IF - Instituto de Física

URI Permanente desta comunidade

http://200.137.215.59//handle/ri/841

O IF - Instituto de Física, da Universidade Federal de Goiás, oferece Graduação em: Bacharelado em Física; Licenciatura em Física; Física Médica; e, Engenharia Física.

Navegar

Agora exibindo 1 - 20 de 22

Adjusting neutrino interaction models and evaluating uncertainties using NOvA near detector data
(2020) Acero Ortega, Mario A.; Adamson, P.; Agam, G.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Asquith, Lily; Aurisano, Adam; Gomes, Ricardo Avelino
The two-detector design of the NOvA neutrino oscillation experiment, in which two functionally identical detectors are exposed to an intense neutrino beam, aids in canceling leading order effects of cross-section uncertain ties. However, limited knowledge of neutrino interaction cross sections still gives rise to some of the largest system atic uncertainties in current oscillation measurements. We show contemporary models of neutrino interactions to be discrepant with data from NOvA, consistent with discrep ancies seen in other experiments. Adjustments to neutrino interaction models in GENIE are presented, creating an effec tive model that improves agreement with our data. We also describe systematic uncertainties on these models, includ ing uncertainties on multi-nucleon interactions from a newly developed procedure using NOvA near detector data.
Design, construction and operation of the ProtoDUNE-SP Liquid Argon TPC
(2022) Abud, Adam Abed; Abi, Babaki; Acciarri, Roberto; Acero Ortega, Mario A.; Adames, Márcio Rostirolla; Adamov, George; Adams, David; Adinolfi, Marco; Gomes, Ricardo Avelino
The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber (LArTPC) that was constructed and operated in the CERN North Area at the end of the H4 beamline. This detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment (DUNE), which will be constructed at the Sandford Underground Research Facility (SURF) in Lead, South Dakota, U.S.A. The ProtoDUNE-SP detector incorporates full-size components as designed for DUNE and has an active volume of 7 × 6 × 7.2 m3 . The H4 beam delivers incident particles with well-measured momenta and high-purity particle identification. ProtoDUNE-SP’s successful operation between 2018 and 2020 demonstrates the effectiveness of the single-phase far detector design. This paper describes the design, construction, assembly and operation of the detector components.
Extended search for supernovalike neutrinos in NOvA coincident with LIGO/Virgo detections
(2021) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Asquith, Lily; Aurisano, Adam; Back, A.; Backhouse, C.; Gomes, Ricardo Avelino
A search is performed for supernovalike neutrino interactions coincident with 76 gravitational wave events detected by the LIGO/Virgo Collaboration. For 40 of these events, full readout of the time around the gravitational wave is available from the NOvA Far Detector. For these events, we set limits on the fluence of the sum of all neutrino flavors of F < 7ð4Þ × 1010 cm−2 at 90% C.L. assuming energy and time distributions corresponding to the Garching supernova models with masses 9.6ð27Þ M⊙. Under the hypothesis that any given gravitational wave event was caused by a supernova, this corresponds to a distance of r > 29ð50Þ kpc at 90% C.L. Weaker limits are set for other gravitational wave events with partial Far Detector data and/or Near Detector data.
First measurement of neutrino oscillation parameters using neutrinos and antineutrinos by NOvA
(2019) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Altakarli, Sef; Anfimov, Nikolay; Antoshkin, A.; Aurisano, Adam; Back, A.; Gomes, Ricardo Avelino
The NOvA experiment has seen a 4.4σ signal of ¯νe appearance in a 2 GeV ¯νμ beam at a distance of 810 km. Using 12.33 × 1020 protons on target delivered to the Fermilab NuMI neutrino beamline, the experiment recorded 27 ¯νμ → ¯νe candidates with a background of 10.3 and 102 ¯νμ → ¯νμ candidates. This new antineutrino data are combined with neutrino data to measure the parameters jΔm2 32j ¼ 2.48þ0.11 −0.06 × 10−3 eV2=c4 and sin2 θ23 in the ranges from (0.53–0.60) and (0.45–0.48) in the normal neutrino mass hierarchy. The data exclude most values near δCP ¼ π=2 for the inverted mass hierarchy by more than 3σ and favor the normal neutrino mass hierarchy by 1.9σ and θ23 values in the upper octant by 1.6σ.
