https://doi.org/10.1140/epjc/s10052-025-14967-4
Regular Article - Experimental Physics
Strong enhancement of electromagnetic shower development in oriented scintillating crystals and implications for particle detectors
1
INFN Laboratori Nazionali di Frascati, Frascati, Italy
2
Università degli Studi di Trieste, Trieste, Italy
3
INFN Sezione di Trieste, Trieste, Italy
4
Università degli Studi dell’Insubria, Como, Italy
5
INFN Sezione di Milano Bicocca, Milan, Italy
6
Università degli Studi di Padova, Padua, Italy
7
INFN Laboratori Nazionali di Legnaro, Legnaro, Italy
8
INFN Sezione di Ferrara, Ferrara, Italy
9
Università degli Studi di Ferrara, Ferrara, Italy
10
Institute for Nuclear Problems, Belarusian State University, Minsk, Belarus
11
Università degli Studi di Brescia, Brescia, Italy
12
CERN, Meyrin, Switzerland
13
École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
a
This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
11
July
2025
Accepted:
17
October
2025
Published online:
2
November
2025
Abstract
A particle traversing a crystal aligned with one of its crystallographic axes experiences a strong electromagnetic field that is constant along the direction of motion over macroscopic distances. For e± and 
-rays with energies above a few 
, this field is amplified by the Lorentz boost, to the point of exceeding the Schwinger critical field 
. In this regime, nonlinear quantum-electrodynamical effects occur, such as the enhancement of intense electromagnetic radiation emission and pair production, so that the electromagnetic shower development is accelerated and the effective shower length is reduced compared to amorphous materials. We have investigated this phenomenon in lead tungstate (
), a high-Z scintillator widely used in particle detection. We have observed a substantial increase in scintillation light at small incidence angles with respect to the main lattice axes. Measurements with 
electrons and -rays between 5 and 
demonstrate up to a threefold increase in energy deposition in oriented samples. These findings challenge the current models of shower development in crystal scintillators and could guide the development of next-generation accelerator- and space-borne detectors.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.
