LHCf experiment Homepage

Welcome to the LHCf - Florence web page

Short info about the LHCf experiment
A strong link between cosmic-ray and accelerator physics

LHCf is the smallest one of the six official LHC experiments. It will be installed on the LHC accelerator ring near the ATLAS experiment region. The aim of this experiment is the study at the LHC accelerator of the neutral-particle production cross sections in the very forward region of proton-proton and nucleus-nucleus interactions. Neutral pions, gammas and neutrons production will be investigated during the initial phase of the LHC running, at low luminosity (below 10³⁰cm^-2s^-1). This study will give important information for understanding the development of atmospheric showers induced by very high energy cosmic rays hitting the Earth atmosphere. Methods which are used to extract information about primary cosmic-ray radiation by means of atmospheric-shower experiments data, depend on the interaction model which is considered in shower development simulations. Using the statistics which can be accumulated in a few hours of data taking, LHCf will be able to check the validity of several interaction models' predictions in proton-proton interaction at an equivalent energy of 10¹⁷ev in the laboratory frame. Kinematical region accessed by the experiment can be improved during non-zero beam crossing angle runs and by moving the LHCf detectors with respect to their initial position by means of a remote control system, in such a way that different forward regions can be covered at different times.

In particular two main problems can be addressed by LHCf results at this energy: the first is the uncertainty of cosmic-ray spectrum composition between 10¹⁵eV and 10¹⁹eV; the latter is the interpretation of data around and beyond 10²⁰eV on the basis of GZK cutoff. Both these items are crucial for understanding the origin of cosmic rays.

The activity in Florence - Physics Department and INFN

"Polo Scientifico e Tecnologico" of the University of Florence is a campus which is operative since 2001 and which houses an important part of the scientific research in the Florence area. The main center of this campus is located near the Sesto Fiorentino village, at north-west of the Florence town. Since the opening of this campus, the Physics Department and the Section of Florence of INFN have been moved there, thus abandoning the historical location in Arcetri, now occupied by the GGI theoretical center.

Aiming to achieve important information concerning cosmic-ray interactions in atmosphere, the LHCf project has met the interest of the INFN Cosmic-Ray and High Energy Physics groups working in Florence. Thanks to the competence of these groups in the development of traking systems for high energy particles, based on the sophisticated technology of microstrip silicon detectors (see for example the PAMELA satellite experiment and the CMS experiment at LHC), a tracker based on this technology has been developed in Florence to be used for one of the two similar detectors which will be installed by the LHCf collaboration at the LHC. For details about the detectors technology you can visit section "The Experiment" in this site.