Search results for "decay [Higgs particle]"

Discovery of the new isotopes ²⁴⁰Es and ²³⁶Bk and in-beam spectroscopic studies of ²⁴⁴Cf

2017

The hitherto unknown neutron-deficient nuclei 240Es and 236Bk were synthesised using the fusion-evaporation reaction 209Bi(34S,3n)240Es. The ritu gas-filled recoil separator and the great spectrometer were used in this decay spectroscopic study. The measured electron-capture delayed fission (ECDF) branches in both of the new isotopes complement the experimental data available in the heavier odd-odd Es and Bk isotopes. Furthermore, the ECDF branches show a continuation in the exponential increase of the ECDF probabilities as a function of QEC − Bsf when approaching the proton dripline. In addition, an in-beam γ-ray spectroscopic study of the neutron-deficient isotope 244Cf was made using the fus…

Decay spectroscopy of the very neutron-deficient lead and thallium isotopes 178,179Pb and ¹⁷⁹Tl

2018

This thesis reports on the production of the very neutron-deficient isotopes 178,179Pb and 179Tl, using heavy-ion fusion-evaporation reactions. The gas-filled separator RITU and the GREAT spectrometer at its focal plane position were used for the decay spectroscopy study. The α decay of 178Pb and its α-decay chain were studied through α-α correlations. The α-particle energy and half-life were measured for 178Pb as, Eα= 7610(30) keV and t1/2 = 0.21−+0.21 0.08 ms, respectively. The half-life is consistent with recent theoretical calculations using the Coulomb and Proximity Potential Model (CPPM). The hindrance factor for 178Pb was deduced and corresponds to an unhindered Δl = 0 transition. Th…

Detailed spectroscopy of the neutron-deficient bismuth isotopes ¹⁹³,¹⁹⁵Bi

2015

Two experiments aiming to study the shape coexistence and competing structures in 193Bi and 195Bi isotopes have been performed at the Accelerator laboratory of the University of Jyv askyl a, Finland (JYFL). Many new states have been found, hugely extending the previously known level schemes for both isotopes. The i13=2 bands were extended up to I = 45/2+ in both the 193;195Bi isotopes. In case of 193Bi, the I = 31/2+ member of the i13=2 band was found to de-excite also to a long-lived isomeric state. This link determines the energy of the isomeric state to be 2350(1) keV and suggests a spin and parity of 29/2+. The half-life of the isomeric state was measured to be 85(3) s. A level structur…

Laser assisted decay spectroscopy at the CRIS beam line at ISOLDE

2012

A new collinear resonant ionization spectroscopy (Cris)beam line has recently been installed at Isolde, Cern utilising lasers to combine collinear laser spectroscopy and resonant ionization spectroscopy. The combined technique offers the ability to purify an ion beam that is heavily contaminated with radioactive isobars, including the ground state of an isotope from its isomer, allowing sensitive secondary experiments to be performed. A new programme aiming to use the Cris technique for the separation of nuclear isomeric states for decay spectroscopy will commence in 2011. A decay spectroscopy station, consisting of a rotating wheel implantation system for alpha decay spectroscopy, and thre…

Spectroscopic studies of 173Pt and 175Pt

2014

A spectroscopic study of low-lying states in neutron-deficient astatine and francium nuclei

2013

Spectroscopy of [sub 199,201]At

2015

The excited states of 199At and 201At were studied using fusion evaporation reactions, a gas-filled recoil separator and various tagging methods. The level scheme of 201At was extended a lot including a cascade of magnetic dipole transitions, that is suggested to form a shears band. In addition, a 29/2+ [T1/2 = 3.39(9) s] isomeric state was observed. The 29/2+ state is suggested to originate from the p(h9/2) j200Po; 11􀀀i configuration, and it depopulates through 269-keV E2 and 339-keV E3 transitions. In both nuclei 199,201At we have observed also the isomeric 1/2+ [T1/2 = 273(9), 45(3) ms, respectively] intruder state, that is suggested to originate from the p(s1/2)􀀀1 configuration. The 1…

Alpha-decay studies of the nuclides 195Rn and 196Rn

2001

The new neutron deficient nuclide 195 Rn and the nuclide 196 Rn have been produced in fusion evaporation reactions using 56 Fe ions on 142 Nd targets. A gas-filled recoil separator was used to separate the fusion products from the scattered beam. The activities were implanted in a position sensitive silicon detector. The isotopes were identified using spatial and time correlations between implants and decays. Two α decaying isomeric states, with E α = 7536 ( 11 ) keV [ T 1 / 2 = ( 6 + 3 − 2 ) ms ] for the ground state and E α = 7555 ( 11 ) keV [ T 1 / 2 = ( 5 + 3 − 2 ) ms ] for an isomeric state were identified in 195 Rn . In addition, the half-life and α decay energy of 196 Rn were measure…

High-spin states beyond the proton drip-line: Quasiparticle alignments in Cs-113

2015

Excited states have been studied in the deformed proton emitter 113Cs. Gamma-ray transitions have been unambiguously assigned to 113Cs by correlation with its characteristic proton decay, using the method of recoil-decay tagging. Two previously identified rotational bands have been observed and extended to tentative spins of 45/2 and 51/2 h¯, with excitation energies over 8 MeV above the lowest state. These are the highest angular momenta and excitation energies observed to date in any nucleus beyond the proton drip-line. Transitions in the bands have been rearranged compared to previous work. A study of aligned angular momenta, in comparison to the predictions of Woods–Saxon cranking calcu…

Azimuthal Anisotropy of Heavy-Flavor Decay Electrons in p-Pb Collisions at √sNN = 5.02 TeV

2019

Angular correlations between heavy-flavor decay electrons and charged particles at midrapidity (|η|<0.8) are measured in p-Pb collisions at √sNN=5.02  TeV. The analysis is carried out for the 0%–20% (high) and 60%–100% (low) multiplicity ranges. The jet contribution in the correlation distribution from high-multiplicity events is removed by subtracting the distribution from low-multiplicity events. An azimuthal modulation remains after removing the jet contribution, similar to previous observations in two-particle angular correlation measurements for light-flavor hadrons. A Fourier decomposition of the modulation results in a positive second-order coefficient (v2) for heavy-flavor decay ele…