Physics Commons^™

Deep Exclusive Π+ Electroproduction Off The Proton At Clas, K. P. Adhikari, M. J. Amaryan, R. P. Bennett, G. E. Dodge, S. E. Kuhn, M. Mayer, C. S. Nepali, H. Seraydaryan, L. B. Weinstein, J. Zhang

Physics Faculty Publications

The exclusive electroproduction of π ⁺ above the resonance region was studied using the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Laboratory by scattering a 6GeV continuous electron beam off a hydrogen target. The large acceptance and good resolution of CLAS, together with the high luminosity, allowed us to measure the cross section for the γ ^* p → nπ ⁺ process in 140 (Q ², x _B , t) bins: 0.16 < x _B < 0.58, 1.6 GeV² < Q ² < 4.5 GeV² and 0.1 GeV² < −t < 5.3 GeV². For most bins, the statistical accuracy is on the order of a …

Demonstration Of A Novel Technique To Measure Two-Photon Exchange Effects In Elastic E±P Scattering, M. Niroula, L. B. Weinstein, D. Adikaram, J. Lanchiet, K. P. Adhikari, M. J. Amaryan, R. P. Bennett, C. E. Hyde, S.E. Kuhn, H. Seraydaryan

Physics Faculty Publications

Background: The discrepancy between proton electromagnetic form factors extracted using unpolarized and polarized scattering data is believed to be a consequence of two-photon exchange (TPE) effects. However, the calculations of TPE corrections have significant model dependence, and there is limited direct experimental evidence for such corrections.

Purpose: The TPE contributions depend on the sign of the lepton charge in e±p scattering, but the luminosities of secondary positron beams limited past measurement at large scattering angles, where the TPE effects are believe to be most significant. We present the results of a new experimental technique for making direct e±p comparisons, which …

Transverse Polarization Of Σ+ (1189) In Photoproduction On A Hydrogen Target In Clas, Clas Collaboration, C. S. Nepali, M. Amaryan, K. P. Adhikari, H. Baghdasaryan, S. Bültmann, N. Guler, C. E. Hyde, A. Klein, S. E. Kuhn, M. Mayer, H. Seraydaryan, B. Torayev, L. B. Weinstein

Physics Faculty Publications

Experimental results on the Σ⁺(1189) hyperon transverse polarization in photoproduction on a hydrogen target using the CLAS detector at Jefferson Laboratory are presented. The Σ⁺(1189) was reconstructed in the exclusive reaction γ+p→K⁰_S+Σ+(1189) via the Σ+→pπ⁰ decay mode. The K⁰_S was reconstructed in the invariant mass of two oppositely charged pions with the π⁰ identified in the missing mass of the detected pπ⁺π⁻ final state. Experimental data were collected in the photon energy range Eγ=1.0 –3.5 GeV (√s range 1.66–2.73 GeV). We observe a large negative polarization …

Rapidity Evolution Of Wilson Lines At The Next-To-Leading Order, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

At high energies, particles move very fast, so the proper degrees of freedom for the fast gluons moving along the straight lines are Wilson-line operators—infinite gauge factors ordered along the line. In the framework of operator expansion in Wilson lines, the energy dependence of the amplitudes is determined by the rapidity evolution of Wilson lines. We present the next-to-leading order hierarchy of the evolution equations for Wilson-line operators.

Photon Impact Factor And 𝑘T Factorization For Dis In The Next-To-Leading Order, Ian Balitsky, Giovanni A. Chirilli

Physics Faculty Publications

The photon impact factor for the Balitsky-Fadin-Kuraev-Lipatov pomeron is calculated in the next-to-leading order approximation using the operator expansion in Wilson lines. The result is represented as a next-to-leading order 𝑘_T-factorization formula for the structure functions of small-𝓍 deep inelastic scattering.