Search results for " Decay"

Direct measurement of the mass difference of $^{72}$As-$^{72}$Ge rules out $^{72}$As as a promising $\beta$-decay candidate to determine the neutrino…

2021

We report the first direct determination of the ground-state to ground-state electron-capture $Q$-value for the $^{72}$As to $^{72}$Ge decay by measuring their atomic mass difference utilizing the double Penning trap mass spectrometer, JYFLTRAP. The $Q$-value was measured to be 4343.596(75)~keV, which is more than a 50-fold improvement in precision compared to the value in the most recent Atomic Mass Evaluation 2020. Furthermore, the new $Q$-value was found to be 12.4(40)~keV (3.1 $\sigma$) lower. With the significant reduction of the uncertainty of the ground-state to ground-state $Q$-value value combined with the level scheme of $^{72}$Ge from $\gamma$-ray spectroscopy, we confirm that th…

Evolution of deformation in neutron-rich Ba isotopes up to A=150

2018

12 pags., 11 figs., 3 tabs. -- Open Access funded by Creative Commons Atribution Licence 4.0

Photoluminescence time decay of surface oxygen deficient centers in un‐doped and Ge‐doped silica

2005

We report a study of the emission decay from the singlet excited state of two fold coordinated Si and Ge centers stabilized on the surface of silica and Ge-doped silica. The PL lifetimes are of the order of nanoseconds and increase on decreasing the temperature. The results suggest that, for the surface centers, the phonon assisted intersystem-crossing process linking the excited states affects the decay rates, is effective down to low temperatures and is distributed because of the inhomogeneity of the defects. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

The strong coupling constant: State of the art and the decade ahead

2022

This document provides a comprehensive summary of the state-of-the-art, challenges, and prospects in the experimental and theoretical study of the strong coupling $\alpha_s$. The current status of the seven methods presently used to determine $\alpha_s$ based on: (i) lattice QCD, (ii) hadronic $\tau$ decays, (iii) deep-inelastic scattering and parton distribution functions fits, (iv) electroweak boson decays, hadronic final-states in (v) e+e-, (vi) e-p, and (vii) p-p collisions, and (viii) quarkonia decays and masses, are reviewed. Novel $\alpha_s$ determinations are discussed, as well as the averaging method used to obtain the PDG world-average value at the reference Z boson mass scale, $\…

Testing the nature of the Λ(1520)-resonance in proton-induced production

2006

The $\Lambda(1520)$ resonance has been recently studied in a unitarized coupled channel formalism with $\pi\Sigma(1385)$, $K\Xi(1530)$, $\bar{K}N$ and $\pi\Sigma$ as constituents blocks. We provide a theoretical study of the predictions of this model in physical observables of the $pp\to pK^+K^-p$ and $pp\to pK^+\pi^0\pi^0\Lambda$ reactions. In particular, we show that the ratio between the $\pi^0\pi^0\Lambda$ and $K^-p$ mass distributions can provide valuable information on the ratio of the couplings of the $\Lambda(1520)$ resonance to $\pi\Sigma(1385)$ and $\bar{K}N$ that the theory predicts. Calculations are done for energies which are accessible in an experimental facility like COSY at …

Genetic analysis of familial Alzheimer’s disease, primary lateral sclerosis and paroxysmal kinesigenic dyskinesia: a tool to uncover common mechanist…

2021

Tesis doctoral 270 p. figuras y tablas

Comparative Analysis of Nuclear Matrix Elements of 0νβ+β+ Decay and Muon Capture in 106Cd

2021

Comparative analyses of the nuclear matrix elements (NMEs) related to the 0νβ+β+ decay of 106Cd to the ground state of 106Pd and the ordinary muon capture (OMC) in 106Cd are performed. This is the first time the OMC NMEs are studied for a nucleus decaying via positron-emitting/electron-capture modes of double beta decay. All the present calculations are based on the proton-neutron quasiparticle random-phase approximation with large no-core single-particle bases and realistic two-nucleon interactions. The effect of the particle-particle interaction parameter gpp of pnQRPA on the NMEs is discussed. In the case of the OMC, the effect of different bound-muon wave functions is studied. peerRevie…

Lowest order perturbative quantum field theory calculations of bound state decay widths

2017

Alimman kertaluvun häiriöteoreettisia kvanttikenttäteorialaskuja sidottujen tilojen hajoamisleveyksille. Työssä lasketaan sidottujen tilojen hajoamisleveydet prosesseille $J/ \psi \rightarrow l^+ l^-$, $\eta_c \rightarrow gg$, $\text{O-Ps}\rightarrow \gamma\gamma\gamma$, $J/ \psi \rightarrow ggg$ ja $J/ \psi \rightarrow \gamma gg$. Prosessit lasketaan perturbatiivisen QED:n ja QCD:n alimmassa kertaluvussa. Laskuissa käydään läpi kolme erilaista tekniikkaa invariantin amplitudin käsittelemiseksi. Johdetut hajoamisleveystulokset käyvät yksiin kirjallisuudesta löytyvien tulosten kanssa. Lisäksi tarkastellaan kokeellisesti varmistettavissa olevia hajoamisleveyssuhteita. Teoreettiset ennusteet o…

Majorana parameters of the interacting boson model of nuclear structure and their implication for 0νββ decay

2021

Ordinary Muon Capture on 136Ba : Comparative Study Using the Shell Model and pnQRPA

2023

In this work, we present a study of ordinary muon capture (OMC) on 136136Ba, the daughter nucleus of 136136Xe double beta decay (DBD). The OMC rates at low-lying nuclear states (below 1 MeV of excitation energy) in 136136Cs are assessed by using both the interacting shell model (ISM) and proton–neutron quasiparticle random-phase approximation (pnQRPA). We also add chiral two-body (2BC) meson-exchange currents and use an exact Dirac wave function for the captured s-orbital muon. OMC can be viewed as a complementary probe of the wave functions in 136136Cs, the intermediate nucleus of the 136136Xe DBD. At the same time, OMC can be considered a powerful probe of the effective values of weak axi…