1
artículo
Publicado 2014
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El presente trabajo de investigación es una contribución al aprovechamiento industrial de las algas cianofitas del género Nostoc como aditivo viscosante para la elaboración de productos alimenticios. En el estudiose realizó la recolección, estabilización y extracción de polisacáridos de muestras de Junín, Ancash, Cajamarca y Pachacamac (Lima). Así mismo se realizó el análisis fisicoquímico, microbiológico y toxicológico, con la finalidad de garantizar su inocuidad y seguridad para el consumo humano.Los resultados son: pH neutro: 7.115 (N. sphaericum) y 7.679 (N. commune).El análisis de la viscosidad de N. sphaericumdio un mayor valor de38.3 cps, mientras que en N. communese obtuvo 4.5 cps. El punto de gelificación dio un mayor valor para N. sphaericum comparado con N. commune. En el análisis microbiológico se encontró ausencia de microorganismos patógenos. La dosi...
2
artículo
Publicado 2014
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El presente trabajo de investigación es una contribución al aprovechamiento industrial de las algas cianofitas del género Nostoc como aditivo viscosante para la elaboración de productos alimenticios. En el estudiose realizó la recolección, estabilización y extracción de polisacáridos de muestras de Junín, Ancash, Cajamarca y Pachacamac (Lima). Así mismo se realizó el análisis fisicoquímico, microbiológico y toxicológico, con la finalidad de garantizar su inocuidad y seguridad para el consumo humano.Los resultados son: pH neutro: 7.115 (N. sphaericum) y 7.679 (N. commune).El análisis de la viscosidad de N. sphaericumdio un mayor valor de38.3 cps, mientras que en N. communese obtuvo 4.5 cps. El punto de gelificación dio un mayor valor para N. sphaericum comparado con N. commune. En el análisis microbiológico se encontró ausencia de microorganismos patógenos. La dosi...
3
artículo
Publicado 2017
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Charged-current νμ interactions on carbon, iron, and lead with a final state hadronic system of one or more protons with zero mesons are used to investigate the influence of the nuclear environment on quasielasticlike interactions. The transferred four-momentum squared to the target nucleus, Q2, is reconstructed based on the kinematics of the leading proton, and differential cross sections versus Q2 and the cross-section ratios of iron, lead, and carbon to scintillator are measured for the first time in a single experiment. The measurements show a dependence on the atomic number. While the quasielasticlike scattering on carbon is compatible with predictions, the trends exhibited by scattering on iron and lead favor a prediction with intranuclear rescattering of hadrons accounted for by a conventional particle cascade treatment. These measurements help discriminate between different mod...
4
artículo
Publicado 2018
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Construction support also was granted by the United States National Science Foundation under Award PHY-0619727 and by the University of Rochester. Additional support for participating scientists was provided by NSF and DOE (U.S.A.) by CAPES and CNPq (Brazil), by CoNaCyT (Mexico), by Proyecto Basal FB 0821, CONICYT PIA ACT1413, Fondecyt 3170845 and 11130133 (Chile), by PIIC (DGIP-UTFSM), by CONCYTEC, DGI-PUCP and IDI/IGI-UNI (Peru)
5
artículo
Publicado 2017
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The semiexclusive channel νμ þ CH → μ−π0 þ nucleonðsÞ is analyzed using MINERvA exposed to the low-energy NuMI νμ beam with spectral peak at Eν ≃ 3 GeV. Differential cross sections for muon momentum and production angle, π0 kinetic energy and production angle, and for squared four-momentum transfer are reported, and the cross section σðEνÞ is obtained over the range 1.5 GeV ≤ Eν < 20 GeV. Results are compared to GENIE and NuWro predictions and to published MINERvA cross sections for charged-current πþðπ0Þ production by νμðν¯μÞ neutrinos. Disagreements between data and simulation are observed at very low and relatively high values for muon angle and for Q2 that may reflect shortfalls in modeling of interactions on carbon. For π0 kinematic distributions, however, the data are consistent with the simulation and provide support for generator treatments o...
6
artículo
Publicado 2016
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The total cross sections are important ingredients for the current and future neutrino oscillation experiments. We present measurements of the total charged-current neutrino and antineutrino cross sections on scintillator (CH) in the NuMI low-energy beamline using an in situ prediction of the shape of the flux as a function of neutrino energy from 2–50 GeV. This flux prediction takes advantage of the fact that neutrino and antineutrino interactions with low nuclear recoil energy (ν) have a nearly constant cross section as a function of incident neutrino energy. This measurement is the lowest energy application of the low-ν flux technique, the first time it has been used in the NuMI antineutrino beam configuration, and demonstrates that the technique is applicable to future neutrino beams operating at multi-GeVenergies. The cross section measurements presented are the most precise mea...
