This paper reports the first simultaneous measurement of the double differential muon neutrino charged-current cross section on oxygen and carbon without pions in the final state as a function of the ...outgoing muon kinematics, made at the ND280 off-axis near detector of the T2K experiment. The ratio of the oxygen and carbon cross sections is also provided to help validate various models' ability to extrapolate between carbon and oxygen nuclear targets, as is required in T2K oscillation analyses. The data are taken using a neutrino beam with an energy spectrum peaked at 0.6 GeV. The extracted measurement is compared with the prediction from different Monte Carlo neutrino-nucleus interaction event generators, showing particular model separation for very forward-going muons. Overall, of the models tested, the result is best described using local Fermi gas descriptions of the nuclear ground state with RPA suppression.
This paper presents the first combined measurement of the double-differential muon neutrino and antineutrino charged-current cross sections with no pions in the final state on hydrocarbon at the ...off-axis near detector of the T2K experiment. The data analyzed in this work comprise 5.8 × 10 20 and 6.3 × 10 20 protons on target in neutrino and antineutrino mode respectively, at a beam energy peak of 0.6 GeV. Using the two measured cross sections, the sum, difference, and asymmetry were calculated with the aim of better understanding the nuclear effects involved in such interactions. The extracted measurements have been compared with the prediction from different Monte Carlo generators and theoretical models showing that the difference between the two cross sections have interesting sensitivity to nuclear effects.
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 uncertainties. However, limited knowledge of neutrino interaction cross sections still gives rise to some of the largest systematic uncertainties in current oscillation measurements. We show contemporary models of neutrino interactions to be discrepant with data from NOvA, consistent with discrepancies seen in other experiments. Adjustments to neutrino interaction models in GENIE are presented, creating an effective model that improves agreement with our data. We also describe systematic uncertainties on these models, including uncertainties on multi-nucleon interactions from a newly developed procedure using NOvA near detector data.
A
bstract
The electron (anti-)neutrino component of the T2K neutrino beam constitutes the largest background in the measurement of electron (anti-)neutrino appearance at the far detector. The ...electron neutrino scattering is measured directly with the T2K off-axis near detector, ND280. The selection of the electron (anti-)neutrino events in the plastic scintillator target from both neutrino and anti-neutrino mode beams is discussed in this paper. The flux integrated single differential charged-current inclusive electron (anti-)neutrino cross-sections,
dσ/dp
and
dσ/d
cos(
θ
), and the total cross-sections in a limited phase-space in momentum and scattering angle (
p >
300 MeV/c and
θ ≤
45°) are measured using a binned maximum likelihood fit and compared to the neutrino Monte Carlo generator predictions, resulting in good agreement.
Electron antineutrino appearance is measured by the T2K experiment in an accelerator-produced antineutrino beam, using additional neutrino beam operation to constrain parameters of the ...Pontecorvo-Maki-Nakagawa-Sakata (PMNS) mixing matrix. T2K observes 15 candidate electron antineutrino events with a background expectation of 9.3 events. Including information from the kinematic distribution of observed events, the hypothesis of no electron antineutrino appearance is disfavored with a significance of 2.40σ and no discrepancy between data and PMNS predictions is found. A complementary analysis that introduces an additional free parameter which allows non-PMNS values of electron neutrino and antineutrino appearance also finds no discrepancy between data and PMNS predictions.
1-0-Alkyl-2-0-methyl-sn-glycero-3-phosphocholine (alkylmethoxy-GPC) exerts a highly selective cytotoxic activity towards a variety of tumor cells that is not seen in normal cells. Human promyelocytic ...leukemia (HL-60) cells are particularly sensitive to this cytotoxic action. In this report we show that when HL-60 cells are differentiated into a granulocytic form by dimethylsulfoxide (Me2SO)they become resistant toward the cytotoxic effects of alkylmethoxy-GPC. Also, after short-term exposures of the HL-60 cells to alkylmethoxy-GPC, the uptake of methyl-3Hcholine is inhibited in the undifferentiated cells, but not in those differentiated with Me2SO. Thus, cellular choline uptake appears to be a useful index for assessing the susceptibility of cells to the cytotoxic effects of antitumor phospholipids. 3HAlkylmethoxy-GPC is poorly metabolized by both cell populations as is evident by the trace quantities of labeled metabolites formed; also, alkylmethoxyglycerols do not exert any cytotoxic activity toward undifferentiated cells. These results demonstrate that differences in the cytotoxic response of sensitive (undifferentiated) and resistant (differentiated) cells to alkylmethoxy-GPC are not due to differences in their ability to metabolize alkylmethoxy-GPC or to a phospholipase C-generated toxic metabolite. Instead the data support our earlier hypothesis that the antitumor action of alkylmethoxy-GPC is, at least in part, caused by an impaired transport of small molecules across the membrane of sensitive cells.
Cytotoxic actions of the unnatural phospholipid 1-O-alkyl-2-O-methyl-sn-glycero-3-phosphocholine (alkylmethyl-GPC) appear to be targeted to the plasma membrane of sensitive cells. We analyzed the ...distribution of 3Halkylmethoxy-GPC in subcellular membranes isolated from human promyelocytic leukemia (HL-60) cells. 3HAlkylmethyl-GPC added to intact cells selectively labels plasma membrane-enriched fractions of the postnuclear supernatant, but the labeling profile is independent of the temperature and duration of the incubation, and concentration of the molecule. Also, an identical distribution pattern is obtained when 3Halkylmethyl-GPC is directly added to postnuclear supernatants. Moreover, 3Halkylmethyl-GPC translocates between subcellular membranes in a manner that does not depend on membrane-adsorbed or cytosolic transfer proteins. These results indicate that the subcellular localization studies reported for alkylmethyl-GPC and structurally-related molecules must be interpreted with caution.
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