The DAMA/LIBRA experiment, operating at the Gran Sasso National Laboratory, has reported the first results of annual modulation in the search for dark matter (DM) particles. The experiment, which uses highly radiopure NaI(Tl) detectors, has an exposure of 0.53 ton·yr. Combined with the DAMA/NaI experiment, the total exposure is 0.82 ton·yr. The results show a modulation amplitude of (0.0131 ± 0.0016) cpd/kg/keV in the energy interval (2–6) keV, with a period of one year and a phase around June 2nd. These results support the presence of DM particles in the galactic halo at 8.2 σ confidence level. The annual modulation signature is distinctive and requires the modulation to occur in a specific energy range, with a single-hit event pattern, and a phase consistent with the Earth's orbital motion. The results are consistent with the DM annual modulation signature and are not explained by known systematic effects or side reactions. The experiment also confirms the presence of annual modulation in the (2–6) keV energy interval, with modulation amplitudes compatible with zero in higher energy intervals. The results are further supported by statistical analyses and power spectrum studies. The DAMA/LIBRA experiment has also confirmed the absence of significant background modulation in other energy regions. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature. The experiment has also shown that the modulation amplitudes are statistically well distributed in all the detectors and energy bins. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature. The experiment has also confirmed the absence of significant background modulation in other energy regions. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature.The DAMA/LIBRA experiment, operating at the Gran Sasso National Laboratory, has reported the first results of annual modulation in the search for dark matter (DM) particles. The experiment, which uses highly radiopure NaI(Tl) detectors, has an exposure of 0.53 ton·yr. Combined with the DAMA/NaI experiment, the total exposure is 0.82 ton·yr. The results show a modulation amplitude of (0.0131 ± 0.0016) cpd/kg/keV in the energy interval (2–6) keV, with a period of one year and a phase around June 2nd. These results support the presence of DM particles in the galactic halo at 8.2 σ confidence level. The annual modulation signature is distinctive and requires the modulation to occur in a specific energy range, with a single-hit event pattern, and a phase consistent with the Earth's orbital motion. The results are consistent with the DM annual modulation signature and are not explained by known systematic effects or side reactions. The experiment also confirms the presence of annual modulation in the (2–6) keV energy interval, with modulation amplitudes compatible with zero in higher energy intervals. The results are further supported by statistical analyses and power spectrum studies. The DAMA/LIBRA experiment has also confirmed the absence of significant background modulation in other energy regions. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature. The experiment has also shown that the modulation amplitudes are statistically well distributed in all the detectors and energy bins. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature. The experiment has also confirmed the absence of significant background modulation in other energy regions. The results are consistent with the presence of DM particles in the galactic halo and provide strong evidence for the annual modulation signature.