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PRESENTED IN PREPRINT ON FIG 3.
Results of the experimental study of inclusive φ meson production off berillium nuclei by 70 GeV/ c protons in the beam fragmentation region x > 0.41 are presented. Fitting of the measured differential cross sections to the forms d σ d x ∼ (1 − x) n x and d σ d p 2 t ∼ exp (−bp 2 t ) gives the parameters n = 6.0 ± 1.7 and b = (2.4 ± 0.7) (GeV/ c ) −2 . In the framework of a quark-parton model the measured φ meson x -distribution suggests that in the region of x > 0.41 nearly 90% of the φ mesons are produced via a strange sea quark fusion. The ratio of the OZI-forbidden and OZI-allowed transition coupling constants has been found to be ten times smaller than the same ratio calculated from the partial decay widths. The total inclusive cross section is estimated to be σ (pN → φ X) = (0.7 ± 0.2) × 10 −27 cm 2 .
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THE RATIO SIG(RHO0)/SIG(OMEGA) IS FREE PARAMETER.
THE RATIO SIG(RHO0)/SIG(OMEGA)=1. AND FIXED.
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Invariant mass spectrum of μ + μ − pairs produced by 70 GeV/ c protons in Be target are presented. Distinct enhancements in the mass regions of ϱ, ω mesons, φ meson and J/ψ particle are observed. For J/ψ production x and p ⊥ 2 distributions are given. The total cross section for the reaction p + Be → ( J ψ → μ + μ − ) + … is equal to 9.5 ± 2.5 nb/nucleus .
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ASSUME B.R.(MU+MU-) = 0.069.
ASSUME A**(2/3) DEPENDENCE FOR SIGMA.
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The reaction π−A→Aπ− γ at 40 GeV/c was studied on “Sigma” spectrometer on six different nuclear targets in the region of four-momentum transfer |t|<0.05 (GeV/c)2. A phenomenon of elastic scattering of pions on the nuclear Coulomb field photons was observed, its total and differential cross sections were measured. The cross section of Compton effect on π−-meson was measured.
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A measurement of novel event shapes quantifying the isotropy of collider events is performed in 140 fb$^{-1}$ of proton-proton collisions with $\sqrt s=13$ TeV centre-of-mass energy recorded with the ATLAS detector at CERN's Large Hadron Collider. These event shapes are defined as the Wasserstein distance between collider events and isotropic reference geometries. This distance is evaluated by solving optimal transport problems, using the 'Energy-Mover's Distance'. Isotropic references with cylindrical and circular symmetries are studied, to probe the symmetries of interest at hadron colliders. The novel event-shape observables defined in this way are infrared- and collinear-safe, have improved dynamic range and have greater sensitivity to isotropic radiation patterns than other event shapes. The measured event-shape variables are corrected for detector effects, and presented in inclusive bins of jet multiplicity and the scalar sum of the two leading jets' transverse momenta. The measured distributions are provided as inputs to future Monte Carlo tuning campaigns and other studies probing fundamental properties of QCD and the production of hadronic final states up to the TeV-scale.
IRing2 for HT2>=500 GeV, NJets>=2
IRing2 for HT2>=500 GeV, NJets>=3
IRing2 for HT2>=500 GeV, NJets>=4
A polarized proton beam extracted from SATURNE II and the Saclay polarized proton target were used to measure the rescattering observables$K_{onno}$and
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$Z$ boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from Standard Model predictions. All previous measurements of $Z$ boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins. In this analysis, a machine learning method called OmniFold is used to produce a simultaneous measurement of twenty-four $Z$+jets observables using $139$ fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV collected with the ATLAS detector. Unlike any previous fiducial differential cross-section measurement, this result is presented unbinned as a dataset of particle-level events, allowing for flexible re-use in a variety of contexts and for new observables to be constructed from the twenty-four measured observables.
Differential cross-section in bins of dimuon $p_\text{T}$. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
Differential cross-section in bins of dimuon rapidity. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
Differential cross-section in bins of leading muon $p_\mathrm{T]$. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
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