Isotope identification is a recurrent problem in $\gamma $ spectroscopy with high-purity germanium detectors. In this work, new strategies are introduced to facilitate this type of analysis. Five criteria are used to identify the parent isotopes making a query on a large database of $\gamma $ lines from a multitude of isotopes producing an output list whose entries are sorted so that the $\gamma $ lines with the highest chance of being present in a sample are placed at the top. A metric to evaluate the performance of the different criteria is introduced and used to compare them. Two of the criteria are found to be superior than the others: one based on fuzzy logic and another that makes use of the $\gamma $ relative emission probabilities. A program called histoGe implements these criteria using an SQLite database containing the $\gamma $ lines of isotopes which was parsed from WWW Table of Radioactive Isotopes. histoGe is Free Software and is provided along with the database so they can be used to analyze spectra obtained with generic $\gamma $ -ray detectors.

Proportional electroluminescence (EL) in noble gases is used in two-phase detectors for dark matter searches to record (in the gas phase) the ionization signal induced by particle scattering in the liquid phase. The “standard” EL mechanism is considered to be due to noble gas excimer emission in the vacuum ultraviolet (VUV). In addition, there are two alternative mechanisms, producing light in the visible and near infrared (NIR) ranges. The first is due to bremsstrahlung of electrons scattered on neutral atoms (“neutral bremsstrahlung”, NBrS). The second, responsible for electron avalanche scintillation in the NIR at higher electric fields, is due to transitions between excited atomic states. In this work, we have for the first time demonstrated two alternative techniques of the optical readout of two-phase argon detectors, in the visible and NIR range, using a silicon photomultiplier matrix and electroluminescence due to either neutral bremsstrahlung or avalanche scintillation. The amplitude yield and position resolution were measured for these readout techniques, which allowed to assess the detection threshold for electron and nuclear recoils in two-phase argon detectors for dark matter searches. To the best of our knowledge, this is the first practical application of the NBrS effect in detection science.

Large liquid argon detectors offer one of the best avenues for the detection of galactic weakly interacting massive particles (WIMPs) via their scattering on atomic nuclei. The liquid argon target allows exquisite discrimination between nuclear and electron recoil signals via pulse-shape discrimination of the scintillation signals. Atmospheric argon (AAr), however, has a naturally occurring radioactive isotope, ^39Ar, a β emitter of cosmogenic origin. For large detectors, the atmospheric ^39Ar activity poses pile-up concerns. The use of argon extracted from underground wells, deprived of ^39Ar, is key to the physics potential of these experiments. The DarkSide-20k dark matter search experiment will operate a dual-phase time projection chamber with 50 tonnes of radio-pure underground argon (UAr), that was shown to be depleted of ^39Ar with respect to AAr by a factor larger than 1400. Assessing the ^39Ar content of the UAr during extraction is crucial for the success of DarkSide-20k, as well as for future experiments of the Global Argon Dark Matter Collaboration (GADMC). This will be carried out by the DArT in ArDM experiment, a small chamber made with extremely radio-pure materials that will be placed at the centre of the ArDM detector, in the Canfranc Underground Laboratory (LSC) in Spain. The ArDM LAr volume acts as an active veto for background radioactivity, mostly γ-rays from the ArDM detector materials and the surrounding rock. This article describes the DArT in ArDM project, including the chamber design and construction, and reviews the background required to achieve the expected performance of the detector.

This paper explores the prospect of CMOS devices to assay lead in drinking water, using calorimetry. Lead occurs together with traces of radioisotopes, e.g., 210Pb, producing g-emissions with energies ranging from 10 keV to several 100 keV when they decay; this range is detectable in silicon sensors. In this paper we test a CMOS camera (OXFORD INSTRUMENTS Neo 5.5) for its general performance as a detector of X-rays and low energy g-rays and assess its sensitivity relative to the World Health Organization upper limit on lead in drinking water. Energies from 6 keV to 60 keV are examined. The CMOS camera has a linear energy response over this range and its energy resolution is for the most part slightly better than 2%. The Neo sCMOS is not sensitive to X-rays with energies below ~10 keV. The smallest detectable rate is 40 ± 3 mHz, corresponding to an incident activity on the chip of 7 ± 4 Bq. The estimation of the incident activity sensitivity from the detected activity relies on geometric acceptance and the measured efficiency vs. energy. We report the efficiency measurement, which is 0.08(2)% (0.0011(2)%) at 26.3 keV (59.5 keV). Taking calorimetric information into account we measure a minimal detectable rate of 4 ± 1 mHz (1.5 ± 0.1 mHz) for 26.3 keV (59.5 keV) g-rays, which corresponds to an incident activity of 1.0 ± 0.6 Bq (57 ± 33 Bq). Toy Monte Carlo and Geant4 simulations agree with these results. These results show this CMOS sensor is well-suited as a g- and X-ray detector with sensitivity at the few to 100 ppb level for 210Pb in a sample.

