Hard Exclusive Electroproduction of $π^+π^-$ Pairs
| dc.creator | The HERMES Collaboration | |
| dc.creator | Airapetian, A. | |
| dc.date | 2004-06-18 | |
| dc.date | 2004-07-22 | |
| dc.date.accessioned | 2026-07-07T13:03:49Z | |
| dc.date.available | 2026-07-07T13:03:49Z | |
| dc.description | Hard exclusive electroproduction of $π^+π^-$ pairs off hydrogen and deuterium targets has been studied by the HERMES experiment at DESY. Legendre moments $<P_1>$ and $<P_3>$ of the angular distributions of $π^+$ mesons in the center-of-mass frame of the pair have been measured for the first time. Their dependence on the $π^+π^-$ invariant mass can be understood as being due to the interference between relative $P$-wave (isovector) and $S,D$-wave (isoscalar) states of the two pions. % The increase in magnitude of $<P_1>$ as Bjorken $x$ increases is interpreted in the framework of Generalized Parton Distributions as an enhancement of flavour {non-singlet} $q\bar{q}$ exchange for larger values of $x$, which leads to a sizable admixture of isoscalar and isovector pion pairs. % In addition, the interference between {$P$-wave} and {$D$-wave} states separately for transverse and longitudinal pion pairs has been studied. The data indicate that at {$\la Q^2 \ra = 3 $ GeV$^2$} higher twist effects can be as large as the leading-twist longitudinal component | |
| dc.identifier | https://arxiv.org/abs/hep-ex/0406052 | |
| dc.identifier | http://arxiv.org/abs/hep-ex/0406052 | |
| dc.identifier | Phys.Lett.B599:212-222,2004 | |
| dc.identifier | doi:10.1016/j.physletb.2004.08.059 | |
| dc.identifier.uri | http://salesiana.dossiersoluciones.com/handle/123456789/226944 | |
| dc.subject | High Energy Physics - Experiment | |
| dc.title | Hard Exclusive Electroproduction of $π^+π^-$ Pairs | |
| dc.type | text |