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Search for new physics in jet scaling patterns of multilepton events at = 13 TeV
No full textA first search for beyond the standard model physics in jet scaling patterns of multilepton events is presented, using a data sample corresponding to an integrated luminosity of 138 fb of 13 TeV proton-proton collisions recorded by the CMS detector at the LHC. The search uses observed jet multiplicity distributions in one-, two-, and four-lepton events to explore possible enhancements in jet production rate in three-lepton events with and without bottom quarks. The data are found to be consistent with the standard model expectation. The results are interpreted in terms of supersymmetric production of electroweak chargino-neutralino superpartners with cascade decays terminating in prompt hadronic -parity violating interactions
Search for the associated production of a Higgs boson with a charm quark in the diphoton decay channel in pp collisions at = 13 TeV
No full textThis paper presents the first search for the associated production of a Higgs boson with a charm quark (cH), with the Higgs boson decaying to two photons. Associated cH production provides an opportunity to probe the coupling of the Higgs boson to charm quarks. The results are based on a data set of proton-proton collisions at a center-of-mass energy of 13 TeV collected with the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb. Assuming the standard model (SM) rates for all other Higgs boson production processes, the observed (expected) upper limit at 95% confidence level on the cH signal strength is 243 (355) times the SM prediction. Under the same assumption, the observed (expected) allowed interval on the Higgs boson to charm quark coupling modifier, , is 38.1 ( 72.5) at 95% confidence level
Direct Observation of Early-Stage Polymer Crystallization Driven by Surface Wrinkling and Compressive Stress in Thin Films
No full textThe early stages of crystallization and occurrence of surface wrinkling were investigated using poly(butadiene)-block-poly(ε-caprolactone) with an ordered lamellar structure. Direct evidence has demonstrated that surface wrinkling precedes nucleation and crystal growth. This study examined the relationship between surface wrinkling, nucleation, and the formation of crystalline supramolecular structures using atomic force microscopy (AFM) and X-ray scattering measurements. Surface wrinkling is attributed to curving induced by accumulated stresses, including residual stress from the sample preparation and thermal stress during cooling. These stresses cause large-scale material flow and corresponding changes in the molecular conformations, potentially reducing the nucleation barrier. This hypothesis is supported by the rapid crystal growth observed following the spread of surface wrinkles. Additionally, the surface curving of the polymer thin film creates local minima of the free energy, facilitating nucleation. The nuclei subsequently grow into crystalline supramolecular structures by incorporating polymer molecules from the melt. This mechanism highlights the role of localized structural inhomogeneity in the early stages of crystallization and provides new insights into structure formation processes
A Pathway Toward Sub-10 nm Surface Nanostructures Utilizing Block Copolymer Crystallization Control
No full textIt is elucidated how crystallization can be used to create lateral surface nanostructures in a size regime toward sub-10 nm using molecular self-assembly of short chain crystallizable block copolymers (BCP) and assist in overcoming the high-χ barrier for microphase separation. In this work, an amphiphilic double-crystalline polyethylene-b-polyethylene oxide (PE-b-PEO) block co-oligomer is used. A crystallization mechanism of the short-chain BCP in combination with neutral wetting of the functionalized substrate surface that permits to form edge-on, extended chain crystal lamellae with enhanced thermodynamic stability. In situ atomic force microscopy (AFM) analysis along with surface energy considerations suggest that upon cooling from the polymer melt, the PE-b-PEO first forms a segregated horizontal lamellar morphology. AFM analysis indicates that the PEO crystallization triggers a morphological transition involving a rotation of the forming extended chain crystals in edge-on orientation. Exposing their crystal side facets to the top surface permits to minimize their interfacial energy and form vertical nanostructures. Moreover, the edge-on lamellae can be macroscopically aligned by directed self-assembly (DSA), one necessity for various nanotechnological applications. It is believed that the observed mechanism to form stable edge-on lamellae can be transferred to other crystallizable short chain BCPs, providing potential pathways for sub-10 nm nanotechnology
Investigating the effect of aerosol variations in high-level analyses of Cherenkov telescope data
No full textAs aerosols influence the optical transmission properties of the atmosphere, variations in atmospheric aerosols yield variations in the signals from extensive air-showers (EAS) as measured with imaging atmospheric Cherenkov telescopes (IACTs). With the optical transmission of the atmosphere affecting the amount of Cherenkov light reaching IACTs, wrongly accounted aerosol levels yield a misinterpretation of the brightness of the detected signals. And as the number of Cherenkov photons produced in an EAS is related to its primary particle's energy, such unaccounted aerosol variations cause errors in the reconstructed particle energies. As this reconstructed energy is commonly used to bin the data for further spectral, morphological or temporal modelling, any error on the reconstructed air-shower energy propagates to all higher levels of an analysis. In this contribution, the effect of unaccounted aerosol variations on high-level results obtained from IACT data is investigated by simulating observations with the CTAO South in gammapy and adapting the reconstructed EAS energies as expected for variations in atmospheric aerosol content observed around the observatory site. This data is then used to reconstruct the properties of the simulated gamma-ray sources and the results are compared to results obtained from simulated observations which are not affected by deviations in aerosol conditions
