Z. Bagdasarian
A5018509178- Neutrino Physics Research
- Dark Matter and Cosmic Phenomena
- Particle physics theoretical and experimental studies
- Astrophysics and Cosmic Phenomena
- Atomic and Subatomic Physics Research
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Quantum Chromodynamics and Particle Interactions
- Atmospheric Ozone and Climate
- Solar and Space Plasma Dynamics
- Advanced NMR Techniques and Applications
- Particle accelerators and beam dynamics
- Nuclear Physics and Applications
- Particle Accelerators and Free-Electron Lasers
- Atomic and Molecular Physics
- Particle Detector Development and Performance
- High-Energy Particle Collisions Research
- Astro and Planetary Science
- Superconducting Materials and Applications
- Cosmology and Gravitation Theories
- Neonatal Health and Biochemistry
- Computational Physics and Python Applications
- Advanced X-ray Imaging Techniques
- Gamma-ray bursts and supernovae
- Ultrasonics and Acoustic Wave Propagation
University of California, Berkeley
2021-2024
Lawrence Berkeley National Laboratory
2021-2024
Forschungszentrum Jülich
2014-2023
Istituto Nazionale di Fisica Nucleare, Sezione di Milano Bicocca
2023
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Gran Sasso
2019-2022
Istituto Nazionale di Fisica Nucleare, Sezione di Genova
2022
Johannes Gutenberg University Mainz
2021
RWTH Aachen University
2018-2020
University of Milan
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Milano
2018-2020
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...
Abstract New developments in liquid scintillators, high-efficiency, fast photon detectors, and chromatic sorting have opened up the possibility for building a large-scale detector that can discriminate between Cherenkov scintillation signals. Such could reconstruct particle direction species using light while also having excellent energy resolution low threshold of scintillator detector. Situated deep underground, utilizing new techniques computing reconstruction, this achieve unprecedented...
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...
A new method to determine the spin tune is described and tested. In an ideal planar magnetic ring, tune-defined as number of precessions per turn-is given by ν(s)=γG (γ Lorentz factor, G gyromagnetic anomaly). At 970 MeV/c, deuteron spins coherently precess at a frequency ≈120 kHz in Cooler Synchrotron COSY. The deduced from up-down asymmetry deuteron-carbon scattering. time interval 2.6 s, was determined with precision order 10^{-8}, 1×10^{-10} for continuous 100 s accelerator cycle. This...
We observe a deuteron beam polarization lifetime near 1000 s in the horizontal plane of magnetic storage ring (COSY). This long spin coherence time is maintained through combination bunching, electron cooling, sextupole field corrections, and suppression collective effects current limits. record required for search an intrinsic electric dipole moment on at statistical sensitivity level approaching 10^{-29} e cm.
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...
We report on an improved measurement of the $^{8}\mathrm{B}$ solar neutrino interaction rate with Borexino experiment at Laboratori Nazionali del Gran Sasso. Neutrinos are detected via their elastic scattering electrons in a large volume liquid scintillator. The measured scattered above 3 MeV energy is ${0.223}_{\ensuremath{-}0.016}^{+0.015}(\mathrm{stat}){\text{ }}_{\ensuremath{-}0.006}^{+0.006}(\mathrm{syst})\text{ }\text{ }\mathrm{cpd}/100\text{ }\mathrm{t}$, which corresponds to observed...
EOS is a technology demonstrator, designed to explore the capabilities of hybrid event detection technology, leveraging both Cherenkov and scintillation light simultaneously. With fiducial mass four tons, operate in high-precision regime, with sufficient size utilize time-of-flight information for full reconstruction, flexibility demonstrate range cutting edge technologies, simplicity design facilitate potential future deployment at alternative sites. Results from can inform neutrino...
This Letter reports the successful use of feedback from a spin polarization measurement to revolution frequency $0.97\text{ }\text{ }\mathrm{GeV}/c$ bunched and polarized deuteron beam in Cooler Synchrotron (COSY) storage ring order control both precession rate ($\ensuremath{\approx}121\text{ }\mathrm{kHz}$) phase horizontal component. Real time synchronization with radio (rf) solenoid made possible rotation out plane, yielding demonstration method manipulate polarization. In particular,...
