Test of low-energy theorems for 1H(γover-right-arrow,π0)1H in the threshold region -: art. no. 232501

被引:74
作者
Schmidt, A
Achenbach, P
Ahrens, J
Arends, HJ
Beck, R [1 ]
Bernstein, AM
Hejny, V
Kotulla, M
Krusche, B
Kuhr, V
Leukel, R
MacGregor, IJD
McGeorge, JC
Metag, V
de León, VMO
Rambo, F
Siodlaczek, U
Ströher, H
Walcher, T
Weiss, J
Wissmann, F
Wolf, M
机构
[1] Johannes Gutenberg Univ Mainz, Inst Kernphys, D-55099 Mainz, Germany
[2] MIT, Dept Phys, Boston, MA USA
[3] MIT, Nucl Sci Lab, Boston, MA USA
[4] Forschungszentrum Julich, Inst Kernphys, D-52425 Julich, Germany
[5] Univ Giessen, Inst Phys 2, D-35392 Giessen, Germany
[6] Univ Basel, Dept Phys & Astron, CH-4056 Basel, Switzerland
[7] Univ Gottingen, Inst Phys 2, D-37073 Gottingen, Germany
[8] Univ Glasgow, Dept Phys & Astron, Glasgow G12 8QQ, Lanark, Scotland
[9] Univ Tubingen, Inst Phys, D-72076 Tubingen, Germany
关键词
D O I
10.1103/PhysRevLett.87.232501
中图分类号
O4 [物理学];
学科分类号
0702 ;
摘要
The photon asymmetry in the reaction H-1(<(<gamma>)over right arrow>, pi (0))H-1 close to threshold has been measured for the first time with the photon spectrometer TAPS using linearly polarized photons from the tagged-photon facility at the Mainz Microtron MAMI. The total and differential cross sections were also measured simultaneously with the photon asymmetry. This allowed determination of the S-wave and all three P-wave amplitudes. The values obtained at threshold are E0+ = [-1.33 +/- 0.08(stat) +/- 0.03(syst)] x 10(-3)/m(pi+), P-1 = [9.47 +/- 0.08(stat) +/- 0.29(syst)] x 10(-3)q /m(pi+)(2) P-2 [-9.46 +/- 0.1(stat) +/- 0.29(syst)] x 10(-3)q/m(pi+)(2), and P-3 = [11.48 +/- 0.06(stat) +/- 0.35(syst)] x 10(-3)q/m(pi+)(2).
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页码:232501 / 1
页数:4
相关论文
共 27 条
[1]   DESIGN OF A TAGGED PHOTON SPECTROMETER FOR USE WITH THE MAINZ 840MEV MICROTRON [J].
ANTHONY, I ;
KELLIE, JD ;
HALL, SJ ;
MILLER, GJ ;
AHRENS, J .
NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT, 1991, 301 (02) :230-240
[2]   MEASUREMENT OF THE P(GAMMA,PI-0) CROSS-SECTION AT THRESHOLD [J].
BECK, R ;
KALLEICHER, F ;
SCHOCH, B ;
VOGT, J ;
KOCH, G ;
STROHER, H ;
METAG, V ;
MCGEORGE, JC ;
KELLIE, JD ;
HALL, SJ .
PHYSICAL REVIEW LETTERS, 1990, 65 (15) :1841-1844
[3]   Measurement of the H-1(gamma,pi(0)) cross section near threshold [J].
Bergstrom, JC ;
Vogt, JM ;
Igarashi, R ;
Keeter, KJ ;
Hallin, EL ;
Retzlaff, GA ;
Skopik, DM ;
Booth, EC .
PHYSICAL REVIEW C, 1996, 53 (03) :R1052-R1056
[4]   Measurement of the H-1(gamma,pi(0)) cross section near threshold .2. Pion angular distributions [J].
Bergstrom, JC ;
Igarashi, R ;
Vogt, JM .
PHYSICAL REVIEW C, 1997, 55 (04) :2016-2023
[5]   Chiral symmetry and the reaction gamma p->pi(0)p [J].
Bernard, V ;
Kaiser, N ;
Meissner, UG .
PHYSICS LETTERS B, 1996, 378 (1-4) :337-341
[6]   Neutral pion photoproduction off nucleons revisited [J].
Bernard, V ;
Kaiser, N ;
Meissner, UG .
ZEITSCHRIFT FUR PHYSIK C-PARTICLES AND FIELDS, 1996, 70 (03) :483-497
[7]   Aspects of near-threshold neutral pion photoproduction off protons [J].
Bernard, V ;
Kaiser, N ;
Meissner, UG .
EUROPEAN PHYSICAL JOURNAL A, 2001, 11 (02) :209-216
[8]   NEUTRAL PION-PHOTOPRODUCTION AT THRESHOLD [J].
BERNARD, V ;
KAISER, N ;
GASSER, J ;
MEISSNER, UG .
PHYSICS LETTERS B, 1991, 268 (02) :291-295
[9]   Observation of a unitary cusp in the threshold gamma p->pi(0)p reaction [J].
Bernstein, AM ;
Shuster, E ;
Beck, R ;
Fuchs, M ;
Krusche, B ;
Merkel, H ;
Stroher, H .
PHYSICAL REVIEW C, 1997, 55 (03) :1509-1516
[10]   Light quark mass difference and isospin breaking in electromagnetic pion production [J].
Bernstein, AM .
PHYSICS LETTERS B, 1998, 442 (1-4) :20-27