arXiv subjects

A. Ivanova

Publications and source records attributed to A. Ivanova.

13 recordsLinked to original sources

arXiv2026

The NOvA Test Beam Experiment

NOvA is a long-baseline neutrino oscillation experiment designed to study the neutrino mixing parameters, mass ordering, and CP violation in the lepton sector. A key component of the success of the experiment is a robust understanding of the systematic uncertainties associated with detector response and calibration. To address this, NOvA deployed a Test Beam experiment at the Fermilab Test Beam Facility, which collected data from April 2019 through July 2022. The NOvA Test Beam experiment used a 30-ton segmented liquid scintillator detector functionally identical to the NOvA Near and Far Detectors to analyze tagged particles produced from p-Cu collisions, with instrumentation capable of selecting and identifying electrons, muons, pions, kaons, and protons with momentum ranging from 0.4-1.5GeV/c. Analysis of the collected data provides a better understanding of the largest systematic uncertainties impacting NOvA's analyses, which include the detector response, energy calibration, and hadronic and electromagnetic energy resolutions.

hep-ex↗

arXiv2026

NOvA Dual-Baseline Search for Active-to-Sterile Neutrino Oscillations using Neutrino- and Antineutrino-Enriched Samples

We report a search for neutrino oscillations to sterile neutrinos in the NOvA detectors under a model with three active and one sterile neutrinos. This search simultaneously fits data in the two NOvA detectors and is the first from NOvA to use both neutrino- and antineutrino-mode beams, with exposures of $26.61\times10^{20}$ and $12.50\times10^{20}$ protons on target, respectively. There is no evidence for sterile neutrinos in the data and we are able to exclude regions of parameter space that were allowed by previous experiments, including most of the allowed region reported by IceCube.

hep-ex↗

arXiv2026

Neutron detector response modeling in NOvA

Neutrons can present a significant challenge for neutrino experiments in which energy reconstruction is critical. With the ability to escape detection completely and with a weak correlation between their kinetic energy and any eventual energy deposition, it is difficult to fully account for neutrons produced in neutrino interactions. This in turn leads to significant model dependence when evaluating neutron-related systematic uncertainties. The NOvA experiment is a long-baseline neutrino oscillation experiment with a high-statistics sample of antineutrino data collected by its near detector. We report an excess relative to data of simulated neutron candidates with low energy depositions when using standard Geant4 physics lists. The simulation excess is traced to an overabundance of secondary photons produced from interactions of neutrons with kinetic energy greater than \SI{20}{\mega\eV}. Improved agreement with data is obtained by applying the data-driven neutron-on-carbon \menate model for neutrons between \SI{20}{\mega\eV} and ${\sim}$\SI{100}{\mega\eV}. With \menate, the residual oversimulation is more uniform across the calorimetric neutron energy spectrum, suggesting possible overproduction of primary neutrons by the GENIE neutrino interaction generator. These results motivate the adoption of \menate-supplemented Geant4 simulation as the nominal simulation in the production of future \nova simulation.

hep-ex↗

arXiv2025

Precision measurement of neutrino oscillation parameters with 10 years of data from the NOvA experiment

This Letter reports measurements of muon-neutrino disappearance and electron-neutrino appearance and the corresponding antineutrino processes between the two NOvA detectors in the NuMI neutrino beam. These measurements use a dataset with double the neutrino mode beam exposure that was previously analyzed, along with improved simulation and analysis techniques. A joint fit to these samples in the three-flavor paradigm results in the most precise single-experiment constraint on the atmospheric neutrino mass splitting, $\Delta m^2_{32}= 2.431^{+0.036}_{-0.034} (-2.479^{+0.036}_{-0.036}) \times 10^{-3}~\mathrm{eV}^2$ if the mass ordering is normal (inverted). In both orderings, a region close to maximal mixing with $\sin^2 \theta_{23}=0.55^{+0.02}_{-0.06}$ is preferred. The NOvA data show a mild preference for the normal mass ordering with a Bayes factor of 2.4 (corresponding to 70% of the posterior probability), indicating that the normal ordering is 2.4 times more probable than the inverted ordering. When incorporating a 2D $\Delta m^2_{32}\text{--}\sin^2 2\theta_{13}$ constraint based on Daya Bay data, this preference strengthens to a Bayes factor of 6.6 (87%).

hep-ex↗

arXiv2025

Search for Accelerator-Produced Sub-GeV Dark Matter with the NOvA Near Detector

The NuMI facility at Fermilab produces a high-intensity beam of muon neutrinos and antineutrinos, designed to study neutrino oscillations. This beam may also be a source of dark matter particles produced through a light mediator. We search for dark matter particles with masses between 1 and 200 MeV that interact with Standard Model particles via a vector portal, producing forward-scattered single-electron events in the NOvA near detector. We set limits on the dark-visible coupling based on an exposure of 2.55x10^21 protons of 120 GeV energy on the NuMI target. For the dark matter mass range 10-20 MeV, this analysis sets the tightest constraints on the coupling to date.

