The Experts below are selected from a list of 147036 Experts worldwide ranked by ideXlab platform
A Poves - One of the best experts on this subject based on the ideXlab platform.
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sense and sensitivity of double beta decay experiments
Journal of Cosmology and Astroparticle Physics, 2011Co-Authors: J J Gomezcadenas, J Martinalbo, M Sorel, P Ferrario, F Monrabal, Jorge Munoz, P Novella, A PovesAbstract:The search for neutrinoless double beta decay is a very active field in which the number of proposals for next-generation experiments has proliferated. In this paper we attempt to address both the sense and the sensitivity of such proposals. Sensitivity comes first, by means of proposing a simple and unambiguous statistical recipe to derive the sensitivity to a putative Majorana neutrino mass, m{sub ββ}. In order to make sense of how the different experimental approaches compare, we apply this recipe to a selection of proposals, comparing the resulting sensitivities. We also propose a ''physics-motivated range'' (PMR) of the Nuclear matrix elements as a unifying criterium between the different Nuclear Models. The expected performance of the proposals is parametrized in terms of only four numbers: energy resolution, background rate (per unit time, isotope mass and energy), detection efficiency, and ββ isotope mass. For each proposal, both a reference and an optimistic scenario for the experimental performance are studied. In the reference scenario we find that all the proposals will be able to partially explore the degenerate spectrum, without fully covering it, although four of them (KamLAND-Zen, CUORE, NEXT and EXO) will approach the 50 meV boundary. In the optimistic scenario, wemore » find that CUORE and the xenon-based proposals (KamLAND-Zen, EXO and NEXT) will explore a significant fraction of the inverse hierarchy, with NEXT covering it almost fully. For the long term future, we argue that {sup 136}Xe-based experiments may provide the best case for a 1-ton scale experiment, given the potentially very low backgrounds achievable and the expected scalability to large isotope masses.« less
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influence of pairing on the Nuclear matrix elements of the neutrinoless ββ decays
Physical Review Letters, 2008Co-Authors: E Caurier, J F Menendez, F Nowacki, A PovesAbstract:We study in this Letter the neutrinoless double beta decay Nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the Nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different Nuclear Models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.
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influence of pairing on the Nuclear matrix elements of the neutrinoless betabeta decays
Physical Review Letters, 2008Co-Authors: E Caurier, J F Menendez, F Nowacki, A PovesAbstract:We study in this Letter the neutrinoless double beta decay Nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the Nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different Nuclear Models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.
Shun Zhou - One of the best experts on this subject based on the ideXlab platform.
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neutral current background induced by atmospheric neutrinos at large liquid scintillator detectors i model predictions
Physical Review D, 2021Co-Authors: Jie Cheng, L J Wen, Shun ZhouAbstract:The experimental searches for diffuse supernova neutrino background and proton decay in next-generation large liquid-scintillator (LS) detectors are competitive with and complementary to those in the water-Cherenkov detectors. In this paper, we carry out a systematic study of the dominant background induced by atmospheric neutrinos via their neutral-current (NC) interactions with the $^{12}\mathrm{C}$ nuclei in the LS detectors. The atmospheric neutrino fluxes at the location of Jiangmen Underground Neutrino Observatory (JUNO) are used, as the JUNO detector is obviously a suitable representative for future LS detectors. Then, we implement the sophisticated generators genie and nuwro to simulate the neutrino interactions with the carbon nuclei, and the package talys to deal with the deexcitations of final-state nuclei. Finally, the event rates for the production of additional nucleons, $\ensuremath{\gamma}$'s, $\ensuremath{\alpha}$'s, pions, and kaons are obtained and categorized, and the systematic uncertainty of the NC background represented by a variety of data-driven Nuclear Models is estimated. The implications of the NC background from atmospheric neutrinos for the detection of diffuse supernova neutrino background and proton decay are also discussed.
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neutral current background induced by atmospheric neutrinos at large liquid scintillator detectors i model predictions
arXiv: High Energy Physics - Phenomenology, 2020Co-Authors: Jie Cheng, L J Wen, Shun ZhouAbstract:The experimental searches for diffuse supernova neutrino background and proton decay in next-generation large liquid-scintillator (LS) detectors are competitive with and complementary to those in the water-Cherenkov detectors. In this paper, we carry out a systematic study of the dominant background induced by atmospheric neutrinos via their neutral-current (NC) interactions with the $^{12}{\rm C}$ nuclei in the LS detectors. The atmospheric neutrino fluxes at the location of Jiangmen Underground Neutrino Observatory (JUNO) are used, as the JUNO detector is obviously a suitable representative for future LS detectors. Then, we implement the sophisticated generators GENIE and NuWro to simulate the neutrino interactions with the carbon nuclei, and the package TALYS to deal with the deexcitations of final-state nuclei. Finally, the event rates for the production of additional nucleons, $\gamma$'s, $\alpha$'s, pions and kaons are obtained and categorized, and the systematic uncertainty of the NC background represented by a variety of data-driven Nuclear Models is estimated. The implications of the NC background from atmospheric neutrinos for the detection of diffuse supernova neutrino background and proton decay are also discussed.
Bernard Gottschalk - One of the best experts on this subject based on the ideXlab platform.
