Measurement of Exclusive<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi>π</mml:mi><mml:mn>0</mml:mn></mml:msup></mml:math>Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

Bedlinskiy, I.; Kubarovsky, V.; Niccolai, S.; Stoler, P.; Adhikari, K. P.; Aghasyan, M.; Amaryan, M. J.; Anghinolfi, M.; Avakian, H.; Baghdasaryan, H.; Ball, J.; Baltzell, N. A.; Battaglieri, M.; Bennett, R.; Biselli, A. S.; Bookwalter, C.; Boiarinov, S.; Briscoe, W. J.; Brooks, W. K.; Burkert, V. D.; Carman, D. S.; Celentano, A.; Chandavar, S.; Charles, G.; Contalbrigo, M.; Credé, V.; D’Angelo, A.; Daniel, A.; Dashyan, N.; Vita, R. De; Sanctis, E. De; Deur, A.; Djalali, C.; Doughty, D.; Dupré, R.; Egiyan, H.; Alaoui, A. El; Fassi, L. El; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fleming, J. A.; Forest, T. A.; Fradi, A.; Garçon, M.; Gevorgyan, N.; Giovanetti, K. L.; Girod, F. X.; Gohn, W.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guo, L.; Hafidi, K.; Hakobyan, H.; Hanretty, C.; Heddle, D.; Hicks, K.; Holtrop, M.; Ilieva, Y.; Ireland, D. G.; Ишханов, Б. С.; Isupov, E. L.; Jo, H. S.; Joo, K. S.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, F. J.; Koirala, S.; Kubarovsky, A.; Kuhn, S. E.; Kuleshov, S.; Kvaltine, N. D.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Mao, Y.; Markov, N.; Martinez, D.; Mayer, M.; McKinnon, B.; Meyer, C. A.; Mineeva, T.; Mirazita, M.; Mokeev, V.; Moutarde, H.; Munévar, E.; Camacho, C. Muñoz; Nadel-Turoński, P.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Pappalardo, L. L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Pereira, S. Anefalos; Phelps, E.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Puckett, A. J. R.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Rosner, G.; Rossi, P.; Sabatié, F.; Saini, M. S.; Salgado, C.; Saylor, N. A.; Schott, D.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Sokhan, D.; Stepanyan, S.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C.; Tian, Ye; Tkachenko, S.; Ungaro, M.; Vineyard, M. F.; Vlassov, A. V.; Voskanyan, H.; Voutier, E.; Walford, N. K.; Watts, D. P.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zachariou, N.; Zhang, J.; Zhao, Z. W.; Zonta, I.

doi:10.1103/physrevlett.109.112001

Cited by 58 publications

(32 citation statements)

References 18 publications

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“…The d(e, e π 0 )d structure functions are found compatible with zero within uncertainties. The nucleon results show a dominance of the transverse response confirming previous indications from σ U measurements in Jefferson Lab [10,11], while the terms involving a longitudinal response are compatible with zero within uncertainties. The interference term σ T T is found negative and larger than σ T L .…”

Section: π 0 Electroproduction Resultssupporting

confidence: 85%

Photon and $\pi^0$ electroproduction in Jlab Hall A (6 GeV experiements)

Mazouz¹

2018

Proceedings of XVII International Conference on Hadron Spectroscopy and Structure — PoS(Hadron2017)

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Generalized Parton Distribution (GPDs) are universal functions which provide a comprehensive description of hadron properties in terms of quarks and gluons. GPDs can be accessed experimentally with hard exclusive processes such as Deeply Virtual Compton Scattering (DVCS) and deeply virtual π 0 production. Two experiments were performed in the Hall A of Jefferson Lab to measure the unpolarized cross sections of these two processes off the proton and off the neutron in the valence region (x B =0,36) at Q 2 ≈2 GeV 2 . After a brief description of the experimental setup, the DVCS off the proton results will be discussed and interpreted as being unexpectedly sensitive to gluons. Then, the longitudinal/transverse separation of the π 0 electoproduction cross sections, showing a dominance of the transverse terms, will be presented. Finally, an estimation of the quarks up and down contributions to the π 0 electroproduction cross sections, by combining the proton and the neutron measurements, will be shown.

