Search results for " Decay"

showing 10 items of 1838 documents

Role of the N-*(1535) in the J/psi -> pp and J/psi -> p(+)Lambda reactions

2009

We study the J/psi -> p eta p and J/psi -> pK(+)Lambda reactions with a unitary chiral approach. We find that the unitary chiral approach, which generates the N-*(1535) dynamically, can describe the data reasonably well, particularly the ratio of the integrated cross sections. This study provides further support for the unitary chiral description of the N-*(1535). We also discuss some subtle differences between the coupling constants determined from the unitary chiral approach and those determined from phenomenological studies

ratio [width]High Energy Physics::LatticeJ/psi(3100) --> p anti-p etaJ/psi(3100) --> Lambda anti-p K+Físicahadronic decay [J/psi(3100)]coupling constant [N(1535)]mass spectrumwidth [J/psi(3100)]unitarityddc:530chiral [effective Lagrangian]numerical calculations
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Total Absorption Spectroscopy of Fission Fragments Relevant for Reactor Antineutrino Spectra and Decay Heat Calculations

2016

Beta decay of fission products is at the origin of decay heat and antineutrino emission in nuclear reactors. Decay heat represents about 7% of the reactor power during operation and strongly impacts reactor safety. Reactor antineutrino detection is used in several fundamental neutrino physics experiments and it can also be used for reactor monitoring and non-proliferation purposes. 92,93Rb are two fission products of importance in reactor antineutrino spectra and decay heat, but their β-decay properties are not well known. New measurements of 92,93Rb β-decay properties have been performed at the IGISOL facility (Jyväskylä, Finland) using Total Absorption Spectroscopy (TAS). TAS is complemen…

rubidiumdecay heatfission productsHigh Energy Physics::Experimentbeta decayantineutrino emissionNuclear ExperimentPhysics::Geophysics
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Beta-decay studies for applied and basic nuclear physics

2020

In this review we will present the results of recent beta-decay studies using the total absorption technique that cover topics of interest for applications, nuclear structure and astrophysics. The decays studied were selected primarily because they have a large impact on the prediction of a) the decay heat in reactors, important for the safety of present and future reactors and b) the reactor electron antineutrino spectrum, of interest for particle/nuclear physics and reactor monitoring. For these studies the total absorption technique was chosen, since it is the only method that allows one to obtain beta decay probabilities free from a systematic error called the Pandemonium effect. The me…

safetyNuclear and High Energy PhysicsAstrophysics::High Energy Astrophysical PhenomenaPenning trapFOS: Physical sciencesnucleus: structure functionnuclear model[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciences7. Clean energylaw.inventionNuclear physicslawnuclear physics0103 physical sciencesNuclear fusionNeutronDecay heatNuclear Experiment (nucl-ex)n: capture010306 general physicsNuclear ExperimentNuclear ExperimentPhysicsantineutrino: spectrum010308 nuclear & particles physicsPandemonium effectsemileptonic decayNuclear reactorNeutron capturemonitoring13. Climate actionnuclear reactorDelayed neutronElectron neutrinoabsorptionThe European Physical Journal A
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Cross section for bb¯ production via dielectrons in d + Au collisions at √sNN = 200 GeV

2015

We report a measurement of e+e− pairs from semileptonic heavy-flavor decays in d + Au collisions at √sNN = 200 GeV. By exploring the mass and transverse-momentum dependence of the yield, the bottom decay contribution can be isolated from charm, and quantified by comparison to PYTHIA and MC@NLO simulations. The resulting bb¯-production cross section is σdAu bb¯ = 1.37 ± 0.28 (stat) ± 0.46 (syst) mb, which is equivalent to a nucleon-nucleon cross section of σ NN bb = 3.4 ± 0.8 (stat) ± 1.1 (syst) μb. peerReviewed

semileptonic heavy-flavor decaysHigh Energy Physics::Phenomenologyd+Au collisions at sNN=200 GeVHigh Energy Physics::ExperimentNuclear Experimentmeasurement of e+e- pairs
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"Table 7" of "Cross section for $b\bar{b}$ production via dielectrons in d$+$Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV"

2023

$b\bar{b}$ cross section

semileptonic heavy-flavor decaysb ̄b-production cross sectionmc@nloppg156pythia$d$ + Au200.0
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"Postfit yields Y(4S)" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

