Ana Martina Botti
A5019296229- Dark Matter and Cosmic Phenomena
- Astrophysics and Cosmic Phenomena
- Particle Detector Development and Performance
- CCD and CMOS Imaging Sensors
- Particle physics theoretical and experimental studies
- Neutrino Physics Research
- Radio Astronomy Observations and Technology
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- Infrared Target Detection Methodologies
- Pulsars and Gravitational Waves Research
- Photocathodes and Microchannel Plates
- Astronomical Observations and Instrumentation
- Cosmology and Gravitation Theories
- Atmospheric Ozone and Climate
- Advanced Optical Sensing Technologies
- High-Energy Particle Collisions Research
- Ionosphere and magnetosphere dynamics
- Particle Accelerators and Free-Electron Lasers
- Lightning and Electromagnetic Phenomena
- Adaptive optics and wavefront sensing
- Noncommutative and Quantum Gravity Theories
- Calibration and Measurement Techniques
- Advanced Semiconductor Detectors and Materials
- Computational Physics and Python Applications
Fermi National Accelerator Laboratory
2021-2025
University of Chicago
2024
University of Washington
2024
Instituto de Tecnologías en Detección y Astropartículas
2016-2023
Consejo Nacional de Investigaciones Científicas y Técnicas
2016-2023
National University of General San Martín
2016-2023
Karlsruhe Institute of Technology
2016-2023
University of Buenos Aires
2021-2023
Laboratoire AstroParticule et Cosmologie
2023
Fundación Ciencias Exactas y Naturales
2023
Cosmic rays are atomic nuclei arriving from outer space that reach the highest energies observed in nature. Clues to their origin come studying distribution of arrival directions. Using 3 × 104 cosmic with above 8 1018 electron volts, recorded Pierre Auger Observatory a total exposure 76,800 km2 sr year, we determined existence anisotropy The anisotropy, detected at more than 5.2σ level significance, can be described by dipole an amplitude [Formula: see text] percent toward right ascension...
We present a combined fit of simple astrophysical model UHECR sources to both the energy spectrum and mass composition data measured by Pierre Auger Observatory. The has been performed for energies above 5 ⋅ 1018 eV, i.e. region all-particle so-called "ankle" feature. we adopted consists identical uniformly distributed in comoving volume, where nuclei are accelerated through rigidity-dependent mechanism. results suggest characterized relatively low maximum injection energies, hard spectra...
Abstract A new analysis of the data set from Pierre Auger Observatory provides evidence for anisotropy in arrival directions ultra-high-energy cosmic rays on an intermediate angular scale, which is indicative excess arrivals strong, nearby sources. The consist 5514 events above with zenith angles up to 80° recorded before 2017 April 30. Sky models have been created two distinct populations extragalactic gamma-ray emitters: active galactic nuclei second catalog hard Fermi -LAT sources (2FHL)...
Ultrahigh energy cosmic ray air showers probe particle physics at energies beyond the reach of accelerators. Here we introduce a new method to test hadronic interaction models without relying on absolute calibration, and apply it events with primary 6–16 EeV (ECM=110–170 TeV), whose longitudinal development lateral distribution were simultaneously measured by Pierre Auger Observatory. The average shower is 1.33±0.16 (1.61±0.21) times larger than predicted using leading LHC-tuned EPOS-LHC...
We report a measurement of the energy spectrum cosmic rays for energies above 2.5×1018 eV based on 215,030 events recorded with zenith angles below 60°. A key feature work is that estimates are independent assumptions about unknown hadronic physics or primary mass composition. The most precise made hitherto accumulated exposure being so large measurements flux dominated by systematic uncertainties except at 5×1019 eV. principal conclusions (1) flattening near 5×1018 eV, so-called "ankle,"...
Many low-threshold experiments observe sharply rising event rates of yet unknown origins below a few hundred eV, and larger than expected from known backgrounds. Due to the significant impact this excess on dark matter or neutrino sensitivity these experiments, collective effort has been started share knowledge about individual observations. For this, EXCESS Workshop was initiated. In its first iteration in June 2021, ten rare search collaborations contributed initiative via talks...
We present the first results from a dark matter search using six Skipper-CCDs in SENSEI detector operating at SNOLAB. employ bias-mitigation technique of hiding approximately 46% our total data and aggressively mask images to remove backgrounds. Given exposure after masking 100.72 gram-days well-performing sensors, we observe 55 two-electron events, 4 three-electron no events containing 4-10 electrons. The are consistent with pileup one-electron events. Among 2 appear pixels that likely...
We report a measurement of the energy spectrum cosmic rays above 2.5×1018 eV based on 215 030 events. New results are presented: at about 1.3×1019 eV, spectral index changes from 2.51±0.03(stat)±0.05(syst) to 3.05±0.05(stat)±0.10(syst), evolving 5.1±0.3(stat)±0.1(syst) beyond 5×1019 while no significant dependence features declination is seen in accessible range. These can be reproduced models with energy-dependent mass composition. The density 5×1018 [5.66±0.03(stat)±1.40(syst)]×1053 erg...
Neutrinos with energies above $10^{17}$ eV are detectable the Surface Detector Array of Pierre Auger Observatory. The identification is efficiently performed for neutrinos all flavors interacting in atmosphere at large zenith angles, as well Earth-skimming $\tau$ nearly tangential trajectories relative to earth. No neutrino candidates were found $\sim\,14.7$ years data taken up 31 August 2018. This leads restrictive upper bounds on their flux. $90\%$ C.L. single-flavor limit diffuse flux...
