Davide Franco
@in2p3.fr
CNRS/APC
RESEARCH, TEACHING, or OTHER INTERESTS
Nuclear and High Energy Physics, Astronomy and Astrophysics, Instrumentation
Scopus Publications
Scopus Publications
C. Adams, M. Alrashed, R. An, J. Anthony, J. Asaadi, A. Ashkenazi, S. Balasubramanian, B. Baller, C. Barnes, G. Barr,et al.
IOP Publishing
Liquid argon time projection chambers (LArTPCs) are now a standard detector technology for making accelerator neutrino measurements, due to their high material density, precise tracking, and calorimetric capabilities. An electric field (E-field) is required in such detectors to drift ionization electrons to the anode where they are collected. The E-field of a TPC is often approximated to be uniform between the anode and the cathode planes. However, significant distortions can appear from effects such as mechanical deformations, electrode failures, or the accumulation of space charge generated by cosmic rays. The latter effect is particularly relevant for detectors placed near the Earth's surface and with large drift distances and long drift time. To determine the E-field in situ, an ultraviolet (UV) laser system is installed in the MicroBooNE experiment at Fermi National Accelerator Laboratory. The purpose of this system is to provide precise measurements of the E-field, and to make it possible to correct for 3D spatial distortions due to E-field non-uniformities. Here we describe the methodology developed for deriving spatial distortions, the drift velocity and the E-field from UV-laser measurements.
R. Acciarri, C. Adams, C. Andreopoulos, J. Asaadi, M. Babicz, C. Backhouse, W. Badgett, L.F. Bagby, D. Barker, C. Barnes,et al.
IOP Publishing
The Short-Baseline Near Detector time projection chamber is unique in the design of its charge readout planes. These anode plane assemblies (APAs) have been fabricated and assembled to meet strict accuracy and precision requirements: wire spacing of 3 mm ± 0.5 mm and wire tension of 7 N ± 1 N across 3,964 wires per APA, and flatness within 0.5 mm over the 4 m × 2.5 m extent of each APA . This paper describes the design, manufacture and assembly of these key detector components, with a focus on the quality assurance at each stage.
Sandra Zavatarelli, M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick,et al.
IOP Publishing
Abstract The Borexino liquid scintillator neutrino observatory has a unique capability to perform high-precision solar neutrino observations thanks to its exceptional radiopurity and good energy resolution (5% at 1 MeV). A comprehensive study of the pp-chain neutrinos was presented that includes the direct measurements of 7Be, pp and pep neutrino fluxes with the highest precision ever achieved (down to 2.8% in the 7Be component), the 8B with the lowest energy threshold, the best limit on CNO neutrinos and the first Borexino limit on hep neutrinos. These results are important to validate the MSW-LMA oscillation paradigm across the full solar energy range and to exclude possible Non-Standard neutrino Interactions (NSIs). In particular the effects of neutrino-flavor-diagonal Neutral-Current (NC) interactions that modify the vee and vτe couplings while preserving their chiral and flavor structures, have been investigated. At detection, the shape of the electron-recoil spectrum is affected by changes in the vee and vτe couplings, quantified by the parameters ε e L / R and ε τ L / R . New bounds to all four parameters were obtained, quite stringent compared to the global ones. In particular, the best constraint to-date on ε e L was achieved. A comprehensive summary of all the recent results on solar neutrinos from Borexino is reported in the present paper.
Sindhujha Kumaran, M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick,et al.
IOP Publishing
Abstract Borexino is a 280-ton liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy and is one of the two detectors that has measured geoneutrinos so far. The unprecedented radio-purity of the scintillator, the shielding with highly purified water, and the placement of the detector at a 3800 m w.e. depth have resulted in very low background levels and have made Borexino an excellent apparatus for geoneutrino measurements. The analysis techniques of the latest geoneutrino results with Borexino were presented using the data obtained from December 2007 to April 2019, corresponding to an exposure of (1.12 ± 0.05) × 1032 protons × yr. Enhanced analysis techniques, such as an increased fiducial volume, improved veto for cosmogenic backgrounds, extended energy and coincidence time windows, as well as a more efficient α/β particle discrimination have been adopted in this measurement. The updated statistics and these elaborate resulted in a geoneutrino signal of 47.0 − 7.7 + 8.4 ( stat ) − 1.9 + 2.4 ( sys ) TNU with − 17.2 + 18.3 % total precision.