Early Detection of Multiwavelength Blazar Variability
No full textBlazars are a subclass of active galactic nuclei with relativistic jets pointing toward the observer. They are notable for their flux variability at all observed wavelengths and timescales. Together with simultaneous measurements at lower energies, the very-high-energy (VHE) emission observed during blazar flares may be used to probe the population of accelerated particles. However, optimally triggering observations of blazar high states can be challenging. Notable examples include identifying a flaring episode in real time and predicting VHE flaring activity based on lower-energy observables. For this purpose, we have developed a novel deep learning analysis framework, based on data-driven anomaly detection techniques. It is capable of detecting various types of anomalies in real-world, multiwavelength light curves, ranging from clear high states to subtle correlations across bands. Based on unsupervised anomaly detection and clustering methods, we differentiate source variability from noisy background activity, without the need for a labeled training data set of flaring states. The framework incorporates measurement uncertainties and is robust given data quality challenges, such as varying cadences and observational gaps. We evaluate our approach using both historical data and simulations of blazar light curves in two energy bands, corresponding to sources observable with the Fermi Large Area Telescope and the upcoming Cherenkov Telescope Array Observatory. In a statistical analysis, we show that our framework can reliably detect known historical flares
A landscape of 4d SCFTs with
No full textWe study a landscape of four-dimensional superconformal field theories (SCFTs) with identical central charges. These theories are obtained by renormalization group flows triggered by supersymmetry-preserving superpotential deformations of the gauging of the flavor symmetry of a collection of Argyres--Douglas SCFTs. In this work, we focus on the fixed points in the landscape of the gauging of three copies of the theory together with an adjoint-valued chiral multiplet. We catalogue the network of fixed points, and, along the way, we find a variety of dualities and instances of supersymmetry enhancement
Direct observation of time-dependent coherent chiral tunneling dynamics
No full textSuperpositions of handed molecular states give rise to achiral eigenstates, delocalized across a double-well potential via tunneling. In principle, a coherent superposition of these stationary eigenstates could dynamically relocalize the molecules into chiral states, which has only been demonstrated theoretically. Here, we present a microwave six-wave mixing pump-probe study to create and probe coherent chiral tunneling dynamics in a rotational state. Through a time-resolved scheme, we uncover the periodic time evolution of the induced chiral wavepacket under field-free conditions, using enantiomeric excess as the observable. We also demonstrate precise phase control of this coherence via phase modulation during pump excitation. Our results offer foundational evidence for the superposition principle in chiral tunneling systems, with implications for advancing quantum control in these system
Thermal transmittance measurements of niobium at cryogenic temperatures
No full textThe first (100s\,nm) of the inner surface Niobium-based superconducting RF (SRF) cavities are crucial to achieve high accelerating fields and a low surface resistance. Recent treatments aim to improve superconducting properties by tailoring the interstitial atom concentration or by depositing thin superconducting films. Yet, no investigation of the thermal characteristics of those surfaces after such treatments has been done, although this is a crucial property to cool the induced RF losses away and to maintain the superconducting state while high surface magnetic fields are applied. In this contribution, a newly developed experimental set up is described, which allowed the first ever measurement of the thermal transmittance of Mid-T heat treated and Superconductor-Insulator-Superconductor (SIS) coated Niobium samples. The results show that SIS samples perform the same as standard Niobium and that Mid-T heat treated samples have an improved thermal transmittance of 30\%
Drell-Yan transverse-momentum spectra at NLL and approximate NLL with SCETlib
No full textWe provide state-of-the-art precision QCD predictions for the fiducial W and Z boson transverse momentum spectra at the LHC at NLL and approximate NLL in resummed perturbation theory, matched to available fixed-order results. Our predictions consistently combine all information from across the spectrum in a unified way, ranging from the nonperturbative region of small transverse momenta to the fixed-order tail, with an emphasis on estimating the magnitude of residual perturbative uncertainties, and in particular of those related to the matching. Parametric uncertainties related to the strong coupling, the collinear PDFs, and the nonperturbative transverse momentum-dependent (TMD) dynamics are studied in detail. To assess the latter, we explicitly demonstrate how the full complexity of flavor and Bjorken x-dependent TMD dynamics can be captured by a single, effective nonperturbative function for the resonant production of any given vector boson at a given collider. We point out that the cumulative cross section at the level of precision enabled by our predictions provides strong constraining power for PDF determinations at full NLO