The OPERA experiment has conclusively observed the appearance of tau neutrinos in the muon neutrino CNGS beam. Exploiting the OPERA detector capabilities, it was possible to isolate high purity ...samples of νe, νμ and ντ charged current weak neutrino interactions, as well as neutral current weak interactions. In this paper, the full dataset is used for the first time to test the three-flavor neutrino oscillation model and to derive constraints on the existence of a light sterile neutrino within the framework of the 3+1 neutrino model. For the first time, tau and electron neutrino appearance channels are jointly used to test the sterile neutrino hypothesis. A significant fraction of the sterile neutrino parameter space allowed by LSND and MiniBooNE experiments is excluded at 90% C.L. In particular, the best-fit values obtained by MiniBooNE combining neutrino and antineutrino data are excluded at 3.3σ significance.
The PEANUT experiment was designed to study the NuMi neutrino beam at Fermilab. The detector uses a hybrid technique, being made of nuclear emulsions and scintillator trackers. Emulsion films act as ...a micrometric tracking device and are interleaved with lead plates used as passive material. The detector is designed to precisely reconstruct the topology of neutrino interactions and hence to measure the different contributions to the cross section. We present here the full reconstruction and analysis of 147 neutrino interactions and the measurement of the quasi-elastic, resonance and deep-inelastic contributions to the total charged current cross section at the energies of the NuMi neutrino beam. This technique could be applied for beam monitoring in future neutrino facilities, and this paper shows its proof-of-principle.
The OPERA experiment was designed to search for ν_{μ}→ν_{τ} oscillations in appearance mode, i.e., by detecting the τ leptons produced in charged current ν_{τ} interactions. The experiment took data ...from 2008 to 2012 in the CERN Neutrinos to Gran Sasso beam. The observation of the ν_{μ}→ν_{τ} appearance, achieved with four candidate events in a subsample of the data, was previously reported. In this Letter, a fifth ν_{τ} candidate event, found in an enlarged data sample, is described. Together with a further reduction of the expected background, the candidate events detected so far allow us to assess the discovery of ν_{μ}→ν_{τ} oscillations in appearance mode with a significance larger than 5σ.
Recently, the Vernier effect has been proved to be very efficient for significantly improving the sensitivity and the limit of detection (LOD) of chemical, biochemical and gas photonic sensors. In ...this paper a review of compact and efficient photonic sensors based on the Vernier effect is presented. The most relevant results of several theoretical and experimental works are reported, and the theoretical model of the typical Vernier effect-based sensor is discussed as well. In particular, sensitivity up to 460 μm/RIU has been experimentally reported, while ultra-high sensitivity of 2,500 μm/RIU and ultra-low LOD of 8.79 × 10(-8) RIU have been theoretically demonstrated, employing a Mach-Zehnder Interferometer (MZI) as sensing device instead of an add drop ring resonator.
The OPERA experiment has conclusively observed the appearance of tau neutrinos in the muon neutrino CNGS beam. Exploiting the OPERA detector capabilities, it was possible to isolate high purity ...samples of \(\nu_{e}\), \(\nu_{\mu}\) and \(\nu_{\tau}\) charged current weak neutrino interactions, as well as neutral current weak interactions. In this Letter, the full dataset is used for the first time to test the three-flavor neutrino oscillation model and to derive constraints on the existence of a light sterile neutrino within the framework of the \(3+1\) neutrino model. For the first time, tau and electron neutrino appearance channels are jointly used to test the sterile neutrino hypothesis. A significant fraction of the sterile neutrino parameter space allowed by LSND and MiniBooNE experiments is excluded at 90% C.L. In particular, the best-fit values obtained by MiniBooNE combining neutrino and antineutrino data are excluded at 3.3 \(\sigma\) significance.
A measurement of Λc+ production in neutrino nucleon charged-current interactions is presented. In a subsample of about 50000 interactions located in the emulsion target of the CHORUS detector, ...exposed to the wide band neutrino beam of the CERN SPS, candidates for decays of short-lived particles were identified using new automatic scanning systems and later confirmed through visual inspection. Criteria based on the flight length allowed a statistical separation among the different charm species thus enabling a sample particularly rich in Λc+ to be defined. At an average neutrino energy of 27 GeV, the product σ(Λc+)/σ(CC)×BR(Λc+→3p) was measured to be (0.37±0.10(stat)±0.02(syst))×10−2, while the values of (1.54±0.35(stat)±0.18(syst))×10−2 and of 0.24±0.07(stat)±0.04(syst) were obtained for σ(Λc+)/σ(CC) and BR(Λc+→3p), respectively.
During the years 1994–1997, the emulsion target of the CHORUS detector was exposed to the wide-band neutrino beam of the CERN SPS of 27 GeV average neutrino energy. In total about 100 000 ...charged-current neutrino interactions were located in the nuclear emulsion target and fully reconstructed. A high-statistics sample of neutrino interactions with a D0 in the final state was collected. Using the decay mode D*+→D0π+ a production cross-section measurement of the D*+ in neutrino–nucleon charged-current interactions was performed. The low Q-value of the decay was used to isolate a sample of candidate events containing a positive hadron with a small pT with respect to the D0 direction. A signal of 22.1±5.5D*+ events was obtained. The D*+ production cross-section relative to the D0 production cross-section, σ(D*+)/σ(D0), was estimated to be 0.38±0.09(stat)±0.05(syst). From this result, the fraction of D0's produced via the decay of a D* was deduced to be 0.63±0.17. The D*+ production cross-section relative to the νμ charged-current interaction, σ(D*+)/σ(CC), was estimated to be 1.02±0.25(stat)±0.15(syst)%.
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