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Organic compounds in the atmosphere play a pivotal role in atmospheric chemistry, and clouds are significant in the genesis and alteration of these compounds. Di-carboxylic organic anions such as oxalate serve as tracers for aqueous processing. This poster details our findings from summer measurements of three major organic acids (formic acid, acetic acid, oxalic acid), as well as inorganic anions (sulfate, chloride, nitrate) and cations (sodium, potassium, ammonium, calcium, magnesium) in cloud water, aerosol, and cloud droplet residual samples collected at the summit of Whiteface Mountain (WFM) in the Adirondack Mountains, northern New York State. We also evaluate the contribution of these organic acids to water-soluble organic carbon (WSOC) concentrations. Previous studies have explored the oxalate: WSOC ratio with ozone levels, aiming to deduce the influence of biogenic Volatile Organic Compounds (VOCs) on Secondary Organic Aerosol (SOA) formation from nearby forest ecosystems. Our poster presents new observations that significantly broaden this understanding by comparing to diverse global environments and analyzing both cloud water and aerosol phases. Additionally, we introduce oxalate: sulfate ratios from our dataset, proposed by other researchers as a key indicator of aqueous processing due to the enhanced production rates of these ions by liquid water content (sulfate ion) or droplet surface area (oxalate ion). We compare the observed range of oxalate: sulfate ratios with those from field campaigns conducted in other regions. Moreover, for the first time, we examine the relationship between ammonium and organic acids across cloud water, aerosol, and droplet residual samples collected in 2023, and discuss the influence of wildfire smoke on these dynamics. 

A<sc>bstract</sc> Inclusive and differential cross sections for Higgs boson production in proton-proton collisions at a centre-of-mass energy of 13.6 TeV are measured using data collected with the CMS detector at the LHC in 2022, corresponding to an integrated luminosity of 34.7 fb⁻¹. Events with the diphoton final state are selected, and the measured inclusive fiducial cross section is$${\sigma }_{\text{fid}}={74}\pm {11}{\left({\text{stat}}\right)}_{-4}^{+5}\left({\text{syst}}\right)$$fb, in agreement with the standard model prediction of 67.8 ± 3.8 fb. Differential cross sections are measured as functions of several observables: the Higgs boson transverse momentum and rapidity, the number of associated jets, and the transverse momentum of the leading jet in the event. Within the uncertainties, the differential cross sections agree with the standard model predictions. 

Incoherent $J/\psi$photoproduction in heavy ion ultraperipheral collisions (UPCs) provides a sensitive probe of localized, fluctuating gluonic structures within heavy nuclei. This Letter reports the first measurement of the photon-nucleon center-of-mass energy ( $W_{\gamma \mathrm{N}}$) dependence of this process in PbPb UPCs at a nucleon-nucleon center-of-mass energy of 5.02 TeV, using $1.52{\mathrm{nb}}^{-1}$of data recorded by the CMS experiment. The measurement covers a wide $W_{\gamma \mathrm{N}}$range of $\approx 40–400\mathrm{GeV}$, probing gluons carrying a fraction $x$of nucleon momentum down to an unexplored regime of $6.5\times {10}^{-5}$. Compared to baseline predictions neglecting nuclear effects, the measured cross sections exhibit significantly greater suppression at lower $x$. Additionally, the ratio of incoherent to coherent photoproduction is found to be constant across the probed $W_{\gamma \mathrm{N}}$and $x$range, disfavoring the establishment of the black disk limit. This Letter provides critical insights into the $x$-dependent evolution of fluctuating gluonic structures within nuclei and calls for further advancements in theoretical models incorporating nuclear shadowing and gluon saturation. 

A<sc>bstract</sc> A search for the production of a single top quark in association with invisible particles is performed using proton-proton collision data collected with the CMS detector at the LHC at$$\sqrt{s}=13$$TeV, corresponding to an integrated luminosity of 138 fb⁻¹. In this search, a flavor-changing neutral current produces a single top quark or antiquark and an invisible state nonresonantly. The invisible state consists of a hypothetical spin-1 particle acting as a new mediator and decaying to two spin-1/2 dark matter candidates. The analysis searches for events in which the top quark or antiquark decays hadronically. No significant excess of events compatible with that signature is observed. Exclusion limits at 95% confidence level are placed on the masses of the spin-1 mediator and the dark matter candidates, and are compared to constraints from the dark matter relic density measurements. In a vector (axial-vector) coupling scenario, masses of the spin-1 mediator are excluded up to 1.85 (1.85) TeV with an expectation of 2.0 (2.0) TeV, whereas masses of the dark matter candidates are excluded up to 0.75 (0.55) TeV with an expectation of 0.85 (0.65) TeV.