O. Smirnov
A5007202775- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Atomic and Subatomic Physics Research
- Radiation Detection and Scintillator Technologies
- Particle Detector Development and Performance
- Radio Astronomy Observations and Technology
- Astronomy and Astrophysical Research
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Spacecraft and Cryogenic Technologies
- Stellar, planetary, and galactic studies
- Scientific Research and Discoveries
- Antenna Design and Optimization
- Nuclear Physics and Applications
- Galaxies: Formation, Evolution, Phenomena
- Software Engineering Research
- Nuclear physics research studies
- Astronomical Observations and Instrumentation
- Radioactive Decay and Measurement Techniques
- Astro and Planetary Science
- Radioactivity and Radon Measurements
- Photocathodes and Microchannel Plates
- Quantum, superfluid, helium dynamics
Joint Institute for Nuclear Research
2016-2025
Université Libre de Bruxelles
2022-2024
Pontifical Catholic University of Rio de Janeiro
2022-2024
Universidade Estadual de Londrina
2022-2024
A. Alikhanyan National Laboratory
2022-2024
Beijing Normal University
2022-2024
Dubna State University
2008-2024
Kurchatov Institute
2010-2024
China Institute of Atomic Energy
2024
China Academy of Space Technology
2024
A direct measurement of the 0.862 MeV 7Be solar neutrino interaction rate performed with Borexino detector at Laboratori Nazionali del Gran Sasso yields 46.0$\pm1.5_{\rm stat}$$^{+1.6}_{-1.5\,\rm syst}$ counts/day/(100 tons). Our result is first a sub-MeV an accuracy better than 5%. The hypothesis no oscillation for neutrinos rejected 4.9$\sigma$ C.L. Using latest Standard Solar Model (SSM) flux predictions, leads directly to precise determination survival probability $\nu_e$'s in vacuum,...
We report the measurement of electron neutrino elastic scattering from 8B solar neutrinos with 3 MeV energy threshold by Borexino detector in Gran Sasso (Italy). The rate neutrino-induced events above this is 0.217 +- 0.038 (stat) 0.008 (syst) cpd/100 t, which corresponds to equivalent unoscillated flux (2.4 0.4 0.1 (syst))x10^6 cm^-2 s^-1, good agreement measurements SNO and SuperKamiokaNDE. Assuming predicted high metallicity Standard Solar Model, average survival probability measured be...
Borexino has been running since May 2007 at the LNGS with primary goal of detecting solar neutrinos. The detector, a large, unsegmented liquid scintillator calorimeter characterized by unprecedented low levels intrinsic radioactivity, is optimized for study lower energy part spectrum. During Phase-I (2007-2010) first detected and then precisely measured flux 7Be neutrinos, ruled out any significant day-night asymmetry their interaction rate, made direct observation pep set tightest upper...
We observed, for the first time, solar neutrinos in 1.0-1.5 MeV energy range. measured rate of pep neutrino interactions Borexino to be [3.1+-0.6(stat)+-0.3(syst)] counts/(day x 100 ton) and provided a constraint on CNO interaction <7.9 (95% C.L.). The absence signal is disfavored at 99.97% C.L., while 98% C.L. This unprecedented sensitivity was achieved by adopting novel data analysis techniques rejection cosmogenic 11C, dominant background 1-2 region. Assuming MSW-LMA solution...
Geo-neutrinos, electron anti-neutrinos produced in beta decays of naturally occurring radioactive isotopes the Earth, are a unique direct probe our planet's interior. We report first observation at more than 3$\sigma$ C.L. geo-neutrinos, performed with Borexino detector Laboratori Nazionali del Gran Sasso. Anti-neutrinos detected through neutron inverse decay reaction. With 252.6 ton-yr fiducial exposure after all selection cuts, we 9.9^{+4.1}_{-3.4}(^{+14.6}_{-8.2}) geo-neutrino events,...
A search for the solar neutrino effective magnetic moment has been performed using data from 1291.5 days exposure during second phase of Borexino experiment. No significant deviations expected shape electron recoil spectrum neutrinos have found, and a new upper limit on $\mu_{\nu}^{eff}$ $<$ 2.8$\cdot$10$^{-11}$ $\mu_{B}$ at 90\% c.l. set constraints sum fluxes implied by radiochemical gallium experiments.Using moment, limits moments flavor states, elements matrix Dirac Majorana neutrinos,...
We present the simultaneous measurement of interaction rates ${R}_{pp}$, ${R}_{\mathrm{Be}}$, ${R}_{pep}$ $pp$, $^{7}\mathrm{Be}$, and $pep$ solar neutrinos performed with a global fit to Borexino data in an extended energy range (0.19--2.93) MeV particular attention details analysis methods. This result was obtained by analyzing 1291.51 days Phase-II data, collected after extensive scintillator purification campaign. Using counts per day $(\mathrm{cpd})/100\text{ }\mathrm{ton}$ as unit, we...