Livia Ludhova, M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick,et al.
IOP Publishing
Abstract Borexino is a 280-ton liquid scintillator detector located at the Laboratori Nazionali del Gran Sasso (LNGS), Italy and is one of the two detectors that has measured geoneutrinos so far. The unprecedented radio-purity of the scintillator, the shielding with highly purified water, and the placement of the detector at a 3800 m w.e. depth have resulted in very low background levels and has made Borexino an excellent apparatus for geoneutrino measurements. The new update of the Borexino geoneutrino measurement, using the data obtained from December 2007 to April 2019, has been presented. Enhanced analysis techniques, adopted in this measurement, have been also presented (poster presentation #39 by S. Kumaran). The updated statistics and the new elaborate analysis have led to more than a factor two increase in exposure ((1.12 ± 0.05) × 1032 protons × yr) when compared to the latest Borexino result from 2015. The resulting geoneutrino signal of 47.0 − 7.7 + 8.4 ( stat ) − 1.9 + 2.4 ( sys ) TNU has − 17.2 + 18.3 % total precision. The geological interpretations of this measurement have been discussed. In particular, the 99% C.L. observation of the mantle signal by exploiting the relatively well-known lithospheric contribution, the estimation of the radiogenic heat, as well as the comparison of these results to the predictions based on different geological models. The upper limits on the power of a hypothetical georeactor that might be present at different locations inside the Earth have been set.
M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick, D. Bravo,et al.
American Physical Society (APS)
We report on an improved measurement of the $^8$B solar neutrino interaction rate with the Borexino experiment at the Laboratori Nazionali del Gran Sasso. Neutrinos are detected via their elastic scattering on electrons in a large volume of liquid scintillator. The measured rate of scattered electrons above 3 MeV of energy is $0.223\\substack{+0.015 \\\\ -0.016}\\,(stat)\\,\\substack{+0.006 \\\\ -0.006}\\,(syst)$ cpd/100 t, which corresponds to an observed solar neutrino flux assuming no neutrino flavor conversion of $\\Phi\\substack{\\rm ES \\\\ ^8\\rm B}=2.57\\substack{+0.17 \\\\ -0.18}(stat)\\substack{+0.07\\\\ -0.07}(syst)\\times$10$^6$ cm$^{-2}\\,$s$^{-1}$. This measurement exploits the active volume of the detector in almost its entirety for the first time, and takes advantage of a reduced radioactive background following the 2011 scintillator purification campaign and of novel analysis tools providing a more precise modeling of the background. Additionally, we set a new limit on the interaction rate of solar $hep$ neutrinos, searched via their elastic scattering on electrons as well as their neutral current-mediated inelastic scattering on carbon, $^{12}$C($\\nu,\\nu'$)$^{12}$C* ($E_{\\gamma}$= 15.1 MeV).
P. Agnes, I. F. M. Albuquerque, T. Alexander, A. K. Alton, M. Ave, H. O. Back, G. Batignani, K. Biery, V. Bocci, G. Bonfini,et al.
American Physical Society (APS)
We reanalize data collected with the DarkSide-50 experiment and recently used to set limits on the spin-independent interaction rate of weakly interacting massive particles (WIMPs) on argon nuclei with an effective field theory framework. The dataset corresponds to a total (16660 $\\pm$ 270) kg d exposure using a target of low-radioactivity argon extracted from underground sources. We obtain upper limits on the effective couplings of the 12 leading operators in the nonrelativistic systematic expansion. For each effective coupling we set constraints on WIMP-nucleon cross sections, setting upper limits between $2.4 \\times 10^{-45} \\, \\mathrm{cm}^2$ and $2.3 \\times 10^{-42} \\, \\mathrm{cm}^2$ (8.9 $\\times 10^{-45} \\, \\mathrm{cm}^2$ and 6.0 $\\times 10^{-42} \\, \\mathrm{cm}^2$) for WIMPs of mass of 100 $\\mathrm{GeV/c^2}$ (1000 $\\mathrm{GeV/c^2}$) at 90\\% confidence level.
