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1. Measurement of the $$\gamma n\rightarrow K^0\Sigma ^0$$ differential cross section over the $$K^*$$ threshold

   https://doi.org/10.1140/epja/s10050-023-01133-1  

   BGOOD Collaboration ; Kohl, K. ; Jude, T. C. ; Alef, S. ; Beck, R. ; Braghieri, A. ; Cole, P. L. ; Elsner, D. ; Di Salvo, R. ; Fantini, A. ; et al ( November 2023 , The European Physical Journal A)

   The differential cross section for the quasi-free photoproduction reaction$$\gamma n\rightarrow K^0\Sigma ^0$$$\gamma n\to K^0{\Sigma }^0$was measured at BGOOD at ELSA from threshold to a centre-of-mass energy of$$2400\,\hbox {MeV}$$$2400\text{MeV}$. Close to threshold the results are consistent with existing data and are in agreement with partial wave analysis solutions over the full measured energy range, with a large coupling to the$$\Delta (1900)1/2^-$$$\Delta \left(1900\right)1/2^{-}$evident. This is the first dataset covering the$$K^*$$$K^{\ast }$threshold region, where there are model predictions of dynamically generated vector meson-baryon resonance contributions.

    

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2. Non-simple conformal loop ensembles on Liouville quantum gravity and the law of CLE percolation interfaces

   https://doi.org/10.1007/s00440-021-01070-4  

   Miller, Jason ; Sheffield, Scott ; Werner, Wendelin ( June 2021 , Probability Theory and Related Fields)

   We study the structure of the Liouville quantum gravity (LQG) surfaces that are cut out as one explores a conformal loop-ensemble$$\hbox {CLE}_{\kappa '}$$${\text{CLE}}_{{\kappa }^{\prime }}$for$$\kappa '$$${\kappa }^{\prime }$in (4, 8) that is drawn on an independent$$\gamma $$$\gamma$-LQG surface for$$\gamma ^2=16/\kappa '$$${\gamma }^2=16/{\kappa }^{\prime }$. The results are similar in flavor to the ones from our companion paper dealing with$$\hbox {CLE}_{\kappa }$$${\text{CLE}}_{\kappa }$for$$\kappa $$$\kappa$in (8/3, 4), where the loops of the CLE are disjoint and simple. In particular, we encode the combined structure of the LQG surface and the$$\hbox {CLE}_{\kappa '}$$${\text{CLE}}_{{\kappa }^{\prime }}$in terms of stable growth-fragmentation trees or their variants, which also appear in the asymptotic study of peeling processes on decorated planar maps. This has consequences for questions that do a priori not involve LQG surfaces: In our paper entitled “CLE Percolations” described the law of interfaces obtained when coloring the loops of a$$\hbox {CLE}_{\kappa '}$$${\text{CLE}}_{{\kappa }^{\prime }}$independently into two colors with respective probabilitiespand$$1-p$$$1-p$. This description was complete up to one missing parameter$$\rho $$$\rho$. The results of the present paper about CLE on LQG allow us to determine its value in terms ofpand$$\kappa '$$${\kappa }^{\prime }$. It shows in particular that$$\hbox {CLE}_{\kappa '}$$${\text{CLE}}_{{\kappa }^{\prime }}$and$$\hbox {CLE}_{16/\kappa '}$$${\text{CLE}}_{16/{\kappa }^{\prime }}$are related via a continuum analog of the Edwards-Sokal coupling between$$\hbox {FK}_q$$${\text{FK}}_q$percolation and theq-state Potts model (which makes sense even for non-integerqbetween 1 and 4) if and only if$$q=4\cos ^2(4\pi / \kappa ')$$$q=4{cos}^2(4\pi /{\kappa }^{\prime })$. This provides further evidence for the long-standing belief that$$\hbox {CLE}_{\kappa '}$$${\text{CLE}}_{{\kappa }^{\prime }}$and$$\hbox {CLE}_{16/\kappa '}$$${\text{CLE}}_{16/{\kappa }^{\prime }}$represent the scaling limits of$$\hbox {FK}_q$$${\text{FK}}_q$percolation and theq-Potts model whenqand$$\kappa '$$${\kappa }^{\prime }$are related in this way. Another consequence of the formula for$$\rho (p,\kappa ')$$$\rho (p,{\kappa }^{\prime })$is the value of half-plane arm exponents for such divide-and-color models (a.k.a. fuzzy Potts models) that turn out to take a somewhat different form than the usual critical exponents for two-dimensional models.

