Demonstration of Sub-Percent Energy Resolution in the NEXT-100 Detector
Abstract
NEXT-100 is a high-pressure xenon time projection chamber with electroluminescent amplification, designed to operate with up to approximately 70.5 kg at 13.5 bar. It is the most recent detector developed by the NEXT collaboration to search for the neutrinoless double-beta decay () of Xe-136. The NEXT gas TPC technology offers the best energy resolution near the Q-value of the decay ( = 2458 keV) among xenon detectors, which is set by design to be <1% FWHM. We report here the high-energy calibration of the detector using a Th-228 source, demonstrating linear response and an energy resolution of % FWHM at the Tl-208 photopeak (2615 keV). This performance extrapolates to a resolution at the double-beta decay end-point of = % FWHM, confirming the detector's capability for precision energy measurement in the search for .
Keywords
Cite
@article{arxiv.2511.02467,
title = {Demonstration of Sub-Percent Energy Resolution in the NEXT-100 Detector},
author = {NEXT Collaboration and M. Pérez Maneiro and M. Martínez-Vara and S. Torelli and G. Martínez-Lema and P. Novella and J. A. Hernando Morata and J. J. Gómez-Cadenas and C. Adams and H. Almazán and V. Álvarez and A. I. Aranburu and L. Arazi and I. J. Arnquist and F. Auria-Luna and S. Ayet and Y. Ayyad and C. D. R. Azevedo and K. Bailey and F. Ballester and J. E. Barcelon and M. del Barrio-Torregrosa and A. Bayo and J. M. Benlloch-Rodríguez and F. I. G. M. Borges and A. Brodoline and N. Byrnes and A. Castillo and E. Church and L. Cid and M. Cid and X. Cid and C. A. N. Conde and C. Cortes-Parra and F. P. Cossío and R. Coupe and E. Dey and P. Dietz and C. Echeverria and M. Elorza and R. Esteve and R. Felkai and L. M. P. Fernandes and P. Ferrario and F. W. Foss and Z. Freixa and J. García-Barrena and J. W. R. Grocott and R. Guenette and J. Hauptman and C. A. O. Henriques and P. Herrero-Gómez and V. Herrero and C. Hervés Carrete and Y. Ifergan and A. F. B. Isabel and B. J. P. Jones and F. Kellerer and L. Larizgoitia and A. Larumbe and F. Lopez and N. López-March and R. Madigan and R. D. P. Mano and A. Marauri and A. P. Marques and J. Martín-Albo and A. Martínez and R. L. Miller and K. Mistry and J. Molina-Canteras and F. Monrabal and C. M. B. Monteiro and F. J. Mora and K. E. Navarro and D. R. Nygren and E. Oblak and J. Palacio and B. Palmeiro and I. Parmaksiz and A. Pazos and J. Pelegrin and M. Querol and J. Renner and I. Rivilla and C. Rogero and L. Rogers and B. Romeo and C. Romo-Luque and E. Ruiz-Chóliz and P. Saharia and F. P. Santos and J. M. F. dos Santos and M. Seemann and I. Shomroni and A. L. M. Silva and P. A. O. C. Silva and A. Simón and S. R. Soleti and M. Sorel and J. Soto-Oton and J. M. R. Teixeira and S. Teruel-Pardo and J. F. Toledo and C. Tonnelé and J. Torrent and A. Trettin and P. R. G. Valle and M. Vanga and P. Vázquez Cabaleiro and J. F. C. A. Veloso and J. D. Villamil and J. Waiton and A. Yubero-Navarro},
journal= {arXiv preprint arXiv:2511.02467},
year = {2026}
}