7
artículo
Publicado 2018
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Neutrino induced coherent charged pion production on nuclei, ν¯μA → μ π∓A, is a rare inelastic interaction in which the four-momentum squared transferred to the nucleus is nearly zero, leaving it intact. We identify such events in the scintillator of MINERvA by reconstructing jtj from the final state pion and muon momenta and by removing events with evidence of energetic nuclear recoil or production of other final state particles. We measure the total neutrino and antineutrino cross sections as a function of neutrino energy between 2 and 20 GeV and measure flux integrated differential cross sections as a function of Q2, Eπ, and θπ. The Q2 dependence and equality of the neutrino and antineutrino cross sections at finite Q2 provide a confirmation of Adler’s partial conservation of axial current hypothesis.
8
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Muon-neutrino elastic scattering on electrons is an observable neutrino process whose cross section is precisely known. Consequently a measurement of this process in an accelerator-based νμ beam can improve the knowledge of the absolute neutrino flux impinging upon the detector; typically this knowledge is limited to ∼10% due to uncertainties in hadron production and focusing. We have isolated a sample of 135±17 neutrino-electron elastic scattering candidates in the segmented scintillator detector of MINERvA, after subtracting backgrounds and correcting for efficiency. We show how this sample can be used to reduce the total uncertainty on the NuMI νμ flux from 9% to 6%. Our measurement provides a flux constraint that is useful to other experiments using the NuMI beam, and this technique is applicable to future neutrino beams operating at multi-GeV energies. © 2016 American Physic...
9
artículo
Publicado 2018
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Final-state kinematic imbalances are measured in mesonless production of νμ þ A → μ− þ p þ X in the MINERvA tracker. Initial- and final-state nuclear effects are probed using the direction of the μ−-p transverse momentum imbalance and the initial-state momentum of the struck neutron. Differential cross sections are compared to predictions based on current approaches to medium modeling. These models underpredict the cross section at intermediate intranuclear momentum transfers that generally exceed the Fermi momenta. As neutrino interaction models need to correctly incorporate the effect of the nucleus in order to predict neutrino energy resolution in oscillation experiments, this result points to a region of phase space where additional cross section strength is needed in current models, and demonstrates a new technique that would be suitable for use in fine-grained liquid a...
10
artículo
Publicado 2018
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We report on multinucleon effects in low momentum transfer (< 0.8 GeV=c) antineutrino interactions on plastic (CH) scintillator. These data are from the 2010–2011 antineutrino phase of the MINERvA experiment at Fermilab. The hadronic energy spectrum of this inclusive sample is well described when a screening effect at a low energy transfer and a two-nucleon knockout process are added to a relativistic Fermi gas model of quasielastic, Δ resonance, and higher resonance processes. In this analysis, model elements introduced to describe previously published neutrino results have quantitatively similar benefits for this antineutrino sample. We present the results as a double-differential cross section to accelerate the investigation of alternate models for antineutrino scattering off nuclei.
11
artículo
Publicado 2019
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MINERvA presents a new analysis of neutrino induced quasielastic-like interactions in a hydrocarbon tracking target. We report a double-differential cross section using the muon transverse and longitudinal momentum. In addition, differential cross sections as a function of the square of the four-momentum transferred and the neutrino energy are calculated using a quasielastic hypothesis. Finally, an analysis of energy deposited near the interaction vertex is presented. These results are compared to modified genie predictions as well as a NuWro prediction. All results use a data set produced by 3.34×1020 protons on target creating a neutrino beam with a peak energy of approximately 3.5 GeV. .
12
artículo
Publicado 2017
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We present measurements of the neutrino and antineutrino total charged-current cross sections on carbon and their ratio using the MINERvA scintillator-tracker. The measurements span the energy range 2–22 GeV and were performed using forward and reversed horn focusing modes of the Fermilab low-energy NuMI beam to obtain large neutrino and antineutrino samples. The flux is obtained using a subsample of charged-current events at low hadronic energy transfer along with precise higher energy external neutrino cross section data overlapping with our energy range between 12–22 GeV.We also report onthe antineutrino-neutrino cross section ratio, RCC, which does not rely on external normalization information. Our ratio measurement, obtained within the same experiment using the same technique, benefits from the cancellation of common sample systematic uncertainties and reaches a precision of ...
13
artículo
Publicado 2016
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The MINERvA experiment observes an excess of events containing electromagnetic showers relative to the expectation from Monte Carlo simulations in neutral-current neutrino interactions with mean beam energy of 4.5 GeV on a hydrocarbon target. The excess is characterized and found to be consistent with neutral-current π0 production with a broad energy distribution peaking at 7 GeV and a total cross section of 0.26 0.02ðstat.Þ 0.08ðsys:Þ × 10−39 cm2. The angular distribution, electromagnetic shower energy, and spatial distribution of the energy depositions of the excess are consistent with expectations from neutrino neutral-current diffractive π0 production from hydrogen in the hydrocarbon target. These data comprise the first direct experimental observation and constraint for a reaction that poses an important background process in neutrino-oscillation experiments searching for ...