Kinematic distributions from an inclusive sample of 1.41 x 10^6 charged-current nu_mu interactions on iron, obtained using the MINOS Near Detector exposed to a wide-band beam with peak flux at 3 GeV, are compared to a conventional treatment of neutrino scattering within a Fermi gas nucleus. Results are used to guide the selection of a subsample enriched in quasielastic nu_mu Fe interactions, containing an estimated 123,000 quasielastic events of incident energies 1 < E_nu < 8 GeV, with = 2.79 GeV. Four additional subsamples representing topological and kinematic sideband regions to quasielastic scattering are also selected for the purpose of evaluating backgrounds. Comparisons using subsample distributions in four-momentum transfer Q^2 show the Monte Carlo model to be inadequate at low Q^2. Its shortcomings are remedied via inclusion of a Q^2-dependent suppression function for baryon resonance production, developed from the data. A chi-square fit of the resulting Monte Carlo simulation to the shape of the Q^2 distribution for the quasielastic-enriched sample is carried out with the axial-vector mass M_A of the dipole axial-vector form factor of the neutron as a free parameter. The effective M_A which best describes the data is 1.23 +0.13/-0.09 (fit) +0.12/-0.15 (syst.) GeV.

Y. Kurimoto, J. L. Alcaraz-Aunion, S. J. Brice, L. Bugel, J. Catala-Perez, G. Cheng, J. M. Conrad, Z. Djurcic, U. Dore, D. A. Finley, A. J. Franke, C. Giganti, ∗ J. J. Gomez-Cadenas, P. Guzowski, A. Hanson, Y. Hayato, K. Hiraide, † G. Jover-Manas, G. Karagiorgi, T. Katori, Y. K. Kobayashi, T. Kobilarcik, H. Kubo, W. C. Louis, P. F. Loverre, L. Ludovici, K. B. M. Mahn, ‡ C. Mariani, S. Masuike, K. Matsuoka, V. T. McGary, W. Metcalf, G. B. Mills, G. Mitsuka, § Y. Miyachi, ¶ S. Mizugashira, C. D. Moore, Y. Nakajima, T. Nakaya, R. Napora, P. Nienaber, D. Orme, M. Otani, A. D. Russell, F. Sanchez, M. H. Shaevitz, T.-A. Shibata, M. Sorel, R. J. Stefanski, H. Takei, ∗∗ H.-K. Tanaka, M. Tanaka, R. Tayloe, I. J. Taylor, †† R. J. Tesarek, Y. Uchida, R. Van de Water, J. J. Walding, M. O. Wascko, H. B. White, M. J. Wilking, ‡ M. Yokoyama, G. P. Zeller, and E. D. Zimmerman

The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of (nu) over bar (mu) at Fermilab's Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the nu(mu) background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on (nu) over bar (mu) disappearance that dramatically improves upon prior limits in the Delta m(2) = 0.1-100 eV(2) region.

The MiniBooNE and SciBooNE collaborations report the results of a joint search for short baseline disappearance of ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ at Fermilab's Booster Neutrino Beamline. The MiniBooNE Cherenkov detector and the SciBooNE tracking detector observe antineutrinos from the same beam, therefore the combined analysis of their data sets serves to partially constrain some of the flux and cross section uncertainties. Uncertainties in the ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ background were constrained by neutrino flux and cross section measurements performed in both detectors. A likelihood ratio method was used to set a 90% confidence level upper limit on ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$ disappearance that dramatically improves upon prior limits in the $\ensuremath{\Delta}{m}^{2}=0.1--100\text{ }\text{ }{\mathrm{eV}}^{2}$ region.