C.E. Aalseth, S. Abdelhakim, F. Acerbi, P. Agnes, R. Ajaj, I.F.M. Albuquerque, T. Alexander, A. Alici, A.K. Alton, P. Amaudruz,et al.
IOP Publishing
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.
S. K. Agarwalla, , M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger,et al.
Springer Science and Business Media LLC
Abstract The Borexino detector measures solar neutrino fluxes via neutrino-electron elastic scattering. Observed spectra are determined by the solar-νe survival probability Pee(E), and the chiral couplings of the neutrino and electron. Some theories of physics beyond the Standard Model postulate the existence of Non-Standard Interactions (NSI’s) which modify the chiral couplings and Pee(E). In this paper, we search for such NSI’s, in particular, flavor-diagonal neutral current interactions that modify the νee and ντe couplings using Borexino Phase II data. Standard Solar Model predictions of the solar neutrino fluxes for both high- and low-metallicity assumptions are considered. No indication of new physics is found at the level of sensitivity of the detector and constraints on the parameters of the NSI’s are placed. In addition, with the same dataset the value of sin2θW is obtained with a precision comparable to that achieved in reactor antineutrino experiments.
M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick, G. Bonfini,et al.
American Physical Society (APS)
This paper presents a comprehensive geoneutrino measurement using the Borexino detector, located at Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The analysis is the result of 3262.74 days of data between December 2007 and April 2019. The paper describes improved analysis techniques and optimized data selection, which includes enlarged fiducial volume and sophisticated cosmogenic veto. The reported exposure of (1.29±0.05)×1032 protons ×year represents an increase by a factor of two over a previous Borexino analysis reported in 2015. By observing 52.6-8.6+9.4(stat)-2.1+2.7(sys) geoneutrinos (68% interval) from U238 and Th232, a geoneutrino signal of 47.0-7.7+8.4(stat)-1.9+2.4(sys) TNU with -17.2+18.3% total precision was obtained. This result assumes the same Th/U mass ratio as found in chondritic CI meteorites but compatible results were found when contributions from U238 and Th232 were both fit as free parameters. Antineutrino background from reactors is fit unconstrained and found compatible with the expectations. The null-hypothesis of observing a geoneutrino signal from the mantle is excluded at a 99.0% C.L. when exploiting detailed knowledge of the local crust near the experimental site. Measured mantle signal of 21.2-9.0+9.5(stat)-0.9+1.1(sys) TNU corresponds to the production of a radiogenic heat of 24.6-10.4+11.1 TW (68% interval) from U238 and Th232 in the mantle. Assuming 18% contribution of K40 in the mantle and 8.1-1.4+1.9 TW of total radiogenic heat of the lithosphere, the Borexino estimate of the total radiogenic heat of the Earth is 38.2-12.7+13.6 TW, which corresponds to the convective Urey ratio of 0.78-0.28+0.41. These values are compatible with different geological predictions, however there is a ∼2.4σ tension with those Earth models which predict the lowest concentration of heat-producing elements in the mantle. In addition, by constraining the number of expected reactor antineutrino events, the existence of a hypothetical georeactor at the center of the Earth having power greater than 2.4 TW is excluded at 95% C.L. Particular attention is given to the description of all analysis details which should be of interest for the next generation of geoneutrino measurements using liquid scintillator detectors.
S Marcocci, M Agostini, K Altenmüller, S Appel, V Atroshchenko, Z Bagdasarian, D Basilico, G Bellini, J Benziger, D Bick,et al.
IOP Publishing
Abstract Borexino is a 300 ton sub-MeV liquid scintillator solar neutrino detector which has been running at the Laboratori Nazionali del Gran Sasso (Italy) since 2007. Thanks to its unprecedented radio-purity, it was able to measure the flux of 7Be, 8B, pp, and pep solar neutrinos and to detect geo-neutrinos. A reliable simulation of the detector is an invaluable tool for all Borexino physics analyses. The simulation accounts for the energy loss of particles in all the detector components, the generation of the scintillation photons, their propagation within the liquid scintillator volume, and a detailed simulation of the electronics chain. A novel efficient method for simulating the external background which survives the Borexino passive shield was developed. This technique allows to reliably predict the effect of the contamination in the peripheral construction materials. The techniques developed to simulate the Borexino detector and their level of refinement are of possible interest to the neutrino and dark matter communities, especially for current and future large-volume liquid scintillator experiments.