First results on ProtoDUNE-SP liquid argon time projection chamber performance from a beam test at the CERN Neutrino Platform
(2020) Abi, Babak; Abu, Adam Abed; Acciarri, Roberto; Acero Ortega, Mario A.; Adamov, George; Adamowski, M.; Adams, David; Adrien, P.; Adinolfi , Marco; Ahmad‬, ‪Zulfequar; Gomes, Ricardo Avelino
The ProtoDUNE-SP detector is a single-phase liquid argon time projection chamber with an active volume of 7.2 × 6.1 × 7.0 m3 . It is installed at the CERN Neutrino Platform in a specially-constructed beam that delivers charged pions, kaons, protons, muons and electrons with momenta in the range 0.3 GeV/𝑐 to 7 GeV/𝑐. Beam line instrumentation provides accurate mo mentum measurements and particle identification. The ProtoDUNE-SP detector is a prototype for the first far detector module of the Deep Underground Neutrino Experiment, and it incorporates full-size components as designed for that module. This paper describes the beam line, the time projection chamber, the photon detectors, the cosmic-ray tagger, the signal processing and particle reconstruction. It presents the first results on ProtoDUNE-SP’s performance, including noise and gain measurements, 𝑑𝐸/𝑑𝑥 calibration for muons, protons, pions and electrons, drift electron life time measurements, and photon detector noise, signal sensitivity and time resolution measurements. The measured values meet or exceed the specifications for the DUNE far detector, in several cases by large margins. ProtoDUNE-SP’s successful operation starting in 2018 and its production of large samples of high-quality data demonstrate the effectiveness of the single-phase far detector design.
Improved measurement of neutrino oscillation parameters by the NOvA experiment
(2022) Acero Ortega, Mario A.; Soplin‬, ‪Leonidas Aliaga; Adamson, P.; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Asquith, Lily; Aurisano, Adam; Back, A.; Backhouse, C.; Gomes, Ricardo Avelino
We present new νμ → νe, νμ → νμ, ¯νμ → ¯νe, and ¯νμ → ¯νμ oscillation measurements by the NOvA experiment, with a 50% increase in neutrino-mode beam exposure over the previously reported results. The additional data, combined with previously published neutrino and antineutrino data, are all analyzed using improved techniques and simulations. A joint fit to the νe, νμ, ¯νe, and ¯νμ candidate samples within the 3-flavor neutrino oscillation framework continues to yield a best-fit point in the normal mass ordering and the upper octant of the θ23 mixing angle, with Δm2 32 ¼ ð2.41 0.07Þ × 10−3 eV2 and sin2 θ23 ¼ 0.57þ0.03 −0.04 . The data disfavor combinations of oscillation parameters that give rise to a large asymmetry in the rates of νe and ¯νe appearance. This includes values of the charge parity symmetry (CP) violating phase in the vicinity of δCP ¼ π=2 which are excluded by > 3σ for the inverted mass ordering, and values around δCP ¼ 3π=2 in the normal ordering which are disfavored at 2σ confidence.
Long-baseline neutrino oscillation physics potential of the DUNE experiment
(2020) Abi, Babak; Acciarri, Roberto; Acero Ortega, Mario A.; Adamov, George; Adams, David; Adinolfi, Marco; Ahmad‬, Zulfequar; Ahmed, J.; Alion, T.; Alonso Monsalve, Saúl; Gomes, Ricardo Avelino
The sensitivity of the Deep Underground Neu trino Experiment (DUNE) to neutrino oscillation is deter mined, based on a full simulation, reconstruction, and event selection of the far detector and a full simulation and param eterized analysis of the near detector. Detailed uncertain ties due to the flux prediction, neutrino interaction model, and detector effects are included. DUNE will resolve the neutrino mass ordering to a precision of 5σ, for all δCP values, after 2 years of running with the nominal detec tor design and beam configuration. It has the potential to observe charge-parity violation in the neutrino sector to a precision of 3σ (5σ) after an exposure of 5 (10) years, for 50% of all δCP values. It will also make precise mea surements of other parameters governing long-baseline neu trino oscillation, and after an exposure of 15 years will achieve a similar sensitivity to sin2 2θ13 to current reactor experiments.
Measurement of neutrino-induced neutral-current coherent π0 production in the NOvA near detector
