Identification of patterns for space-time event networks

This paper provides new tools for analyzing spatio-temporal event networks. We build time series of directed event networks for a set of spatial distances, and based on scan-statistics, the spatial distance that generates the strongest change of event network connections is chosen. In addition, we propose an empirical random network event generator to detect significant motifs throughout time. This generator preserves the spatial configuration but randomizes the order of the occurrence of events. To prevent the large number of links from masking the count of motifs, we propose using standardized counts of motifs at each time slot. Our methodology is able to detect interaction radius in space, build time series of networks, and describe changes in its topology over time, by means of identification of different types of motifs that allows for the understanding of the spatio-temporal dynamics of the phenomena. We illustrate our methodology by analyzing thefts occurred in Medellín (Colombia) between the years 2003 and 2015.

Hadron interactions for arbitrary energies and species, with applications to cosmic rays

The Pythia event generator is used in several contexts to study hadron and lepton interactions, notably $$\mathrm{p}\mathrm{p}$$ p p and $$\mathrm{p}{\bar{\mathrm{p}}}$$ p p ¯ collisions. In this article we extend the hadronic modelling to encompass the collision of a wide range of hadrons h with either a proton or a neutron, or with a simplified model of nuclear matter. To this end we model $$h\mathrm{p}$$ h p total and partial cross sections as a function of energy, and introduce new parton distribution functions for a wide range of hadrons, as required for a proper modelling of multiparton interactions. The potential usefulness of the framework is illustrated by a simple study of the evolution of cosmic rays in the atmosphere, and by an even simpler one of shower evolution in a solid detector material. The new code will be made available for future applications.

Forming molecular states with hadronic rescattering

A method for modelling the prompt production of molecular states using the hadronic rescattering framework of the general-purpose Pythia event generator is introduced. Production cross sections of possible exotic hadronic molecules via hadronic rescattering at the LHC are calculated for the $$\chi _{c1}(3872)$$ χ c 1 ( 3872 ) resonance, a possible tetraquark state, as well as three possible pentaquark states, $$P_c^+(4312)$$ P c + ( 4312 ) , $$P_c^+(4440)$$ P c + ( 4440 ) , and $$P_c^+(4457)$$ P c + ( 4457 ) . For the $$P_c^+$$ P c + states, the expected cross section from $$\Lambda _b$$ Λ b decays is compared to the hadronic-rescattering production. The $$\chi _{c1}(3872)$$ χ c 1 ( 3872 ) cross section is compared to the fiducial $$\chi _{c1}(3872)$$ χ c 1 ( 3872 ) cross-section measurement by LHCb and found to contribute at a level of $${\mathcal {O}({1\%})}$$ O ( 1 % ) . Finally, the expected yields of $$\mathrm {P_c^{+}}$$ P c + production from hadronic rescattering during Run 3 of LHCb are estimated. The prompt background is found to be significantly larger than the prompt $$\mathrm {P_c^{+}}$$ P c + signal from hadronic rescattering.

Strangeness Enhancement at LHC Energies Using the Thermal Model and EPOSLHC Event Generator

The strangeness enhancement signature of QGP formation at LHC energies is carefully tackled in the present study. Based on HRG, the particle ratios of mainly strange and multistrange particles are studied at energies from lower s ~ 0.001 up to 13 TeV. The strangeness enhancement clearly appeared at more high energies, and the ratios are confronted to the available experimental data. The particle ratios are also studied using the Cosmic Ray Monte Carlo (CRMC) interface model with its two different event generators, namely, EPOS 1.99 and EPOSlhc, which show a good agreement with the model calculations at the whole range of the energy. We utilize them to produce some particles ratios. EPOS 1.99 is used to estimate particle ratios at lower energies from AGS up to the Relativistic Heavy Ion Collider (RHIC) while EPOSlhc is used at LHC energies. The production of kaons and lambda particles is studied in terms of the mean multiplicity in p-p collisions at energies ranging from 4 to 26 GeV. We find that both HRG model and the used event generators, EPOS 1.99 and EPOSlhc, can describe the particle ratios very well. Additionally, the freeze-out parameters are estimated for different collision systems, such as p-p and Pb-Pb, at LHC energies using both models.