We have measured the flux of cosmic muons in 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 Borexino data acquired between May 2007 and 2017. A seasonal modulation with a period (366.3 0.6) d relative amplitude (1.36 ±0.04)% is observed. The phase (181.7 0.4) d, corresponding maximum 1st July. Using inferred from global atmospheric models, we show muon positively correlated temperature measure effective coefficient αT = 0.90 0.02....
This paper presents studies of the performance water-based liquid scintillators (WbLS) in both 1-kt and 50-kt detectors. Performance is evaluated comparison to pure water Cherenkov detectors a nominal model for scintillator metrics include energy, vertex, angular resolution, along with metric ability separate from scintillation signal as being representative various particle identification capabilities that depend on Cherenkov/scintillation ratio. We also modify time profile light study same...
Liquid scintillator detectors play a central role in the detection of neutrinos from various sources. In particular, it is only technique used so far for precision spectroscopy sub-MeV solar neutrinos, as demonstrated by Borexino experiment at Gran Sasso National Laboratory Italy. The benefit high light yield, and thus low energy threshold good resolution, comes cost directional information featured water Cherenkov detectors, measuring 8B above few MeV. this paper we provide first...
This paper describes a time-marking system that enables measurement of the in-plane (horizontal) polarization 0.97-GeV/c deuteron beam circulating in Cooler Synchrotron (COSY) at Forschungszentrum J\"ulich. The clock time each polarimeter event is used to unfold 120-kHz spin precession and assign events bins according direction horizontal polarization. After accumulation for one or more seconds, down-up scattering asymmetry can be calculated matched sinusoidal function whose magnitude...
The stable spin direction of polarized particles in a storage ring was determined first experimentally, through an accurate measurement the tune and its response to longitudinal magnetic fields.
Abstract Neutrinos emitted in the carbon, nitrogen, oxygen (CNO) fusion cycle Sun are a sub-dominant, yet crucial component of solar neutrinos whose flux has not been measured yet. The Borexino experiment at Laboratori Nazionali del Gran Sasso (Italy) unique opportunity to detect them directly thanks detector’s radiopurity and precise understanding detector backgrounds. We discuss sensitivity CNO neutrinos, which is based on strategies we adopted constrain rates two most relevant background...
Abstract The Accelerator Neutrino Neutron Interaction Experiment (ANNIE) is a 26-ton water Cherenkov neutrino detector installed on the Booster Beam (BNB) at Fermilab. Its main physics goals are to perform measurement of neutron yield from neutrino-nucleus interactions, as well charged-current cross section muon neutrinos. An equally important focus research and development new technologies target media. Specifically, water-based liquid scintillator (WbLS) interest novel medium, it allows...
We report on measurements of the differential cross section $d\ensuremath{\sigma}/d\mathrm{\ensuremath{\Omega}}$ and first measurement analyzing power ${A}_{y}$ in $\mathrm{\ensuremath{\Delta}}(1232)$ excitation energy region reaction $pp\ensuremath{\rightarrow}{{pp}}_{s}{\ensuremath{\pi}}^{0}$ where ${{pp}}_{s}$ is a $^{1}S_{0}$ proton pair. The experiment has been performed with ANKE spectrometer at COSY-J\"ulich. data reveal peak dependence forward section, minimum zero degrees its...
We present the results of a low-energy neutrino search using Borexino detector in coincidence with gravitational wave (GW) events GW150914, GW151226 and GW170104. searched for correlated energies greater than 250 keV within time window $\pm500$ s centered around GW detection time. A total five candidates were found all three This is consistent number expected solar background events. As result, we have obtained best current upper limits on event fluence flavors ($\nu_e, \nu_{\mu},...
The paper describes the commissioning of experimental equipment and machine studies required for first spin-filtering experiment with protons at a beam kinetic energy 49.3 MeV in COSY. implementation low-$\ensuremath{\beta}$ insertion made it possible to achieve lifetimes ${\ensuremath{\tau}}_{b}=8000\text{ }\text{ }\mathrm{s}$ presence dense polarized hydrogen storage-cell target areal density...