Recent results from the LHCf and RHICf experiments

¹ The LHCf Collaboration
² The RHICf Collaboration
³ Institute for Space-Earth Environment Research, Nagoya University, Nagoya, Japan
⁴ Kobayashi-Maskawa Institute for the Origin of Particles and the Universe, Nagoya University, Nagoya, Japan
⁵ Institute for Cosmic Ray Research, University of Tokyo, Kashiwa, Chiba, Japan
⁶ Research Institute for Science and Engineering, Waseda University, Shinjuku, Tokyo, Japan
⁷ Kanagawa University, Kanagawa, Japan
⁸ Tokushima University, Tokushima, Japan
⁹ Ecole-Polytechnique, Palaiseau, France
¹⁰ LBNL, Berkeley, CA, USA
¹¹ INFN Section of Florence, Florence, Italy
¹² University of Florence, Florence, Italy
¹³ IFAC-CNR, Florence, Italy
¹⁴ INFN Section of Catania, Catania, Italy
¹⁵ University of Catania, Catania, Italy
¹⁶ Riken Nishina Center for Accelerator-Based Science, Saitama, Japan
¹⁷ Riken BNL Research Center, Brookhaven National Laboratory, New York, USA
¹⁸ Seoul National University, Seoul, South Korea
¹⁹ Korea University, Seoul, South Korea
²⁰ Japan Atomic Energy Agency, Ibraki, Japan

^* e-mail: sako@icrr.u-tokyo.ac.jp

Published online: 10 May 2019

Abstract

The Large Hadron Collider forward and the Relativistic Heavy Ion Collider forward experiments measured forward particles produced in high-energy hadron collisions at the LHC and RHIC. Using compact calorimeters neutral particles produced in pseudorapidities η >8.4 and η >6.0 are observed by the respective experiments. Because the collision energies ranging from 0.51 TeV to 13 TeV correspond to the cosmic-ray equivalent energies of 10¹⁴ to 10¹⁷ eV, the measurements are important to understand the hadronic interaction relevant to extensive air shower measurements. This paper reviews recent results of LHCf and initial performance of RHICf that took data in the 2017 RHIC operation.