The SciBooNE and MiniBooNE collaborations report the results of a νμ disappearance search in the Δ'm2 region of 0.5-40 eV2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) limits on νμ disappearance in the 0.5-40 eV2 Δm2 region, with an improvement over previous experimental constraints between 10 and 30 eV2

We report a measurement of muon-neutrino disappearance in the T2K experiment. The 295-km muon-neutrino beam from Tokai to Kamioka is the first implementation of the off-axis technique in a long-baseline neutrino oscillation experiment. With data corresponding to 1.43 x 10(20) protons on target, we observe 31 fully-contained single mu-like ring events in Super-Kamiokande, compared with an expectation of 104 +/- 14 (syst) events without neutrino oscillations. The best-fit point for two-flavor nu(mu) -> nu(tau) oscillations is sin(2)(2 theta(23)) = 0.98 and vertical bar Delta m(32)(2)vertical bar = 2.65 x 10(-3) eV(2). The boundary of the 90% confidence region includes the points sin(2)(2 theta(23)), vertical bar Delta m(32)(2)vertical bar = (1.0, 3.1 x 10(-3) eV(2)), (0.84, 2.65 x 10(-3) eV(2)) and (1.0, 2.2 x 10(-3) eV(2)).

We have searched for sidereal variations in the rate of antineutrino interactions in the MINOS Near Detector. Using antineutrinos produced by the NuMI beam, we find no statistically significant sidereal modulation in the rate. When this result is placed in the context of the Standard Model Extension theory we are able to place upper limits on the coefficients defining the theory. These limits are used in combination with the results from an earlier analysis of MINOS neutrino data to further constrain the coefficients.

Precise measurement of neutrino beam direction and intensity was achieved based on a new concept with modularized neutrino detectors. INGRID (Interactive Neutrino GRID) is an on-axis near detector for the T2K long baseline neutrino oscillation experiment. INGRID consists of 16 identical modules arranged in horizontal and vertical arrays around the beam center. The module has a sandwich structure of iron target plates and scintillator trackers. INGRID directly monitors the muon neutrino beam profile center and intensity using the number of observed neutrino events in each module. The neutrino beam direction is measured with accuracy better than 0.4 mrad from the measured profile center. The normalized event rate is measured with 4% precision.

This paper reports measurements of atmospheric neutrino and antineutrino interactions in the MINOS Far Detector, based on 2553 live-days (37.9 kton-years) of data. A total of 2072 candidate events are observed. These are separated into 905 contained-vertex muons and 466 neutrino-induced rock-muons, both produced by charged-current nu(mu) and (nu) over bar (mu) interactions, and 701 contained-vertex showers, composed mainly of charged-current nu(e) and (nu) over bar (e) interactions and neutral-current interactions. The curvature of muon tracks in the magnetic field of the MINOS Far Detector is used to select separate samples of nu(mu) and (nu) over bar (mu) events. The observed ratio of (nu) over bar (mu) to v(mu) events is compared with the Monte Carlo ( MC) simulation, giving a double ratio of R((nu) over bar/nu)data/R(nu) over bar/nu MC = 1.03 +/- 0.08(stat) +/- 0.08(syst). The v(mu) and (nu) over bar (mu) data are separated into bins of L/E resolution, based on the reconstructed energy and direction of each event, and a maximum likelihood fit to the observed L/E distributions is used to determine the atmospheric neutrino oscillation parameters. This fit returns 90% confidence limits of |Delta m(2)| = (1.9 +/- 0.4) x 10(-3) eV(2) and sin(2)2 theta > 0.86. The fit is extended to incorporate separate nu(mu) and (nu) over bar mu oscillation parameters, returning 90% confidence limits of |Delta m(2)| - |Delta(m) over bar (2)| = 0.6(-0.8)(+2.4) x 10(-3) eV(2) on the difference between the squared-mass splittings for neutrinos and antineutrinos.

The SciBooNE and MiniBooNE collaborations report the results of a ν_μdisappearance search in the Δm^2 region of 0.5-40 eV^2. The neutrino rate as measured by the SciBooNE tracking detectors is used to constrain the rate at the MiniBooNE Cherenkov detector in the first joint analysis of data from both collaborations. Two separate analyses of the combined data samples set 90% confidence level (CL) limits on ν_μdisappearance in the 0.5-40 eV^2 Δm^2 region, with an improvement over previous experimental constraints between 10 and 30 eV^2.

