The Telescope Array (TA) is the largest ultra-high-energy cosmic ray (UHECR) observatory in the northern hemisphere. It consists of 507 surface scintillator detectors covering approximately 700 km
2
..., and three fluorescence telescope sites overlooking the surface array. The aim of the TA is to explore the origin and nature of UHECR by measuring the energy spectrum and the distribution of arrival directions and mass composition of UHECR. Here, the recent results obtained by the TA are reported. Additionally, two extensions are presented: an extension of the observation area (TAx4) for detecting the highest-energy cosmic rays and the TA Low-Energy extension (TALE) exploring the transition from galactic to extragalactic cosmic rays.
We tabulate the atomic mass excesses and binding energies, ground-state shell-plus-pairing corrections, ground-state microscopic corrections, and nuclear ground-state deformations of 9318 nuclei ...ranging from 16O to A=339. The calculations are based on the finite-range droplet macroscopic and the folded-Yukawa single-particle microscopic nuclear-structure models, which are completely specified. Relative to our FRDM(1992) mass table in Möller et al. (1995), the results are obtained in the same model, but with considerably improved treatment of deformation and fewer of the approximations that were necessary earlier, due to limitations in computer power. The more accurate execution of the model and the more extensive and more accurate experimental mass data base now available allow us to determine one additional macroscopic-model parameter, the density-symmetry coefficient L, which was not varied in the previous calculation, but set to zero. Because we now realize that the FRDM is inaccurate for some highly deformed shapes occurring in fission, because some effects are derived in terms of perturbations around a sphere, we only adjust its macroscopic parameters to ground-state masses.
The values of ten constants are determined directly from an optimization to fit ground-state masses of 2149 nuclei ranging from 16O to 106265Sg and 108264Hs. The error of the mass model is 0.5595 MeV for the entire region of nuclei included in the adjustment, but is only 0.3549 MeV for the region N≥65.
We also provide masses in the FRLDM, which in the more accurate treatments now has an error of 0.6618 MeV, with 0.5181 MeV for nuclei with N≥65, both somewhat larger than in the FRDM. But in contrast to the FRDM, it is suitable for studies of fission and has been extensively so applied elsewhere, with FRLDM(2002) constants. The FRLDM(2012) fits 31 fission-barrier heights from 70Se to 252Cf with a root-mean-square deviation of 1.052 MeV.
We analyze and propose a solution to the apparent inconsistency between our current knowledge of the equation of state of asymmetric nuclear matter, the energy of the isobaric analog state (IAS) in a ...heavy nucleus such as ^{208}Pb, and the isospin symmetry breaking forces in the nuclear medium. This is achieved by performing state-of-the-art Hartree-Fock plus random phase approximation calculations of the IAS that include all isospin symmetry breaking contributions. To this aim, we propose a new effective interaction that is successful in reproducing the IAS excitation energy without compromising other properties of finite nuclei.
.
The experimental and theoretical studies of Giant Resonances, or more generally of the nuclear collective vibrations, are a well-established domain in which sophisticated techniques have been ...introduced and firm conclusions reached after an effort of several decades. From it, information on the nuclear equation of state can be extracted, albeit not far from usual nuclear densities. In this contribution, which complements other contributions appearing in this topical issue, we survey some of the constraints that have been extracted recently concerning the parameters of the nuclear symmetry energy. Isovector modes, in which neutrons and protons are in opposite phase, are a natural source of information and we illustrate the values of symmetry energy around saturation deduced from isovector dipole and isovector quadrupole states. The isotopic dependence of the isoscalar monopole energy has also been suggested to provide a connection to the symmetry energy: relevant theoretical arguments and experimental results are thoroughly discussed. Finally, we consider the case of the charge-exchange spin-dipole excitations in which the sum rule associated with the total strength gives in principle access to the neutron skin and thus, indirectly, to the symmetry energy.
