Deep Exclusive Electroproduction of π0 at High Q2 in the Quark Valence Regime

M. Dlamini , B. Karki , S.F. Ali , P.J. Lin (1) , F. Georges (1) , H.S. Ko (1) , N. Israel , M.N.H. Rashad , A. Stefanko , D. Adikaram , Z. Ahmed , H. Albataineh , B. Aljawrneh , K. Allada , S. Allison , S. Alsalmi , D. Androic , K. Aniol , J. Annand , H. Atac , T. Averett , C. Ayerbe Gayoso , X. Bai , J. Bane , S. Barcus , K. Bartlett , V. Bellini , R. Beminiwattha , J. Bericic , D. Biswas , E. Brash , D. Bulumulla , J. Campbell , A. Camsonne , M. Carmignotto , J. Castellano , C. Chen , J.P. Chen , T. Chetry , M.E. Christy , E. Cisbani , B. Clary , E. Cohen , N. Compton , J.C. Cornejo , S. Covrig Dusa , B. Crowe , S. Danagoulian , T. Danley , F. de Persio , W. Deconinck , M. Defurne (2) , C. Desnault (1) , D. Di , M. Duer , B. Duran , R. Ent , C. Fanelli , G. Franklin , E. Fuchey , C. Gal , D. Gaskell , T. Gautam , O. Glamazdin , K. Gnanvo , V.M. Gray , C. Gu , T. Hague , G. Hamad , D. Hamilton , K. Hamilton , O. Hansen , F. Hauenstein , W. Henry , D.W. Higinbotham , T. Holmstrom , T. Horn , Y. Huang , G.M. Huber , C. Hyde , H. Ibrahim , C.M. Jen , K. Jin , M. Jones , A. Kabir , C. Keppel , V. Khachatryan , P.M. King , S. Li , W. Li , J. Liu , H. Liu , A. Liyanage , J. Magee , S. Malace , J. Mammei , P. Markowitz , E. Mcclellan , F. Meddi , D. Meekins , K. Mesik , R. Michaels , A. Mkrtchyan , R. Montgomery , C. Munoz Camacho (1) , L.S. Myers , P. Nadel-Turonski , S.J. Nazeer , V. Nelyubin , D. Nguyen , N. Nuruzzaman , M. Nycz , O.F. Obretch , L. Ou , C. Palatchi , B. Pandey , S. Park , K. Park , C. Peng , R. Pomatsalyuk , E. Pooser , A.J.R. Puckett , V. Punjabi , B. Quinn , S. Rahman , P.E. Reimer , J. Roche , I. Sapkota , A. Sarty , B. Sawatzky , N.H. Saylor , B. Schmookler , M.H. Shabestari , A. Shahinyan , S. Sirca , G.R. Smith , S. Sooriyaarachchilage , N. Sparveris , R. Spies , T. Su , A. Subedi , V. Sulkosky , A. Sun , L. Thorne , Y. Tian , N. Ton , F. Tortorici , R. Trotta , G.M. Urciuoli , E. Voutier (1) , B. Waidyawansa , Y. Wang , B. Wojtsekhowski , S. Wood , X. Yan , L. Ye , Z. Ye , C. Yero , J. Zhang , Y. Zhao , P. Zhu

1 IJCLab - Laboratoire de Physique des 2 Infinis Irène Joliot-Curie
2 CEA - Commissariat à l'énergie atomique et aux énergies alternatives

We report measurements of the exclusive neutral pion electroproduction cross section off protons at large values of $x_B$ (0.36, 0.48, and 0.60) and $Q^2$ (3.1 to $8.4{\mathrm{GeV}}^2$) obtained from Jefferson Lab Hall A experiment E12-06-014. The corresponding structure functions $d{\sigma }_T/dt+\epsilon d{\sigma }_L/dt$, $d{\sigma }_{TT}/dt$, $d{\sigma }_{LT}/dt$, and $d{\sigma }_{L{T}^{\prime }}/dt$ are extracted as a function of the proton momentum transfer $t-t_{\min }$. The results suggest the amplitude for transversely polarized virtual photons continues to dominate the cross section throughout this kinematic range. The data are well described by calculations based on transversity generalized parton distributions coupled to a helicity flip distribution amplitude of the pion, thus providing a unique way to probe the structure of the nucleon.

Mots clés: experimental results; pi: distribution amplitude; pi0: electroproduction; generalized parton distribution: transversity; photon: virtual; quark: valence; p: structure function; momentum transfer dependence; Jefferson Lab; kinematics; helicity; polarization: transverse

Domaines: Physique des Hautes Energies - Expérience [hep-ex]; Physique Nucléaire Expérimentale [nucl-ex]

M. Dlamini, B. Karki, S.F. Ali, P.J. Lin, F. Georges, et al.. Deep Exclusive Electroproduction of π0 at High Q2 in the Quark Valence Regime. Physical Review Letters, 2021, 127 (15), pp.152301. ⟨10.1103/PhysRevLett.127.152301⟩. ⟨hal-03070639⟩