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test of geant3 and geant4 Nuclear Models for 160 mev protons stopping in ch2
Medical Physics, 2003Co-Authors: H Paganetti, Bernard GottschalkAbstract:Monte Carlo simulations are used for many problems in protonradiation therapy, some of which are sensitive to the Nuclear interaction model. The available Models have been little tested in the regime of interest, namely in their ability to predict the secondary particle yield, including their angle and energy, when 70–250 MeV protons stop in various materials. The present study provides one such test in carbon, complementing a previous one in copper. Using a multilayerFaraday cup we have measured the projected range distribution of charged Nuclear secondaries from 160 MeV protons stopping in polyethylene ( CH 2 ). To test the popular GEANTMonte Carlo we have simulated the experiment with GEANT3 using the “Gheisha” (default) and “Fluka” Models and with GEANT4.5 using the “low-energy” and “precompound” Models. The GEANT3/Fluka and GEANT4/precompound simulations agree moderately well with the observed range distribution. The data are given in a convenient form for testing other Monte Carlo programs.
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Nuclear interactions of 160 MeV protons stopping in copper: A test of Monte Carlo Nuclear Models
Medical Physics, 1999Co-Authors: Bernard Gottschalk, Rachel Platais, Harald PaganettiAbstract:To estimate the influence of Nuclear interactions on dose or biological effect one uses Monte Carlo programs which include Nuclear Models. We introduce an experimental method to check these Models at proton therapy energies. We have measured the distribution of charge deposited by 160 MeV protons stopping in a stack of insulated copper plates. A buildup region ahead of the main peak contains ≈20% of the total charge and is entirely due to charged secondaries from inelastic Nuclear interactions. The acceptance for charged secondaries is 100%. Therefore the data are a good benchmark for Nuclear Models. We have simulated the stack using GEANT with two Nuclear Models. FLUKA agrees fairly well with the measurement but GHEISHA, designed for much higher energies, does not. The experimental method will work for many other materials, including insulators. Therefore it can also be used for light nuclei.
E Caurier - One of the best experts on this subject based on the ideXlab platform.
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influence of pairing on the Nuclear matrix elements of the neutrinoless ββ decays
Physical Review Letters, 2008Co-Authors: E Caurier, J F Menendez, F Nowacki, A PovesAbstract:We study in this Letter the neutrinoless double beta decay Nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the Nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different Nuclear Models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.
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influence of pairing on the Nuclear matrix elements of the neutrinoless betabeta decays
Physical Review Letters, 2008Co-Authors: E Caurier, J F Menendez, F Nowacki, A PovesAbstract:We study in this Letter the neutrinoless double beta decay Nuclear matrix elements (NME's) in the framework of the interacting shell model. We analyze them in terms of the total angular momentum of the decaying neutron pair and as a function of the seniority truncations in the Nuclear wave functions. This point of view turns out to be very adequate to gauge the accuracy of the NME's predicted by different Nuclear Models. In addition, it gives back the protagonist role in this process to the pairing interaction, the one which is responsible for the very existence of double beta decay emitters. We show that low seniority approximations, comparable to those implicit in the quasiparticle RPA in a spherical basis, tend to overestimate the NME's in several decays.
Harald Paganetti - One of the best experts on this subject based on the ideXlab platform.
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An integral test of FLUKA Nuclear Models with 160 MeV proton beams in multi-layer Faraday cups
Physics in Medicine and Biology, 2011Co-Authors: I. Rinaldi, Katia Parodi, Andrea Mairani, Alfredo Ferrari, Harald Paganetti, Paola SalaAbstract:Monte Carlo (MC) codes are useful tools to simulate the complex processes of proton beam interactions with matter. In proton therapy, Nuclear reactions influence the dose distribution. Therefore, the validation of Nuclear Models adopted in MC codes is a critical requisite for their use in this field. A simple integral test can be performed using a multi-layer Faraday cup (MLFC). This method allows separation of the Nuclear and atomic interaction processes, which are responsible for secondary particle emission and the finite primary proton range, respectively. In this work, the propagation of 160 MeV protons stopping in two MLFCs made of polyethylene and copper has been simulated by the FLUKA MC code. The calculations have been performed with and without secondary electron emission and transport, as well as charge sharing in the dielectric layers. Previous results with other codes neglected those two effects. The impact of this approximation has been investigated and found to be relevant only in the proximity of the Bragg peak. Longitudinal charge distributions computed with FLUKA with both approaches have been compared with experimental data from the literature. Moreover, the contribution of different processes to the measurable signal has been addressed. A thorough analysis of the results has demonstrated that the Nuclear and electromagnetic Models of FLUKA reproduce the two sets of experimental data reasonably well.
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Nuclear interactions of 160 MeV protons stopping in copper: A test of Monte Carlo Nuclear Models
Medical Physics, 1999Co-Authors: Bernard Gottschalk, Rachel Platais, Harald PaganettiAbstract:To estimate the influence of Nuclear interactions on dose or biological effect one uses Monte Carlo programs which include Nuclear Models. We introduce an experimental method to check these Models at proton therapy energies. We have measured the distribution of charge deposited by 160 MeV protons stopping in a stack of insulated copper plates. A buildup region ahead of the main peak contains ≈20% of the total charge and is entirely due to charged secondaries from inelastic Nuclear interactions. The acceptance for charged secondaries is 100%. Therefore the data are a good benchmark for Nuclear Models. We have simulated the stack using GEANT with two Nuclear Models. FLUKA agrees fairly well with the measurement but GHEISHA, designed for much higher energies, does not. The experimental method will work for many other materials, including insulators. Therefore it can also be used for light nuclei.
