Matter effects in neutrino visible decay at future long-baseline experiments

Neutrino visible decay in the presence of matter is re-evaluated. We study these effects in two future long-baseline experiments where matter effects are relevant: DUNE (1300 km) and a hypothetical beam aimed towards ANDES (7650 km). We find that matter effects are negligible for the visible component of neutrino decay at DUNE, being much more relevant at ANDES. We perform a detailed simulation of DUNE, considering $\nu_\mu$ disappearance and $\nu_e$ appearance channels, for both FHC and RHC modes. The sensitivity to the decay constant $\alpha_3$ can be as low as $2\times10^{-6}$ eV$^2$ at 90% C.L., depending on the neutrino masses and type of coupling. We also show the impact of neutrino decay in the determination of $\theta_{23}$ and $\delta_{\rm CP}$, and find that the best-fit value of $\theta_{23}$ can move from a true value at the lower octant towards the higher octant.Comment: 18 pages; v2: Minor changes, version accepted for publication in EPJ

Efecto del estadio de desarrollo de la onda folicular sobre la respuesta ovárica y tasa de recuperación y calidad de embriones en alpacas

The effect of the stage of development of the follicular wave (growth phase, static and regression of the dominant follicle) prior to the natural mounting on the ovulation rate, and the recovery rate and embryo quality in alpacas was evaluated. It was used 51 female alpacas with presence of dominant follicle greater than or equal to 7 mm, which were synchronized with a GnRH analogue. The groups were T1 (n=16): growth phase; T2 (n=19): Static phase and T3 (n=18): Regression phase. The day of the copula was considered as day 0. Ultrasonographic evaluations were conducted on day 2 (occurrence of ovulation) and on day 7 (to measure the size of the corpus luteum). The embryo recovering was done 7 days after the service. Two animals of T1 did not ovulate. There were no significant differences between groups by size of the dominant follicle at the time of service, ovulation rate or size of the corpus luteum on the day of embryo recover. In 52.9% (n=27) of the alpacas, 27 embryos were recovered without significant differences between treatments; however, the embryos of T1 and T2 were of better quality than those of T3 (p<0.05).Se evaluó el efecto del estadio de desarrollo de la onda folicular (fase de crecimiento, estático y regresión del folículo dominante) previo a la monta natural sobre la tasa de ovulación, y tasa de recuperación y calidad embrionaria en alpacas. Se trabajó con 51 alpacas hembra con presencia de folículo dominante mayor o igual a 7 mm, las que fueron sincronizadas con un análogo de GnRH. Los grupos fueron T1 (n=16): Fase crecimiento; T2 (n=19): Fase estática y T3 (n=18): Fase regresión. El día de la monta fue considerado como día 0. Se hicieron evaluaciones ecográficas en el día 2 (ocurrencia de la ovulación) y en el día 7 (para medir el tamaño del cuerpo lúteo). El lavado uterino se realizó a los 7 días del servicio. Dos animales de T1 no llegaron a ovular. No hubo diferencias significativas entre grupos por tamaño del folículo dominante en el momento del servicio, tasa de ovulación ni por tamaño del cuerpo lúteo en el día del lavado uterino. En el 52.9% (n=27) de las alpacas servidas se recuperaron 27 embriones sin diferencias significativas entre tratamientos; no obstante, los embriones de T1 y T2 fueron de mejor calidad que los de T3 (p<0.05)

Efecto de la inclusión de probiótico, prebiótico y simbiótico en la dieta sobre los parámetros productivos del cuy (Cavia porcellus)

The present study evaluated the effect of the inclusion of probiotic, prebiotic and the combination of both (symbiotic) in the diet on the productive parameters of guinea pigs (Cavia porcellus). Fifty 3-day-old male guinea pigs were selected from a Prolific-Dairy maternal line developed in the IVITA-El Mantaro Research Station (Peru) and randomly distributed in five treatments consisting of a basal diet of forages (rye-grass and red clover). supplemented with wheat bran (T5), plus probiotic (T1), prebiotic (T2), symbiotic (T3) and antibiotic growth-promoter (AGP) (T4). The probiotic was a mixture of six bacterial species isolated from the intestine and guinea pig faeces; the prebiotic was a commercial mannanoligosaccharide and the APC was Zn-bacitracin. The response to treatments was evaluated for 56 days in terms of body weight gain, feed intake and feed conversion ratio. No significant or consistent responses were observed as effect of the treatments. The lack of response to AGP and the good body weight gains obtained suggested that, under the conditions of the study, the intestinal microbial balance of the animals was appropriate.El presente estudio evaluó el efecto de la inclusión de probiótico, prebiótico y la combinación de ambos (simbiótico) en la dieta sobre los parámetros productivos del cuy (Cavia porcellus). Se seleccionaron 50 cuyes machos de 3 días de edad de una línea materna Prolífica-Lechera desarrollada en la Estación IVITA-El Mantaro (Perú) y fueron distribuidos aleatoriamente en cinco tratamientos consistentes en una dieta basal de forrajes (rye-grass y trébol rojo) complementada con afrechillo de trigo (T5), más probiótico (T1), prebiótico (T2), simbiótico (T3) y antibiótico promotor del crecimiento (APC) (T4). El probiótico fue un consorcio de seis especies bacterianas aisladas del intestino y heces de cuy; el prebiótico fue un mananoligosacárido comercial y el APC fue Zn-bacitracina. La respuesta a los tratamientos fue evaluada por 56 días en términos de ganancia de peso, consumo de alimento y conversión alimenticia. No se observaron respuestas significativas ni consistentes por efecto de los tratamientos. La falta de respuesta al APC y las buenas ganancias de peso obtenidas sugieren que, bajo las condiciones del estudio, el balance microbiano intestinal de los animales era apropiado