Yields in on-resonance data and as predicted by the simultaneous fit to the on- and off-resonance data, corresponding to an integrated luminosity of 63 and 9 fb$^{−1}$, respectively. The predicted yields are shown individually for charged and neutral B-meson decays and the five continuum background categories. The leftmost three bins belong to the first control region (CR1) with BDT$_{2} \in [0.93; 0.95]$ and the other nine bins correspond to the signal region (SR), three for each range of BDT$_{2} \in [0.95; 0.97; 0.99; 1.0]$. Each set of three bins is defined by $p_{T}(K^{+}) \in [0.5; 2.0; 2.4; 3.5] \rm{GeV}/c^{2}$.

signal strenghth $\mu$electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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"Postfit yields off-resonance" of "Search for $B^{+}\to K^{+}\nu\bar{\nu}$ decays using an inclusive tagging method at Belle II"

2022

Yields in off-resonance data and as predicted by the simultaneous fit to the on- and off-resonance data, corresponding to an integrated luminosity of 63 and 9 fb$^{−1}$, respectively. The predicted yields are shown individually for the five continuum background categories. The leftmost three bins belong to the third control region (CR3) with BDT$_{2} \in [0.93; 0.95]$ and the other nine bins correspond to the second control region (CR2), three for each range of BDT$_{2} \in [0.95; 0.97; 0.99; 1.0]$. Each set of three bins is defined by $p_{T}(K^{+}) \in [0.5; 2.0; 2.4; 3.5] \rm{GeV}/c^{2}$.

signal strenghth $\mu$electroweak penguin decay$B^+ \rightarrow K^+\nu\bar\nu$FCNCmissing energyb --> s l l transition
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Occupation probabilities of single particle levels using the microscopic interacting boson model: Application to some nuclei of interest in neutrinol…

2016

We have developed a new method to calculate the occupancies of single particle levels in atomic nuclei. This method has been developed in the context of the microscopic interacting boson model, in which neutron and proton degrees of freedom are treated explicitly. The energies of the single particle levels constitute a very important input for the calculation of the occupancies in this method. In principle these energies can be considered as input parameters that can be fitted to reproduce the experimental occupancies. Instead of fitting, in this study we have extracted the single particle energies from experimental data on nuclei with a particle more or one particle less than a shell closu…

single particle levelsatomic nucleimicroscopic interacting boson modelNuclear Theorydouble beta decay
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The NUMEN project @ LNS: Status and perspectives

2017

The NUMEN project aims at accessing experimentally driven information on Nuclear Matrix Elements (NME) involved in the half-life of the neutrinoless double beta decay (0νββ), by high-accuracy measurements of Heavy Ion (HI) induced Double Charge Exchange (DCE) reaction cross sections. In particular, the (18O,18Ne) and (20Ne,20O) reactions are used as tools for β+β+ and β−β− decays, respectively. In the experiments, performed at INFN - Laboratory Nazionali del Sud (LNS) in Catania, the beams are accelerated by the Superconducting Cyclotron (CS) and the reaction ejectiles are detected the MAGNEX magnetic spectrometer. The measured cross sections are challengingly low (a few nb), being the tota…

spectroscopyacceleratorspektroskopiaCyclotronnucleus: energyContext (language use)Scintillator[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]7. Clean energy01 natural scienceslaw.inventionNuclear physicsPhysics and Astronomy (all)double-beta decay: (0neutrino)lawDouble beta decay0103 physical sciencescyclotron010306 general physicsPhysicsSpectrometerta114operator: transition010308 nuclear & particles physicscyclotrons nuclear structureNuclear structureradioactive decaysemileptonic decaycross section: measuredmagnetic spectrometercharge exchangecharge exchange reactionsheavy ionUpgradeOrder of magnitudeexperimental results
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Total absorption γ -ray spectroscopy of niobium isomers

2019

15 pags. 17 figs., 5 tabs.

spektroskopiaNiobiumchemistry.chemical_element[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]Nuclear Structure7. Clean energy01 natural sciences0103 physical sciencesDecay heat010306 general physicsSpectroscopyAbsorption (electromagnetic radiation)Nuclear ExperimentPhysicsZirconiumSpectrometer010308 nuclear & particles physicsPandemonium effectPenning trapnuclear structure and decayschemistry13. Climate actionFísica nuclearbeta decayAtomic physicsisomer decaysydinfysiikka
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