http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Bosted, P. E.,Amaryan, M. J.,Anefalos Pereira, S.,Avakian, H.,Badui, R. A.,Ball, J.,Baltzell, N. A.,Battaglieri, M.,Batourine, V.,Bedlinskiy, I.,Biselli, A. S.,Briscoe, W. J.,Bü,ltmann, S.,Burkert American Physical Society 2017 Physical Review C Vol.95 No.3
<P>Beam-target double-spin asymmetries and target single-spin asymmetries were measured for the exclusive pi(+) electroproduction reaction. gamma(*) p -> n pi(+). The results were obtained from scattering of 6-GeV longitudinally polarized electrons off longitudinally polarized protons using the CEBAF Large Acceptance Spectrometer at Jefferson Laboratory. The kinematic range covered is 1.1 < W < 3 GeV and 1 < Q(2) < 6 GeV2. Results were obtained for about 6000 bins in W, Q(2), cos(theta(*)), and phi(*). Except at forward angles, very large target-spin asymmetries are observed over the entire W region. Reasonable agreement is found with phenomenological fits to previous data for W < 1.6 GeV, but very large differences are seen at higher values of W. A generalized parton distributions (GPD)-based model is in poor agreement with the data. When combined with cross-sectional measurements, the present results provide powerful constraints on nucleon resonance amplitudes at moderate and large values of Q(2), for resonances with masses as high as 2.4 GeV.</P>
Exclusive η electroproduction at W>2 GeV with CLAS and transversity generalized parton distributions
Bedlinskiy, I.,Kubarovsky, V.,Stoler, P.,Adhikari, K. P.,Akbar, Z.,Anefalos Pereira, S.,Avakian, H.,Ball, J.,Baltzell, N. A.,Battaglieri, M.,Batourine, V.,Biselli, A. S.,Boiarinov, S.,Briscoe, W. J.,B American Physical Society 2017 Physical Review C Vol.95 No.3
<P>The cross section of the exclusive eta electroproduction reaction ep -> e'p'eta was measured at Jefferson Laboratorywith a 5.75 GeV electron beam and the CLAS detector. Differential cross sections d(4) sigma/dtdQ(2) dx(B)d phi(eta) and structure functions sigma(U) = sigma(T) + epsilon sigma(L), sigma(TT), and sigma(LT), as functions of t, were obtained over a wide range of Q(2) and x(B). The eta structure functions are compared with those previously measured for pi(0) at the same kinematics. At low t, both pi(0) and eta are described reasonably well by generalized parton distributions (GPDs) in which chiral-odd transversity GPDs are dominant. The pi(0) and eta data, when taken together, can facilitate the flavor decomposition of the transversity GPDs.</P>
Beam-target double-spin asymmetry in quasielastic electron scattering off the deuteron with CLAS
Mayer, M.,Kuhn, S. E.,Adhikari, K. P.,Akbar, Z.,Anefalos Pereira, S.,Asryan, G.,Avakian, H.,Badui, R. A.,Ball, J.,Baltzell, N. A.,Battaglieri, M.,Bedlinskiy, I.,Biselli, A. S.,Boiarinov, S.,Bosted, P. American Physical Society 2017 Physical Review C Vol.95 No.2
<P>Conclusions: Final-state interactions seem to play a lesser role for polarization observables in deuteron two-body electrodisintegration than for absolute cross sections. Our data, while limited in statistical power, indicate that PWIA models work reasonably well to understand the asymmetries at lower missing momenta. In turn, this information can be used to extract the product of beam and target polarization (PbPt) from quasielastic electron-deuteron scattering, which is useful for measurements of spin observables in electron-neutron inelastic scattering. However, at the highest missing (neutron) momenta, FSI effects become important and must be accounted for.</P>
Dharmawardane, K.V.,Kuhn, S.E.,Bosted, P.,Prok, Y.,Adams, G.,Ambrozewicz, P.,Anghinolfi, M.,Asryan, G.,Avakian, H.,Bagdasaryan, H.,Baillie, N.,Ball, J.P.,Baltzell, N.A.,Barrow, S.,Batourine, V.,Battag Elsevier 2006 Physics letters: B Vol.641 No.1