Running axial mass of the nucleon as a phenomenological tool for calculating quasielastic neutrino–nucleus cross sections

We suggest an empirical rule-of-thumb for calculating the cross sections of charged-current quasielastic (CCQE) and CCQE-like interactions of neutrinos and antineutrinos with nuclei. The approach is based on the standard relativistic Fermi-gas model and on the notion of neutrino energy dependent axial-vector mass of the nucleon, governed by a couple of adjustable parameters, one of which is the conventional charged-current axial-vector mass. The inelastic background contributions and final-state interactions are therewith simulated using GENIE 3 neutrino event generator. An extensive comparison of our calculations with earlier and current accelerator CCQE and CCQE-like data for different nuclear targets shows good or at least qualitative overall agreement over a wide energy range. We also discuss some problematical issues common to several competing contemporary models of the CCQE (anti)neutrino–nucleus scattering and to the current neutrino interaction generators.

Study of theoretical luminosity precision for electron colliders at higher energies

We present an estimation of the theoretical precision of low angle Bhabha scattering at the proposed future ILC collider at 500 GeV. The analysis is an extension of the previous analysis done for the FCCee collider at $$\sqrt{s}=M_Z$$ s = M Z . As the state-of-the-art and the reference point we use the Monte Carlo event generator. Based on the current precision status of for LEP analysis, we estimate how various error components evolve from the LEP to ILC setups. The conclusion of our work is that for the ILC the precision of the current version of 4.04 deteriorates to 0.5%, by more than an order of magnitude w.r.t. the present precision for LEP. With the expected future improvements, the precision of can change to 0.016%, nearly as good as for the FCCee at the $$M_Z$$ M Z setup (0.01%). Based on the developed methodology we present also results for ILC$$_{1000}$$ 1000 , FCCee$$_{350}$$ 350 and CLIC$$_{3000}$$ 3000 setups.

Matching N3LO QCD calculations to parton showers

The search for new interactions and particles in high-energy collider physics relies on precise background predictions. This has led to many advances in combining precise fixed-order cross-section calculations with detailed event generator simulations. In recent years, fixed-order qcd calculations of inclusive cross sections at n3lo precision have emerged, followed by an impressive progress at producing differential results. Once differential results become publicly available, it would be prudent to embed these into event generators to allow the community to leverage these advances. This note offers some concrete thoughts on me+ps matching at third order in qcd. As a method for testing these thoughts, a toy calculation of e+e− → u$$ \overline{u} $$ u ¯ at $$ \mathcal{O} $$ O ($$ {\alpha}_s^3 $$ α s 3 ) is constructed, and combined with an event generator through unitary matching. The toy implementation may serve also as blueprint for high-precision qcd predictions at future lepton colliders. As a byproduct of the n3lo matching formula, a new nnlo+ps formula for processes with “additional” jets is obtained.

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.

Three-photon productions within the $$k_t$$-factorization at the LHC

Recently, the ATLAS data of isolated three-photon production showed that the next-to-leading order (NLO) collinear factorization is not enough to describe experimental data. Therefore, one needs to calculate the cross section beyond the NLO, and as showed later, these data can be well described by the NNLO calculation within the collinear factorization framework. However, it is shown that the $$k_t$$ k t -factorization can be quite successful in describing exclusive and high energy collision processes, henceforth we decided to calculate isolated three-photon production within this framework. In this work we use the Martin, Ryskin, and Watt unintegrated parton distribution functions (MRW UPDFs) at LO and NLO levels, in addition to parton branching (PB) UPDFs in order to calculate cross section which we utilize the KATIE parton level event generator. It will be shown that in contrast to collinear factorization, the $$k_t$$ k t -factorization can describe quiet well the three-photon production ATLAS data. Interestingly our results using the NLO-MRW and PB UPDFs can cover the data within their uncertainty bands, similar to the NNLO collinear results.