In this paper we will present the design and expected performance for the Electromagnetic and Small Angle Calorimeters (ECAL, SAC) of the PADME experiment. The design of the calorimeters has been ...optimized for the detection of the final state γ from the annihilation production (and subsequent “invisible” decay) of a “Dark Photon” produced by a positron beam on a thin, low Z target. Beam tests have been made in 2016 and 2017 at the INFN Frascati National Laboratories Linac Beam Test Facility (BTF) with positron beams of energy 100–400 MeV and results are presented. The PADME experiment will be built at the INFN Frascati National Laboratories by the end of 2017 and will be taking data in 2018 (and possibly also 2019). At the moment the collaboration is composed by the following institutions: INFN Roma and “La Sapienza” University of Roma, INFN Frascati, INFN Lecce and University of Salento, MTA Atomki Debrecen, University of Sofia, Cornell University, U.S. William and Mary College.
A
bstract
This paper presents a detailed characterization of the positron beam delivered by the Beam Test Facility at Laboratori Nazionali of Frascati to the PADME experiment during Run III, which ...took place from October to December 2022. It showcases the methodology used to measure the main beam parameters such as the position in space, the absolute momentum scale, the beam energy spread, and its intensity through a combination of data analysis and Monte Carlo simulations. The results achieved include an absolute precision in the momentum of the beam to within ~1–2 MeV
/c
, a relative beam energy spread below 0.25%, and an absolute precision in the intensity of the beam at the level of 2%.
The PADME beam line Monte Carlo simulation Bossi, F.; Branchini, P.; Buonomo, B. ...
The journal of high energy physics,
09/2022, Letnik:
2022, Številka:
9
Journal Article
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A
bstract
The PADME experiment at the DAΦNE Beam-Test Facility (BTF) of the INFN Laboratory of Frascati is designed to search for invisible decays of dark sector particles produced in ...electron-positron annihilation events with a positron beam and a thin fixed target, by measuring the missing mass of single-photon final states. The presence of backgrounds originating from beam halo particles can significantly reduce the sensitivity of the experiment. To thoroughly understand the origin of the beam background contribution, a detailed G
eant
4-based Monte Carlo simulation has been developed, containing a full description of the detector together with the beam line and its optical elements. This simulation allows the full interactions of each particle to be described, both during beam line transport and during detection, a possibility which represents an innovative way to obtain reliable background predictions.
The PADME experiment will search for the <inline-formula> <tex-math notation="LaTeX">e^{+} e^{-} \rightarrow \gamma A^{\prime } </tex-math></inline-formula> process in a positron-on-target ...experiment, assuming a decay of the <inline-formula> <tex-math notation="LaTeX">A^{\prime } </tex-math></inline-formula> into invisible particles of the hidden sector. The 550-MeV positron beam of the DA<inline-formula> <tex-math notation="LaTeX">\Phi </tex-math></inline-formula>NE beam-test facility (BTF), at Laboratori Nazionali di Frascati, Istituto Nazionale di Fisica Nucleare, will be used. The suppression of the background, due to bremsstrahlung emission from the beam positrons, requires highly efficient charged-particle detectors with optimized geometry. A fine-grained plastic scintillator veto composed of three stations operating in vacuum is proposed. Two stations, placed inside a dipole magnet with 0.6-T magnetic field, will also provide momentum measurement at the percent level. Different prototypes for the design of the detector elements, the photosensor, and the front-end electronics were studied with single electron beam at the DA<inline-formula> <tex-math notation="LaTeX">\Phi </tex-math></inline-formula>NE BTF to choose the optimal technologies and construction solutions. PADME is currently under construction, and it is planned to begin data collection in 2018. The design of the charged-particle vetoes and the test beam performance of the prototypes are reviewed.
Abstract
The PADME experiment is designed to search for a
hypothetical dark photon
A
'
produced in positron-electron
annihilation using a bunched positron beam at the Beam Test Facility
of the INFN ...Laboratori Nazionali di Frascati. The expected
sensitivity to the
A
'
-photon mixing parameter
ϵ
is 10
-3
, for
A
'
mass ≤ 23.5 MeV/
c
2
after
collecting ∼ 10
13
positrons-on-target.
This paper presents the PADME detector status after commissioning in
July 2019. In addition, the software algorithms employed to
reconstruct physics objects, such as photons and charged particles,
and the calibration procedures adopted are illustrated in detail.
The results show that the experimental apparatus reaches the design
performance, and is able to identify and measure standard
electromagnetic processes, such as positron bremsstrahlung and
electron-positron annihilation into two photons.
ABSTRACT We present results demonstrating the time resolution and /e separation capabilities of a new concept for an EAS detector capable of measuring cosmic rays arriving with large zenith angles. ...This kind of detector has been designed to be part of a large area (several square kilometer) surface array designed to measure ultra high energy (10-200 PeV) τ neutrinos using the Earth-skimming technique. A criterion to identify electron-gammas is also shown and the particle identification capability is tested by measurements in coincidence with the KASKADE-GRANDE experiment in Karlsruhe, Germany.
Abstract
During 2022 data taking (Run III) PADME searched for a resonant production and a visible decay of the X17 particle into e
+
e
-
. A precise knowledge within 1% uncertainty of the number of ...positrons was required for the observation. To that purpose, an array of 2 × 6 Timepix3 (total of 512 × 1536 pixels) hybrid pixel detectors operated in data-streaming mode with ToA resolution of 1.56 ns for every pixel was employed. Two methods for data acquisition were developed. A frame-based method, integrating the number of hits for each individual pixel for a predefined period of time served for monitoring the beam conditions and to provide a rough estimation of the beam distribution and number of positrons. A data streaming mode exploiting the nanosecond time resolution of Timepix3 detector was used for precise characterization of the transverse beam profile and the distribution of the incident positrons within each bunch of ∼ 200 ns duration.
The PADME experiment at the LNF Beam Test Facility searches for dark photons produced in the annihilation of positrons with the electrons of a fixed target. The strategy is to look for the reaction ...e++e−→γ+A′, where A′ is the dark photon, which cannot be observed directly or via its decay products. The electromagnetic calorimeter plays a key role in the experiment by measuring the energy and position of the final-state γ. The missing four-momentum carried away by the A′ can be evaluated from this information and the particle mass inferred. This paper presents the design, construction, and calibration of the PADME's electromagnetic calorimeter. The results achieved in terms of equalisation, detection efficiency and energy resolution during the first phase of the experiment demonstrate the effectiveness of the various tools used to improve the calorimeter performance with respect to earlier prototypes.
Abstract
The PADME experiment at LNF-INFN employs positron-on-target-annihilation
to search for new light particles. Crucial parts of the experiment are the charged
particle detectors, composed of ...plastic scintillator bars with light transmitted
by wavelength shifting fibers to silicon photomultipliers (SiPMs). The location of
the detector — close to a turbomolecular pump, inside a vacuum tank, and exposed
to 0.5 T magnetic field — has driven the design of custom modular SiPM front-end
and power supply electronics. The design of the system and its performance, confirming
the desired sub-ns resolution on the reconstructed particle flying times, is shown
and discussed.
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