arXiv subjects

P. Perez

Publications and source records attributed to P. Perez.

6 recordsLinked to original sources

arXiv2025

CERN AD/ELENA Antimatter Program

The CERN AD/ELENA Antimatter program studies the fundamental charge, parity, time (CPT) reversal invariance through high-precision studies of antiprotons, antihydrogen, and antiprotonic atoms. Utilizing the world-unique Antiproton Decelerator (AD) and the Extra Low Energy Antiproton (ELENA) decelerator, the program supports multiple groundbreaking experiments aimed at testing fundamental symmetries, probing gravity with antimatter, and investigating potential asymmetric antimatter/dark matter interactions. Some experiments focus on precision spectroscopy of antihydrogen, while others conduct the most precise tests of CPT invariance in the baryon sector by comparing proton and antiproton properties. Other efforts are dedicated to measure the ballistic properties of antihydrogen under gravity and performing antiproton-based studies of neutron skins in exotic nuclei. These efforts have led to major breakthroughs, including the first trapped antihydrogen, antihydrogen's first gravitational acceleration measurement, and record-breaking precision CPT-tests in the baryon sector. With continuous advancements in antimatter cooling, trapping, and transport, CERN's program is opening new frontiers in fundamental physics. Future goals, described in this document and reaching to timelines beyond 2040, include further improving the precision of antimatter studies, developing transportable antimatter traps, and advancing our understanding of quantum field theory, gravity, and dark matter interactions. Furthermore, new areas of hadron physics with antiprotons will be explored through studies of the Pontecorvo reaction, antineutron annihilation dynamics and hypernuclei decays. The CERN AD/ELENA Antimatter program remains at the forefront of experimental physics, pushing the limits of precision measurements to unravel the mysteries of the universe.

nucl-ex↗

arXiv2022

Positron accumulation in the GBAR experiment

We present a description of the GBAR positron (e+) trapping apparatus, which consists of a three stage Buffer Gas Trap (BGT) followed by a High Field Penning Trap (HFT), and discuss its performance. The overall goal of the GBAR experiment is to measure the acceleration of the neutral antihydrogen (H) atom in the terrestrial gravitational field by neutralising a positive antihydrogen ion (H+), which has been cooled to a low temperature, and observing the subsequent H annihilation following free fall. To produce one H+ ion, about 10^10 positrons, efficiently converted into positronium (Ps), together with about 10^7 antiprotons (p), are required. The positrons, produced from an electron linac-based system, are accumulated first in the BGT whereafter they are stacked in the ultra-high vacuum HFT, where we have been able to trap 1.4(2) x 10^9 positrons in 1100 seconds.

physics.plasm-ph↗

arXiv2020

Positron production using a 9 MeV electron linac for the GBAR experiment

For the GBAR (Gravitational Behaviour of Antihydrogen at Rest) experiment at CERN's Antiproton Decelerator (AD) facility we have constructed a source of slow positrons, which uses a low-energy electron linear accelerator (linac). The driver linac produces electrons of 9 MeV kinetic energy that create positrons from bremsstrahlung-induced pair production. Staying below 10 MeV ensures no persistent radioactive activation in the target zone and that the radiation level outside the biological shield is safe for public access. An annealed tungsten-mesh assembly placed directly behind the target acts as a positron moderator. The system produces $5\times10^7$ slow positrons per second, a performance demonstrating that a low-energy electron linac is a superior choice over positron-emitting radioactive sources for high positron flux.

physics.ins-det↗

arXiv2011

The Vista Variables in the Via Lactea (VVV) ESO Public Survey: Current Status and First Results

Vista Variables in the Via Lactea (VVV) is an ESO Public Survey that is performing a variability survey of the Galactic bulge and part of the inner disk using ESO's Visible and Infrared Survey Telescope for Astronomy (VISTA). The survey covers 520 deg^2 of sky area in the ZYJHK_S filters, for a total observing time of 1929 hours, including ~ 10^9 point sources and an estimated ~ 10^6 variable stars. Here we describe the current status of the VVV Survey, in addition to a variety of new results based on VVV data, including light curves for variable stars, newly discovered globular clusters, open clusters, and associations. A set of reddening-free indices based on the ZYJHK_S system is also introduced. Finally, we provide an overview of the VVV Templates Project, whose main goal is to derive well-defined light curve templates in the near-IR, for the automated classification of VVV light curves.

astro-ph.GA↗

arXiv2004

Intense Source of Slow Positrons

We describe a novel design for an intense source of slow positrons based on pair production with a beam of electrons from a 10 MeV accelerator hitting a thin target at a low incidence angle. The positrons are collected with a set of coils adapted to the large production angle. The collection system is designed to inject the positrons in a Greaves-Surko trap [1]. Such a source could be the basis for a series of experiments in fundamental and applied research and would also be a prototype source for industrial applications which concern the field of defect characterization in the nanometer scale.

hep-ex↗

arXiv1996

Determination of the mass of the W boson

Previous studies of the physics potential of LEP2 indicated that with the design luminosity of 500 inverse picobarn one may get a direct measurement of the mass of the W-boson with a precision in the range 30 - 50 MeV. This report presents an updated evaluation of the estimated error on the mass of the W-boson based on recent simulation work and improved theoretical input. The most efficient experimental methods which will be used are also described.

hep-ph↗