# A measurement of the proton plus helium spectrum of cosmic rays in the TeV region with HAWC

### Submission summary

 As Contributors: Juan Carlos Arteaga-Velazquez Arxiv Link: https://arxiv.org/abs/2208.13350v2 (pdf) Date accepted: 2022-10-03 Date submitted: 2022-09-28 15:40 Submitted by: Arteaga-Velazquez, Juan Carlos Submitted to: SciPost Physics Proceedings Proceedings issue: 21st International Symposium on Very High Energy Cosmic Ray Interactions (ISVHECRI 2022) Academic field: Physics Specialties: Gravitation, Cosmology and Astroparticle Physics Approaches: Experimental, Observational

### Abstract

HAWC is an air-shower detector designed to study TeV gamma and cosmic rays. The observatory is composed of a $22000 \, m^2$ array of $300$ water Cherenkov tanks ($4.5 \, m$ deep x $7.3 \, m$ diameter) with $4$ photomultipliers (PMT) each. The instrument registers the number of hit PMTs, the timing information and the total charge at the PMTs during the event. From these data, shower observables such as the arrival direction, the core position at ground, the lateral age and the primary energy are estimated. In this work, we study the distribution of the shower age vs the primary energy of a sample of shower data collected by HAWC from June 2015 to June 2019 and employ a shower-age cut based on predictions of QGSJET-II-04 to separate a subsample of events dominated by H and He primaries. Using these data and a dedicated analysis, we reconstruct the cosmic ray spectrum of H+He from $6$ to $158$ TeV, which shows the presence of a softening at around $24$ TeV with a statistical significance of $4.1\sigma$.

###### Current status:
Publication decision taken: accept

Editorial decision: For Journal SciPost Physics Proceedings: Publish
(status: Editorial decision fixed and (if required) accepted by authors)