Accelerator Neutrinos

Abstract:

The decays D → K π π π and D → K π π are studied in a sample of quantum-correlated DD¯ pairs produced through the process e e → ψ(3770) → DD¯ , exploiting a data set collected by the BESIII experiment that corresponds to an integrated luminosity of 2.93 fb . Here D indicates a quantum superposition of a D and a D¯ meson. By reconstructing one neutral charm meson in a signal decay, and the other in the same or a different final state, observables are measured that contain information on the coherence factors and average strong-phase differences of each of the signal modes. These parameters are critical inputs in the measurement of the angle γ of the Unitarity Triangle in B → DK decays at the LHCb and Belle II experiments. The coherence factors are determined to be R = 0.52−0.10+0.12 and RKππ0 = 0.78 ± 0.04, with values for the average strong-phase differences that are δDK3π=(167−19+31)° and δDKππ0=(196−15+14)°, where the uncertainties include both statistical and systematic contributions. The analysis is re-performed in four bins of the phase-space of the D → K π π π to yield results that will allow for a more sensitive measurement of γ with this mode, to which the BESIII inputs will contribute an uncertainty of around 6°. [Figure not available: see fulltext.] − + + − − + 0 + − −1 0 − − − + + − K3π

Abstract:

We investigate the feasibility of using deep learning techniques, in the form of a one-dimensional convolutional neural network (1D-CNN), for the extraction of signals from the raw waveforms produced by the individual channels of liquid argon time projection chamber (LArTPC) detectors. A minimal generic LArTPC detector model is developed to generate realistic noise and signal waveforms used to train and test the 1D-CNN, and evaluate its performance on low-level signals. We demonstrate that our approach overcomes the inherent shortcomings of traditional cut-based methods by extending sensitivity to signals with ADC values below their imposed thresholds. This approach exhibits great promise in enhancing the capabilities of future generation neutrino experiments like DUNE to carry out their low-energy neutrino physics programs

Abstract:

Abstract A search for a heavy neutral Higgs boson, A , decaying into a Z boson and another heavy Higgs boson, H , is performed using a data sample corresponding to an integrated luminosity of 139 fb $$^{-1}$$ -1 from proton–proton collisions at $$\sqrt{s} = 13$$ s=13 $$\text {TeV}$$ TeV recorded by the ATLAS detector at the LHC. The search considers the Z boson decaying into electrons or muons and the H boson into a pair of b -quarks or W bosons. The mass range considered is 230–800 $$\text {GeV}$$ GeV for the A boson and 130–700 $$\text {GeV}$$ GeV for the H boson. The data are in good agreement with the background predicted by the Standard Model, and therefore 95% confidence-level upper limits for $$\sigma \times B(A\rightarrow ZH)\times B(H\rightarrow bb \; \text {or} \; H \rightarrow WW)$$ σ×B(A→ZH)×B(H→bborH→WW) are set. The upper limits are in the range 0.0062–0.380 pb for the $$H\rightarrow bb$$ H→bb channel and in the range 0.023–8.9 pb for the $$H\rightarrow WW$$ H→WW channel. An interpretation of the results in the context of two-Higgs-doublet models is also given.