measure (mathematics)Lambda(1405) --> Lambda photonK- p --> Lambda pi0 photonK- p --> Sigma0 pi0 photonAtompi- p --> Lambda K0 photonpi- p --> Sigma0 K0 photonRadiative transferddc:530Invariant massnumerical calculationsPhysicsLambda(1405) --> Sigma0 photonSigma0inelastic scattering [K- p]Físicapole [approximation]hadroproduction [Lambda(1405)]High Energy Physics - Phenomenology(Lambda photon) [mass spectrum]Isobarinelastic scattering [pi- p]hadroproduction [hyperon]width [Lambda(1405)]
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Improved measurements of cross sections and asymmetries at the Z0 resonance

1994

During the 1992 running period of the LEP e+e- collider, the DELPHI experiment accumulated approximately 24 pb-1 of data at the Z0 peak. The decays into hadrons and charged leptons have been analysed to give values for the cross sections and leptonic forward-backward asymmetries which are significantly improved with respect to those previously published by the DELPHI collaboration. Incorporating these new data, more precise values for the Z0 resonance parameters are obtained from model-independent fits. The results are interpreted within the framework of the Standard Model, yielding for the top quark mass m(t) = 157(-48)+36(expt.)-20(+19)(Higgs) GeV, and for the effective mixing angle sin2 …

Nuclear and High Energy PhysicsParticle physicsTop quarkLUND MONTE-CARLOElectron–positron annihilationLEP-SLC ENERGIESElementary particle7. Clean energy01 natural sciencesJET FRAGMENTATIONStandard ModelPHYSICSNuclear physicsBHABHA SCATTERINGParticle decay0103 physical sciencesPROGRAM[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]RADIATIVE-CORRECTIONSZ0010306 general physicsDELPHIPhysicsLOWEST-ORDER CALCULATIONScross section010308 nuclear & particles physicsDELPHI; Bhabha scattering; cross section; Z0High Energy Physics::PhenomenologyLARGE ELECTRON POSITRON COLLIDERLUND MONTE-CARLO; ELECTRON-POSITRON COLLISIONS; LOWEST-ORDER CALCULATIONS; LEP-SLC ENERGIES; BHABHA SCATTERING; RADIATIVE-CORRECTIONS; JET FRAGMENTATION; PROGRAM; PHYSICSPARTICLE PHYSICS; LARGE ELECTRON POSITRON COLLIDER; DELPHILarge Electron–Positron ColliderHiggs bosonPARTICLE PHYSICSFísica nuclearHigh Energy Physics::ExperimentELECTRON-POSITRON COLLISIONSParticle Physics - ExperimentLepton
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Search for the standard model Higgs boson

1993

Using a data sample corresponding to about 1 233 000 hadronic Z decays collected by the ALEPH experiment at LEP, the reaction e+e- --> HZ* has been used to search for the standard model Higgs boson, in association with missing energy when Z* --> nunuBAR, or with a pair of energetic leptons when Z* --> e+e- or mu+mu-. No signal was found and, at the 95% confidence level, m(H) exceeds 58.4 GeV/c2. RI ANTONELLI, ANTONELLA/C-6238-2011; Buttar, Craig/D-3706-2011; Stahl, Achim/E-8846-2011; Passalacqua, Luca/F-5127-2011; Murtas, Fabrizio/B-5729-2012; St.Denis, Richard/C-8997-2012; Forti, Francesco/H-3035-2011; Ferrante, Isidoro/F-1017-2012

Nuclear and High Energy PhysicsParticle physics[PHYS.HEXP] Physics [physics]/High Energy Physics - Experiment [hep-ex]Electron–positron annihilationHadronElementary particle01 natural sciencesinternet searchingdistance calculationsStandard ModelALEPH Experiment0103 physical sciencesgraph applications.[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]010306 general physicsALEPH experimentPhysicsMissing energy010308 nuclear & particles physicsPhysicsHigh Energy Physics::Phenomenologymetric spacelcsh:QC1-999Higgs bosonHigh Energy Physics::Experimentlcsh:PhysicsParticle Physics - ExperimentLepton
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s-wave pion-nucleus optical potential

2007

We calculate the s-wave part of the pion-nucleus optical potential using a unitarized chiral approach that has been previously used to simultaneously describe pionic hydrogen and deuterium data as well as low energy pi N scattering in the vacuum. This energy dependent model allows for additional isoscalar parts in the potential from multiple rescattering. We consider Pauli blocking and pion polarization in an asymmetric nuclear matter environment. Also, higher order corrections of the pi N amplitude are included. The model can accommodate the repulsion required by phenomenological fits, though the theoretical uncertainties are bigger than previously thought. At the same time, we also find a…

Nuclear and High Energy PhysicsParticle physicsscattering amplitude [pi nucleon]Nuclear Theorymedia_common.quotation_subjectIsoscalarpartial waveNuclear TheoryFOS: Physical sciencesAsymmetryrenormalizationNuclear physicsNuclear Theory (nucl-th)symbols.namesakePionPauli exclusion principlemesic atom [deuterium]unitarityddc:530higher-order [Feynman graph]nuclear reaction [pi nucleus]numerical calculationsNuclear Experimentmedia_commonPhysicschiral [symmetry]UnitarityIsovectorN(1440)FísicaNuclear mattermesic atom [hydrogen]propagator [pi]Scattering amplitudenuclear mattersymbolsoptical [potential]correction [vertex function]
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Pion-photon transition distribution amplitudes in the Nambu-Jona-Lasinio model

2007

12 pages, 6 figures.-- PACS nrs.: 13.60.-r; 11.10.St; 12.38.Lg; 24.10.Jv.-- ISI Article Identifier: 000251327200049.-- ArXiv pre-print available at: http://arxiv.org/abs/0707.3366

