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We have measured a large number of proton-induced radionuclide production cross sections from tellurium targets of natural isotopic composition at incident energies of 0.80, 1.4, and 23 GeV. The results of these measurements are compared to semi-empirical calculations.
Electromagnetic emission in the form of photons or dileptons provide important information on the onset and evolution of a heavy ion collision at ultrarelativistic energies. We briefly summarize the theoretical assessments of the thermalized electromagnetic emissivities from a hot partonic and hadronic medium, and compare them to current experiments at collider energies.
The history of how chiral symmetry has entered in nuclear physics, in which Gerry Brown and I have participated from 1970 up to today, is described from my personal viewpoint. The route of development we have traversed together goes from meson exchange currents, to "little chiral bag," to chiral effective field theory, to "Brown-Rho scaling" and then to dense matter and chiral phase transition. It has been a great fun and exciting, some right and some wrong in what we have done together, but none that can be dismissed as "not even wrong." We have found all along that whatever signal there may be for the manifestation of chiral symmetry in nuclear medium, be it at low density in meson exchange currents or at high density approaching the chiral phase transition, is very similar in its intricacy and subtlety.
With the help of transport and statistical models, we find that the ratios of higher net-proton cumulants measured at RHIC are dominated by the statistical fluctuations. Future measurements should focus on the dynamical fluctuations, which are relevant to the underlying mechanisms of particle production, the critical phenomena in particular. We also demonstrate that a proton-antiproton correlation directly show if protons and antiprotons are emitted independently.
The merits of searching for η-mesic nuclei by use of the (π, N) reaction at J-PARC is discussed, by comparison with an old experiment with the same reaction at BNL in 1980's. The importance of a pilot experiment using deuterium target is also stressed for a better understanding of the background which should exist even after the coincidence of the decay particles of η-mesic nuclei.
We review recent results on hadron form factors and nucleon generalized parton distibutions obtained with dynamical lattice QCD simulations. We discuss lattice artifacts and open questions, and present the connection of lattice results to hadron structure and to the corresponding quantities measured in experiment.
Have been analyzed the latest experimental data for $γ+ p \to K^{+} + Λ$ reaction of $C_{x'}$ and $C_{z'}$ double polarizations. In theoretical calculation, all of these observables can be classified into four Legendre classes and represented by associated Legendre polynomial function itself \cite{fasano92}. In this analysis we attempt to determine the best data model for both observables. We use the bayesian technique to select the best model by calculating the posterior probabilities and comparing the posterior among the models. The posteriors probabilities for each data model are computed using a Nested sampling integration. From this analysis we concluded that $C_{x'}$ and $C_{z'}$ double polarizations require two and three order of associated Legendre polynomials respectively to describe the data well. The extracted coefficients of each observable will also be presented. It shows the structure of baryon resonances qualitatively
Neutrinoless double beta decay is a process of fundamental importance for particle physics. It can be mediated by light massive Majorana neutrinos (standard interpretation) or by something else (non-standard interpretations). We review its dependence on the neutrino parameters, its complementarity to other observables sensitive to neutrino mass, and emphasize its ability to distinguish different neutrino mass models. Then we discuss mechanisms different from light Majorana neutrino exchange, and show what can be learned from those and how they could be tested.
We present measurements of both $p_t$-integral and $p_t$-differential azimuth quadrupole components of two-particle correlations on azimuth ($ϕ$) and pseudorapidity ($η$) for unidentified hadrons in Au-Au collisions at $\sqrt{s_{NN}}=62$ and 200 GeV. The azimuth quadrupole component is distinguished from $η$-localized same-side correlations by taking advantage of the $η$ dependence. The quadrupole component is related to conventional $v_2$ measures. Both $p_t$-integral and $p_t$-differential results are presented as functions of Au-Au centrality. We observe simple universal energy and centrality trends for the $p_t$-integral quadrupole component. $p_t$-differential results are constructed using $v_{2}^{2}$ marginal distributions on $p_t$. These results can be transformed to reveal quadrupole $p_t$ spectra that are nearly independent of centrality. A parametrization of the $p_t$-differential quadrupole shows a simple $p_t$ dependence that can be factorized from the centrality and collision energy dependence above 0.75 GeV/c.
