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ATLAS Collaboration(Aaboud, M. et al), Alvarez Piqueras, D., Barranco Navarro, L., Cabrera Urban, S., Castillo Gimenez, V., Cerda Alberich, L., et al. (2017). Measurement of WW/WZ -> lvqq ' production with the hadronically decaying boson reconstructed as one or two jets in pp collisions at root s=8 TeV with ATLAS, and constraints on anomalous gauge couplings. Eur. Phys. J. C, 77(8), 563–31pp.
Abstract: This paper presents a study of the production of WW or WZ boson pairs, with one W boson decaying to ev or μv and one W or Z boson decaying hadronically. The analysis uses 20.2 fb(-1) of root s = 8 TeV pp collision data, collected by the ATLAS detector at the Large Hadron Collider. Crosssections for WW/WZ production are measured in high-p(T) fiducial regions defined close to the experimental event selection. The cross-section is measured for the case where the hadronically decaying boson is reconstructed as two resolved jets, and the case where it is reconstructed as a single jet. The transverse momentum distribution of the hadronically decaying boson is used to search for new physics. Observations are consistent with the Standard Model predictions, and 95% confidence intervals are calculated for parameters describing anomalous triple gauge-boson couplings.
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Garcia, A. R., Mendoza, E., Cano-Ott, D., Nolte, R., Martinez, T., Algora, A., et al. (2017). New physics model in GEANT4 for the simulation of neutron interactions with organic scintillation detectors. Nucl. Instrum. Methods Phys. Res. A, 868, 73–81.
Abstract: The accurate determination of the response function of organic scintillation neutron detectors complements their experimental characterization. Monte Carlo simulations with GEANT4 can reduce the effort and cost implied, especially for complex detection systems for which the characterization is more challenging. Previous studies have reported on the inaccuracy of GEANT4 in the calculation of the neutron response of organic scintillation detectors above 6 MeV, due to an incomplete description of the neutron-induced alpha production reactions on carbon. We have improved GEANT4 in this direction by incorporating models and data from NRESP, an excellent Monte Carlo simulation tool developed at the Physikalisch-Technische Bundesanstalt (PTB), Germany, for the specific purpose of calculating the neutron response function of organic scintillation detectors. The results have been verified against simulations with NRESP and validated against Time-Of-Flight measurements with an NE213 detector at PTB. This work has potential applications beyond organic scintillation detectors, to other types of detectors where reactions induced by fast neutrons on carbon require an accurate description.
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Colovic, P. et al, & Gadea, A. (2017). Stretched configuration of states as inferred from gamma-ray angular distributions in Ar-40+Pb-208 neutron transfer reactions. Eur. Phys. J. A, 53(8), 166–6pp.
Abstract: Angular distributions of.-rays for selected transitions in Ar-40,Ar-41,Ar-42 isotopes have been studied with the PRISMA magnetic spectrometer coupled to the CLARA gamma array. These transitions were populated in Ar isotopes reached via neutron transfer in the Ar-40 + Pb-208 reaction. By comparison with the shape of the experimental angular distribution of the known E2 transitions we established more firmly the spin and parity of excited states. In particular, in Ar-41 for the (11/2(-)) state through the (11/2(-)) -> 7/2(-) transition whose structure was discussed in terms of a phonon-fermion coupled state. The comparison with the expected fully aligned spin indicated that a high level of spin alignment has been reached.
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AGATA Collaboration(Vogt, A. et al), & Gadea, A. (2017). High-spin structures in Xe-132 and Xe-133 and evidence for isomers along the N=79 isotones. Phys. Rev. C, 96(2), 024321–14pp.
Abstract: The transitional nuclei Xe-132 and Xe-133 are investigated after multinucleon-transfer (MNT) and fusionevaporation reactions. Both nuclei are populated (i) in Xe-136 + 2(08P)b MNT reactions employing the highresolution Advanced GAmma Tracking Array (AGATA) coupled to the magnetic spectrometer PRISMA, (ii) in the Xe-136 + Pt-198 MNT reaction employing the GAMMASPHERE spectrometer in combination with the gas-detector array CHICO, and (iii) as an evaporation residue after a Te-130(alpha, xn) Xe134-xn fusion-evaporation reaction employing the HORUS gamma-ray array at the University of Cologne. The high-spin level schemes are considerably extended above the J(pi) = (7(-)) and (10+) isomers in Xe-132 and above the 11/2(-) isomer in Xe-133. The results are compared to the high-spin systematics of the Z = 54 as well as the N = 78 and N = 79 chains. Furthermore, evidence is found for a long-lived (T-1/2 >> μs) isomer in Xe-133 which closes a gap along the N = isotones. Shell-model calculations employing the SN100PN and PQM130 effective interactions reproduce the experimental findings and provide guidance to the interpretation of the observed high-spin features.
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Muñoz, E., Barrio, J., Etxebeste, A., Ortega, P. G., Lacasta, C., Oliver, J. F., et al. (2017). Performance evaluation of MACACO: a multilayer Compton camera. Phys. Med. Biol., 62(18), 7321–7341.
Abstract: Compton imaging devices have been proposed and studied for a wide range of applications. We have developed a Compton camera prototype which can be operated with two or three detector layers based on monolithic lanthanum bromide (LaBr3) crystals coupled to silicon photomultipliers (SiPMs), to be used for proton range verification in hadron therapy. In this work, we present the results obtained with our prototype in laboratory tests with radioactive sources and in simulation studies. Images of a Na-22 and an Y-88 radioactive sources have been successfully reconstructed. The full width half maximum of the reconstructed images is below 4 mm for a Na-22 source at a distance of 5 cm.
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