Nuclear and High Energy PhysicsPhotonBethe–Salpeter equationHigh Energy Physics::LatticeNuclear TheoryFOS: Physical sciences[PACS] Relativistic models of nucleiPartícules (Física nuclear)PionHigh Energy Physics - Phenomenology (hep-ph)Nambu–Jona-Lasinio modelBound stateVirtual Compton-scatteringCovariant transformation[PACS] Photon and charged-lepton interactions with hadrons[PACS] Bound and unstable statesMathematical physicsQuantum chromodynamicsPhysicsHigh Energy Physics::PhenomenologyGeneralized Parton distributions[PACS] Bound and unstable states; Bethe-Salpeter equations[PACS] Other nonperturbative calculations in QCDHigh Energy Physics - PhenomenologyAmplitudeQuantum electrodynamicsBethe-Salpeter equationsFísica nuclear
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Radioactivity control strategy for the JUNO detector

2021

JUNO is a massive liquid scintillator detector with a primary scientific goal of determining the neutrino mass ordering by studying the oscillated anti-neutrino flux coming from two nuclear power plants at 53 km distance. The expected signal anti-neutrino interaction rate is only 60 counts per day, therefore a careful control of the background sources due to radioactivity is critical. In particular, natural radioactivity present in all materials and in the environment represents a serious issue that could impair the sensitivity of the experiment if appropriate countermeasures were not foreseen. In this paper we discuss the background reduction strategies undertaken by the JUNO collaboration…

Nuclear and High Energy PhysicsPhysics - Instrumentation and DetectorsPhysics::Instrumentation and DetectorsNuclear engineeringMonte Carlo methodControl (management)measurement methodsFOS: Physical sciencesQC770-798Scintillator7. Clean energy01 natural sciencesNOPE2_2Nuclear and particle physics. Atomic energy. Radioactivity0103 physical sciences[PHYS.HEXP]Physics [physics]/High Energy Physics - Experiment [hep-ex]ddc:530Sensitivity (control systems)010306 general physicsPhysicsJUNOliquid [scintillation counter]010308 nuclear & particles physicsbusiness.industryDetectorSettore FIS/01 - Fisica Sperimentaleradioactivity [background]suppression [background]Instrumentation and Detectors (physics.ins-det)Monte Carlo [numerical calculations]Nuclear powerthreshold [energy]sensitivityNeutrino Detectors and Telescopes (experiments)GEANTNeutrinobusinessEnergy (signal processing)
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Zero-field nuclear magnetic resonance spectroscopy of viscous liquids

2014

Abstract We report zero-field NMR measurements of a viscous organic liquid, ethylene glycol. Zero-field spectra were taken showing resolved scalar spin–spin coupling (J-coupling) for ethylene glycol at different temperatures and water contents. Molecular dynamics strongly affects the resonance linewidth, which closely follows viscosity. Quantum chemical calculations have been used to obtain the relative stability and coupling constants of all ethylene glycol conformers. The results show the potential of zero-field NMR as a probe of molecular structure and dynamics in a wide range of environments, including viscous fluids.

Nuclear and High Energy PhysicsZero field NMRzero-field NMRBiophysicsAnalytical chemistryNMR spectroscopy; low field nmr; Density functional calculationsViscous liquidBiochemistrychemistry.chemical_compoundViscosityMolecular dynamicsNMR spectroscopyMoleculePhysics::Chemical Physicsdensity functional theoryCoupling constantlow field nmrtechnology industry and agricultureZero-field NMRNuclear magnetic resonance spectroscopyviscous liquidsCondensed Matter PhysicsScalar couplingDensity functional calculationschemistryChemical physicsDensity functional theoryscalar couplingEthylene glycolViscous liquidsJournal of Magnetic Resonance
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Efficiency and timing performance of the MuPix7 high-voltage monolithic active pixel sensor

2018

The MuPix7 is a prototype high voltage monolithic active pixel sensor with 103 times 80 um2 pixels thinned to 64 um and incorporating the complete read-out circuitry including a 1.25 Gbit/s differential data link. Using data taken at the DESY electron test beam, we demonstrate an efficiency of 99.3% and a time resolution of 14 ns. The efficiency and time resolution are studied with sub-pixel resolution and reproduced in simulations.

Nuclear and High Energy Physicsirradiation [electron]Physics - Instrumentation and DetectorsFOS: Physical sciencesElectron01 natural sciencesHigh Energy Physics - ExperimentHigh Energy Physics - Experiment (hep-ex)0103 physical sciencesddc:530DESY Lab010306 general physicsnumerical calculationsInstrumentationtime resolutionPhysicspixel [semiconductor detector]CMOS sensorPixel010308 nuclear & particles physicsbusiness.industryResolution (electron density)High voltageDESYTime resolutionInstrumentation and Detectors (physics.ins-det)Test beamefficiencyOptoelectronicsbusinessperformance
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Mirror energy differences above the 0f7/2 shell: First γ-ray spectroscopy of the Tz = −2 nucleus 56Zn

2021

5 pags., 4 figs.

Nuclear and High Energy Physicssinkki (metallit)QC1-999Nuclear Theory01 natural sciencesnucleon removalmirror nuclei0103 physical sciencesSubatomic Physicsmedicine010306 general physicsSpectroscopyradioactive ion beamsNuclear ExperimentNucleonsPhysics[PHYS]Physics [physics]isotoopitValence (chemistry)Isovector010308 nuclear & particles physicsYrastPhysicsFísicaSymmetry Breakingmedicine.anatomical_structureisospin symmetryshell-model calculationsExcited stateEnergy DifferenceAtomic physicsMultipole expansionydinfysiikkaNucleusBeam (structure)
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