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Fernandez-Carames, T., Valcarce, A., & Vijande, J. (2010). Charged charmonium molecules. Phys. Rev. D, 82(5), 054032–5pp.
Abstract: We make use of a self-consistent quark-model based study of four-quark charmonium-like states to interpret recent charmonium experimental data. We conclude that there exists a D*(D) over bar* meson-meson molecule with quantum numbers (I-G) J(PC) = (1(-))2(++). Our study confirms the presence of charged charmonium-like resonances on the excited charmonium spectrum. We find support from recent experimental data by the Belle Collaboration [R. Mizuk et al. (Belle Collaboration), Phys. Rev. D 78, 072004 (2008)]. Confirmation of the experimental data by the Belle Collaboration and the determination of the quantum numbers of the new structures would help in discriminating among different theoretical models and would give further support to the theoretical analysis of T. Fernandez-Carames, A. Valcarce, and J. Vijande [Phys. Rev. Lett. 103, 222001 (2009)].
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CDF Collaboration(Aaltonen, T. et al), & Cabrera, S. (2010). Measurement of Z gamma production in p(p)over-bar collisions at root s=1.96 TeV. Phys. Rev. D, 82(3), 031103–8pp.
Abstract: The production rate and kinematics of photons produced in association with Z bosons are studied using 2 fb(-1) of p (p) over bar collision data collected at the Collider Detector at Fermilab. The cross section for p (p) over bar -> l(+)l(-)gamma + X ( where the leptons l are either muons or electrons with dilepton mass M-ll > 40 GeV/c(2), and where the photon has transverse energy E-T(gamma) > 7 GeV and is well separated from the leptons) is 4.6 +/- 0.2(stat) +/- 0.3 (syst) +/- 0.3 (lum) pb, which is consistent with standard model expectations. We use the photon E-T distribution from Z gamma events where the Z has decayed to mu(+) mu(-) ,e(+) e(-), or nu(+) nu(-) to set limits on anomalous (non standard model) trilinear couplings between photons and Z bosons.
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Mukha, I. et al. (2010). Spectroscopy of proton-unbound nuclei by tracking their decay products in-flight: One- and two-proton decays of F-15, Ne-16, and Na-19. Phys. Rev. C, 82(5), 054315–14pp.
Abstract: A powerful method of investigating proton-unbound nuclear states by tracking their decay products in flight is discussed in detail. To verify the method, four known levels in F-15, Ne-16, and Na-19 were investigated by measuring the angular correlations between protons and the respective heavy-ion fragments stemming from the precursor decays in flight. The parent nuclei of interest were produced in nuclear reactions of one-neutron removal from Ne-17 and Mg-20 projectiles at energies of 410-450 A MeV. The trajectories of the respective decay products, O-14 + p + p and Ne-18 + p + p, were measured by applying a tracking technique with microstrip detectors. These data were used to reconstruct the angular correlations of the fragments, which provided information on energies and widths of the parent states. In addition for reproducing properties of known states, evidence for hitherto unknown excited states in F-15 and Ne-16 was found. This tracking technique has an advantage in studies of exotic nuclei beyond the proton drip line measuring the resonance energies and widths with a high precision although by using low-intensity beams and very thick targets.
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n_TOF Collaboration(Paradela, C. et al), Domingo-Pardo, C., & Tain, J. L. (2010). Neutron-induced fission cross section of U-234 and Np-237 measured at the CERN Neutron Time-of-Flight (n_TOF) facility. Phys. Rev. C, 82(3), 034601–11pp.
Abstract: A high-resolution measurement of the neutron-induced fission cross section of U-234 and Np-237 has been performed at the CERN Neutron Time-of-Flight facility. The cross sections have been determined in a wide energy range from 1 eV to 1 GeV using the evaluated U-235 cross section as reference. In these measurements the energy determination for the U-234 resonances could be improved, whereas previous discrepancies for the Np-237 resonances were confirmed. New cross-section data are provided for high neutron energies that go beyond the limits of prior evaluations, obtaining important differences in the case of Np-237.
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Broda, R. et al, & Gadea, A. (2010). Proton-hole states in the N=30 neutron-rich isotope K-49. Phys. Rev. C, 82(3), 034319–7pp.
Abstract: Excited states in the N = 30 neutron-rich isotope K-49 have been studied using multinucleon transfer reactions with thin targets and the PRISMA-CLARA spectrometer combined with thick-target gamma-coincidence data from Gammasphere. The d(3/2) proton-hole state is located 92 keV above the s(1/2) ground state, and the proton-particle f(7/2) state is suggested at 2104 keV. Three other levels are established as involving the coupling to 2(+) of two neutrons above the N = 28 shell. The measured or estimated lifetimes served to reinforce the interpretation of the observed level structure, which is found to be in satisfactory agreement with shell-model calculations.
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