Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (πN) TDAs from ¯pp → e+e−π0 reaction with the future PANDA detector at the FAIR facility. At high center- ¯ of-mass energy and high invariant mass squared of the lepton pair q2, the amplitude of the signal channel pp¯ → e+e−π0 admits a QCD factorized description in terms of πN TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring ¯pp → e+e−π0 with the PANDA detector. Detailed ¯ simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. pp¯ → π+π−π0 were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q2 < 4.3 GeV2 and 5 < q2 < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone | cos θπ0 | > 0.5 in the proton-antiproton center-of-mass frame
Experimental access to Transition Distribution Amplitudes with the P̄ANDA experiment at FAIR
BOCA, GIANLUIGI;COSTANZA, SUSANNA;LAVEZZI, LIA;MONTAGNA, PAOLO MARIA;ROTONDI, ALBERTO;
2015-01-01
Abstract
Baryon-to-meson Transition Distribution Amplitudes (TDAs) encoding valuable new information on hadron structure appear as building blocks in the collinear factorized description for several types of hard exclusive reactions. In this paper, we address the possibility of accessing nucleon-to-pion (πN) TDAs from ¯pp → e+e−π0 reaction with the future PANDA detector at the FAIR facility. At high center- ¯ of-mass energy and high invariant mass squared of the lepton pair q2, the amplitude of the signal channel pp¯ → e+e−π0 admits a QCD factorized description in terms of πN TDAs and nucleon Distribution Amplitudes (DAs) in the forward and backward kinematic regimes. Assuming the validity of this factorized description, we perform feasibility studies for measuring ¯pp → e+e−π0 with the PANDA detector. Detailed ¯ simulations on signal reconstruction efficiency as well as on rejection of the most severe background channel, i.e. pp¯ → π+π−π0 were performed for the center-of-mass energy squared s = 5 GeV2 and s = 10 GeV2, in the kinematic regions 3.0 < q2 < 4.3 GeV2 and 5 < q2 < 9 GeV2, respectively, with a neutral pion scattered in the forward or backward cone | cos θπ0 | > 0.5 in the proton-antiproton center-of-mass frameI documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.