The eta'-carbon potential at low meson momenta

TY - JOUR

T1 - The eta'-carbon potential at low meson momenta

AU - CBELSA/TAPS Collaboration

AU - Nanova, M.

AU - Friedrich, S.

AU - Metag, V.

AU - Paryev, E. Ya.

AU - Afzal, F. N.

AU - Bayadilov, D.

AU - Bantes, B.

AU - Beck, R.

AU - Becker, M.

AU - Böse, S.

AU - Brinkmann, K. -T.

AU - Crede, V.

AU - Drexler, P.

AU - Eberhardt, H.

AU - Elsner, D.

AU - Frommberger, F.

AU - Funke, Ch.

AU - Gottschall, M.

AU - Grüner, M.

AU - Gutz, E.

AU - Hammann, Ch.

AU - Hannappel, J.

AU - Hartmann, J.

AU - Hillert, W.

AU - Hoffmeister, Ph.

AU - Honisch, Ch.

AU - Jude, T.

AU - Kaiser, D.

AU - Kalischewski, F.

AU - Keshelashvili, I.

AU - Klein, F.

AU - Koop, K.

AU - Krusche, B.

AU - Lang, M.

AU - Makonyi, K.

AU - Messi, F.

AU - Müller, J.

AU - Müllers, J.

AU - Piontek, D.

AU - Rostomyan, T.

AU - Schaab, D.

AU - Schmidt, Ch.

AU - Schmieden, H.

AU - Schmitz, R.

AU - Seifen, T.

AU - Sokhoyan, V.

AU - Sowa, C.

AU - Spieker, K.

AU - Werthmüller, D.

N1 - © SIF, Springer-Verlag GmbH Germany, part of Springer Nature 2018. This is an author-produced version of the published paper. Uploaded in accordance with the publisher’s self-archiving policy. Further copying may not be permitted; contact the publisher for details.

PY - 2018/10/26

Y1 - 2018/10/26

N2 - The production of backslasheta^backslashprime$mesons in coincidence with forward-going protons has been studied in photon-induced reactions on 12C and on a liquid hydrogen (LH2) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The backslasheta^backslashprime$mesons have been identified via the backslasheta^backslashprime backslashrightarrow backslashpi^0 backslashpi^0backslasheta backslashrightarrow 6 backslashgamma$textrightarrow$0$0$textrightarrow6$decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF2 array at polar angles of 2^backslashcirc backslashle backslashthetap backslashle 11^backslashcirc2∘≤$p≤11∘. Under these kinematic constraints the backslasheta^backslashprime$mesons are produced with relatively low kinetic energy (backslashapprox 150≈150MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the backslasheta^backslashprime$-carbon potential at low meson momenta by comparing with collision model calculations of the backslasheta^backslashprime$kinetic energy distribution and excitation function. Fitting the latter data for backslasheta^backslashprime$mesons going backwards in the center-of-mass system yields a potential depth of V = -(44 backslashpm 16(stat) backslashpm 15(syst))V=-(44textpm16(stat)textpm15(syst))MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average backslasheta^backslashprime$momenta of backslashapprox 1.1≈1.1GeV/c. Within the experimental uncertainties, there is no indication of a momentum dependence of the backslasheta^backslashprime$-carbon potential. The LH2 data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for backslasheta^backslashprime$photoproduction off the free proton.

AB - The production of backslasheta^backslashprime$mesons in coincidence with forward-going protons has been studied in photon-induced reactions on 12C and on a liquid hydrogen (LH2) target for incoming photon energies of 1.3-2.6 GeV at the electron accelerator ELSA. The backslasheta^backslashprime$mesons have been identified via the backslasheta^backslashprime backslashrightarrow backslashpi^0 backslashpi^0backslasheta backslashrightarrow 6 backslashgamma$textrightarrow$0$0$textrightarrow6$decay registered with the CBELSA/TAPS detector system. Coincident protons have been identified in the MiniTAPS BaF2 array at polar angles of 2^backslashcirc backslashle backslashthetap backslashle 11^backslashcirc2∘≤$p≤11∘. Under these kinematic constraints the backslasheta^backslashprime$mesons are produced with relatively low kinetic energy (backslashapprox 150≈150MeV) since the coincident protons take over most of the momentum of the incident-photon beam. For the C-target this allows the determination of the real part of the backslasheta^backslashprime$-carbon potential at low meson momenta by comparing with collision model calculations of the backslasheta^backslashprime$kinetic energy distribution and excitation function. Fitting the latter data for backslasheta^backslashprime$mesons going backwards in the center-of-mass system yields a potential depth of V = -(44 backslashpm 16(stat) backslashpm 15(syst))V=-(44textpm16(stat)textpm15(syst))MeV, consistent with earlier determinations of the potential depth in inclusive measurements for average backslasheta^backslashprime$momenta of backslashapprox 1.1≈1.1GeV/c. Within the experimental uncertainties, there is no indication of a momentum dependence of the backslasheta^backslashprime$-carbon potential. The LH2 data, taken as a reference to check the data analysis and the model calculations, provide differential and integral cross sections in good agreement with previous results for backslasheta^backslashprime$photoproduction off the free proton.

U2 - 10.1140/epja/i2018-12639-6

DO - 10.1140/epja/i2018-12639-6

M3 - Article

SN - 1434-601X

VL - 54

JO - European Physical Journal A : Hadrons and Nuclei

JF - European Physical Journal A : Hadrons and Nuclei

IS - 10

M1 - 182

ER -