A bstract The very low radioactive background of the Borexino detector, its large size, and well proved capability to detect both energy electron neutrinos antineutrinos make an ideal case for study short distance neutrino oscillations with artificial sources at Gran Sasso. This paper describes possible layouts 51 Cr ( ν e ) 144 Ce- Pr $$ \left( {{{\overline{\nu}}_e}} \right) source experiments in shows expected sensitivity eV mass sterile three different phases experiment. Expected results...
We present a measurement of the geo--neutrino signal obtained from 1353 days data with Borexino detector at Laboratori Nazionali del Gran Sasso in Italy. With fiducial exposure (3.69 $\pm$ 0.16) $\times$ $10^{31}$ proton year after all selection cuts and background subtraction, we detected (14.3 4.4) geo-neutrino events assuming fixed chondritic mass Th/U ratio 3.9. This corresponds to $S_{geo}$ = (38.8 12.0) TNU just 6 $10^{-6}$ probability for null measurement. U Th left as free parameters...
We report an improved geo-neutrino measurement with Borexino from 2056 days of data taking. The present exposure is $(5.5\pm0.3)\times10^{31}$ proton$\times$yr. Assuming a chondritic Th/U mass ratio 3.9, we obtain $23.7 ^{+6.5}_{-5.7} (stat) ^{+0.9}_{-0.6} (sys)$ events. null observation geo-neutrinos alone has probability $3.6 \times 10^{-9}$ (5.9$\sigma$). A signal the mantle obtained at 98\% C.L. radiogenic heat production for U and Th best-fit result restricted to range 23-36 TW, taking...
We present an improved measurement of the carbon-nitrogen-oxygen (CNO) solar neutrino interaction rate at Earth obtained with complete Borexino Phase-III dataset. The measured rate, R_{CNO}=6.7_{-0.8}^{+2.0} counts/(day×100 tonnes), allows us to exclude absence CNO signal about 7σ C.L. correspondent flux is 6.6_{-0.9}^{+2.0}×10^{8} cm^{-2} s^{-1}, taking into account flavor conversion. use new evaluate C and N abundances in Sun respect H abundance for first time neutrinos. Our result...
The characteristic outer scale of turbulence and the ratio random to ordered components magnetic field are key parameters characterise in interstellar gas, which affects propagation cosmic rays within Galaxy. We provide new constraints those two parameters. use LOw Frequency ARray (LOFAR) image diffuse continuum emission Fan region at (l,b) (137.0,+7.0) 80"x70" resolution range [146,174] MHz. detect multi-scale fluctuations Galactic synchrotron compute their power spectrum. Applying...
Borexino, a liquid scintillator detector at LNGS, is designed for the detection of neutrinos and antineutrinos from Sun, supernovae, nuclear reactors, Earth. The feeble nature these signals requires strong suppression backgrounds below few MeV. Very low intrinsic radiogenic contamination all components needs to be accompanied by efficient identification muons muon-induced backgrounds. Muons produce unstable nuclei spallation processes along their trajectory through whose decays can mimic...
We have measured the muon flux at underground Gran Sasso National Laboratory (3800 m w.e.) to be (3.41 \pm 0.01) \times 10-4m-2s-1 using four years of Borexino data. A modulation this signal is observed with a period (366\pm3) days and relative amplitude (1.29 0.07)%. The phase (179 6) days, corresponding maximum on 28th June. Using most complete atmospheric data models available, rate fluctuations are shown positively correlated temperature, an effective coefficient {\alpha}T = 0.93 0.04....
A search for 5.5-MeV solar axions produced in the $p+d\rightarrow\rm{^3He}+A (5.5 \rm{MeV})$ reaction was performed using Borexino detector. The Compton conversion of to photons, ${\rm A}+e\rightarrow e+\gamma$; axio-electric effect, A}+e+Z\rightarrow e+Z$; decay into two A}\rightarrow2\gamma$; and inverse Primakoff on nuclei, A}+Z\rightarrow\gamma+Z$, are considered. Model independent limits axion-electron ($g_{Ae}$), axion-photon ($g_{A\gamma}$), isovector axion-nucleon ($g_{3AN}$)...
We discuss the ground-breaking science that will be possible with a wide area survey, using MeerKAT telescope, known as MeerKLASS (MeerKAT Large Area Synoptic Survey). The current specifications of make it great fit for applications require large survey speeds but not necessarily high angular resolutions. In particular, cosmology, over $\sim 4,000 \, {\rm deg}^2$ 4,000$ hours potentially provide first ever measurements baryon acoustic oscillations 21cm intensity mapping technique, enough...
This paper presents a comprehensive geoneutrino measurement using the Borexino detector, located at Laboratori Nazionali del Gran Sasso (LNGS) in Italy. The analysis is result of 3262.74 days data between December 2007 and April 2019. describes improved techniques optimized selection, which includes enlarged fiducial volume sophisticated cosmogenic veto. reported exposure (1.29±0.05)×1032 protons ×year represents an increase by factor two over previous 2015. By observing...