Bandyopadhyay, P., Jangid, S., & Karan, A. (2022). Constraining scalar doublet and triplet leptoquarks with vacuum stability and perturbativity. Eur. Phys. J. C, 82(6), 516–44pp.
Abstract: We investigate the constraints on the leptoquark Yukawa couplings and the Higgs-leptoquark quartic couplings for scalar doublet leptoquark (R) over tilde (2), scalar triplet leptoquark S-3 and their combination with both three generations and one generation with respect to perturbative unitarity and vacuum stability. The perturbative unitarity of all the dimensionless couplings is studied via one- and two-loop beta functions. New SU(2)(L) multiplets in terms of these leptoquarks are introduced to fabricate Landau poles at the two-loop level in the gauge coupling g(2) at 10(19.7) GeV and 10(14.4) GeV, respectively, for the S-3 and (R) over tilde (2) + S-3 models with three generations. However, such Landau poles cease to exist for (R) over tilde (2) and any of these extensions with both one and two generations up to Planck scale. The Higgs-leptoquark quartic couplings acquire severe constraints to protect Planck scale perturbativity, whereas leptoquark Yukawa couplings acquire some upper bound in order to respect Planck scale stability of Higgs vacuum. The Higgs quartic coupling at the two-loop level constrains the leptoquark Yukawa couplings for (R) over tilde (2), S-3, (R) over tilde (2) + S-3 with values less than or similar to 1.30, 3.90, 1.00 with three generations. In the effective potential approach, the presence of any of these leptoquarks with any number of generations pushes the metastable vacuum of the Standard Model to the stable region.
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Camarda, S., Cieri, L., & Ferrera, G. (2022). Fiducial perturbative power corrections within the q(T) subtraction formalism. Eur. Phys. J. C, 82(6), 575–8pp.
Abstract: We consider higher-order QCD corrections to the production of high-mass systems in hadron collisions within the transverse-momentum (q(T)) subtraction formalism. We present amethod to consistently remove the linear power corrections in q(T) which appears when fiducial kinematical cuts are applied on the final state system. We consider explicitly the case of fiducial cross sections for Drell-Yan lepton pair production at the Large Hadron Collider up to next-to-nextto-next-to-leading order (N3LO) in QCD. We have implemented our method within the DYTurbo numerical program and we have obtained perturbative predictions which are in agreement at the permille level with those obtained with local subtraction formalisms up to the next-to-next-toleading order (NNLO). At the N3LO we are able to provide predictions for fiducial cross sections with numerical accuracy at the permille level.
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DUNE Collaboration(Abud, A. A. et al), Antonova, M., Barenboim, G., Cervera-Villanueva, A., De Romeri, V., Fernandez Menendez, P., et al. (2022). Scintillation light detection in the 6-m drift-length ProtoDUNE Dual Phase liquid argon TPC. Eur. Phys. J. C, 82(7), 618–29pp.
Abstract: DUNE is a dual-site experiment for long-baseline neutrino oscillation studies, neutrino astrophysics and nucleon decay searches. ProtoDUNE Dual Phase (DP) is a 6 x 6 x 6 m(3) liquid argon time-projection-chamber (LArTPC) that recorded cosmic-muon data at the CERN Neutrino Platform in 2019-2020 as a prototype of the DUNE Far Detector. Charged particles propagating through the LArTPC produce ionization and scintillation light. The scintillation light signal in these detectors can provide the trigger for non-beam events. In addition, it adds precise timing capabilities and improves the calorimetry measurements. In ProtoDUNE-DP, scintillation and electroluminescence light produced by cosmic muons in the LArTPC is collected by photomultiplier tubes placed up to 7m away from the ionizing track. In this paper, the ProtoDUNE-DP photon detection system performance is evaluated with a particular focus on the different wavelength shifters, such as PEN and TPB, and the use of Xe-doped LAr, considering its future use in giant LArTPCs. The scintillation light production and propagation processes are analyzed and a comparison of simulation to data is performed, improving understanding of the liquid argon properties.
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ATLAS Collaboration(Aad, G. et al), Alvarez Piqueras, D., Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Castillo, F. L., et al. (2022). Two-particle Bose-Einstein correlations in pp collisions at root s=13 TeV measured with the ATLAS detector at the LHC. Eur. Phys. J. C, 82(7), 608–38pp.
Abstract: This paper presents studies of Bose-Einstein correlations (BEC) in proton-proton collisions at a centre-of-mass energy of 13 TeV, using data from the ATLAS detector at the CERN Large Hadron Collider. Data were collected in a special low-luminosity configuration with a minimum-bias trigger and a high-multiplicity track trigger, accumulating integrated luminosities of 151 μb(-1) and 8.4 nb(-1), respectively. The BEC are measured for pairs of like-sign charged particles, each with vertical bar eta vertical bar < 2.5, for two kinematic ranges: the first with particle pr > 100 MeV and the second with particle pr > 500 MeV. The BEC parameters, characterizing the source radius and particle correlation strength, are investigated as functions of charged-particle multiplicity (up to 300) and average transverse momentum of the pair (up to 1.5 GeV). The double-differential dependence on charged-particle multiplicity and average transverse momentum of the pair is also studied. The BEC radius is found to be independent of the charged-particle multiplicity for high charged-particle multiplicity (above 100), confirming a previous observation at lower energy. This saturation occurs independent of the transverse momentum of the pair.
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ATLAS Collaboration(Aad, G. et al), Aparisi Pozo, J. A., Bailey, A. J., Cabrera Urban, S., Cardillo, F., Castillo Gimenez, V., et al. (2022). Search for long-lived charginos based on a disappearing-track signature using 136 fb(-1) of pp collisions at root s=13 TeV with the ATLAS detector. Eur. Phys. J. C, 82(7), 606–34pp.
Abstract: A search for long-lived charginos produced either directly or in the cascade decay of heavy prompt gluino states is presented. The search is based on proton- proton collision data collected at a centre-of-mass energy of root s = 13 TeV between 2015 and 2018 with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 136 fb(-1). Long-lived charginos are characterised by a distinct signature of a short and then disappearing track, and are reconstructed using at least four measurements in the ATLAS pixel detector, with no subsequent measurements in the silicon-microstrip tracking volume nor any associated energy deposits in the calorimeter. The final state is complemented by a large missing transverse-momentum requirement for triggering purposes and at least one high-transversemomentum jet. No excess above the expected backgrounds is observed. Exclusion limits are set at 95% confidence level on the masses of the chargino and gluino for different chargino lifetimes. Chargino masses up to 660 (210) GeV are excluded in scenarios where the chargino is a pure wino (higgsino). For charginos produced during the cascade decay of a heavy gluino, gluinos with masses below 2.1 TeV are excluded for a chargino mass of 300 GeV and a lifetime of 0.2 ns.
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