(2020) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Diaz, Enrique Arrieta; Aurisano, Adam; Back, A.; Gomes, Ricardo Avelino
The cross section of neutrino-induced neutral-current coherent π0 production on a carbon-dominated target is measured in the NOvA near detector. This measurement uses a narrow-band neutrino beam with an average neutrino energy of 2.7 GeV, which is of interest to ongoing and future long-baseline neutrino oscillation experiments. The measured, flux-averaged cross section is σ ¼ 13.8 0.9ðstatÞ 2.3ðsystÞ × 10−40 cm2=nucleus, consistent with model prediction. This result is the most precise measure ment of neutral-current coherent π0 production in the few-GeV neutrino energy region.
Neutrino interaction classification with a convolutional neural network in the DUNE far detector
(2020) Abi, Babak; Acciarri, Roberto; Acero Ortega, Mario A.; Adamov, George; Adinolfi, Marco; Ahmad‬, ‪Zulfequar; Ahmad, Ali Junaid; Alion, T.; Alonso Monsalve, Saúl; Alt, C.; Gomes, Ricardo Avelino
The Deep Underground Neutrino Experiment is a next-generation neutrino oscillation experiment that aims to measure CP-violation in the neutrino sector as part of a wider physics program. A deep learning approach based on a convolutional neural network has been developed to provide highly efficient and pure selections of electron neutrino and muon neutrino charged-current interactions. The electron neutrino (antineutrino) selection efficiency peaks at 90% (94%) and exceeds 85% (90%) for reconstructed neutrino energies between 2–5 GeV. The muon neutrino (antineutrino) event selection is found to have a maximum efficiency of 96% (97%) and exceeds 90% (95%) efficiency for reconstructed neutrino energies above 2 GeV. When considering all electron neutrino and antineutrino interactions as signal, a selection purity of 90% is achieved. These event selections are critical to maximize the sensitivity of the experiment to CP-violating effects.
New constraints on oscillation parameters from νe appearance and νμ disappearance in the NOvA experiment
(2018) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Aurisano, Adam; Back, A.; Gomes, Ricardo Avelino
We present updated results from the NOvA experiment for νμ → νμ and νμ → νe oscillations from an exposure of 8.85 × 1020 protons on target, which represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for νμ disappearance and νe appearance gives the best-fit point as normal mass hierarchy, Δm2 32 ¼ 2.44 × 10−3 eV2=c4, sin2 θ23 ¼ 0.56, and δCP ¼ 1.21π. The 68.3% confidence intervals in the normal mass hierarchy are Δm2 32 ∈ ½2.37; 2.52 × 10−3 eV2=c4, sin2 θ23 ∈ ½0.43; 0.51 ∪ ½0.52; 0.60 , and δCP ∈ ½0; 0.12π ∪ ½0.91π; 2π . The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
New constraints on oscillation parameters from νe appearance and νμ disappearance in the NOvA experiment
(2018) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Aurisano, Adam; Back, A.; Gomes, Ricardo Avelino
We present updated results from the NOvA experiment for νμ → νμ and νμ → νe oscillations from an exposure of 8.85 × 1020 protons on target, which represents an increase of 46% compared to our previous publication. The results utilize significant improvements in both the simulations and analysis of the data. A joint fit to the data for νμ disappearance and νe appearance gives the best-fit point as normal mass hierarchy, Δm2 32 ¼ 2.44 × 10−3 eV2=c4, sin2 θ23 ¼ 0.56, and δCP ¼ 1.21π. The 68.3% confidence intervals in the normal mass hierarchy are Δm2 32 ∈ ½2.37; 2.52 × 10−3 eV2=c4, sin2 θ23 ∈ ½0.43; 0.51 ∪ ½0.52; 0.60 , and δCP ∈ ½0; 0.12π ∪ ½0.91π; 2π . The inverted mass hierarchy is disfavored at the 95% confidence level for all choices of the other oscillation parameters.
Observation of seasonal variation of atmospheric multiple-muon events in the NOvA Near Detector
(2019) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Altakarli, Sef; Anfimov, Nikolay; Antoshkin, A.; Aurisano, Adam; Back, A.; Gomes, Ricardo Avelino
Using two years of data from the NOvA Near Detector at Fermilab, we report a seasonal variation of cosmic ray induced multiple-muon (Nμ ≥ 2) event rates which has an opposite phase to the seasonal variation in the atmospheric temperature. The strength of the seasonal multiple-muon variation is shown to increase as a function of the muon multiplicity. However, no significant dependence of the strength of the seasonal variation of the multiple-muon variation is seen as a function of the muon zenith angle, or the spatial or angular separation between the correlated muons.