Davide D’Angelo, M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick,et al.
IOP Publishing
Abstract The Borexino detector at Gran Sasso has now accumulated over ten years of continuous data which represent a magnificent opportunity to study the cosmic muon flux at a deep underground location. We present here a precision measurement of the flux and of the expected seasonal modulation. We present the correlation with the atmospheric temperature variations from global atmospheric models. We measure the correlation parameters and infer the kaon-to-pion ratio in the production of cosmic muons from high energy primaries. We also find evidence of a long term modulation that is not present in the atmospheric data and we investigate a possible positive correlation with the solar activity. Finally we observe a seasonal modulation of the production rate of cosmogenic neutrons that is in phase with the muon modulation but shows a surprisingly larger amplitude.
P. Agnes, I.F.M. Albuquerque, T. Alexander, A.K. Alton, M. Ave, H.O. Back, G. Batignani, K. Biery, V. Bocci, G. Bonfini,et al.
IOP Publishing
We report measurements of the charged daughter fraction of 218Po as a result of the 222Rn alpha decay, and the mobility of 218Po+ ions, using radon-polonium coincidences from the 238U chain identified in 532 live-days of DarkSide-50 WIMP-search data. The fraction of 218Po that is charged is found to be 0.37 ± 0.03 and the mobility of 218Po+ is (8.6 ± 0.1) × 10−4 cm2/Vs.
M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, G. Bonfini, D. Bravo,et al.
American Physical Society (APS)
We present the first simultaneous measurement of the interaction rates of $pp$, $^7$Be, and $pep$ solar neutrinos performed with a global fit to the Borexino data in an extended energy range (0.19-2.93)$\\,$MeV. This result was obtained by analyzing 1291.51$\\,$days of Borexino Phase-II data, collected between December 2011 and May 2016 after an extensive scintillator purification campaign. We find: rate($pp$)$\\,$=$\\,$$134$$\\,$$\\pm$$\\,$$10$$\\,$($stat$)$\\,$$^{\\rm +6}_{\\rm -10}$$\\,$($sys$)$\\,$cpd/100$\\,$t, rate($^7$Be)$\\,$=$\\,$$48.3$$\\,$$\\pm$$\\,$$1.1$$\\,$($stat$)$\\,$$^{\\rm +0.4}_{\\rm -0.7}$$\\,$($sys$)$\\,$cpd/100$\\,$t, and rate($pep$)$\\,$=$\\,$$2.43$$\\pm$$\\,$$0.36$$\\,$($stat$)$^{+0.15}_{-0.22}$$\\,$($sys$)$\\,$cpd/100$\\,$t. These numbers are in agreement with and improve the precision of our previous measurements. In particular, the interaction rate of $^7$Be $\\nu$'s is measured with an unprecedented precision of 2.7%, showing that discriminating between the high and low metallicity solar models is now largely dominated by theoretical uncertainties. The absence of $pep$ neutrinos is rejected for the first time at more than 5$\\,$$\\sigma$. An upper limit of $8.1$$\\,$cpd/100$\\,$t (95%$\\,$C.L.) on the CNO neutrino rate is obtained by setting an additional constraint on the ratio between the $pp$ and $pep$ neutrino rates in the fit. This limit has the same significance as that obtained by the Borexino Phase-I (currently providing the tightest bound on this component), but is obtained by applying a less stringent constraint on the $pep$ $\\nu$ flux.