The state of the art in dibaryons with strangeness is reviewed, including the K^{-}pp dibaryon which signals the onset of antikaon-nuclear binding. A new type of strange dibaryons is highlighted, where the primary binding mechanism is provided by strong p-wave pion interactions, as demonstrated by a quasibound (I=3/2,JP=2+) pion-hyperon-nucleon dibaryon calculation.
We construct a model for inelastic neutrino- and electron-nucleon scattering cross sections using effective leading order parton distribution functions with a new scaling variable $ξ_w$. Non-perturbative effects are well described using the $ξ_w$ scaling variable, in combination with multiplicative $K$ factors at low $Q^2$.Our model describes all inelastic charged lepton-nucleon scattering (including resonance) data (HERA/NMC/BCDMS/SLAC/JLab) ranging from very high $Q^2$ to very low $Q^2$ and down to the photo-production region. The model describes existing inelastic neutrino-nucleon scattering measurements, and has been developed to be used in analysis of neutrino oscillation experiments in the few GeV region.
NA61/SHINE is a fixed-target experiment to study hadron production in hadron-nucleus and nucleus-nucleus collisions at the CERN SPS. Due to the very good acceptance and particle identification in forward direction, NA61/SHINE is well suited for measuring particle production to improve the reliability of air shower simulations. Data with proton and pion beams have been taken in 2007 and 2009. First analysis results for the pion yield in proton-carbon interactions at 31 GeV will be shown and compared to predictions from models used in air shower simulations.
Based on the isospin-dependent Boltzmann-Uehling-Uhlenbeck transport model and the scaling model according to nucleon effective mass, effects of elastic and inelastic NN scattering cross sections on pion-/pion+ in the neutron-rich reaction of Ca48+Ca48 at a beam energy of 400 MeV/nucleon are studied. It is found that cross-section effects of both NN elastic and inelastic scatterings affect Delta_1232, pion- and pion+ production, as well as the value of pion-/pion+.
The results obtained in Mainz in 1982 year were check up. The analysis of data from this work was made at momentum transfer range $q = 0.25 ÷0.75 fm^{-1}$ using the model independent form factor (the expansion of form factor in a power series of $q^2$) and the form factor corresponding to the distribution of charge density in the shell model framework. We found a 3% systematical overestimation in Mainz data.
We discuss a standard model of heavy ion collisions that has emerged both from the experimental results of the RHIC program and associated theoretical developments. We comment briefly on the impact of early results of the LHC program on this picture. We consider how this standard model of heavy ion collisions could be solidified or falsified in future experiments at RHIC, the LHC and a future Electron-Ion Collider.
Three-dimensional source images for mid-rapidity, low transverse momentum kaon and pion pairs have been extracted from central Au+Au collisions data at \sqrt{s_{NN}} = 200 GeV by the STAR experiment at RHIC. The pion source function displays significant non-Gaussian features implying a finite pion emission duration. On the other hand, the kaon source function is essentially Gaussian, consistent with instantaneous emission from the fireball.
At the Institut für Kernphysik in Mainz, Germany, the microtron MAMI has been upgraded to 1.5-GeV electron beam energy. The magnetic spectrometer Kaos is now operated by the A1 collaboration to study strangeness electro-production. Its compact design and its capability to detect negative and positive charged particles simultaneously under forward scattering angles complements the existing spectrometers. In 2008 kaon production off a liquid hydrogen target was measured at = 0.050 (GeV/c)^2 and 0.036 (GeV/c)^2. Associated Lambda and Sigma hyperons were identified in the missing mass spectra. Major modifications to the beam-line are under construction and a new electron arm focal-surface detector system was built in order to use Kaos as a double-arm spectrometer under zero degree scattering angle.
In the new millennium hypernuclear physics is undergoing a renewed interest, both theoretically and experimentally.