Non-thermal fermions can be produced non-perturbatively in the early universe during coherent oscillations of a scalar field. We explore fermion production in λϕ^4 inflation through this mechanism and analyze the momentum spectrum of the fermions produced, which depends on a coupling parameter q. For q ≳ 0.01, the main contribution to the total number density comes from an approximately half-filled Fermi sphere as a result of non-adiabaticity. For q≲ 0.01, we find that the major contributions instead come from resonance peaks at higher momentum values. We find a simple relation to predict the momentum values corresponding to resonance peaks for any q. We also obtain analytic power-law approximations for the total number density of fermions and find that it is proportional to q^1/2 for q≲ 0.01 and proportional to q^3/4 for q≳ 10. If fermions produced by this mechanism make up the entirety of dark matter, we estimate lower bounds on their mass.

We study the conditions under which the CP violation in the quark mixing matrix can leak into the scalar potential of the real two-Higgs-doublet model (2HDM) via divergent radiative corrections, thereby spoiling the renormalizability of the model. We show that any contributing diagram must involve 12 Yukawa-coupling insertions and a factor of the $U(1)_{PQ}$-breaking scalar potential parameter $\lambda_5$, thereby requiring at least six loops; this also implies that the 2HDM with only softly-broken $U(1)_{PQ}$ is safe from divergent leaks of CP violation to all orders. We demonstrate that additional symmetries of the six-loop diagrams in the type I and II 2HDMs guarantee that all of the divergent CP-violating contributions cancel at this order. We also show that these symmetries are violated at seven loops and enumerate the classes of diagrams that can contribute to CP-violating divergences, providing evidence that the real 2HDM is theoretically inconsistent starting at the seven-loop level.

We provide strong evidence that the widely studied real two-Higgs-doublet model is inconsistent under renormalization due to quark-induced divergent CP violation (CPV). We identify the necessary ingredients for the CPV to enter the renormalization-group equations based on symmetry proprieties of the divergent diagrams. We demonstrate that while these ingredients are present starting at six loops, the divergent CPV is zero at that order due to approximate symmetries. We show that these symmetries are broken at seven loops and determine the parameter dependence of the resulting divergent CPV.

Objective Deliberate foreign body ingestion (DFBI) is characterised by recurrent presentations among patients with mental health conditions, intellectual disabilities and in prisoners. We aimed to profile the characteristics and evaluate the care of such patients in this study. Methods Adult patients with an endoscopic record of attempted foreign body retrieval between January 2013 and September 2020 were identified at three Australian hospitals. Those with a documented mental health diagnosis were included and their standard medical records reviewed. Presentation history, demographics, comorbidities and endoscopic findings were recorded and described. Results A total of 166 admissions were accounted for by 35 patients, 2/3 of which had borderline personality disorder (BPD). Repetitive presentations occurred in more than half of the cohort. There was an increased trend of hospital admissions throughout the years. At least half of the cohort had a documented mental health review during their admission. An average of 3.3 (2.9) foreign bodies were ingested per single episode. Endoscopic intervention was performed in 76.5% of incidents. The combined Length of stay for all patients was 680 days. Conclusion Deliberate foreign body ingestion in mental health patients is a common, recurring and challenging problem that is increasing in frequency and requires collaborative research to further guide holistic management.

