http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Kim, A.,Avakian, H.,Burkert, V.,Joo, K.,Kim, W.,Adhikari, K.P.,Akbar, Z.,Anefalos Pereira, S.,Badui, R.A.,Battaglieri, M.,Batourine, V.,Bedlinskiy, I.,Biselli, A.S.,Boiarinov, S.,Bosted, P.,Briscoe, W North-Holland Pub. Co 2017 Physics letters. Section B Vol.768 No.-
<P><B>Abstract</B></P> <P>The target and double spin asymmetries of the exclusive pseudoscalar channel e → p → → e p <SUP> π 0 </SUP> were measured for the first time in the deep-inelastic regime using a longitudinally polarized 5.9 GeV electron beam and a longitudinally polarized proton target at Jefferson Lab with the CEBAF Large Acceptance Spectrometer (CLAS). The data were collected over a large kinematic phase space and divided into 110 four-dimensional bins of <SUP> Q 2 </SUP> , <SUB> x B </SUB> , −<I>t</I> and <I>ϕ</I>. Large values of asymmetry moments clearly indicate a substantial contribution to the polarized structure functions from transverse virtual photon amplitudes. The interpretation of experimental data in terms of generalized parton distributions (GPDs) provides the first insight on the chiral-odd GPDs <SUB> H ˜ T </SUB> and <SUB> E T </SUB> , and complement previous measurements of unpolarized structure functions sensitive to the GPDs <SUB> H T </SUB> and <SUB> E ¯ T </SUB> . These data provide a crucial input for parametrizations of essentially unknown chiral-odd GPDs and will strongly influence existing theoretical calculations based on the handbag formalism.</P>
Radiative decays of theΣ0(1385)andΛ(1520)hyperons
Taylor, S.,Mutchler, G. S.,Adams, G.,Ambrozewicz, P.,Anciant, E.,Anghinolfi, M.,Asavapibhop, B.,Asryan, G.,Audit, G.,Avakian, H.,Bagdasaryan, H.,Ball, J. P.,Barrow, S.,Batourine, V.,Battaglieri, M.,Be American Physical Society 2005 PHYSICAL REVIEW C - Vol.71 No.5
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>
Photoproduction of the<sub>f1</sub>(1285)meson
Dickson, R.,Schumacher, R. A.,Adhikari, K. P.,Akbar, Z.,Amaryan, M. J.,Anefalos Pereira, S.,Badui, R. A.,Ball, J.,Battaglieri, M.,Batourine, V.,Bedlinskiy, I.,Biselli, A.,Boiarinov, S.,Briscoe, W. J. American Physical Society 2016 Physical Review C Vol.93 No.6
<P>The f(1)(1285) meson withmass 1281.0 +/- 0.8MeV/c(2) and width 18.4 +/- 1.4MeV (full width at half maximum) was measured for the first time in photoproduction from a proton target using CLAS at Jefferson Lab. Differential cross sections were obtained via the eta pi(+)pi(-), K+(K) over bar (0) pi(-), and (K-K0)pi(+) decay channels from threshold up to a center-of-mass energy of 2.8 GeV. The mass, width, and an amplitude analysis of the eta pi(+)pi(-) final-state Dalitz distribution are consistent with the axial-vector J(P) = 1(+) f(1)(1285) identity, rather than the pseudoscalar 0(-) eta(1295). The production mechanism is more consistent with s-channel decay of a high-mass N* state and not with t-channel meson exchange. Decays to eta pi pi go dominantly via the intermediate a(0)(+/-) (980)pi(-/+) states, with the branching ratio Gamma [a(0)pi (no (K) over barK)]/Gamma[eta pi pi (all)] = 0.74 +/- 0.09. The branching ratios Gamma (K (K) over bar pi)/Gamma(eta pi pi) = 0.216 +/- 0.033 and Gamma (gamma rho(0))/Gamma(eta pi pi) = 0.047 +/- 0.018 were also obtained. The first is in agreement with previous data for the f(1)(1285), while the latter is lower than the world average.</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>
The extraction of φ–N total cross section from d(γ,p<sup>K+</sup><sup>K−</sup>)n
Qian, X.,Chen, W.,Gao, H.,Hicks, K.,Kramer, K.,Laget, J.M.,Mibe, T.,Stepanyan, S.,Tedeschi, D.J.,Xu, W.,Adhikari, K.P.,Amaryan, M.,Anghinolfi, M.,Baghdasaryan, H.,Ball, J.,Battaglieri, M.,Batourine, V Elsevier 2009 Physics letters: B Vol.680 No.5
<P><B>Abstract</B></P><P>We report on the first measurement of the differential cross section of <I>φ</I>-meson photoproduction for the d(γ,p<SUP>K+</SUP><SUP>K−</SUP>)n exclusive reaction channel. The experiment was performed using a tagged-photon beam and the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab. A combined analysis using data from the d(γ,p<SUP>K+</SUP><SUP>K−</SUP>)n channel and those from a previous publication on coherent <I>φ</I> production on the deuteron has been carried out to extract the φ−N total cross section, <SUB>σφN</SUB>. The extracted φ−N total cross section favors a value above 20 mb. This value is larger than the value extracted using vector-meson dominance models for <I>φ</I> photoproduction on the proton.</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>