G. Cheng, a W. Huelsnitz, b A. A. Aguilar-Arevalo, J. L. Alcaraz-Aunion, S. J. Brice, B. C. Brown, 2 L. Bugel, J. Catala-Perez, E. D. Church, J. M. Conrad, R. Dharmapalan, Z. Djurcic, U. Dore, 3 D. A. Finley, R. Ford, A. J. Franke, F. G. Garcia, G. T. Garvey, C. Giganti, c J. J. Gomez-Cadenas, 4 J. Grange, P. Guzowski, d A. Hanson, Y. Hayato, K. Hiraide, e C. Ignarra, R. Imlay, R. A. 5 Johnson, B. J. P. Jones, G. Jover-Manas, G. Karagiorgi, 17 T. Katori, 17 Y. K. Kobayashi, 6 T. Kobilarcik, H. Kubo, Y. Kurimoto, f W. C. Louis, P. F. Loverre, L. Ludovici, K. B. M. Mahn, g 7 C. Mariani, h W. Marsh, S. Masuike, K. Matsuoka, V. T. McGary, W. Metcalf, G. B. Mills, 8 J. Mirabal, G. Mitsuka, i Y. Miyachi, j S. Mizugashira, C. D. Moore, J. Mousseau, Y. Nakajima, k 9 T. Nakaya, R. Napora, l P. Nienaber, D. Orme, B. Osmanov, M. Otani, Z. Pavlovic, D. Perevalov, 10 C. C. Polly, H. Ray, B. P. Roe, A. D. Russell, F. Sanchez, M. H. Shaevitz, T.-A. Shibata, 11 M. Sorel, J. Spitz, I. Stancu, R. J. Stefanski, H. Takei, m H.-K. Tanaka, M. Tanaka, R. Tayloe, 12 I. J. Taylor, n R. J. Tesarek, Y. Uchida, R. G. Van de Water, J. J. Walding, o M. O. Wascko, 13 D. H. White, H. B. White, D. A. Wickremasinghe, M. Yokoyama, p G. P. Zeller, and E. D. Zimmerman 14

The SciBooNE Collaboration reports K+ production cross section and rate measurements using high energy daughter muon neutrino scattering data off the SciBar polystyrene (C8H8) target in the SciBooNE detector. The K+ mesons are produced by 8 GeV protons striking a beryllium target in Fermilab Booster Neutrino Beam line (BNB). Using observed neutrino and antineutrino events in SciBooNE, we measure d2{\sigma}/dpd{\Omega} = (5.34 \times 0.76) mb/(GeV/c \times sr) for p + Be -> K+ + X at mean K+ energy of 3.9 GeV and angle (with respect to the proton beam direction) of 3.7 degrees, corresponding to the selected K+ sample. Compared to Monte Carlo predictions using previous higher energy K+ production measurements, this measurement, which uses the NUANCE neutrino interaction generator, is consistent with a normalization factor of 0.85\times0.12. This agreement is evidence that the extrapolation of the higher energy K+ measurements to an 8 GeV beam energy using Feynman scaling is valid. This measurement reduces the error on the K+ production cross section from 40% to 14%.

The SciBooNE Collaboration reports a measurement of inclusive charged current interactions of muon neutrinos on carbon with an average energy of 0.8 GeV using the Fermilab Booster Neutrino Beam. We compare our measurement with two neutrino interaction simulations: NEUT and NUANCE. The charged current interaction rates (product of flux and cross section) are extracted by fitting the muon kinematics, with a precision of 6-15% for the energy dependent and 3% for the energy integrated analyses. We also extract CC inclusive interaction cross sections from the observed rates, with a precision of 10-30% for the energy dependent and 8% for the energy integrated analyses. This is the first measurement of the CC inclusive cross section on carbon around 1 GeV. These results can be used to convert previous SciBooNE cross section ratio measurements to absolute cross section values.

We report constraints on antineutrino oscillation parameters that were obtained by using the two MINOS detectors to measure the 7% muon antineutrino component of the NuMI neutrino beam. In the Far Detector, we select 130 events in the charged-current muon antineutrino sample, compared to a prediction of 136.4 +/- 11.7(stat)(-8.9)(+10.2)(syst) events under the assumption vertical bar Delta(m) over bar (2)vertical bar = 2.32 x 10(-3) eV(2), sin(2)(2 (theta) over bar = 1.0. Assuming no oscillations occur at the Near Detector baseline, a fit to the two-flavor oscillation approximation constrains vertical bar Delta m(2)vertical bar < 3.37 x 10(-3) eV(2) at the 90% confidence level with sin(2)(2<(theta)over bar>) = 1.0.