We present a new method for probing the hadronic interaction models at ultrahigh energy and extracting details about mass composition. This is done using time profiles of signals recorded with water-Cherenkov detectors Pierre Auger Observatory. The arise from mix muon electromagnetic components air showers. Using risetimes signals, we define parameter, which use to compare our observations predictions simulations. find, first, inconsistencies between data over greater range substantially...
We present a detailed study of the large-scale anisotropies cosmic rays with energies above 4 EeV measured using Pierre Auger Observatory. For energy bins [4,8] and $E\geq 8$ EeV, most significant signal is dipolar modulation in right ascension at 8 as previously reported. In this paper we further scrutinize highest-energy bin by splitting it into three ranges. find that amplitude dipole increases EeV. The growth can be fitted power law index $\beta=0.79\pm 0.19$. directions dipoles are...
We report a first measurement for ultra-high energy cosmic rays of the correlation between depth shower maximum and signal in water Cherenkov stations air-showers registered simultaneously by fluorescence surface detectors Pierre Auger Observatory. Such is unique feature hybrid air-shower observatory with sensitivity to both electromagnetic muonic components. It allows an accurate determination spread primary masses cosmic-ray flux. Up till now, constraints on have been dominated systematic...
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation power between photon and hadron primaries achieved combining measurements longitudinal air-shower development particle content at ground measured fluorescence surface detectors, respectively. Only three candidates 1–2 are found, which compatible expected hadron-induced background. Upper limits on...
We present a measurement of the cosmic-ray spectrum above 100\,PeV using part surface detector Pierre Auger Observatory that has spacing 750~m. An inflection is observed, confirming presence so-called \emph{second-knee} feature. The then combined with 1500\,m array to produce single flux, linking this spectral feature three additional breaks at highest energies. spectrum, an energy scale set calorimetrically via fluorescence telescopes and type, results in most statistically systematically...
We present the first measurement of fluctuations in number muons extensive air showers produced by ultrahigh energy cosmic rays. find that measured are good agreement with predictions from shower simulations. This observation provides new insights into origin previously reported deficit simulations and constrains models hadronic interactions at energies. Our is compatible muon originating small deviations interaction particle production accumulate as develop.
A promising energy range to look for angular correlation between cosmic rays of extragalactic origin and their sources is at the highest energies, above few tens EeV ($1\:{\rm EeV}\equiv 10^{18}\:$eV). Despite flux these particles being extremely low, area ${\sim}\:3{,}000 \: \text{km}^2$ covered Pierre Auger Observatory, 17-year data-taking period Phase 1 its operations, have enabled us measure arrival directions more than 2,600 ultra-high $32\:\text{EeV}$. We publish this data set, largest...
A novel readout architecture that uses multiple nondestructive floating-gate amplifiers (FGAs) to achieve subelectron noise in a thick, fully depleted silicon detector is presented. This multiple-amplifier sensing charge-coupled device (MAS-CCD) can perform independent charge measurements with each amplifier; then be combined further reduce the noise. allows getting operation less time compared single-nondestructive-amplifier CCDs. The performance of this demonstrated, emphasizing ability...
Millicharged particles, proposed by various extensions of the standard model, can be created in pairs high-energy photons within nuclear reactors and interact electromagnetically with electrons matter. Recently, existence a plasmon peak interaction cross section silicon eV range was highlighted as promising approach to enhance low-energy sensitivities. The CONNIE Atucha-II reactor neutrino experiments utilize Skipper-CCD sensors, which enable detection interactions range. We present...
We present measurements of the large-scale cosmic-ray anisotropies in right ascension, using data collected by surface detector array Pierre Auger Observatory over more than 14 years. determine equatorial dipole component, $\vec{d}_\perp$, through a Fourier analysis ascension that includes weights for each event so as to account main detector-induced systematic effects. For energies at which trigger efficiency is small, ``East-West'' method employed. Besides from with detectors separated...
With the Auger Engineering Radio Array (AERA) of Pierre Observatory, we have observed radio emission from 561 extensive air showers with zenith angles between 60$^\circ$ and 84$^\circ$. In contrast to more vertical incidence, these inclined illuminate large ground areas several km$^2$ signals detectable in 30 80\,MHz band. A comparison measured radio-signal amplitudes Monte Carlo simulations a subset 50 events for which reconstruct energy using surface detector shows agreement within...
Abstract The hybrid design of the Pierre Auger Observatory allows for measurement properties extensive air showers initiated by ultra-high energy cosmic rays with unprecedented precision. By using an array prototype underground muon detectors, we have performed first direct measurement, Collaboration, content between $$2\times 10^{17}$$ <mml:math...
We use a science-grade skipper charge-coupled device (skipper CCD) operating in low-radiation background environment to develop semiempirical model that characterizes the origin of single-electron events CCDs. identify, separate, and quantify three independent contributions events, which were previously bundled together classified as ``dark counts'': dark current, amplifier light, spurious charge. measure depends on exposure,...
Ultra-high-energy photons with energies exceeding $10^{17}$ eV offer a wealth of connections to different aspects cosmic-ray astrophysics as well gamma-ray and neutrino astronomy. The recent observations in the $10^{15}$ range further motivate searches for even higher-energy photons. In this paper, we present search $2{\times}10^{17}$ using about 5.5 years hybrid data from low-energy extensions Pierre Auger Observatory. upper limits on integral photon flux derived here are most stringent...