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Section: π 0 Electroproduction Resultssupporting

confidence: 85%

Photon and $\pi^0$ electroproduction in Jlab Hall A (6 GeV experiements)

Mazouz¹

2018

Proceedings of XVII International Conference on Hadron Spectroscopy and Structure — PoS(Hadron2017)

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“…The fact that ðdσ T =dtÞ ≫ ðdσ L =dtÞ shows that this kinematic regime is still far from the asymptotic prediction of perturbative QCD. These results are compared to previous unseparated measurements at similar kinematics from the Hall A [12] (Q 2 ¼ 1.9 GeV 2 , x B ¼ 0.36) and CLAS [13,14] …”

mentioning

confidence: 78%

“…On the other hand, the collinear approximation underestimates by about one order of magnitude the total π 0 electroproduction cross sections measured at Q 2 ≃ 2 GeV 2 by the Hall A [12] and CLAS [13,14] Collaborations at Jefferson Lab (JLab). It was suggested in Refs.…”

mentioning

confidence: 94%

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Rosenbluth Separation of the π0 Electroproduction Cross Section

Defurne¹,

Mazouz²,

Ahmed³

et al. 2016

Phys. Rev. Lett.

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“…This novel development emerges from recent experimental and theoretical advances in the study of the 3D structure of the nucleon. Current and future planned experiments on dihadron semi-inclusive and deeply virtual exclusive pseudoscalar meson (π o and η) electroproduction at Jefferson Laboratory [21,22] and COMPASS [23,24] allow us to measure g T with improving accuracy. The main outcome of the analysis presented here is that the new, more precise measurements of the tensor charge provide, for the first time, a constraint from experiment on the hadronic matrix element in BSM searches.…”

mentioning

confidence: 99%

Beyond-Standard-Model Tensor Interaction and Hadron Phenomenology

Courtoy¹,

Baeßler²,

González–Alonso³

et al. 2015

Phys. Rev. Lett.

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We evaluate the impact of recent developments in hadron phenomenology on extracting possible fundamental tensor interactions beyond the standard model. We show that a novel class of observables, including the chiral-odd generalized parton distributions, and the transversity parton distribution function can contribute to the constraints on this quantity. Experimental extractions of the tensor hadronic matrix elements, if sufficiently precise, will provide a, so far, absent testing ground for lattice QCD calculations. DOI: 10.1103/PhysRevLett.115.162001 PACS numbers: 13.60.Hb, 13.40.Gp, 24.85.+p High precision measurements of beta decay observables play an important role in beyond the standard model (BSM) physics searches, as they allow us to probe couplings other than of the V − A type, which could appear at the low energy scale. Experiments using cold and ultracold neutrons [1][2][3][4], nuclei [5][6][7][8], and meson rare decays [9] are being performed, or have been planned, that can reach the per-mil level or even higher precision. Effective field theory (EFT) allows one to connect these measurements and BSM effects generated at TeV scales. In this approach that complements collider searches, the new interactions are introduced in an effective Lagrangian describing semileptonic transitions at the GeV scale including four-fermion terms, or operators up to dimension six for the scalar, tensor, pseudoscalar, and V þ A interactions (for a review of the various EFT approaches, see Ref.[10]). Because the strength of the new interactions is defined with respect to the strength of the known SM interaction, the coefficients of the various terms, ϵ i , (i ¼ S; T; P; L; R) depend on the ratio m 2 W =Λ 2 i , where Λ i is the new physics scale relevant for these nonstandard interactions, and mW Þ. Therefore, the precision with which ϵ i ∝ m 2 W =Λ 2 i , is known determines a lower limit for Λ i . The scalar (S) and tensor (T) operators, in particular, contribute linearly to the beta decay parameters through their interference with the SM amplitude, and they are, therefore, more easily detectable. The matrix elements or transition amplitudes between neutron and proton states of all quark bilinear Lorentz structures in the effective Lagrangian which are relevant for beta decay observables, involve products of the BSM couplings, ϵ i , and the corresponding hadronic charges, g i , i.e., considering only terms with left-handed neutrinos,whereSðTÞ , characterize nucleon structure; however, at variance with the electroweak currents, there exists no fundamental coupling to these charges in the standard model. Therefore, they cannot be measured directly in elastic scattering processes. This Letter is concerned with an alternative approach aimed at extracting the hadronic charges from experimental data obtained in electron scattering. In previous work, various approaches have been developed to calculate these quantities including lattice QCD [11][12][13][14][15], and most recently, Dyson-Schwinger equations [16,17]. Lattice QCD ...

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Measurement of Exclusiveπ0Electroproduction Structure Functions and their Relationship to Transverse Generalized Parton Distributions

Cited by 58 publications

References 18 publications

Photon and $\pi^0$ electroproduction in Jlab Hall A (6 GeV experiements)

Photon and $\pi^0$ electroproduction in Jlab Hall A (6 GeV experiements)

Rosenbluth Separation of the π0 Electroproduction Cross Section

Beyond-Standard-Model Tensor Interaction and Hadron Phenomenology

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