AGATA Collaboration(Clement, E. et al), Domingo-Pardo, C., Gadea, A., Perez-Vidal, R. M., & Civera, J. V. (2017). Conceptual design of the AGATA 1 pi array at GANIL. Nucl. Instrum. Methods Phys. Res. A, 855, 1–12.
Abstract: The Advanced GAmma Tracking Array (AGATA) has been installed at the GANIL facility, Caen-France. This setup exploits the stable and radioactive heavy-ions beams delivered by the cyclotron accelerator complex of GANIL. Additionally, it benefits from a large palette of ancillary detectors and spectrometers to address in-beam gamma-ray spectroscopy of exotic nuclei. The set-up has been designed to couple AGATA with a magnetic spectrometer, charged-particle and neutron detectors, scintillators for the detection of high-energy gamma rays and other devices such as a plunger to measure nuclear lifetimes. In this paper, the design and the mechanical characteristics of the set-up are described. Based on simulations, expected performances of the AGATA l pi array are presented.
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AGATA Collaboration(Ralet, D. et al), Gadea, A., & Perez-Vidal, R. M. (2017). Toward lifetime and g factor measurements of short-lived states in the vicinity of Pb-208. Phys. Scr., 92(5), 054004–4pp.
Abstract: The multi-nucleon transfer reaction mechanism was used to produce and study nuclei in the vicinity of 208Pb. This mass region is a test case for the nuclear shell model. The mass identification of the fragments was performed with the large acceptance magnetic spectrometer VAMOS++ coupled to the AGATA gamma-tracking array. This experiment aimed to determine both lifetimes and gyromagnetic ratios of excited states with the Cologne plunger device. The analysis indicates promising results with the possibility to determine several new lifetimes in this region.
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Marquez-Martin, I., Di Molfetta, G., & Perez, A. (2017). Fermion confinement via quantum walks in (2+1)-dimensional and (3+1)-dimensional space-time. Phys. Rev. A, 95(4), 042112–5pp.
Abstract: We analyze the properties of a two-and three-dimensional quantum walk that are inspired by the idea of a brane-world model put forward by Rubakov and Shaposhnikov [Phys. Lett. B 125, 136 (1983)]. In that model, particles are dynamically confined on the brane due to the interaction with a scalar field. We translated this model into an alternate quantum walk with a coin that depends on the external field, with a dependence which mimics a domain wall solution. As in the original model, fermions (in our case, the walker) become localized in one of the dimensions, not from the action of a random noise on the lattice (as in the case of Anderson localization) but from a regular dependence in space. On the other hand, the resulting quantum walk can move freely along the “ordinary” dimensions.
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BABAR Collaboration(Lees, J. P. et al), Martinez-Vidal, F., & Oyanguren, A. (2017). Dalitz plot analyses of J / psi -> pi(+) pi(-) pi(0), J / psi -> K+ K- pi(0), and J / psi -> (KsK +/-)-K-0 pi(-/+) produced via e (+) e (-) annihilation with initial-state radiation. Phys. Rev. D, 95(7), 072007–19pp.
Abstract: We study the processes e(+)e(-) -> gamma ISRJ (/) (psi), where J / psi pi(+)pi(-) pi(0), J / psi -> K+K-pi(0), and J / psi -> (KSK +/-)-K-0 pi(-/+) using a data sample of 519 fb(-1) recorded with the BABAR detector operating at the SLAC PEP-II asymmetric-energy e(+) e(-) collider at center-of-mass energies at and near the Y(nS) (n = 2, 3, 4) resonances. We measure the ratio of branching fractions R-1 = B(J / psi -> K+K-pi(0))/B(J / psi ->pi(+)pi(-)pi(0)) and R-2 = B(J / psi -> K-S(0) K-+/- p(-/+))/B(J / psi ->pi(+)pi(-)pi(0)). We perform Dalitz plot analyses of the three J / psi decay modes and measure fractions for resonances contributing to the decays. We also analyze the J /psi -> pi(+)pi(-)pi(0) decay using the Veneziano model. We observe structures compatible with the presence of rho(1450) in all three J / psi decay modes and measure the relative branching fraction: R(rho(1450)) = B(rho(1450)-> K+K-)/B(rho(1450)->pi(+)pi(-)) = 0.307 +/- 0.084(stat) +/- 0.082(sys).
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XENON Collaboration(Aprile, E. et al), & Orrigo, S. E. A. (2017). Results from a calibration of XENON100 using a source of dissolved radon-220. Phys. Rev. D, 95(7), 072008–10pp.
Abstract: A Rn-220 source is deployed on the XENON100 dark matter detector in order to address the challenges in calibration of tonne-scale liquid noble element detectors. We show that the Pb-212 beta emission can be used for low-energy electronic recoil calibration in searches for dark matter. The isotope spreads throughout the entire active region of the detector, and its activity naturally decays below background level within a week after the source is closed. We find no increase in the activity of the troublesome Rn-222 background after calibration. Alpha emitters are also distributed throughout the detector and facilitate calibration of its response to Rn-222. Using the delayed coincidence of Rn-220-Po-216, we map for the first time the convective motion of particles in the XENON100 detector. Additionally, we make a competitive measurement of the half-life of Po-212, t(1/2) = (293.9 +/- (1.0)(stat) +/- (0.6)(sys)) ns.
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