Chiara Ghiano and
IOP Publishing
The Borexino experiment, located in the Laboratori Nazionali del Gran Sasso in Italy and widely known for its rich Solar Neutrino physics program, has recently celebrated the 10 years of data taking. Among the achievements of the Borexino experiment solar program are: a precision measurement of 7Be neutrino flux with uncertainty of 3%, limit on its day/night asymmetry, first spectral measurement of pp-neutrinos, first evidence of monoenergetic pep neutrinos at 5 sigma, 8B neutrinos detection with the lowest visible energy threshold of 3 MeV, observation of season modulation of the 7Be solar neutrino rate at 3.8 sigma and the best current limit on CNO neutrino flux. Borexino is now in its high-purity Phase II data taking, thanks to intense purification campaigns of scintillator in 2010-11 that were very successful in further reducing the already low backgrounds. The advanced tecniques of data analysis were improved, allowing to maximize the signal/noise ratio. The detector was thermally insulated in order to improve the fluid stability. As an outcome, quality of the data has significantly increased leading to new levels of sensitivity to all solar neutrino fluxes. This allows a more sensitive probe for CNO neutrinos relevant to the solar metallicity problem.
M. Agostini, K. Altenmüller, S. Appel, V. Atroshchenko, Z. Bagdasarian, D. Basilico, G. Bellini, J. Benziger, D. Bick, I. Bolognino,et al.
IOP Publishing
We have measured the flux of cosmic muons in the Laboratori Nazionali del Gran Sasso at 3800 m w.e. to be (3.432 ± 0.003)⋅ 10−4 m−2s−1 based on ten years of Borexino data acquired between May 2007 and May 2017. A seasonal modulation with a period of (366.3 ± 0.6) d and a relative amplitude of (1.36 ±0.04)% is observed. The phase is measured to be (181.7 ± 0.4) d, corresponding to a maximum at the 1st of July. Using data inferred from global atmospheric models, we show the muon flux to be positively correlated with the atmospheric temperature and measure the effective temperature coefficient αT = 0.90 ± 0.02. The origin of cosmic muons from pion and kaon decays in the atmosphere allows to interpret the effective temperature coefficient as an indirect measurement of the atmospheric kaon-to-pion production ratio rK/π = 0.11+0.11−0.07 for primary energies above 18 TeV. We find evidence for a long-term modulation of the muon flux with a period of ∼ 3000 d and a maximum in June 2012 that is not present in the atmospheric temperature data. A possible correlation between this modulation and the solar activity is investigated. The cosmogenic neutron production rate is found to show a seasonal modulation in phase with the cosmic muon flux but with an increased amplitude of (2.6 ± 0.4)%.
M. Cadeddu, M. Lissia, P. Agnes, G. Batignani, W.M. Bonivento, B. Bottino, M. Caravati, S. Catalanotti, V. Cataudella, C. Cicalò,et al.
IOP Publishing
We examine the sensitivity of a large scale two-phase liquid argon detector to the directionality of the dark matter signal. This study was performed under the assumption that, above 50 keV of recoil energy, one can determine (with some resolution) the direction of the recoil nucleus without head-tail discrimination, as suggested by past studies that proposed to exploit the dependence of columnar recombination on the angle between the recoil nucleus direction and the electric field. In this paper we study the differential interaction recoil rate as a function of the recoil direction angle with respect to the zenith for a detector located at the Laboratori Nazionali del Gran Sasso and we determine its diurnal and seasonal modulation. Using a likelihood-ratio based approach we show that, with the angular information alone, 100 (250) events are enough to reject the isotropic hypothesis at three standard deviation level, for a perfect (400 mrad) angular resolution. For an exposure of 100 tonne years this would correspond to a spin independent WIMP-nucleon cross section of about 10−46 cm2 at 200 GeV WIMP mass. The results presented in this paper provide strong motivation for the experimental determination of directional recoil effects in two-phase liquid argon detectors.
D. Basilico, M. Agostini, K. A. ̈uller, S. Appel, V. Atroshchenko, Z. Bagdasarian, G. Bellini, J. Benziger, D. Bick, I. Bolognino,et al.