    

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3. Observation of four-top-quark production in the multilepton final state with the ATLAS detector

   https://doi.org/10.1140/epjc/s10052-023-11573-0  

   Aad, G. ; Abbott, B. ; Abeling, K. ; Abicht, N. J. ; Abidi, S. H. ; Aboulhorma, A. ; Abramowicz, H. ; Abreu, H. ; Abulaiti, Y. ; Hoffman, A. C. ; et al ( June 2023 , The European Physical Journal C)

   This paper presents the observation of four-top-quark ($$t\bar{t}t\bar{t}$$$t\overline{t}t\overline{t}$) production in proton-proton collisions at the LHC. The analysis is performed using an integrated luminosity of 140 $$\hbox {fb}^{-1}$$${\text{fb}}^{-1}$at a centre-of-mass energy of 13 TeV collected using the ATLAS detector. Events containing two leptons with the same electric charge or at least three leptons (electrons or muons) are selected. Event kinematics are used to separate signal from background through a multivariate discriminant, and dedicated control regions are used to constrain the dominant backgrounds. The observed (expected) significance of the measured$$t\bar{t}t\bar{t}$$$t\overline{t}t\overline{t}$signal with respect to the standard model (SM) background-only hypothesis is 6.1 (4.3) standard deviations. The$$t\bar{t}t\bar{t}$$$t\overline{t}t\overline{t}$production cross section is measured to be$$22.5^{+6.6}_{-5.5}$$$22.5_{-5.5}^{+6.6}$ fb, consistent with the SM prediction of$$12.0 \pm 2.4$$$12.0\pm 2.4$fb within 1.8 standard deviations. Data are also used to set limits on the three-top-quark production cross section, being an irreducible background not measured previously, and to constrain the top-Higgs Yukawa coupling and effective field theory operator coefficients that affect$$t\bar{t}t\bar{t}$$$t\overline{t}t\overline{t}$production.

    

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4. Search for light Higgs bosons from supersymmetric cascade decays in $$\text {pp}$$ collisions at $$\sqrt{s}=13\,\textrm{TeV}$$

   https://doi.org/10.1140/epjc/s10052-023-11581-0  

   Tumasyan, A. ; Adam, W. ; Andrejkovic, J. W. ; Bergauer, T. ; Chatterjee, S. ; Damanakis, K. ; Dragicevic, M. ; Valle, A. Escalante ; Frühwirth, R. ; Jeitler, M. ; et al ( July 2023 , The European Physical Journal C)

   A search is reported for pairs of light Higgs bosons ($${\textrm{H}} _1$$${\text{H}}_1$) produced in supersymmetric cascade decays in final states with small missing transverse momentum. A data set of LHC$$\hbox {pp}$$$\text{pp}$collisions collected with the CMS detector at$$\sqrt{s}=13\,\text {TeV} $$$\sqrt{s}=13\text{TeV}$and corresponding to an integrated luminosity of 138$$\,\text {fb}^{-1}$$${\text{fb}}^{-1}$is used. The search targets events where both$${\textrm{H}} _1$$${\text{H}}_1$bosons decay into Equation missing<#comment/>pairs that are reconstructed as large-radius jets using substructure techniques. No evidence is found for an excess of events beyond the background expectations of the standard model (SM). Results from the search are interpreted in the next-to-minimal supersymmetric extension of the SM, where a “singlino” of small mass leads to squark and gluino cascade decays that can predominantly end in a highly Lorentz-boosted singlet-like$${\textrm{H}} _1$$${\text{H}}_1$and a singlino-like neutralino of small transverse momentum. Upper limits are set on the product of the squark or gluino pair production cross section and the square of the Equation missing<#comment/>branching fraction of the$${\textrm{H}} _1$$${\text{H}}_1$in a benchmark model containing almost mass-degenerate gluinos and light-flavour squarks. Under the assumption of an SM-like Equation missing<#comment/>branching fraction,$${\textrm{H}} _1$$${\text{H}}_1$bosons with masses in the range 40–120$$\,\text {GeV}$$$\text{GeV}$arising from the decays of squarks or gluinos with a mass of 1200–2500$$\,\text {GeV}$$$\text{GeV}$are excluded at 95% confidence level.

    

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5. Measurements of the Higgs boson production cross section and couplings in the W boson pair decay channel in proton-proton collisions at $$\sqrt{s}=13\,\text {Te\hspace{-.08em}V} $$

   https://doi.org/10.1140/epjc/s10052-023-11632-6  

   Tumasyan, A. ; Adam, W. ; Andrejkovic, J. W. ; Bergauer, T. ; Chatterjee, S. ; Damanakis, K. ; Dragicevic, M. ; Escalante Del Valle, A. ; Hussain, P. S. ; Jeitler, M. ; et al ( July 2023 , The European Physical Journal C)

   Production cross sections of the standard model Higgs boson decaying to a pair of W bosons are measured in proton-proton collisions at a center-of-mass energy of 13$$\,\text {Te\hspace{-.08em}V}$$$\text{Te}\text{V}$. The analysis targets Higgs bosons produced via gluon fusion, vector boson fusion, and in association with a W or Z boson. Candidate events are required to have at least two charged leptons and moderate missing transverse momentum, targeting events with at least one leptonically decaying W boson originating from the Higgs boson. Results are presented in the form of inclusive and differential cross sections in the simplified template cross section framework, as well as couplings of the Higgs boson to vector bosons and fermions. The data set collected by the CMS detector during 2016–2018 is used, corresponding to an integrated luminosity of 138$$\,\text {fb}^{-1}$$${\text{fb}}^{-1}$. The signal strength modifier$$\mu $$$\mu$, defined as the ratio of the observed production rate in a given decay channel to the standard model expectation, is measured to be$$\mu = 0.95^{+0.10}_{-0.09}$$$\mu =0.{95}_{-0.09}^{+0.10}$. All results are found to be compatible with the standard model within the uncertainties.

    

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