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Sensitivity to Triple Higgs Couplings via Di-Higgs Production in the RxSM at the (HL-)LHC and future Colliders
No full textThe real Higgs singlet extension of the Standard Model (SM) without symmetry, the RxSM, is the simplest extension of the SM that features a First Order Electroweak Phase Transition (FOEWPT) in the early universe. The FOEWPT is one of the requirements needed for electroweak baryogenesis to explain the baryon asymmetry of the universe (BAU). Thus, the RxSM is a perfect example to study features related to the FOEWPT at current and future collider experiments. The RxSM has two CP-even Higgs bosons, and , with masses is found. In a first step we analyze the di-Higgs production at the (HL-)LHC, , with a focus on the impact of the trilinear Higgs couplings (THCs), and . The interferences of the resonant -exchange diagram involving and the non-resonant diagrams result in a characteristic peak-dip (or dip-peak) structure in the distribution. We analyze how can be accessed, taking into account the experimental smearing and binning. We also demonstrate that the approximation used by ATLAS and CMS for the resonant di-Higgs searches may fail to capture the relevant effects and lead to erroneous results. In a second step we analyze the benchmark plane at a future high-energy collider with GeV (ILC1000). We demonstrate the potential sensitivity to via an experimental determination at the ILC1000
Energy Time Ptychography for one-dimensional Phase Retrieval
No full textPhase retrieval is at the heart of adaptive optics and modern high-resolution imaging. Without phase information, optical systems are limited to intensity-only measurements, hindering full reconstruction of object structures and wavefront dynamics essential for advanced applications. Here, we address a one-dimensional phase problem linking energy and time, which arises in X-ray scattering from ultrasharp nuclear resonances. We leverage the Mössbauer effect, where nuclei scatter radiation without energy loss to the lattice and are sensitive to their magneto-chemical environments. Rather than using traditional spectroscopy with radioactive gamma-ray sources, we measure nuclear forward scattering of synchrotron X-ray pulses in the time domain, providing superior sensitivity and faster data acquisition. Extracting spectral information from a single measurement is challenging due to the missing phase information, typically requiring extensive modeling. Instead, we use multiple energetically overlapping measurements to retrieve both the transmission spectrum and the phase of the scattering response, similar to ptychographic phase retrieval in imaging. Our robust approach can overcome the bandwidth limitations of gamma-ray sources, opening new research directions, to the best of our knowledge, with modern X-ray sources and Mössbauer isotopes
Realizing string breaking dynamics in a lattice gauge theory on quantum hardware
No full textWe investigate static and dynamical aspects of string breaking in a lattice gauge theory coupled to Kogut-Susskind staggered fermions. Using Tensor Network simulations, we demonstrate that the static potential as well as the site-resolved configuration of the matter sites and gauge links allows us to identify the regimes in which string breaking occurs. Furthermore, we develop a variational quantum eigensolver that allows for reliably preparing the ground state of the theory in both the absence and presence of static charges and to capture the static aspects of the phenomenon. Carrying out state preparation on real quantum hardware for up to 19 qubits, we demonstrate its suitability for current quantum devices. In addition, we study the real-time dynamics of a flux tube between two static charges using both Tensor Networks and quantum hardware. Using a trotterization for the time-evolution operator, we are able to show that the breaking process starts with the creation of charges inside the string. These eventually redistribute towards the static charges and screen them, which leads to the breaking of the flux tube
Sparsity in the Numerical Six-point Bootstrap
No full textWe use sparse matrix decompositions to efficiently exploit the banded struc-ture of SDPs occuring in the numerical six-point bootstrap. This reduces the complexity of1d six-point bootstrap computations to that of standard mixed correlator four-point boot-strap in one dimension higher. Thus, SDPBs capability to efficiently solve such four-pointbootstrap problems can directly be applied to the six-point bootstrap. Due to this technicalimprovement, new applications have come into reach. As an example, extremal correlatorsinterpolating between the generalised free Fermion and Boson are discussed
Unravelling the Role of the Multi-Functional Groups in the Adsorption of L-Cysteine on Rutile TiO₂(110)
No full textUnderstanding the interaction between biomolecules and oxide surfaces is essential for advancing technologies in photocatalysis, virus inactivation, and self-cleaning materials. This study investigates the adsorption behavior of L-cysteine on the rutile TiO₂(110) surface using a combined experimental and theoretical approach. By employing X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared reflection absorption spectroscopy (FT-IRRAS), scanning tunneling microscopy (STM), and density functional theory (DFT) calculations, we elucidate the molecular configurations and bonding mechanisms involved in the interaction of cysteine with the TiO₂ surface. The results reveal three distinct adsorption geometries: two bidentate bridging modes involving the carboxylate group and amino group and a configuration involving the interaction of the thiolate group with titanium atoms. Additionally, at higher coverages, cysteine molecules form dimers stabilized by disulfide bonds, while maintaining a zwitterionic state. Our study highlights, for the first time, the key role of the thiol group in cysteine adsorption on TiO2, both for surface direct binding and dimer formation. These findings provide new insights into the fundamental principles of biomolecule-semiconductor interactions, with important implications for surface-functionalized materials in catalysis and sensing