High Temperature Corrosion of Inconel 600 in NaCl-KCl Molten Salts

In this work the corrosion resistance of a high content nickel alloy, Inconel 600, was investigated in mixed NaCl-KCl salts at 700, 800, and 900°C for 100 hours in static air. Investigation was carried out using electrochemical techniques such as polarization curves, rest potential measurements, linear polarization resistance, and electrochemical impedance spectroscopy. Corroded specimens were analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Electrochemical measurements showed an increased degradation rate of Inconel 600 with increasing test temperature. SEM and EDS analysis show that the damage experienced by Inconel 600 is greater than that determined by electrochemical measurements. This damage was identified as internal corrosion due to the reaction of Cl2 with the alloying elements (Cr and Fe); however, at 900°C the internal damage was minor and it was associated with the nickel content in the alloy

Biological Synthesis of Size-Controlled Cadmium Sulfide Nanoparticles Using ImmobilizedRhodobacter sphaeroides

Size-controlled cadmium sulfide nanoparticles were successfully synthesized by immobilizedRhodobacter sphaeroidesin the study. The dynamic process that Cd2+was transported from solution into cell by livingR. sphaeroideswas characterized by transmission electron microscopy (TEM). Culture time, as an important physiological parameter forR. sphaeroidesgrowth, could significantly control the size of cadmium sulfide nanoparticles. TEM demonstrated that the average sizes of spherical cadmium sulfide nanoparticles were 2.3 ± 0.15, 6.8 ± 0.22, and 36.8 ± 0.25 nm at culture times of 36, 42, and 48 h, respectively. Also, the UV–vis and photoluminescence spectral analysis of cadmium sulfide nanoparticles were performed

Measurement of the Multi-Neutron νˉμ\bar{\nu}_{\mu} Charged Current Differential Cross Section at Low Available Energy on Hydrocarbon

Neutron production in antineutrino interactions can lead to bias in energy reconstruction in neutrino oscillation experiments, but these interactions have rarely been studied. MINERvA previously studied neutron production at an average antineutrino energy of ~3 GeV in 2016 and found deficiencies in leading models. In this paper, the MINERvA 6 GeV average antineutrino energy data set is shown to have similar disagreements. A measurement of the cross section for an antineutrino to produce two or more neutrons and have low visible energy is presented as an experiment-independent way to explore neutron production modeling. This cross section disagrees with several leading models' predictions. Neutron modeling techniques from nuclear physics are used to quantify neutron detection uncertainties on this result.Comment: 25 pages, 11 figures; Added ancillary files with cross section values as .csv Matches preprint accepted by publishe

Simultaneous measurement of muon neutrino quasielastic-like cross sections on CH, C, water, Fe, and Pb as a function of muon kinematics at MINERvA

This paper presents the first simultaneous measurement of the quasielastic-like neutrino-nucleus cross sections on C, water, Fe, Pb and scintillator (hydrocarbon or CH) as a function of longitudinal and transverse muon momentum. The ratio of cross sections per nucleon between Pb and CH is always above unity and has a characteristic shape as a function of transverse muon momentum that evolves slowly as a function of longitudinal muon momentum. The ratio is constant versus longitudinal momentum within uncertainties above a longitudinal momentum of 4.5GeV/c. The cross section ratios to CH for C, water, and Fe remain roughly constant with increasing longitudinal momentum, and the ratios between water or C to CH do not have any significant deviation from unity. Both the overall cross section level and the shape for Pb and Fe as a function of transverse muon momentum are not reproduced by current neutrino event generators. These measurements provide a direct test of nuclear effects in quasielastic-like interactions, which are major contributors to long-baseline neutrino oscillation data samples.Comment: 9 pages, 8 flgures, including supplemental materia

Neutrino-induced coherent π+\pi^{+} production in C, CH, Fe and Pb at ⟨Eν⟩∼6\langle E_{\nu}\rangle \sim 6 GeV

MINERvA has measured the $\nu_{\mu}$-induced coherent $\pi^{+}$ cross section simultaneously in hydrocarbon (CH), graphite (C), iron (Fe) and lead (Pb) targets using neutrinos from 2 to 20 GeV. The measurements exceed the predictions of the Rein-Sehgal and Berger-Sehgal PCAC based models at multi-GeV $\nu_{\mu}$ energies and at produced $\pi^{+}$ energies and angles, $E_{\pi}>1$ GeV and $\theta_{\pi}<10^{\circ}$. Measurements of the cross-section ratios of Fe and Pb relative to CH reveal the effective $A$-scaling to increase from an approximate $A^{1/3}$ scaling at few GeV to an $A^{2/3}$ scaling for $E_{\nu}>10$ GeV

Simultaneous measurement of muon neutrino νμ\nu_\mu charged-current single π+\pi^+ production in CH, C, H2_2O, Fe, and Pb targets in MINERvA

Neutrino-induced charged-current single $\pi^+$ production in the $\Delta(1232)$ resonance region is of considerable interest to accelerator-based neutrino oscillation experiments. In this work, high statistics differential cross sections are reported for the semi-exclusive reaction $\nu_\mu A \to \mu^- \pi^+ +$ nucleon(s) on scintillator, carbon, water, iron, and lead targets recorded by MINERvA using a wide-band $\nu_\mu$ beam with \left \approx 6~GeV. Suppression of the cross section at low $Q^2$ and enhancement of low $T_\pi$ are observed in both light and heavy nuclear targets compared to phenomenological models used in current neutrino interaction generators. The cross-section ratios for iron and lead compared to CH across the kinematic variables probed are 0.8 and 0.5 respectively, a scaling which is also not predicted by current generators.Comment: 6 pages, 6 figures, 117 pages of supplementary material; submitted to Physical Review Letter