<P><B>Abstract</B></P><P>We report results for the virtual photon asymmetry <SUB>A1</SUB> on the nucleon from new Jefferson Lab measurements. The experiment, which used the CEBAF Large Acceptance Spectrometer and longitudinally polarized proton (NH315) and deuteron (ND315) targets, collected data with a longitudinally polarized electron beam at energies between 1.6 GeV and 5.7 GeV. In the present Letter, we concentrate on our results for <SUB>A1</SUB>(x,<SUP>Q2</SUP>) and the related ratio <SUB>g1</SUB>/<SUB>F1</SUB>(x,<SUP>Q2</SUP>) in the resonance and the deep inelastic regions for our lowest and highest beam energies, covering a range in momentum transfer <SUP>Q2</SUP> from 0.05 to 5.0<SUP>(GeV/c)2</SUP> and in final-state invariant mass <I>W</I> up to about 3 GeV. Our data show detailed structure in the resonance region, which leads to a strong <SUP>Q2</SUP>-dependence of <SUB>A1</SUB>(x,<SUP>Q2</SUP>) for <I>W</I> below 2 GeV. At higher <I>W</I>, a smooth approach to the scaling limit, established by earlier experiments, can be seen, but <SUB>A1</SUB>(x,<SUP>Q2</SUP>) is not strictly <SUP>Q2</SUP>-independent. We add significantly to the world data set at high <I>x</I>, up to x=0.6. Our data exceed the SU(6)-symmetric quark model expectation for both the proton and the deuteron while being consistent with a negative <I>d</I>-quark polarization up to our highest <I>x</I>. This data set should improve next-to-leading order (NLO) pQCD fits of the parton polarization distributions.</P>
Beam-spin asymmetries from semi-inclusive pion electroproduction
Gohn, W.,Avakian, H.,Joo, K.,Ungaro, M.,Adhikari, K. P.,Aghasyan, M.,Amaryan, M. J.,Anderson, M. D.,Anefalos Pereira, S.,Ball, J.,Baltzell, N. A.,Battaglieri, M.,Biselli, A. S.,Bono, J.,Briscoe, W. J. American Physical Society 2014 PHYSICAL REVIEW D - Vol.89 No.7
Photoproduction ofΛand<sup>Σ0</sup>hyperons using linearly polarized photons
Paterson, C. A.,Ireland, D. G.,Livingston, K.,McKinnon, B.,Adhikari, K. P.,Adikaram, D.,Akbar, Z.,Amaryan, M.,Anefalos Pereira, S.,Badui, R. A.,Ball, J.,Baltzell, N. A.,Battaglieri, M.,Bedlinskiy, I. American Physical Society 2016 Physical review. C Vol.93 No.6
<P>Background: Measurements of polarization observables for the reactions (gamma) over right arrowp -> K+ Lambda and (gamma) over right arrowp -> K+ Sigma(0) have been performed. This is part of a program of measurements designed to study the spectrum of baryon resonances in particular, and nonperturbative QCD in general. Purpose: The accurate measurement of several polarization observables provides tight constraints for phenomenological fits, which allow the study of strangeness in nucleon and nuclear systems. Beam-recoil observables for the (gamma) over right arrowp -> K+ Sigma(0) reaction have not been reported before now. Method: Themeasurements were carried out using linearly polarized photon beams incident on a liquid hydrogen target, and the CLAS detector at the Thomas Jefferson National Accelerator Facility. The energy range of the results is 1.71 < W < 2.19 GeV, with an angular range -0.75 < cos theta(K)* < +0.85. Results: The observables extracted for both reactions are beam asymmetry Sigma, target asymmetry T, and the beam-recoil double polarization observables O-x and O-z. Conclusions: Comparison with theoretical fits indicates that, in the regions where no previous data existed, the new data contain significant new information, and strengthen the evidence for the set of resonances used in the latest Bonn-Gatchina fit.</P>
Measurement of semi-inclusiveπ+electroproduction off the proton
Osipenko, M.,Ripani, M.,Ricco, G.,Avakian, H.,De Vita, R.,Adams, G.,Amaryan, M. J.,Ambrozewicz, P.,Anghinolfi, M.,Asryan, G.,Bagdasaryan, H.,Baillie, N.,Ball, J. P.,Baltzell, N. A.,Barrow, S.,Battagli American Physical Society 2009 PHYSICAL REVIEW D - Vol.80 No.3