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Related papers: Studying the process $\gamma d \to \pi^0\eta d$

200 papers

We consider a pionless effective theory with dibaryon fields for the description of the weak process involving two nucleons. We construct leading order Lagrangians that contain nucleon-dibaryon weak coupling constants. We calculate the…

Nuclear Theory · Physics 2015-05-13 C. H. Hyun , J. W. Shin , S. Ando

We have investigated the process $\Lambda_c^+ \to \pi^+\eta n$ by taking into account the contributions from the nucleon resonance $N(1535)$ and the scalar meson $a_0(980)$, which could be dynamically generated by the interaction of the…

High Energy Physics - Phenomenology · Physics 2025-03-04 Meng-Yuan Li , Wen-Tao Lyu , Li-Juan Liu , En Wang

The first experimental investigation of the near-threshold cross section for incoherent $\pi^-$ photoproduction on the deuteron $\gamma$ d -> $\pi^-$ pp is presented. The experimental technique involved detection of the ~131 MeV gamma ray…

Evidence has recently been presented for the existence of a dibaryon of mass 2380 MeV/c^2 and width 70 MeV/c^2, which decays strongly into the d pi0 pi0 channel [M. Bashkanov et al., Phys.Rev.Lett. 102 (2009) 052301; P. Adlarson et al.,…

Nuclear Theory · Physics 2015-05-28 G. Faldt , C. Wilkin

The contribution of the two-step process gamma + d -> p + n -> pi0 + d to the imaginary part of the amplitude for coherent pion production on the deuteron is calculated exploiting unitarity constraints. The result shows that this absorptive…

Nuclear Theory · Physics 2009-10-30 P. Wilhelm

The reaction d(\vec\gamma,np) has been studied using the tagged and polarised LADON gamma ray beam at an energy 30 - 50 MeV to investigate the existence of narrow dibaryonic resonances recently suggested from the experimental measurements…

Nuclear Experiment · Physics 2009-10-31 D. Babusci , V. Bellini , M. Capogni , L. Casano , A. D'Angelo , F. Ghio , B. Girolami , D. Moricciani , C. Schaerf

We show that the resonance-like structure found by the \emph{CELSIUS-WASA Collaboration} in the two-photon invariant mass spectrum of the reaction $pp \to pp \gamma \gamma$ is rather a signature of the $NN$-decoupled dibaryon resonance…

High Energy Physics - Phenomenology · Physics 2008-11-26 A. S. Khrykin , S. B. Gerasimov

We improve the calculations of the $\eta \to \pi^0 \gamma \gamma$ decay within the context of meson chiral lagrangians. We use a chiral unitary approach for the meson-meson interaction, thus generating the $a_0(980)$ resonance and fixing…

High Energy Physics - Phenomenology · Physics 2008-11-26 E. Oset , J. R. Pelaez , L. Roca

We review our recent calculations of electroweak processes involving the deuteron, based on pionless effective field theory with dibaryon fields. These calculations are concerned with neutron-neutron fusion and np -> d gamma at BBN…

Nuclear Theory · Physics 2007-05-23 Shung-ichi Ando

The $\gamma p \to \pi^0 \eta p$ reaction has been investigated by the CBELSA/TAPS Collaboration, revealing a narrow structure in the $\eta p$ invariant mass distributions at a mass of $1700$ MeV. In this study, we explore the possibility…

High Energy Physics - Phenomenology · Physics 2025-04-25 Ai-Chao Wang , Neng-Chang Wei

We study the reaction mechanism for the correlated $\pi^0\gamma$ emission in the photon induced reaction on the proton target. Since this reaction is studied in the GeV region, we assume that it proceeds through the formation of the vector…

Nuclear Theory · Physics 2009-09-15 Swapan Das

An examination is conducted on a commonly used procedure for extracting (un)polarized $\gamma n\to \pi^-p$ and $\gamma n\to \pi^0n$ observables from $d(\gamma,\pi^-)pp$ and $d(\gamma,\pi^0)pn$ data, using a model that consists of the…

Nuclear Theory · Physics 2018-10-10 Satoshi X. Nakamura

The scalar and vector meson exchange contributions to the doubly radiative decays $\eta^{(\prime)}\to\pi^0\gamma\gamma$ and $\eta^\prime\to\eta\gamma\gamma$ are analysed within the Linear Sigma Model and Vector Meson Dominance frameworks,…

High Energy Physics - Phenomenology · Physics 2020-09-02 Rafel Escribano , Sergi Gonzàlez-Solís , Renata Jora , Emilio Royo

The first experimental results for coherent $\pi^0$-electroproduction on the deuteron, $e+d\to e+d +\pi^0$, at large momentum transfer, are reported. The experiment was performed at Jefferson Laboratory at an incident electron energy of…

Nuclear Experiment · Physics 2008-11-26 E. Tomasi-Gustafsson , L. Bimbot , S. Danagoulian , K. Gustafsson , D. Mack , H. Mrktchyan , M. P. Rekalo

Along with $\pi^0$ and {\eta} mesons, a resonance structure in the invariant mass spectrum of two photons at M{\gamma}{\gamma} = 360 \pm 7 \pm 9 MeV is observed in the reaction d + C \rightarrow {\gamma} + {\gamma} + X at momentum 2.75…

We develop a model for the $pp \to \pi^+ d$ reaction based on the $pp \to \Delta(1232) N$ transition followed by $\Delta(1232) \to \pi N'$ decay and posterior fusion of $N N'$ to give the deuteron. We show that the triangle diagram…

Nuclear Theory · Physics 2021-07-28 Natsumi Ikeno , Raquel Molina , Eulogio Oset

We study $\eta$ photoproduction off the deuteron ($\gamma d\to\eta pn$) at a special kinematics: $\sim 0.94$ GeV of the photon beam energy and $\sim 0^\circ$ of the scattering angle of the proton. This kinematics is ideal to extract the…

Nuclear Theory · Physics 2020-01-08 S. X. Nakamura , H. Kamano , T. Ishikawa

We study the $\eta \to \pi^0 \gamma \gamma$ decay via the quark-box diagram in the three-flavor Nambu--Jona-Lasinio model that includes the $U_A (1)$ breaking effect. We find that the $\eta$-meson mass, the $\eta \to \gamma \gamma$ decay…

High Energy Physics - Phenomenology · Physics 2009-10-28 Y. Nemoto , M. Oka , M. Takizawa

The production of the isoscalar Jp = 3+ didelta dibaryon d* by proton inelastic scattering from deuteron targets is described in a double-scattering Glauber approximation. Each scattering changes a target nucleon into a Delta with the help…

Nuclear Theory · Physics 2008-11-26 Chun Wa Wong

The isoscalar dibaryon resonance $D_{03}(2380)$, discovered at WASA@COSY in the total cross section of the reaction $pn\to d\pi^0\pi^0$ and in the elastic pn scattering in the energy range corresponding to the invariant mass of the pn…

Nuclear Theory · Physics 2025-11-04 Yu. N. Uzikov , A. A. Temerbayev , N. T. Tursunbayev