Effect of color reconnection and rope formation on resonance production in p–p collisions in Pythia 8

Resonance production in proton–proton collisions at $$\sqrt{s} = 7$$ s = 7 TeV and 13 TeV have been investigated using a Pythia 8 event generator within the framework of microscopic processes including color reconnection and rope hadronization. Specifically, the observable effects of different modes of color reconnections on the ratio of yields of mesonic and baryonic resonances with respect to their stable counterpart have been explored as a function of mean charged particle multiplicity. A suppression in the ratio is observed as a function of the mean number of charged particles for mesonic resonances. The $$\phi /\mathrm {K}$$ ϕ / K and $${\phi /\pi }$$ ϕ / π ratios show an enhancement for high-multiplicity events due to enhanced production of strange quarks via the microscopic process of rope hadronization in the partonic phase. The mechanism of the hadronization of color ropes together with the quark–gluon plasma (QCD)-based color reconnection of partons predicted an enhancement in the ratio for baryonic resonances to non-resonance baryons having similar quark content. The yield ratios of resonances are found to be independent of the collision energy and strongly dependent on event activity.

Resonance in dialogue: the interplay between intersubjective motivations and cognitive facilitation

abstract Dialogic resonance, when speakers reproduce constructions from prior turns, is a compelling type of coordination in everyday conversation. This study takes its starting point in resonance in stance-taking sequences with the aim to account for the interplay between intersubjective motivations and cognitive facilitation in resonance production. It analyzes stance-taking sequences in the London–Lund Corpus 2, determining (i) the type of stance alignment (agreement or disagreement), and (ii) the time lapse between the stance-taking turns. The main findings are, firstly, that resonance is more likely than non-resonance to be used by speakers who express disagreement than agreement, which we interpret as a mitigating function of resonance, and, secondly, that the turn transitions are faster in resonating sequences due to cognitive activation in the prior turn. We propose that the face-saving intersubjective motivation of resonance combines with its facilitating cognitive effect to promote appeasing communication.

Spillway preheating

In traditional models only an order one fraction of energy is transferred from the inflaton to radiation through nonperturbative resonance production in preheating immediately after inflation, due to backreaction effects. We propose a particle production mechanism that could improve the depletion of the inflaton energy density by up to four orders of magnitude. The improvement comes from the fast perturbative decays of resonantly produced daughter particles. They act as a “spillway” to drain these daughter particles, reducing their backreaction on the inflaton and keeping the resonant production effective for a longer period. Thus we dub the scenario “spillway preheating”. We also show that the fraction of energy density remaining in the inflaton has a simple inverse power-law scaling in the scenario. In general, spillway preheating is a much more efficient energy dissipation mechanism, which may have other applications in model building for particle physics.

Resonance Reconstruction in the MPD

The study of hadronic resonance production is an essential part of the physical programs of many heavy-ion experiments. Detailed measurement of the resonance properties is also foreseen in the future Multi-Purpose Detector (MPD) experiment at the NICA collider. In this report, we focus on the experimental challenges for the reconstruction of resonances in heavy-ion experiments and examine the MPD capabilities for the reconstruction of ρ(770)0, K*(892)0,±, φ(1020), Λ(1520), Σ(1385)± and Ξ(1530)0.

Comparison of optical potential for nucleons and $$\varDelta $$ resonances

Precise modeling of neutrino interactions on nuclear targets is essential for neutrino oscillations experiments. The modeling of the energy of final state particles in quasielastic (QE) scattering and resonance production on bound nucleons requires knowledge of both the removal energy of the initial state bound nucleon as well as the average Coulomb and nuclear optical potentials for final state leptons and hadrons. We extract the average values of the real part of the nuclear optical potential for final state nucleons ($$U_{opt}^{QE}$$UoptQE) as a function of the nucleon kinetic energy from inclusive electron scattering data on nuclear targets ($$_\mathbf{6 }^\mathbf{12 }{} \mathbf{C} $$612C+$$_\mathbf{8 }^\mathbf{16 }{} \mathbf{O} $$816O, $$_\mathbf{20 }^\mathbf{40 }{} \mathbf{Ca} $$2040Ca+$$_\mathbf{18 }^\mathbf{40 }{} \mathbf{Ar} $$1840Ar, $$_\mathbf{3 }^\mathbf{6 }{} \mathbf{Li} $$36Li, $$_\mathbf{18 }^\mathbf{27 }{} \mathbf{Al} $$1827Al, $$_\mathbf{26 }^\mathbf{56 }{} \mathbf{Fe} $$2656Fe, $$_\mathbf{82 }^\mathbf{208 }{} \mathbf{Pb} $$82208Pb) in the QE region and compare to calculations. We also extract values of the average of the real part of the nuclear optical potential for a $$\varDelta (1232)$$Δ(1232) resonance in the final state ($$U^\varDelta _{opt}$$UoptΔ) within the impulse approximation. We find that $$U^\varDelta _{opt}$$UoptΔ is more negative than $$U_{opt}^{QE}$$UoptQE with $$U^\varDelta _{opt}\approx $$UoptΔ≈1.5 $$U_{opt}^{QE}$$UoptQE for $$_\mathbf{6 }^\mathbf{12 }{} \mathbf{C} $$612C.