arXiv subjects

Ivan Rosario

Publications and source records attributed to Ivan Rosario.

4 recordsLinked to original sources

arXiv2024

NLO QCD parton shower matching for $p p \rightarrow e^{+} ν_e μ^{-} \barν_μ γ+ X$

We present the implementation of a new interface in VBFNLO 3.0 supporting all di-boson and tri-boson processes with fully leptonic final states, enabling NLO+PS matched calculations. To demonstrate its capabilities, we study parton shower effects in the tri-boson production process $p p \rightarrow e^{+} ν_e μ^{-} \barν_μ γ+ X$ using Herwig 7.3 with NLO QCD amplitudes from VBFNLO 3.0. We estimate uncertainties from scale variations and analyze the impact of generation-level cuts on parton shower events. This study showcases the new interface's potential and provides insights into the interplay between fixed-order calculations and parton shower effects in multi-boson production processes, crucial for precision measurements and BSM searches at the LHC and future colliders.

hep-ph↗

arXiv2024

Release Note -- VBFNLO 3.0

VBFNLO is a flexible parton level Monte Carlo program for the simulation of vector boson fusion (VBF), QCD-induced single and double vector boson production plus two jets, and double and triple vector boson production (plus jet) in hadronic collisions at next-to-leading order (NLO) in the strong coupling constant, as well as Higgs boson plus two and three jet production via gluon fusion at the one-loop level. For the new version -- Version 3.0 -- several major enhancements have been included. An interface according to the Binoth Les Houches Accord (BLHA) has been added for all VBF and di/tri-boson processes including fully leptonic decays. For all dimension-8 operators affecting vector boson scattering (VBS) processes, a modified T-matrix unitarization procedure has been implemented. Several new production processes have been added, namely the VBS $Zγjj$ and $γγjj$ processes at NLO, $γγjj $, $WWj$ and $ZZj$ production at NLO including the loop-induced gluon-fusion contributions and the gluon-fusion one-loop induced $Φjjj$ ($Φ$ is a CP-even or CP-odd scalar boson) process at LO, retaining the full top-mass dependence. Finally, the code has been parallelized using OpenMPI.

hep-ph↗

arXiv2023

Ultra-peripheral collisions of charged hadrons in extensive air showers

We discuss the electromagnetic collisions of high energy protons, pions and kaons with atmospheric nuclei. In particular, we use the equivalent photon approximation to estimate (i) the diffractive collisions where the projectile scatters inelastically off a nucleus, and (ii) the usual radiative processes (bremsstrahlung, pair production and photonuclear interactions) of these charged hadrons in the air. We then include the processes in the simulator AIRES and study how they affect the longitudinal development of extensive air showers. For $10^{9-11}$ GeV proton primaries we find that they introduce a very small reduction (below 1%) in the average value of both $X_{\rm max}$ and $ΔX_{\rm max}$. At a given shower age (relative slant depth from $X_{\rm max}$), these electromagnetic processes slightly increase the number of charged particles at the shower maximum and reduce the number of muons when it is old, decreasing by 1% the muon-to-($γ+e$) near the ground level. the muon-to-($γ + e$) near the ground level.

hep-ph↗

arXiv2020

Diphoton production in vector-boson scattering at the LHC at next-to-leading order QCD

In this paper, we present results at next-to-leading order (NLO) QCD for photon pair production in association with two jets via vector boson scattering within the Standard Model (SM), and also in an effective field theory framework with anomalous gauge coupling effects via bosonic dimension-6 and 8 operators. We observe that, compared to other processes in the class of two electroweak (EW) vector boson production in association with two jets, more exclusive cuts are needed in order to suppress the SM QCD-induced background channel. As expected, the NLO QCD corrections reduce the scale uncertainties considerably. Using a well-motivated dynamical scale choice, we find moderate $K$-factors for the EW-induced process while the QCD-induced channel receives much larger corrections. Furthermore, we observe that applying a cut of $Δϕ_{j_2 γ_1}^{\text{cut}} < 2.5$ for the second hardest jet and the hardest photon helps to increase the signal significance and reduces the impact of higher-order QCD corrections.

hep-ph↗