Sequential single pion production explaining the dibaryon "$d^*(2380)$" peak

Molina, R Alfaro; Ikeno, Natsumi

doi:10.48550/arxiv.2102.05575

Cited by 9 publications

(14 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In the present work, we perform the calculations for the pp → π + d reaction which offers a very good example of a TS. There is one more reason to study this reaction: a recent work [24] proposes and explanation for the "d * (2380)" dibaryon peak, observed in the np → π 0 π 0 d, np → π + π − d reactions [25][26][27][28], based on an old idea [29] that the dominant two pion production plus fusion mechanism comes from a two step single pion production process, np → π − pp followed by pp → π + d (plus np → π + nn followed by nn → π − d ).…”

Section: Introductionmentioning

confidence: 99%

Triangle singularity mechanism for the $pp \to π^+ d$ fusion reaction

Ikeno,

Molina,

Oset

2021

Preprint

View full text Add to dashboard Cite

We develop a model for the pp → π + d reaction based on the pp → ∆(1232)N transition followed by ∆(1232) → πN decay and posterior fusion of N N to give the deuteron. We show that the triangle diagram depicting this process develops a triangle singularity leading to a large cross section of this reaction compared to ordinary fusion reactions. The results of the calculation also show that the process is largely dominated by the pp system in L = 2, S = 0, which transfers J = 2 to the final π + d system. This feature is shown to be well suited to provide L = 2, S = 1, J tot = 3 for np in the np(I = 0) → π − pp followed by pp → π + d reaction, which has been proposed recently, as a means of describing the so far assumed dibaryon d * (2380) peak.

show abstract

Section: Introductionmentioning

confidence: 99%

Triangle singularity mechanism for the $pp \to π^+ d$ fusion reaction

Ikeno,

Molina,

Oset

2021

Preprint

View full text Add to dashboard Cite

show abstract

“…This work, together with the one of Ref. [47], present an alternative explanation of the peak observed in the pn → π 0 π 0 d (pn → π + π − d) reaction, so far associated to a dibaryon "d * (2380)" [48].…”

Section: Introductionmentioning

confidence: 99%

The $$\pi f_0(500)$$ decay of the $$a_1(1260)$$

Molina

Döring

2021

Eur. Phys. J. C

Self Cite

View full text Add to dashboard Cite

We evaluate the $$a_1(1260) \rightarrow \pi \sigma (f_0(500))$$ a 1 ( 1260 ) → π σ ( f 0 ( 500 ) ) decay width from the perspective that the $$a_1(1260)$$ a 1 ( 1260 ) resonance is dynamically generated from the pseudoscalar–vector interaction and the $$\sigma $$ σ arises from the pseudoscalar–pseudoscalar interaction. A triangle mechanism with $$a_1(1260) \rightarrow \rho \pi $$ a 1 ( 1260 ) → ρ π followed by $$\rho \rightarrow \pi \pi $$ ρ → π π and a fusion of two pions within the loop to produce the $$\sigma $$ σ provides the mechanism for this decay under these assumptions for the nature of the two resonances. We obtain widths of the order of 13–22 MeV. Present experimental results differ substantially from each other, suggesting that extra efforts should be devoted to the precise extraction of this important partial decay width, which should provide valuable information on the nature of the axial vector and scalar meson resonances and help clarify the role of the $$\pi \sigma $$ π σ channel in recent lattice QCD calculations of the $$a_1$$ a 1 .

show abstract

“…Recent models benefiting from high precision experimental data and theoretical developments however, have described the d * (2380) via OPE mechanisms. For example, following the same principles as Bar-Nir et al [4], the model of Ikeno, Molina and Oset describes the reaction np → π + π − d via a two step model of np → π − pp followed by pp → ∆ + p → π + d without the need of a dibaryon resonance [19,20]. Instead, the second step is driven by a triangle singularity resulting in a peak consistent in invariant mass and width to the d * (2380).…”

Section: Introductionmentioning

confidence: 99%

Evidence of a dibaryon spectrum in coherent $π^0π^0 d$ photoproduction at forward deuteron angles

Jude,

Alef,

Beck

et al. 2022

Preprint

View full text Add to dashboard Cite

The coherent reaction, γd → π 0 π 0 d was studied with the BGOOD experiment at ELSA from threshold to a centre-of-mass energy of 2850 MeV. A full kinematic reconstruction was made, with final state deuterons identified in the forward spectrometer and π 0 decays in the central BGO Rugby Ball. The strength of the differential cross section exceeds what can be described by models of coherent photoproduction and instead supports the three isoscalar dibaryon candidates reported by the ELPH collaboration at 2.38, 2.47 and 2.63 GeV/c 2 . A low mass enhancement in the π 0 π 0 invariant mass is also observed at the d * (2380) centre-of-mass energy which is consistent with the ABC effect. At higher centre-of-mass energies, a narrow peak in the π 0 d invariant mass at 2114 MeV/c 2 with a width of 20 MeV/c 2 supports a sequential two-dibaryon decay mechanism.

show abstract

Sequential single pion production explaining the dibaryon "$d^*(2380)$" peak

Cited by 9 publications

References 20 publications

Triangle singularity mechanism for the $pp \to π^+ d$ fusion reaction

Triangle singularity mechanism for the $pp \to π^+ d$ fusion reaction

The $$\pi f_0(500)$$ decay of the $$a_1(1260)$$

Evidence of a dibaryon spectrum in coherent $π^0π^0 d$ photoproduction at forward deuteron angles

Contact Info

Product

Resources

About