Optimization of neutrino fluxes for future long baseline neutrino oscillation experiments

AbstractOne of the main goals of the Long Baseline Neutrino Oscillation experiment (LBNO) experiment is to study the L/E behaviour of the electron neutrino appearance probability in order to determine the unknown phase δCP. In the standard neutrino 3-flavour mixing paradigm, this parameter encapsulates a possibility of a CP violation in the lepton sector that in turn could help explain the matter-antimatter asymmetry in the universe. In LBNO, the measurement of δCP would rely on the observation of the electron appearance probability in a broad energy range covering the 1st and 2nd maxima of the oscillation probability. An optimization of the energy spectrum of the neutrino beam is necessary to find the best coverage of the neutrino energies of interest. This in general is a complex task that requires exploring a large parameter space describing hadron target and beamline focusing elements. In this paper we will present a numerical approach of finding a solution to this difficult optimization problem often encountered in design of modern neutrino beamlines and we will show the improved LBNO sensitivity to the presence of the leptonic CP violation attained after the neutrino beam optimization

Optimization of neutrino fluxes for future long baseline neutrino oscillation experiments

One of the main goals of the Long Baseline Neutrino Oscillation experiment (LBNO) experiment is to study the L/E behaviour of the electron neutrino appearance probability in order to determine the unknown phase $\delta_{CP}$. In the standard neutrino 3-flavour mixing paradigm, this parameter encapsulates a possibility of a CP violation in the lepton sector that in turn could help explain the matter-antimatter asymmetry in the universe. In LBNO, the measurement of $\delta_{CP}$ would rely on the observation of the electron appearance probability in a broad energy range covering the 1$^{st}$ and 2$^{nd}$ maxima of the oscillation probability. An optimization of the energy spectrum of the neutrino beam is necessary to find the best coverage of the neutrino energies of interest. This in general is a complex task that requires exploring a large parameter space describing hadron target and beamline focusing elements. In this paper we will present a numerical approach of finding a solution to this difficult optimization problem often encountered in design of modern neutrino beamlines and we will show the improved LBNO sensitivity to the presence of the leptonic CP violation attained after the neutrino beam optimization

Study of MDT calibration constants using H8 testbeam data of year 2004

In year 2004 Atlas performed a long campaign of test beam data taking at the H8 Cern beam. Two sectors of the barrel and endcap regions of the Muon Spectrometer were exposed to the beam and large amount of data were collected in well defined and controlled operating conditions. This allowed a careful study on MDT drift properties. A better understanding of the calibration constants, of their definition and determination and of the criteria for their acceptance has been obtained. Systematic effects and time stability of the constants have also been studied

ArDM: first results from underground commissioning

The Argon Dark Matter experiment is a ton-scale double phase argon Time Projection Chamber designed for direct Dark Matter searches. It combines the detection of scintillation light together with the ionisation charge in order to discriminate the background (electron recoils) from the WIMP signals (nuclear recoils). After a successful operation on surface at CERN, the detector was recently installed in the underground Laboratorio Subterr\'aneo de Canfranc, and the commissioning phase is ongoing. We describe the status of the installation and present first results from data collected underground with the detector filled with gas argon at room temperature.Comment: 6 pages, 3 figures, Light Detection In Noble Elements (LIDINE 2013

Neutron irradiation test on ATLAS MDT chambers

Abstract The Monitored Drift Tubes (MDT) chambers of the ATLAS muon spectrometer are crucial for the identification of high-momentum final-state muons, which represent very promising and robust signatures of physics at the LHC. They will operate in a high rate and high background environment and therefore their performances should not significantly degrade for the whole ATLAS data taking. The maximum expected total flux, mainly consisting of neutrons and photons in the MeV range, is of the order of 5 kHz/cm 2 for the barrel MDTs, while at SLHC, with machine working at higher luminosity, fluxes can be 10 times higher. To test detector robustness, a MDT test chamber was exposed to intensive neutron irradiation at the TAPIRO ENEA-Casaccia Research Center facility

The LBNO long-baseline oscillation sensitivities with two conventional neutrino beams at different baselines

The proposed Long Baseline Neutrino Observatory (LBNO) initially consists of $\sim 20$ kton liquid double phase TPC complemented by a magnetised iron calorimeter, to be installed at the Pyh\"asalmi mine, at a distance of 2300 km from CERN. The conventional neutrino beam is produced by 400 GeV protons accelerated at the SPS accelerator delivering 700 kW of power. The long baseline provides a unique opportunity to study neutrino flavour oscillations over their 1st and 2nd oscillation maxima exploring the $L/E$ behaviour, and distinguishing effects arising from $\delta_{CP}$ and matter. In this paper we show how this comprehensive physics case can be further enhanced and complemented if a neutrino beam produced at the Protvino IHEP accelerator complex, at a distance of 1160 km, and with modest power of 450 kW is aimed towards the same far detectors. We show that the coupling of two independent sub-MW conventional neutrino and antineutrino beams at different baselines from CERN and Protvino will allow to measure CP violation in the leptonic sector at a confidence level of at least $3\sigma$ for 50\% of the true values of $\delta_{CP}$ with a 20 kton detector. With a far detector of 70 kton, the combination allows a $3\sigma$ sensitivity for 75\% of the true values of $\delta_{CP}$ after 10 years of running. Running two independent neutrino beams, each at a power below 1 MW, is more within today's state of the art than the long-term operation of a new single high-energy multi-MW facility, which has several technical challenges and will likely require a learning curve.Comment: 21 pages, 12 figure