Prospects for beyond the Standard Model physics searches at the Deep Underground Neutrino Experiment
(2021) Abi, Babak; Acciarri, Roberto; Acero Ortega, Mario A.; Adamov, George; Adams, David; Adinolfi, Marco; Ahmad‬, Zulfequar; Ahmad, Ali Junaid; Alion, T.; Alonso Monsalve, Saúl; Gomes, Ricardo Avelino
The Deep Underground Neutrino Experiment (DUNE) will be a powerful tool for a variety of physics topics. The high-intensity proton beams provide a large neu trino flux, sampled by a near detector system consisting of a combination of capable precision detectors, and by the massive far detector system located deep underground. This configuration sets up DUNE as a machine for discovery, as it enables opportunities not only to perform precision neu trino measurements that may uncover deviations from the present three-flavor mixing paradigm, but also to discover new particles and unveil new interactions and symmetries beyond those predicted in the Standard Model (SM). Of the many potential beyond the Standard Model (BSM) topics DUNE will probe, this paper presents a selection of stud ies quantifying DUNE’s sensitivities to sterile neutrino mix ing, heavy neutral leptons, non-standard interactions, CPT symmetry violation, Lorentz invariance violation, neutrino trident production, dark matter from both beam induced and cosmogenic sources, baryon number violation, and other new physics topics that complement those at high-energy collid ers and significantly extend the present reach.
Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC
(2022) Abud, Adam Abed; Abi, Babak; Acciarri, Roberto; Acero Ortega, Mario A.; Adames, Márcio Rostirolla; Adamov, George; Adamowski, M.; Adams, David; Adinolfi, Marco; Aduszkiewicz, Antoni; Gomes, Ricardo Avelino
DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6×6×6 m3 liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019–2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7 m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.
Search for active-sterile antineutrino mixing using neutral-current interactions with the NOvA experiment
(2021) Acero Ortega, Mario A.; Adamson, P.; Asquith, L.; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Asquith, Lily; Aurisano, Adam; Back, A.; Backhouse, C.; Gomes, Ricardo Avelino
This Letter reports results from the first long-baseline search for sterile antineutrinos mixing in an accelerator-based antineutrino-dominated beam. The rate of neutral-current interactions in the two NOvA detectors, at distances of 1 and 810 km from the beam source, is analyzed using an exposure of 12.51 × 1020 protons-on-target from the NuMI beam at Fermilab running in antineutrino mode. A total of 121 of neutral-current candidates are observed at the far detector, compared to a prediction of 122 11ðstat:Þ 15ðsyst:Þ assuming mixing only between three active flavors. No evidence for ¯νμ → ¯νs oscillation is observed. Interpreting this result within a 3 þ 1 model, constraints are placed on the mixing angles θ24 < 25° and θ34 < 32° at the 90% C.L. for 0.05 eV2 ≤ Δm2 41 ≤ 0.5 eV2, the range of mass splittings that produces no significant oscillations at the near detector. These are the first 3 þ 1 confidence limits set using long-baseline accelerator antineutrinos.
Search for multimessenger signals in NOvA coincident with LIGO/Virgo detections
(2020) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Asquith, Lily; Aurisano, Adam; Avelino, Ricardo Gomes
Using the NOvA neutrino detectors, a broad search has been performed for any signal coincident with 28 gravitational wave events detected by the LIGO/Virgo Collaboration between September 2015 and July 2019. For all of these events, NOvA is sensitive to possible arrival of neutrinos and cosmic rays of GeV and higher energies. For five (seven) events in the NOvA Far (Near) Detector, timely public alerts from the LIGO/Virgo Collaboration allowed recording of MeV-scale events. No signal candidates were found.
Search for slow magnetic monopoles with the NOvA detector on the surface
(2021) Acero Ortega, Mario A.; Adamson, P.; Soplin, Leonidas Aliaga; Alion, T.; Allakhverdian, Vladimir; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Asquith, Lily; Aurisano, Adam; Gomes, Ricardo Avelino
