Abstract: Interactions of cosmic ray protons, atomic nuclei, and electrons in the interstellar medium in the inner part of the Milky Way produce gamma-ray flux from the Galactic Ridge. If the gamma-ray emission is dominated by proton and nuclei interactions, a neutrino flux comparable to the gamma-ray flux is expected from the same sky region. Data collected by the ANTARES neutrino telescope are used to constrain the neutrino flux from the Galactic Ridge in the 1-100 TeV energy range. Neutrino events reconstructed both as tracks and showers are considered in the analysis and the selection is optimized for the search of an excess in the region |l| < 30 degrees, |b| < 2 degrees. The expected background in the search region is estimated using an off-zone region with similar sky coverage. Neutrino signal originating from a power-law spectrum with spectral index ranging from Gamma nu = 1to 4is simulated in both channels. The observed energy distributions are fitted to constrain the neutrino emission from the Ridge. The energy distributions in the signal region are inconsistent with the background expectation at similar to 96% confidence level. The mild excess over the background is consistent with a neutrino flux with a power law with a spectral index 2.45(-0.34)(+0.22) and a flux normalization dN nu/dE nu= 4.0(-2.0)(+2.7) x 10(-16) GeV-1 cm(-2) s(-1) sr(-1) at 40 TeV reference energy. Such flux is consistent with the expected neutrino signal if the bulk of the observed gamma-ray flux from the Galactic Ridge originates from interactions of cosmic ray protons and nuclei with a power-law spectrum extending well into the PeV energy range.

Abstract: We study ultra-violet completions for d = 6 four-fermion operators in the standard model effective field theory (SMEFT), focusing on models that contain cold dark matter candidates. Via a diagrammatic method, we generate systematically lists of possible UV completions, with the aim of providing sets of models, which are complete under certain, well specified assumptions. Within these lists of models we rediscover many known DM models, as diverse as R-parity conserving supersymmetry or the scotogenic neutrino mass model. Our lists, however, also contain many new constructions, which have not been studied in the literature so far. We also briefly discuss how our DM models could be constrained by reinterpretations of LHC searches and the prospects for HL-LHC and future lepton colliders.

Abstract: This paper presents a search for a new Z' vector gauge boson with the ATLAS experiment at the Large Hadron Collider using pp collision data collected at root s = 13TeV, corresponding to an integrated luminosity of 139 fb(-1). The new gauge boson Z' is predicted by L-mu – L-tau models to address observed phenomena that can not be explained by the Standard Model. The search examines the four-muon (4 mu) final state, using a deep learning neural network classifier to separate the Z' signal from the Standard Model background events. The di-muon invariant masses in the 4 μevents are used to extract the Z' resonance signature. No significant excess of events is observed over the predicted background. Upper limits at a 95% confidence level on the Z' production cross-section times the decay branching fraction of pp -> Z' μμ-> 4 μare set from 0.31 to 4.3 fb for the Z' mass ranging from 5 to 81 GeV. The corresponding common coupling strengths, g(Z'), of the Z' boson to the second and third generation leptons above 0.003 – 0.2 have been excluded.

Abstract: In this paper, we place new bounds on CPT violation in the solar neutrino sector analyzing the results from solar experiments and KamLAND. We also discuss the sensitivity of the next-generation experiments DUNE and Hyper-Kamiokande, which will provide accurate measurements of the solar neutrino oscillation parameters. The joint analysis of both experiments will further improve the precision due to cancellations in the systematic uncertainties regarding the solar neutrino flux. In combination with the next-generation reactor experiment JUNO, the bound on CPT violation in the solar sector could be improved by 1 order of magnitude in comparison with current constraints. The distinguishability among CPT-violating neutrino oscillations and neutrino nonstandard interactions in the solar sector is also addressed.

Abstract: Measurements of transverse energy-energy correlations and their associated azimuthal asymmetries in multijet events are presented. The analysis is performed using a data sample corresponding to 139 fb(-1) of proton-proton collisions at a centre-of-mass energy of root s = 13TeV, collected with the ATLAS detector at the Large Hadron Collider. The measurements are presented in bins of the scalar sum of the transverse momenta of the two leading jets and unfolded to particle level. They are then compared to next-to-next-to-leading-order perturbative QCD calculations for the first time, which feature a significant reduction in the theoretical uncertainties estimated using variations of the renormalisation and factorisation scales. The agreement between data and theory is good, thus providing a precision test of QCD at large momentum transfers Q. The strong coupling constant alpha(s) is extracted as a function of Q, showing a good agreement with the renormalisation group equation and with previous analyses. A simultaneous fit to all transverse energy-energy correlation distributions across different kinematic regions yields a value of alpha(s)( mZ) = 0.1175 +/- 0.0006 (exp.)(+0.0034) (-0.0017) (theo.), while the global fit to the asymmetry distributions yields alpha(s)(m(Z)) = 0.1185 +/- 0.0009 (exp.)(+0.0025)(-0.0012)(theo.).