arXiv subjects

J. C. Anjos

Publications and source records attributed to J. C. Anjos.

11 recordsLinked to original sources

arXiv2024

From Safeguards Application to Fundamental Physics: Advancements in Reactor Neutrino Detection with the ν-Angra Experiment

Operating on a surface with high noise rates and requiring susceptible, yet small-scale detectors, the Neutrinos-Angra detector is an excellent platform for technological development and expertise in new detection methods. This report details the primary features of the detector, the electronics involved, and preliminary physics results from the operational phase, particularly the ON-OFF analysis comparing the signals with the reactor in operation (ON) and during the maintenance shut-down (OFF), demonstrating the detector's capability to monitor reactor activity. Additionally, we will briefly discuss the prospects of using a cryogenic calorimeter to detect neutrinos via Coherent Elastic Neutrino-Nucleus Scattering (CEvNS), highlighting potential advancements in neutrino detection technology. Looking ahead, the project promises to play a crucial role in the integration of Latin American scientists and engineers into global scientific collaborations, significantly contributing to the LASF4RI and the broader HECAP strategic framework.

hep-ex↗

arXiv2024

Results from ON-OFF analysis of the Neutrinos-Angra detector

The Neutrinos Angra Experiment, a water-based Cherenkov detector, is located at the Angra dos Reis nuclear power plant in Brazil. Designed to detect electron antineutrinos produced in the nuclear reactor, the primary objective of the experiment is to demonstrate the feasibility of monitoring reactor activity using an antineutrino detector. This effort aligns with the International Atomic Energy Agency (IAEA) program to identify potential and novel technologies applicable to nonproliferation safeguards. Operating on the surface presents challenges such as high noise rates, necessitating the development of very sensitive, yet small-scale detectors. These conditions make the Angra experiment an excellent platform for both developing the application and gaining expertise in new technologies and analysis methods. The detector employs a water-based target doped with gadolinium to enhance its sensitivity to antineutrinos. In this work, we describe the main features of the detector and the electronics chain, including front-end and data acquisition components. We detail the data acquisition strategies and the methodologies applied for signal processing and event selection. Preliminary physics results suggest that the detector can reliably monitor reactor operations by detecting the inverse beta decay induced by electron antineutrinos from the reactor.

hep-ex↗

arXiv2019

Brazilian Report on Safeguards Application of Reactor Neutrinos

The Neutrinos Angra Experiment is a water-based Cherenkov detector located in the Angra dos Reis nuclear power plant. The experiment has completed a major step by finishing the commissioning of the detector and the data acquisition system at the experimental site. The experiment was designed to detect the electron antineutrinos produced by the nuclear reactor with the main purpose to demonstrate the feasibility of monitoring the reactor activity using an antineutrino detector. This effort is within the context of the International Atomic Energy Agency (IAEA) program to identify potential and novel technologies that can be applied for non-proliferation safeguards. Challenges, such as operating at the surface, therefore with huge noise rates, and the need to build very sensitive but small-scale detectors, make the Angra experiment an excellent platform for developing the application itself, as well as acquiring expertise in new technologies and analysis methods. In this report, we describe the main detector features and the electronics chain (front-end and data acquisition). We also report preliminary physics results obtained from the commissioning phase data. Finally, we address conclusions regarding the future perspectives to keep this program active, due to its importance in the insertion of Latin-American scientists and engineers in a world-scale cutting edge scientific program.

physics.ins-det↗

arXiv2019

Neutrinos Angra experiment: commissioning and first operational measurements

The Neutrinos Angra Experiment has completed a major step by finishing the comissioning of the detector and the data acquisition system at the experimental site located in the Angra dos Reis nuclear power plant. The experiment consists of a water-based detector and associated electronics, both designed with the goal of detecting the electron antineutrinos produced by the nuclear reactor. The detection is possible due to the Inverse Beta Decay, where the final products in the water are photons in the UV-to-visible range of the spectrum. The assembled detector comprises three active volumes filled with water: (i) a cubic target detector for electron antineutrinos, covered by 32 8-inches PMTs, (ii) a lateral layer surrounding the target (veto) equipped with 4 PMTs and (iii) a third volume covering the top of both, also equipped with 4~PMTs. In the present document the main features of the detector assembly as well as the integration of the readout electronics on-site are reported. Finally, some operational characteristics are shown based on straightforward analysis of the first measurements performed during the last months with the fully working detector.