We review several experimental and theoretical advances that emphasize common aspects of the study of spin-singlet, T = 1, and spin-triplet, T = 0, pairing correlations in nuclei. We first discuss ...various empirical evidence of the special role played by the T = 1 pairing interaction. In particular, we show the peculiar features of the nuclear pairing interaction in the low-density regime, and possible outcomes such as the BCS-BEC crossover in nuclear matter and, in an analogous way, in loosely bound nuclei. We then move to the competition between T = 1 and T = 0 pairing correlations. The effect of such competition on the low-lying spectra is studied in N = Z odd-odd nuclei by using a three-body model; in this case, it is shown that the inversion of the J π = 0 + and J π = 1 + states near the ground state, and the strong magnetic dipole transitions between them, can be considered as a clear manifestation of strong T = 0 pairing correlations in these nuclei. The effect of T = 0 pairing correlations is also quite evident if one studies charge-changing transitions. The Gamow-Teller (GT) states in N = Z + 2 nuclei are studied here by using self-consistent Hartree-Fock-Bogoliubov (HFB) plus quasiparticle random-phase approximation calculations in which the T = 0 pairing interaction is taken into account. Strong GT states are found, near the ground state of daughter nuclei; these are compared with available experimental data from charge-exchange reactions, and such comparison can pinpoint the value of the strength of the T = 0 interaction. Pair transfer reactions are eventually discussed. While two-neutron transfer has long been proposed as a tool to measure the T = 1 superfluidity in the nuclear ground states, the study of deuteron transfer is still in its infancy, despite its potential interest for revealing effects coming from both T = 1 and T = 0 interactions. We also point out that the reaction mechanism may mask the strong pair transfer amplitudes predicted by the HFB calculations, because of the complexity arising from simultaneous and sequential pair transfer processes.
Abstract We investigate the effects of residual tensor force (TF) and pairing force on the Gamow–Teller (GT) transitions in four magic nuclei, 48Ca, 90Zr, 132Sn and 208Pb. The TF is taken into ...account by using the Brückner G-matrix theory with the charge-dependent (CD) Bonn potential as the residual interaction of charge-exchange quasiparticle random phase approximation (QRPA). We found that particle–particle (p–p) tensor interaction does not affect the GT transitions because of the closed shell nature in the nuclei, but repulsive particle–hole (p–h) residual interaction for the p–h configuration of spin-orbit partners dominates the high-lying giant GT states for all of the nuclei. It is also shown that appreciable GT strengths are shifted to a lower energy region by the attractive p–h TF for the same jπ = jν configuration, and produce the low-lying GT peak about 2.5 MeV in 48Ca. Simultaneously, in 90Zr and 132Sn, the low-energy GT strength appears as a lower energy shoulder near the main GT peak. On the other hand, the shift of the low-lying GT state is not seen clearly for 208Pb because of the strong spin-orbit splitting of high j orbits, which dominates the GT strength.
Proteome Analysis of Walnut Bacterial Blight Disease H D Sagawa, Cíntia; de A B Assis, Renata; Zaini, Paulo A ...
International journal of molecular sciences,
10/2020, Letnik:
21, Številka:
20
Journal Article
Recenzirano
Odprti dostop
The interaction between the plant host, walnut (
; Jr), and a deadly pathogen (
pv.
417; Xaj) can lead to walnut bacterial blight (WB), which depletes walnut productivity by degrading the nut ...quality. Here, we dissect this pathosystem using tandem mass tag quantitative proteomics. Walnut hull tissues inoculated with Xaj were compared to mock-inoculated tissues, and 3972 proteins were identified, of which 3296 are from Jr and 676 from Xaj. Proteins with differential abundance include oxidoreductases, proteases, and enzymes involved in energy metabolism and amino acid interconversion pathways. Defense responses and plant hormone biosynthesis were also increased. Xaj proteins detected in infected tissues demonstrate its ability to adapt to the host microenvironment, limiting iron availability, coping with copper toxicity, and maintaining energy and intermediary metabolism. Secreted proteases and extracellular secretion apparatus such as type IV pilus for twitching motility and type III secretion effectors indicate putative factors recognized by the host. Taken together, these results suggest intense degradation processes, oxidative stress, and general arrest of the biosynthetic metabolism in infected nuts. Our results provide insights into molecular mechanisms and highlight potential molecular tools for early detection and disease control strategies.
The Telescope Array (TA) observatory utilizes fluorescence detectors and surface detectors (SDs) to observe air showers produced by ultra high energy cosmic rays in Earth's atmosphere. Cosmic-ray ...events observed in this way are termed hybrid data. The depth of air shower maximum is related to the mass of the primary particle that generates the shower. This paper reports on shower maxima data collected over 8.5 yr using the Black Rock Mesa and Long Ridge fluorescence detectors in conjunction with the array of SDs. We compare the means and standard deviations of the observed X max distributions with Monte Carlo X max distributions of unmixed protons, helium, nitrogen, and iron, all generated using the QGSJet II-04 hadronic model. We also perform an unbinned maximum likelihood test of the observed data, which is subjected to variable systematic shifting of the data X max distributions to allow us to test the full distributions, and compare them to the Monte Carlo to see which elements are not compatible with the observed data. For all energy bins, QGSJet II-04 protons are found to be compatible with TA hybrid data at the 95% confidence level after some systematic X max shifting of the data. Three other QGSJet II-04 elements are found to be compatible using the same test procedure in an energy range limited to the highest energies where data statistics are sparse.
PDF
