Erratum to: $$\pi ^-p\rightarrow \eta ^{(\prime )} \pi ^- p$$ in the double-Regge region

A Correction to this paper has been published: 10.1140/epjc/s10052-021-09420-1

$$\pi ^-p\rightarrow \eta ^{(\prime )}\, \pi ^- p$$ in the double-Regge region

The production of $$\eta ^{(\prime )}\pi $$ η ( ′ ) π pairs constitutes one of the golden channels to search for hybrid exotics, with explicit gluonic degrees of freedom. Understanding the dynamics and backgrounds associated to $$\eta ^{(\prime )}\pi $$ η ( ′ ) π production above the resonance region is required to impose additional constraints to the resonance extraction. We consider the reaction $$\pi ^-p\rightarrow \eta ^{(\prime )} \pi ^- \,p$$ π - p → η ( ′ ) π - p measured by COMPASS. We show that the data in $$2.4< m_{\eta ^{(\prime )}\pi } < 3.0{\mathrm {\,GeV}} $$ 2.4 < m η ( ′ ) π < 3.0 GeV can be described by amplitudes based on double-Regge exchanges. The angular distribution of the meson pairs, in particular in the $$\eta ' \pi $$ η ′ π channel, can be attributed to flavor singlet exchanges, suggesting the presence of a large gluon content that couples strongly to the produced mesons.

SCATTERING MECHANISM OF HIGH ENERGY STRONG INTERACTION SOFT PROCESSES

Starting from the viewpoint that the constituent quark has its own structure and incorporating the hypothesis of maximum nonperturbative strong interaction reaction (MNSIR), which should be obeyed in high energy strong soft processes, we modified the field theory for soft Pomeron (ℙ) of Landshoff and Nachtmann and proposed a new structure model for the soft Pomeron ℙ and Reggeon ℝ. In this model a pair of constituent quarks coming from colliding hadron in strong soft processes are first disaggregated into a valance quark with a nonperturbative gluon cloud G wrapped about, or, according to the case, into a nonperturbative gluon wrapped by spinor cloud. Corresponding to such mechanism, the relevant structure of soft Pomeron ℙ or Region ℝ is represented by the sum of a series of cut ladder diagrams. In the multi-Regge region, where the energy of the system is very large and the momentum transfer |t| is very small, and in the approximation where only the leading order of log s is preserved, we calculated the [Formula: see text] scattering amplitude and its total cross-section from the sum of such ladder diagrams. The Regge-behavior factor in the form of an exponential power law of s does arise. We also get compact formulas for the trajectories of soft ℙ and ℝ. As example of application, an alternative mechanism of J/Ψ nonquarkonic-hadron decay is proposed.

Proton-Proton Total Cross Sections and the Neglect of Masses in Data Fitting in the Regge Region

It is shown by taking the example of pp total cross .sections that the use of the approximation s ~ 2qs-t while fitting data in the Regge region can be misleading. Several standard fits to O"tot(pp) data are based on the assumption of weak p-f-w-A2 exchange degeneracy (EXD). However, these fits involve the use of the approximation mentioned. We find, quite surprisingly, that it is impossible to fit the O"tot(pp) data in the range 6 ~ Plab ~ 2092 GeVjc using the precise factor 2qs~ in conjunction with weak p-f-w-A2 EXD. OUf investigation shows that O"tot(pp) data alone seem to indicate either a breaking of weak p-f-w-A 2 EXD or the presence of low-lying contributions, or both, provided one does not ignore the masses of the interacting particles in data fitting in the Regge region (Plab ;:;: 5 GeVjc). Caution is therefore urged in the use of such approximations in phenomenological calculations.