M. AckermannM. AjelloA. AlbertA. AllafortL. BaldiniG. BarbielliniD. BastieriK. BechtolR. BellazziniR. D. BlandfordE. D. BloomE. BonamenteE. BottaciniA. BouvierT. J. BrandtM. BrigidaP. BruelR. BuehlerS. BusonG. A. CaliandroR. A. CameronP. A. CaraveoC. CecchiE. CharlesR. C.G. ChavesA. ChekhtmanJ. ChiangG. ChiaroS. CipriniR. ClausJ. Cohen-TanugiJ. ConradS. CutiniM. DaltonF. DammandoA. De AngelisF. De PalmaC. D. DermerS. W. DigelL. Di VenereE. Do Couto E SilvaP. S. DrellA. Drlica-WagnerC. FavuzziS. J. FeganE. C. FerraraW. B. FockeA. FranckowiakY. FukazawaS. FunkP. FuscoF. GarganoD. GasparriniS. GermaniN. GigliettoF. GiordanoM. GirolettiT. GlanzmanG. GodfreyG. A. Gomez-VargasI. A. GrenierJ. E. GroveS. GuiriecM. GustafssonD. HadaschY. HanabataA. K. HardingM. HayashidaK. HayashiJ. W. HewittD. HoranX. HouR. E. HughesY. InoueM. S. JacksonT. JoglerG. JóhannessonA. S. JohnsonT. KamaeDeutsche Elektronen-SynchrotronSpace Sciences Laboratory at UC BerkeleyKavli Institute for Particle Astrophysics and CosmologyIstituto Nazionale di Fisica Nucleare, RomaUniversita degli Studi di TriesteIstituto Nazionale Di Fisica Nucleare, Sezione di PadovaUniversita degli Studi di PadovaUniversita degli Studi di PerugiaSanta Cruz Institute for Particle PhysicsNASA Goddard Space Flight CenterPolitecnico di BariLaboratoire Leprince-RinguetConsorzio Interuniversitario per la Fisica Spaziale (CIFS)INAF Istituto di Astrofisica Spaziale e Fisica Cosmica, MilanInstitut de Recherche sur les Lois Fondamentales de l'UniversGeorge Mason University, Fairfax CampusAgenzia Spaziale ItalianaOsservatorio Astronomico di RomaLaboratoire Univers et Particules de MontpellierStockholms universitetOskar Klein Centre for Cosmoparticle PhysicsKungl. VetenskapsakademienIN2P3 Institut National de Physique Nucleaire et de Physique des ParticulesIstituto Di Radioastronomia, BolognaUniversita degli Studi di UdineNaval Research LaboratoryFermi National Accelerator LaboratoryHiroshima UniversityUniversidad Autonoma de MadridUniversité libre de Bruxelles (ULB)Medizinische Universitat InnsbruckUniversity of TokyoJAXA Institute of Space and Astronautical ScienceOhio State UniversityThe Royal Institute of Technology (KTH)University Science Institute ReykjavikCNRS Centre National de la Recherche ScientifiqueUniversite de ToulouseUniversity of MarylandMahidol University2018-11-092018-11-092014-04-17Physical Review Letters. Vol.112, No.15 (2014)10797114003190072-s2.0-84898959342https://repository.li.mahidol.ac.th/handle/123456789/34926Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the -ray emission from Earthas limb for an indirect measurement of the local spectrum of CR protons in the energy range 90GeV-6TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68±0.04 and 2.61±0.08 above 200GeV, respectively. © 2014 American Physical Society.Mahidol UniversityPhysics and AstronomyArticleSCOPUS10.1103/PhysRevLett.112.151103