We report a search for a magnetic monopole component of the cosmic-ray flux in a 95-day exposure of the NOvA experiment’s Far Detector, a 14 kt segmented liquid scintillator detector designed primarily to observe GeV-scale electron neutrinos. No events consistent with monopoles were observed, setting an upper limit on the flux of 2 × 10−14 cm−2 s−1 sr−1 at 90% C.L. for monopole speed 6 × 10−4 < β < 5 × 10−3 and mass greater than 5 × 108 GeV. Because of NOvA’s small overburden of 3 meters-water equivalent, this constraint covers a previously unexplored low-mass region.
Searching for solar KDAR with DUNE
(2021) Abud, Adam Abed; Abi, Babak; Acero Ortega, Mario A.; Adames, Márcio Rostirolla; Adamov, George; Adams, David; Adinolfi, Marco; Aduszkiewicz, Antoni; Gomes, Ricardo Avelino
The observation of 236 MeV muon neutrinos from kaon-decay-at-rest (KDAR) originating in the core of the Sun would provide a unique signature of dark matter annihila tion. Since excellent angle and energy reconstruction are necessary to detect this monoener getic, directional neutrino flux, DUNE with its vast volume and reconstruction capabilities, is a promising candidate for a KDAR neutrino search. In this work, we evaluate the proposed KDAR neutrino search strategies by realistically modeling both neutrino-nucleus interactions and the response of DUNE. We find that, although reconstruction of the neutrino energy and direction is difficult with current techniques in the relevant energy range, the superb energy resolution, angular resolution, and particle identification offered by DUNE can still permit great signal/background discrimination. Moreover, there are non-standard scenarios in which searches at DUNE for KDAR in the Sun can probe dark matter interactions.
Seasonal variation of multiple-muon cosmic ray air showers observed in the NOvA detector on the surface
(2021) Acero Ortega, Mario A.; Adamson, P.; Soplin, ‪Leonidas Aliaga; Anfimov, Nikolay; Antoshkin, A.; Arrieta Diaz, Enrique; Asquith, Lily; Aurisano, Adam; Back, A.; Backhouse, C.; Gomes, Ricardo Avelino
We report the rate of cosmic ray air showers with multiplicities exceeding 15 muon tracks recorded in the NOvA Far Detector between May 2016 and May 2018. The detector is located on the surface under an overburden of 3.6 meters water equivalent. We observe a seasonal dependence in the rate of multiple-muon showers, which varies in magnitude with multiplicity and zenith angle. During this period, the effective atmospheric temperature and surface pressure ranged between 210 K and 230 K and 940 mbar and 990 mbar, respectively; the shower rates are anticorrelated with the variation in the effective temperature. The variations are about 30% larger for the highest multiplicities than the lowest multiplicities and 20% larger for showers near the horizon than vertical showers.
Separation of track- and shower-like energy deposits in ProtoDUNE-SP using a convolutional neural network
(2022) Abud, Adam Abed; Abi, Babak; Acciarri, Roberto; Acero Ortega, Mario A.; Adames, Márcio Rostirolla; Adamov, George; Adamowski, M.; Adams, David; Adinolfi, Marco; Aduszkiewicz, Antoni; Gomes, Ricardo Avelino
Liquid argon time projection chamber detector technology provides high spatial and calorimetric resolutions on the charged particles traversing liquid argon. As a result, the technology has been used in a number of recent neu trino experiments, and is the technology of choice for the Deep Underground Neutrino Experiment (DUNE). In order to perform high precision measurements of neutrinos in the detector, final state particles need to be effectively identified, and their energy accurately reconstructed. This article pro poses an algorithm based on a convolutional neural network to perform the classification of energy deposits and recon structed particles as track-like or arising from electromagnetic cascades. Results from testing the algorithm on experi mental data from ProtoDUNE-SP, a prototype of the DUNE far detector, are presented. The network identifies track- and shower-like particles, as well as Michel electrons, with high efficiency. The performance of the algorithm is consistent between experimental data and simulation.

Navegar

Navegando IF - Instituto de Física por Autor "Acero Ortega, Mario A."

Resultados por página

Opções de Ordenação