hep-ex↗

arXiv2024

Measurement of the double-differential cross section of muon-neutrino charged-current interactions with low hadronic energy in the NOvA Near Detector

The NOvA collaboration reports cross-section measurements for $\nu_{\mu}$ charged-current interactions with low hadronic energy (maximum kinetic energy of 250 MeV for protons and 175 MeV for pions) in the NOvA Near Detector. The results are presented as a double-differential cross section as a function of the direct observables of the final-state muon kinematics. Results are also presented as a single-differential cross section as a function of the derived square of the four-momentum transfer, $Q^{2}$, and as a function of the derived neutrino energy. The data correspond to an accumulated 8.09$\times10^{20}$ protons-on-target (POT) in the neutrino mode of the NuMI beam, with a narrow band of neutrino energies peaked at 1.8 GeV. The analysis provides a sample of neutrino-nucleus interactions with an enhanced fraction of quasi-elastic and two-particle-two-hole (2p2h) interactions. This enhancement allows quantitative comparisons with various nuclear models. We find strong disagreement between data and theory-based models in various regions of the muon kinematic phase space, especially in the forward muon direction.

hep-ex↗

arXiv2024

Measurement of d2sigma/d|q|dEavail in charged current neutrino-nucleus interactions at = 1.86 GeV using the NOvA Near Detector

Double- and single-differential cross sections for inclusive charged-current neutrino-nucleus scattering are reported for the kinematic domain 0 to 2 GeV/c in three-momentum transfer and 0 to 2 GeV in available energy, at a mean muon-neutrino energy of 1.86 GeV. The measurements are based on an estimated 995,760 muon-neutrino CC interactions in the scintillator medium of the NOvA Near Detector. The subdomain populated by 2-particle-2-hole reactions is identified by the cross-section excess relative to predictions for neutrino-nucleus scattering that are constrained by a data control sample. Models for 2-particle-2- hole processes are rated by chi-square comparisons of the predicted-versus-measured muon-neutrino CC inclusive cross section over the full phase space and in the restricted subdomain. Shortfalls are observed in neutrino generator predictions obtained using the theory-based Val`encia and SuSAv2 2p2h models.

hep-ex↗

arXiv2024

Search for $CP$-Violating Neutrino Nonstandard Interactions with the NOvA Experiment

This Letter reports a search for charge-parity ($CP$) symmetry violating nonstandard interactions (NSI) of neutrinos with matter using the NOvA Experiment, and examines their effects on the determination of the standard oscillation parameters. Data from $\nu_{\mu}(\bar{\nu}_{\mu})\rightarrow\nu_{\mu}(\bar{\nu}_{\mu})$ and $\nu_{\mu}(\bar{\nu}_{\mu})\rightarrow\nu_{e}(\bar{\nu}_{e})$ oscillation channels are used to measure the effect of the NSI parameters $\varepsilon_{e\mu}$ and $\varepsilon_{e\tau}$. With 90% CL the magnitudes of the NSI couplings are constrained to be $|\varepsilon_{e\mu}| \, \lesssim 0.3$ and $|\varepsilon_{e\tau}| \, \lesssim 0.4$. A degeneracy at $|\varepsilon_{e\tau}| \, \approx 1.8$ is reported, and we observe that the presence of NSI limits sensitivity to the standard $CP$ phase $\delta_{\tiny\text{CP}}$.

hep-ex↗

arXiv2023

Doppler confirmation of TESS planet candidate TOI1408.01: grazing transit and likely eccentric orbit

We report an independent Doppler confirmation of the TESS planet candidate orbiting an F-type main sequence star TOI-1408 located 140 pc away. We present a set of radial velocities obtained with a high-resolution fiber-optic spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our self-consistent analysis of these Doppler data and TESS photometry suggests a grazing transit such that the planet obscures its host star by only a portion of the visible disc. Because of this degeneracy, the radius of TOI-1408.01 appears ill-determined with lower limit about $\sim$1 R$_{\rm Jup}$, significantly larger than in the current TESS solution. We also derive the planet mass of $1.69\pm0.20$~$M_{\rm Jup}$ and the orbital period $\sim4.425$ days, thus making this object a typical hot Jupiter, but with a significant orbital eccentricity of $0.259\pm0.026$. Our solution may suggest the planet is likely to experience a high tidal eccentricity migration at the stage of intense orbital rounding, or may indicate possible presence of other unseen companions in the system, yet to be detected.

astro-ph.EP↗

arXiv2023

Improved precision of radial velocity measurements after correction for telluric absorption

