Eur. Phys. J. C (2014) 74: 2827
https://doi.org/10.1140/epjc/s10052-014-2827-1

Regular Article - Experimental Physics

Model independent result on possible diurnal effect in DAMA/LIBRA-phase1

¹ Dip. di Fisica, Università di Roma “Tor Vergata”, 00133 , Rome, Italy
² INFN, sez. Roma “Tor Vergata”, 00133 , Rome, Italy
³ Dip. di Fisica, Università di Roma “La Sapienza”, 00185 , Rome, Italy
⁴ INFN, sez. Roma, 00185 , Rome, Italy
⁵ Laboratori Nazionali del Gran Sasso, INFN, Assergi, Italy
⁶ Institute of High Energy Physics, Chinese Academy of Sciences, P.O. Box 918/3, Beijing, 100049, China
⁷ Dip. di Ingegneria Civile e Ingegneria Informatica, Università di Roma “Tor Vergata”, 00133 , Rome, Italy
⁸ University of Jing Gangshan, Jiangxi, China

^* e-mail: rita.bernabei@roma2.infn.it

Received: 6 December 2013
Accepted: 18 March 2014
Published online: 27 March 2014

Abstract

The results obtained in the search for possible diurnal effect in the single-hit low energy data collected by DAMA/LIBRA-phase1 (total exposure 1.04 ton year) deep underground at the Gran Sasso National Laboratory (LNGS) of the INFN are presented. At the present level of sensitivity the presence of any significant diurnal variation and of diurnal time structures in the data can be excluded for both the cases of solar and sidereal time. In particular, the diurnal modulation amplitude expected, because of the Earth diurnal motion, on the basis of the DAMA dark matter annual modulation results is below the present sensitivity.