Post-compression of a Q-switched laser in a glass-rod multi-pass cell
No full textQ-switched lasers are compact, cost-effective, and highly pulse energy-scalable sources for nanosecond-scale laser pulses. The technology has been developed for many decades and is widely used in scientific, industrial and medical applications. However, their inherently narrow bandwidth imposes a lower limit on pulse duration - typically in the few-hundred-picosecond range - limiting the applicability of Q-switched technology in fields that require ultrafast laser pulses in the few-picosecond or femtosecond regime. In contrast, mode-locked lasers can produce broad-band, ultrafast
How rapid heating and quenching cycles affect phase evolution in advanced γ-TiAl alloys: An in situ synchrotron radiation study
No full textAdditive manufacturing (AM) processes are increasingly considered as an alternative manufacturing route to produce complex aircraft components out of γ-TiAl-based alloys. Due to the process-related high and short-time energy input, extremely fast heating and cooling rates occur which can result in thermodynamic and chemical disequilibrium. We studied the effect of rapid heating and quenching cycles in a Ti–48Al–2Nb–2Cr (in at.%) alloy by carrying out in situ high-energy X-ray diffraction experiments in which AM-related heating cycles were simulated. These in situ experiments allow to determine the influence of cooling rate and a chosen powder bed temperature on phase evolution
Search for dark matter produced in association with one or two top quarks in proton-proton collisions at = 13 TeV
No full textA search is performed for dark matter (DM) produced in association with a single top quark or a pair of top quarks using the data collected with the CMS detector at the LHC from proton-proton collisions at a center-of-mass energy of 13 TeV, corresponding to 138 fb of integrated luminosity. An excess of events with a large imbalance of transverse momentum is searched for across 0, 1 and 2 lepton final states. Novel multivariate techniques are used to take advantage of the differences in kinematic properties between the two DM production mechanisms. No significant deviations with respect to the standard model predictions are observed. The results are interpreted considering a simplified model in which the mediator is either a scalar or pseudoscalar particle and couples to top quarks and to DM fermions. Axion-like particles that are coupled to top quarks and DM fermions are also considered. Expected exclusion limits of 410 and 380 GeV for scalar and pseudoscalar mediator masses, respectively, are set at the 95% confidence level. A DM particle mass of 1 GeV is assumed, with mediator couplings to fermions and DM particles set to unity. A small signal-like excess is observed in data, with the largest local significance observed to be 1.9 standard deviations for the 150 GeV pseudoscalar mediator hypothesis. Because of this excess, mediator masses are only excluded below 310 (320) GeV for the scalar (pseudoscalar) mediator. The results are also translated into model-independent 95% confidence level upper limits on the visible cross section of DM production in association with top quarks, ranging from 1 pb to 0.02 pb
Local structural distortions drive magnetic molecular field in compositionally complex spinel oxide
No full textUnderstanding how local distortions determine the functional properties of high entropy materials, containing five or more elements at the same crystallographic site, is an open challenge. We address this for a compositionally complex spinel oxide (MnCoNiCuZn)CrO (ACrO). By comparatively examining extended X-ray absorption fine structure on ACrO and its parent counterparts, ACrO, along with density functional theory calculations for multiple configurations, we find that the element-specific distortions go beyond the first neighbor. Specifically, the strong Jahn-Teller distortion present in CuCrO is found to be completely suppressed in ACrO even locally. Instead, there is a broad distribution of Cu-O and Cu-Cr bond distances, while other A-O distances acquire certain specific values. This study demonstrates the additional flexibility of a cationic sublattice in maintaining a uniform long-range structure, in contrast to previous reports showing only the accommodative anionic sublattice. The mean-field magnetic interactions of ACrO exhibit a striking resemblance to those of NiCrO, despite the presence of multiple magnetic ions and variable bond lengths. This originates from the comparability of bond lengths around Cr in both materials. Our study paves the way for a deeper understanding of the impact of local structural distortions on the physical properties of compositionally complex quantum materials
Experimental signatures of interstitial electron density in transparent dense sodium
No full textThe transparent hP4 phase of dense sodium (Na), stable above 200 GPa, has been computed to be an electride in which valence electrons are localised on interstitial lattice sites within the structure. However, there is no experimental evidence for this interstitial electron localisation in Na, or indeed in other high-density electride phases. Using static compression and single-crystal X-ray diffraction techniques, we have grown and studied a single-crystal sample of Na in the hP4 phase at 223 GPa. Using atomic form factors for hP4-Na derived from quantum crystallography techniques, we present experimental results to support the electride nature of this phase