0000000000384773

AUTHOR

L.a. Zana

showing 3 related works from this author

Measurement of the decay η′→π0π0η at MAMI

2018

An experimental study of the eta' -> pi(0)pi(0)eta -> 6 gamma decay has been conducted with the best up-to-date statistical accuracy, by measuring. 0 mesons produced in the gamma p -> eta'p reaction with the A2 tagged-photon facility at the Mainz Microtron, MAMI. The results obtained for the standard parametrization of the eta' -> pi(0)pi(0)eta matrix element are consistent with the most recent results for eta' -> pi pi eta decays, but have smaller uncertainties. The available statistics and experimental resolution allowed, for the first time, an observation of a structure below the pi(+)pi(-) thorn p-mass threshold, the magnitude and sign of which, checked within the framewo…

PhysicsHigh Energy Physics::ExperimentNuclear Experimentmatrix-element ; mass ; microtron ; 3-Pi(0) ; cusps ; ratio
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Signatures of the d*(2380) Hexaquark in d(γ,pn→)

2020

We report a measurement of the spin polarization of the recoiling neutron in deuterium photodisintegration, utilizing a new large acceptance polarimeter within the Crystal Ball at MAMI. The measured photon energy range of 300-700 MeV provides the first measurement of recoil neutron polarization at photon energies where the quark substructure of the deuteron plays a role, thereby providing important new constraints on photodisintegration mechanisms. A very high neutron polarization in a narrow structure centered around E_{γ}∼570 MeV is observed, which is inconsistent with current theoretical predictions employing nucleon resonance degrees of freedom. A Legendre polynomial decomposition sugge…

PhysicsPhotonSpin polarizationNuclear TheoryGeneral Physics and AstronomyPhoton energy01 natural sciencesNuclear physicsRecoilPhotodisintegration0103 physical sciencesNeutronNuclear Experiment010306 general physicsNucleonCrystal BallPhysical Review Letters
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Deuteron photodisintegration by polarized photons in the region of the $d^*(2380)$

2019

We report the first large-acceptance measurement of the beam–spin asymmetry for deuteron photodisintegration (γ→d→pn) in the photon energy range 420<Eγ<620MeV. The measurement provides important new constraints on the mechanisms of photodisintegration above the Δ resonance and on the photocoupling of the recently discovered d⁎(2380) hexaquark.

Nuclear and High Energy PhysicsPhotonmedia_common.quotation_subjectNuclear TheoryHexaquarkFOS: Physical sciencesPhoton energy01 natural sciencesAsymmetryResonance (particle physics)Nuclear physics0103 physical sciencesNuclear Experiment (nucl-ex)010306 general physicsNuclear ExperimentNuclear Experimentmedia_commonPhysicsRange (particle radiation)010308 nuclear & particles physicsPhysicslcsh:QC1-999DeuteriumPhotodisintegrationlcsh:Physicsproton polarization ; cross-section ; disintegration ; asymmetry ; energies
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