The detection of planets around other stars by the measurement of the stellar Radial Velocity (RV) variations benefits from improvements of dedicated spectrographs, allowing to achieve a precision of 1 ms$^{-1}$ or better. Spectral intervals within which stellar lines are contaminated by telluric lines are classically excluded from the RV processing. We aim at estimating the potential improvement of telluric absorption removal and subsequent extension of the useful spectral domain on the precision of radial velocity measurements. We developed a correction method based on the on-line web service TAPAS, allowing to determine a synthetic atmospheric transmission spectrum for the time and location of observations. This method was applied to the telluric H$_{2}$O and O$_2$ absorption removal from a series of 200 ESPRESSO consecutive exposures of the K2.5V star HD40307, available in ESO archives. We calculated the radial velocity using the standard Cross-Correlation Function (CCF) method and Gaussian fit of the CCF, with uncorrected spectra and the ESPRESSO standard stellar binary mask on one hand, and telluric-corrected spectra and an augmented binary mask with 696 additional lines on the other hand. We find that the precision of radial velocity measurements is improved in the second case, with a reduction of the average formal error from 1.04 ms$^{-1}$ down to 0.78 ms$^{-1}$ in the case of these ESPRESSO data and this stellar type for the red arm. Using an estimator of the minimal error based on photon noise limit applied to the full CCF, the error is reduced from 0.89 ms$^{-1}$ down to 0.78 ms$^{-1}$. This corresponds to a significant decrease of about 35\% of observing time to reach the same precision in the red part.

astro-ph.EP↗

arXiv2022

Arline Benchmarks: Automated Benchmarking Platform for Quantum Compilers

Efficient compilation of quantum algorithms is vital in the era of Noisy Intermediate-Scale Quantum (NISQ) devices. While multiple open-source quantum compilation and circuit optimization frameworks are available, e.g. IBM Qiskit, CQC Tket, Google Cirq, Rigetti Quilc, PyZX, their relative performance is not always clear to a quantum programmer. The growth of complexity and diversity of quantum circuit compilation algorithms creates a demand for a dedicated tool for cross-benchmarking and profiling of inner workflow of the quantum compilation stack. We present an open-source software package, Arline Benchmarks, that is designed to perform automated benchmarking of quantum compilers with the focus on NISQ applications. The name "Arline" was given in honour of Arline Greenbaum Feynman, the first wife of Richard Feynman, the pioneer of quantum computing. We compared several quantum compilation frameworks based on a set of important metrics such as post-optimization gate counts, circuit depth, hardware-dependent circuit cost function, compiler run time etc. with a detailed analysis of metrics for each compilation stage. We performed a variety of compiler tests for random circuits and structured quantum algorithms (VQE, Trotter decomposition, Grover search, Option Pricing via Amplitude Estimation) for several popular quantum hardware architectures. Leveraging cross-platform functionality of Arline, we propose a concept of composite compilation pipeline that combines compiler-specific circuit optimization subroutines in a single compilation stack and finds an optimized sequence of compilation passes. By providing detailed insights into the compilation flow of quantum compilers, Arline Benchmarks offers a valuable toolkit for quantum computing researchers and software developers to gain additional insights into compilers' characteristics.

quant-ph↗

arXiv2021

Towards a 3D kinetic tomography of Taurus clouds: I -- Linking neutral potassium and dust

Results. We illustrate our profile-fitting technique and present the K\,{\sc i} velocity structure of the dense ISM along the paths to all targets. As a validation test of the dust map, we show comparisons between distances to several reconstructed clouds with recent distance assignments based on different techniques. Target star extinctions estimated by integration in the 3D map are compared with their K\,{\sc i} 7699 A absorptions and the degree of correlation is found comparable to the one between the same K\,{\sc i} line and the total hydrogen column for stars distributed over the sky that are part of a published high resolution survey. We show images of the updated dust distribution in a series of vertical planes in the Galactic longitude interval 150-182.5 deg and our estimated assignments of radial velocities to the opaque regions. Most clearly defined K\,{\sc i} absorptions may be assigned to a dense dust cloud between the Sun and the target star. It appeared relatively straightforward to find a velocity pattern consistent will all absorptions and ensuring coherence between adjacent lines of sight, at the exception of a few weak lines. We compare our results with recent determinations of velocities of several clouds and find good agreement. These results demonstrate that the extinction-K\,{\sc i} relationship is tight enough to allow linking the radial velocity of the K\,{\sc i} lines to the dust clouds seen in 3D, and that their combination may be a valuable tool in building a 3D kinetic structure of the dense ISM. We discuss limitations and perspectives for this technique.

astro-ph.GA↗

arXiv2019

Tunka Advanced Instrument for cosmic rays and Gamma Astronomy

The paper is a script of a lecture given at the ISAPP-Baikal summer school in 2018. The lecture gives an overview of the Tunka Advanced Instrument for cosmic rays and Gamma Astronomy (TAIGA) facility including historical introduction, description of existing and future setups, and outreach and open data activities.

astro-ph.IM↗