physics.ins-det↗

arXiv2005

Angra Neutrino Project: status and plans

We present the status and plans of the Angra Project, a new nuclear reactor neutrino oscillation experiment, proposed to be built in Brazil at the Angra dos Reis nuclear reactor complex. This experiment is aimed to measure theta_13, the last unknown of the three neutrino mixing angles. Combining a high luminosity design, very low background from cosmic rays and careful control of systematic errors at the 1% level, we propose a high sensitivity multi-detector experiment, able to reach a sensitivity to antineutrino disappearance down to sin^2(2*theta_13) = 0.006 in a three years running period, improving present limits constrained by the CHOOZ experiment by more than an order of magnitude.

hep-ex↗

arXiv2003

Asymmetries in the Production of Lambda0 in 250 GeV/c pi+-, K+- and p -- Nucleon Interactions

Using data from Fermilab fixed-target experiment E769, we have measured particle-antiparticle production asymmetries for Lambda0 hyperons in 250 GeV/c pi+-, K+- and p -- nucleon interactions. The asymmetries are measured as functions of Feynman-x (x_F) and p_t^2 over the ranges -0.12<=x_F<=0.12 and 0<=p_t^2<=3 (GeV/c)^2 (for positive beam) and -0.12<=x_F<=0.4 and 0<=p_t^2<=10 (GeV/c)^2 (for negative beam). We find substantial asymmetries, even at x_F around zero. We also observe leading-particle-type asymmetries. These latter effects are qualitatively as expected from valence-quark content of the target and variety of projectiles studied.

hep-ex↗

arXiv2001

On the intrinsic charm and the recombination mechanisms in charm hadron production

We study $Λ_c^\pm$ production in $pN$ and $π^-N$ interactions. Recent experimental data from the SELEX and E791 Collaborations at FNAL provide important information on the production mechanism of charm hadrons. In particular, the production of the $Λ_c$ baryon provides a good test of the intrinsic charm and the recombination mechanisms, which have been proposed to explain the so called leading particle effects.

hep-ph↗

arXiv2000

Recent results on Charm Physics from Fermilab

New high statistics, high resolution fixed target experiments producing $10^5$ - $10^6$ fully reconstructed charm particles are allowing a detailed study of the charm sector. Recent results on charm quark production from Fermilab fixed target experiments E791, SELEX and FOCUS are presented.

hep-ph↗

arXiv1998

Asymmetry studies in Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ production

We present a study on hyperon/anti-hyperon production asymmetries in the framework of the recombination model. The production asymmetries for Lambda 0/Lambda 0-bar, Xi-/Xi+ and Omega-/Omega+ are studied as a function of x_F. Predictions of the model are compared to preliminary data on hyperon/anti-hyperon production asymmetries in 500 GeV/c pi- p interactions from the Fermilab E791 experiment. The model predicts a growing asymmetry with the number of valence quarks shared by the target and the produced hyperons in the x_F < 0 region. In the positive x_F region, the model predicts constant asymmetries for Lambda 0/Lambda 0-bar and Omega-/Omega+ production and a growing asymmetry with x_F for Xi-/Xi+. We found a qualitatively good agreement between the model predictions and data, showing that recombination is a competitive mechanism in the hadronization process.

hep-ph↗

arXiv1997

Production and polarization of $Λ_c^+$ and the charm of the proton

We propose a two-component model involving the parton fusion mechanism and recombination of a $ud$ valence diquark with a sea $c$-quark of the incident proton to describe $Λ_c^+$ inclusive production in $pp$ collisions. We also study the polarization of the produced $Λ_c^+$ in the framework of the Thomas Precession Model for polarization. We show that a measurement of the $Λ_c$ polarization is a sensitive test of its production mechanism. In particular the intrinsic charm model predicts a positive polarization for the $Λ_c$ within the framework of the Thomas Precession Model, while according to the model presented here the $Λ_c$ polarization should be negative. The measurement of the $Λ_c$ polarization provides a close examination of intrinsic charm Fock states in the proton and give interesting information about the hadroproduction of charm.

hep-ph↗

arXiv1996

Asymmetries between the production of D+ and D- mesons from 500 GeV/c pi- nucleon interactions as a function of xF and pt**2

We present asymmetries between the production of D+ and D- mesons in Fermilab experiment E791 as a function of xF and pt**2. The data used here consist of 74,000 fully-reconstructed charmed mesons produced by a 500 GeV/c pi- beam on C and Pt foils. The measurements are compared to results of models which predict differences between the production of heavy-quark mesons that have a light quark in common with the beam (leading particles) and those that do not (non-leading particles). While the default models do not agree with our data, we can reach agreement with one of them, PYTHIA, by making a limited number of changes to parameters used.

hep-ex↗