Measurement of double-differential muon neutrino charged-current interactions on C$_8$H$_8$ without pions in the final state using the T2K off-axis beam

The T2K collaboration Abe, Ko ; Andreopoulos, Costas ; Antonova, Maria ; et al.
Phys.Rev.D 93 (2016) 112012, 2016.
Inspire Record 1421157 DOI 10.17182/hepdata.77052

We report the measurement of muon neutrino charged-current interactions on carbon without pions in the final state at the T2K beam energy using 5.734$\times10^{20}$ protons on target. For the first time the measurement is reported as a flux-integrated, double-differential cross-section in muon kinematic variables ($\cos\theta_\mu$, $p_\mu$), without correcting for events where a pion is produced and then absorbed by final state interactions. Two analyses are performed with different selections, background evaluations and cross-section extraction methods to demonstrate the robustness of the results against biases due to model-dependent assumptions. The measurements compare favorably with recent models which include nucleon-nucleon correlations but, given the present precision, the measurement does not solve the degeneracy between different models. The data also agree with Monte Carlo simulations which use effective parameters that are tuned to external data to describe the nuclear effects. The total cross-section in the full phase space is $\sigma = (0.417 \pm 0.047 \text{(syst)} \pm 0.005 \text{(stat)})\times 10^{-38} \text{cm}^2$ $\text{nucleon}^{-1}$ and the cross-section integrated in the region of phase space with largest efficiency and best signal-over-background ratio ($\cos\theta_\mu>0.6$ and $p_\mu > 200$ MeV) is $\sigma = (0.202 \pm 0.0359 \text{(syst)} \pm 0.0026 \text{(stat)}) \times 10^{-38} \text{cm}^2$ $\text{nucleon}^{-1}$.

10 data tables

Total signal cross-section per nucleon integrated over all the muon kinematics phase space in Analysis I.

Results of the double differential cross-section measurement bin-by-bin in Analysis I.

Covariance matrix for shape systematics error in Analysis I.

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Measurement of Muon Antineutrino Oscillations with an Accelerator-Produced Off-Axis Beam

The T2K collaboration Abe, Ko ; Andreopoulos, Costas ; Antonova, Maria ; et al.
Phys.Rev.Lett. 116 (2016) 181801, 2016.
Inspire Record 1408741 DOI 10.17182/hepdata.73984

T2K reports its first measurements of the parameters governing the disappearance of $\bar{\nu}_\mu$ in an off-axis beam due to flavor change induced by neutrino oscillations. The quasimonochromatic $\bar{\nu}_\mu$ beam, produced with a peak energy of 0.6 GeV at J-PARC, is observed at the far detector Super-Kamiokande, 295 km away, where the $\bar{\nu}_\mu$ survival probability is expected to be minimal. Using a dataset corresponding to $4.01 \times 10^{20}$ protons on target, $34$ fully contained $\mu$-like events were observed. The best-fit oscillation parameters are $\sin^2 (\bar{\theta}_{23}) = 0.45$ and $|\Delta\bar{m}^2_{32}| = 2.51 \times 10^{-3}$ eV$^2$ with 68% confidence intervals of 0.38 - 0.64 and 2.26 - 2.80 $\times 10^{-3}$ eV$^2$ respectively. These results are in agreement with existing antineutrino parameter measurements and also with the $\nu_\mu$ disappearance parameters measured by T2K.

6 data tables

1$\sigma$ C.L. contour in $\sin^{2}\bar{\theta}_{23}$-$\Delta\bar{m}^{2}_{32}$ plane (normal hierarchy).

90% C.L. contour in $\sin^{2}\bar{\theta}_{23}$-$\Delta\bar{m}^{2}_{32}$ plane (normal hierarchy).

Best-fit point in $\sin^{2}\bar{\theta}_{23}$-$\Delta\bar{m}^{2}_{32}$ plane (normal hierarchy).

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