A glimpse of gluons through deeply virtual compton scattering on the proton.
M DefurneA Martí Jiménez-ArgüelloZ AhmedH AlbatainehK AlladaK A AniolV BelliniM BenaliW BoeglinP BertinM BrossardA CamsonneM CananS ChandavarC ChenJ-P ChenC W de JagerR de LeoC DesnaultA DeurL El FassiR EntD FlayM FriendE FucheyS FrullaniF GaribaldiD GaskellA GiusaO GlamazdinS GolgeJ GomezO HansenD HiginbothamT HolmstromT HornJ HuangM HuangC E HydeS IqbalF ItardH KangA KelleherC KeppelS KoiralaI KoroverJ J LeRoseR LindgrenE LongM MagneJ MammeiD J MargaziotisP MarkowitzM MazouzF MeddiD MeekinsR MichaelsM MihovilovicC Muñoz CamachoP Nadel-TuronskiN NuruzzamanR ParemuzyanA PuckettV PunjabiY QiangA RakhmanM N H RashadS RiordanJ RocheG RussoF SabatiéK SaenboonruangA SahaB SawatzkyL SelvyA ShahinyanS SircaP SolvignonM L SperdutoR SubediV SulkoskyC SuteraW A TobiasG M UrciuoliD WangB WojtsekhowskiH YaoZ H YeX ZhanJ ZhangB ZhaoZ ZhaoX ZhengP ZhuPublished in: Nature communications (2017)
The internal structure of nucleons (protons and neutrons) remains one of the greatest outstanding problems in modern nuclear physics. By scattering high-energy electrons off a proton we are able to resolve its fundamental constituents and probe their momenta and positions. Here we investigate the dynamics of quarks and gluons inside nucleons using deeply virtual Compton scattering (DVCS)-a highly virtual photon scatters off the proton, which subsequently radiates a photon. DVCS interferes with the Bethe-Heitler (BH) process, where the photon is emitted by the electron rather than the proton. We report herein the full determination of the BH-DVCS interference by exploiting the distinct energy dependences of the DVCS and BH amplitudes. In the regime where the scattering is expected to occur off a single quark, measurements show an intriguing sensitivity to gluons, the carriers of the strong interaction.