19 research outputs found
Unexpectedly allowed transition in two inductively coupled transmons
We present experimental results in which the unexpected zero-two transition
of a circuit composed of two inductively coupled transmons is observed. This
transition shows an unusual magnetic flux dependence with a clear disappearance
at zero magnetic flux. In a transmon qubit the symmetry of the wave functions
prevents this transition to occur due to selection rule. In our circuit the
Josephson effect introduces strong couplings between the two normal modes of
the artificial atom. This leads to a coherent superposition of states from the
two modes enabling such transitions to occur
Nuclear astrophysics with radioactive ions at FAIR
The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process, ÎČ-decay chains. These nuclei are attributed to the p and rp process. For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections. The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes
Correction to: Cluster identification, selection, and description in Cluster randomized crossover trials: the PREP-IT trials
An amendment to this paper has been published and can be accessed via the original article
New insights into the resonance states of 5H and 5He
The 5H system was produced in the 3H(t, p) 5H reaction studied at small CM angles with a 58MeV tritium ion beam. High statistics data were used to reconstruct the energy and angular correlations between the 5H decay fragments. A broad structure in the 5H missing-mass spectrum showing up above 2.5MeV was identified as a mixture of the 3/2+ and 5/2+ states. The data also present an evidence that the 1/2+ ground state of 5H is located at about 2MeV. Then, the 5H and 5He systems were explored by means of transfer reactions occurring in the interactions of 132MeV 6He beam nuclei with deuterium. In the 2H( 6He, 3H) reaction a T = 3/2 isobaric analog state of 5H in 5He was observed at an excitation energy of 22.0±0.3MeV with a width of 2.5±0.3MeV. © Società Italiana di Fisica / Springer-Verlag 2005.SCOPUS: cp.jinfo:eu-repo/semantics/publishe
Correlation studies of the H5 spectrum
The nuclear system H5 was studied using the H3(t,p)H5 transfer reaction at a laboratory energy of 57.7 MeV and small center of mass angles. The energy and angular correlations among the H5 decay fragments were obtained by complete kinematical reconstruction. A broad structure in the H5 missing mass spectrum above 2.5 MeV with a typical width of several MeV was identified as a mixture of 3/2+ and 5/2+ states. Analysis of interference patterns observed in the measured angular correlations disclosed the 1/2+ ground state of H5 concealed in the smooth missing mass spectrum. The deduced values for the resonance energy and width are Eg.s. 1.8 MeV and Îg.s. 1.3 MeV. The estimated cross sections for population of the ground state and the doublet of excited states at Ξc.m.=5°-10° are 150±50 ÎŒb/sr and 4.6±2 mb/sr, respectively. © 2005 The American Physical Society.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
CALIFA, a Dedicated Calorimeter for the R3B/FAIR
The R3B experiment (Reactions with Relativistic Radioactive Beams) at FAIR (Facility for Antiproton and Ion Research) is a versatile setup dedicated to the study of reactions induced by high-energy radioactive beams. It will provide kinematically complete measurements with high efficiency, acceptance and resolution, making possible a broad physics program with rare-isotopes. CALIFA (CALorimeter for In-Flight detection of gamma-rays and high energy charged pArticles), is a complex detector based on scintillation crystals, that will surround the target of the R3B experiment. CALIFA will act as a total absorption gamma-calorimeter and spectrometer, as well as identifier of charged particles from target residues. This versatility is its most challenging requirement, demanding a huge dynamic range, to cover from low energy gamma-rays up to 300 MeV protons. This fact, along with the high-energy of the beams determine the conceptual design of the detector, presented in this paper, together with the technical solutions proposed for its construction
Nuclear astrophysics with radioactive ions at FAIR
The nucleosynthesis of elements beyond iron is dominated by neutron captures in the s and r processes. However, 32 stable, proton-rich isotopes cannot be formed during those processes, because they are shielded from the s-process flow and r-process ÎČ-decay chains. These nuclei are attributed to the p and rp process.
For all those processes, current research in nuclear astrophysics addresses the need for more precise reaction data involving radioactive isotopes. Depending on the particular reaction, direct or inverse kinematics, forward or time-reversed direction are investigated to determine or at least to constrain the desired reaction cross sections.
The Facility for Antiproton and Ion Research (FAIR) will offer unique, unprecedented opportunities to investigate many of the important reactions. The high yield of radioactive isotopes, even far away from the valley of stability, allows the investigation of isotopes involved in processes as exotic as the r or rp processes