B. Bottino, P. Agnes, I. Albuquerque, T. Alexander, A. Alton, D. Asner, M. Ave, H. Back, G. Batignani, K. Biery,et al.
Summary. — DarkSide is direct-detection dark-matter experimental project based on radiopure argon. The main goal of the DarkSide program is the detection of rare nuclear elastic collisions with hypothetical dark-matter particles. The present detector, DarkSide-50 , placed at Laboratori Nazionali del Gran Sasso (LNGS), is a dual-phase time projection chamber (TPC) filled with ultra-pure liquid argon, extracted from underground sources. Surrounding the TPC to suppress the background there are neutron and muon active vetoes. One of argon key features is the capability to distinguish between electron and nuclear recoils, exploiting the different shapes of the signals. DarkSide-50 new results, obtained using a live-days exposure of 532.4 days, are presented. This analysis sets a 90% C.L. upper limit on the dark matter-nucleon spin-independent cross-section of 1 . 1 × 10 − 44 cm 2 for a WIMP mass of 100 GeV/ c 2 . The next phase of the project, DarkSide-20k , will be a new detector with a fiducial mass of ∼ 20 tons, equipped with cryogenic silicon photomultipliers (SiPM).
S. Sanfilippo, P. Agnes, I. Albuquerque, T. Alexander, A. Alton, D. Asner, M. Ave, H. Back, G. Batignani, K. Biery,et al.
S. Sanfilippo(41)(42)(∗), P. Agnes(), I. F. M. Albuquerque(), T. Alexander(), A. K. Alton(), D. M. Asner(), M. P. Ave(), H. O. Back(), G. Batignani()(), K. Biery(), V. Bocci(), G. Bonfini(), W. Bonivento(), B. Bottino()(), F. Budano()(), S. Bussino()(), M. Cadeddu()(), M. Cadoni()(), F. Calaprice(), A. Caminata(), N. Canci()(), A. Candela(), M. Caravati()(), M. M. Cardenas(), M. Cariello(), M. Carlini(), M. Carpinelli()(), S. Catalanotti()(), V. Cataudella()(), P. Cavalcante()(), S. Cavuoti()(), A. Chepurnov(), C. Cicalò(), L. Cifarelli()(), A. G. Cocco(), G. Covone()(), D. D’Angelo()(), M. D’Incecco(), D. D’Urso()(), S. Davini(), A. De Candia()(), S. De Cecco()(), M. De Deo(), G. De Filippis()(), G. De Rosa()(), M. De Vincenzi()(), A. V. Derbin(), A. Devoto()(), F. Di Eusanio(), G. Di Pietro()(), C. Dionisi()(), E. Edkins(), A. Empl(), G. Fiorillo()(), K. Fomenko(), D. Franco(), F. Gabriele(), C. Galbiati()(), P. Garcia Abia(), C. Ghiano(), S. Giagu()(), C. Giganti(), G. K. Giovanetti(), O. Gorchakov(), A. M. Goretti(), F. Granato(), M. Gromov(), M. Guan(), Y. Guardincerri(17)(∗∗), M. Gulino()(), B. R. Hackett(), K. Herner(), S. Horikawa(), B. Hosseini(), D. Hughes(), P. Humble(), E. V. Hungerford(), An. Ianni()(), V. Ippolito(), I. James()(), K. Keeter(), C. L. Kendziora(), I. Kochanek(), G. Koh(), D. Korablev(), G. Korga()(), A. Kubankin(), M. Kuss(), M. La Commara()(), M. Lai()(), X. Li(), M. Lissia(), G. Longo()(), A. A. Machado(), I. N. Machulin()(), A. Mandarano()(), L. Mapelli(), S. M. Mari()(), J. Maricic(), C. J. Martoff(), A. Messina()(), P. D. Meyers(), R. Milincic(), A. Monte(), M. Morrocchi(), V. N. Muratova(), P. Musico(), R. Nania(), A. Navrer Agasson(), A. O. Nozdrina()(), A. Oleinik(), M. Orsini(), F. Ortica()(), L. Pagani(), M. Pallavicini()(), L. Pandola(), E. Pantic(), E. Paoloni()(), K. Pelczar(), N. Pelliccia()(), V. Pesudo(), E. Picciau()(), A. Pocar(), S. Pordes(), S. S. Poudel(), D. A. Pugachev(), H. Qian(), F. Ragusa()(), M. Razeti(), A. Razeto(), A. L. Renshaw(), M. Rescigno(), Q. Riffard(), A. Romani()(), B. Rossi(), N. Rossi(), D. Sablone()(), O. Samoylov(), W. Sands(), R. Santorelli(), C. Savarese()(), E. Scapparone(), B. Schlitzer(), E. Segreto(), D. A. Semenov(), A. Shchagin(), A. Sheshukov(), M. Simeone()(), P. N. Singh(), M. D. Skorokhvatov()(), O. Smirnov(), A. Sotnikov(), C. Stanford(), S. Stracka(), Y. Suvorov()()(), R. Tartaglia(), G. Testera(), A. Tonazzo(), P. Trinchese()(), E. V. Unzhakov(), M. Verducci()(), A. Vishneva(), B. Vogelaar(), M. Wada(), T. J. Waldrop(), H. Wang(), Y. Wang(), A. W. Watson(), S. Westerdale(), M. M. Wojcik(), X. Xiang(), X. Xiao(), C. Yang(), Z. Ye(), C. Zhu() and G. Zuzel()
Lino Miramonti, Matteo Agostini, Konrad Altenmueller, Simon Appel, Victor Atroshchenko, Zara Bagdasarian, Davide Basilico, Gianpaolo Bellini, Jay Benziger, Daniel Bick,et al.
MDPI AG
Solar neutrinos have played a central role in the discovery of the neutrino oscillation mechanism. They still are proving to be a unique tool to help investigate the fusion reactions that power stars and further probe basic neutrino properties. The Borexino neutrino observatory has been operationally acquiring data at Laboratori Nazionali del Gran Sasso in Italy since 2007. Its main goal is the real-time study of low energy neutrinos (solar or originated elsewhere, such as geo-neutrinos). The latest analysis of experimental data, taken during the so-called Borexino Phase-II (2011-present), will be showcased in this talk—yielding new high-precision, simultaneous wide band flux measurements of the four main solar neutrino components belonging to the “pp” fusion chain (pp, pep, 7 Be, 8 B), as well as upper limits on the remaining two solar neutrino fluxes (CNO and hep).
, H. de Kerret, T. Abrahão, H. Almazan, J. C. dos Anjos, S. Appel, J. C. Barriere, I. Bekman, T. J. C. Bezerra, L. Bezrukov,et al.
Springer Science and Business Media LLC
Abstract The yields and production rates of the radioisotopes 9Li and 8He created by cosmic muon spallation on 12C, have been measured by the two detectors of the Double Chooz experiment. The identical detectors are located at separate sites and depths, which means that they are subject to different muon spectra. The near (far) detector has an overburden of ∼120 m.w.e. (∼300 m.w.e.) corresponding to a mean muon energy of 32.1 ± 2.0 GeV (63.7 ± 5.5 GeV). Comparing the data to a detailed simulation of the 9Li and 8He decays, the contribution of the 8He radioisotope at both detectors is found to be compatible with zero. The observed 9Li yields in the near and far detectors are 5.51 ± 0.51 and 7.90 ± 0.51, respectively, in units of 10−8 μ −1g−1cm2. The shallow overburdens of the near and far detectors give a unique insight when combined with measurements by KamLAND and Borexino to give the first multi-experiment, data driven relationship between the 9Li yield and the mean muon energy according to the power law $$ Y = {Y}_0{\\left(\\left\\langle {E}_{\\mu}\\right\\rangle /1\\ GeV\\right)}^{\\overline{\\alpha}} $$ Y = Y 0 E μ / 1 GeV α ¯ , giving $$ \\overline{\\alpha} = 0.72 \\pm 0.06 $$ α ¯ = 0.72 ± 0.06 and Y 0 = (0.43 ± 0.11) × 10−8 μ −1g−1cm2. This relationship gives future liquid scintillator based experiments the ability to predict their cosmogenic 9Li background rates.
The Borexino Collaboration
Springer Science and Business Media LLC
P. Agnes, I.F. M. Albuquerque, T. Alexander, A.K. Alton, D.M. Asner, M.P. Ave, H.O. Back, B. Baldin, G. Batignani, K. Biery,et al.
Elsevier BV