Abstract Background Vedolizumab is an effective drug in moderate-severe ulcerative colitis (UC) and Crohn’s disease (CD). A previous link between drug exposure and clinical response has been suggested in the literature making therapeutic drug monitoring (TDM) for vedolizumab an attractive idea to try and optimize patient outcomes. Recent data from the ENTERPRET induction study in UC presented at Digestive Diseases 2022 suggest no advantage to dose optimizing based on vedolizumab levels. Thus, there is discordance in the literature regarding the clinical relevance of vedolizumab drug levels. We aimed to clarify the utility of proactive TDM of vedolizumab trough levels in our cohort of maintenance vedolizumab patients using objective markers of disease activity in a treat to target strategy. Methods A single-centre retrospective cross sectional cohort study using proactive TDM was performed on 84 patients with moderate to severe IBD on vedolizumab maintenance therapy. All patients were receiving standard vedolizumab dosing of 300 mg every eight weeks. A vedolizumab trough drug level was paired with clinical and objective markers of disease activity. The two endpoints examined were steroid free clinical remission and objective remission. Objective remission targets were individualized for each patient using a treat to target strategy and benchmarked against a baseline abnormal test. Steroid free clinical remission was defined in Crohn’s disease as a Crohn’s disease activity index (CDAI) of < 150 and in ulcerative colitis as a partial MAYO score of < 1 in a patient off steroids. Objective remission was defined as faecal calprotectin < 150 ug/g, normal bowel wall thickness on intestinal ultrasound or magnetic resonance imaging without associated features of inflammation or absence of ulceration on colonoscopy or sigmoidoscopy within 3 months of the vedolizumab level. Results Median trough vedolizumab levels for patients were numerically higher but not statistically different in patients who had achieved steroid free clinical remission (13.3 ug/ml vs 8.89 ug/ml p = 0.544) or objective remission (15.22 ug/ml vs 10.28 ug/ml p = 0.139). See Figures 1. In addition, quartile analysis showed no statistically significant difference between quartiles of vedolizumab levels and clinical or objective remission (p = 0.822). Conclusion Trough serum vedolizumab levels in our real-life cohort of maintenance moderate severe IBD patients were not associated with clinical or objective remission. Caution should be applied to basing treatment decisions off vedolizumab maintenance levels until more data becomes available to support its routine use in clinical practice.

The Z2-symmetric version of the Georgi-Machacek model does not possess a decoupling limit in which all the new particles can be made arbitrarily heavy, opening the possibility that the model can be entirely excluded if experiments reveal no deviations from the Standard Model. We explore this model, focusing on the part of parameter space in which the vacuum expectation value of the triplets, vx, is small. In the small-vx limit, the second custodial-singlet scalar field S necessarily becomes very light and can contribute to the total width of the 125 GeV Higgs boson h via h -SS. We show that this process, together with LHC measurements of the h -yy rate, entirely excludes masses mS < mh/2 and thereby severely constrains the parameter space, setting an experimental lower bound vx greater than or similar to 12.5 GeV on the vacuum expectation value of the triplets. This lower bound makes it impossible to avoid deviations from the Standard Model in the couplings of h to fermion and vector boson pairs. We study the remaining parameter space after imposing constraints from direct searches for the additional Higgs bosons, and show that it is on the edge of being fully excluded at 95% confidence level by LHC measurements of the 125 GeV Higgs boson's couplings. Measurements of these couplings at the future high-luminosity run of the LHC will have sufficient precision to entirely exclude the model at 5a if no deviations from the Standard Model are observed.

These lectures are a pedagogical introduction to the application of perturbative unitarity to Higgs physics within and beyond the Standard Model (SM). I begin with a review of how perturbative unitarity arises from quantum mechanical scattering theory and apply it to the classic problem of longitudinal vector boson scattering in the SM to derive the famous upper bound on the Higgs boson mass. I then consider extended Higgs sectors, using the two-Higgs-doublet model, the scalar septet model, and the Georgi-Machacek model as case studies. I discuss the resulting Higgs coupling sum rules as well as the intertwined constraints on masses and couplings of the additional Higgs bosons in these models, highlighting the connection between perturbative unitarity and the decoupling limit. I finish with a direct review of the decoupling limit in the two-Higgs-doublet model and a digression on the alignment limit. These notes are based on lectures delivered over the past few years in a graduate-level course on beyond-the-SM phenomenology and are meant as a companion volume to my TASI 2013 lectures on Higgs physics.

The Georgi-Machacek (GM) model is used to motivate and interpret LHC searches for doubly charged scalars decaying to vector bosons pairs. The doubly charged scalars are part of a degenerate fermiophobic custodial fiveplet with states $H_5^{\pm\pm}$, $H_5^\pm$, and $H_5^0$ and common mass $m_5$. The GM model has been extensively studied at the LHC for $m_5 > 200$ GeV but there is a largely unprobed region of parameter space from $120$ GeV $< m_5 < 200$ GeV where light doubly-charged scalars could exist. This region has been neglected by experimental searches due in part to the lack of a benchmark for $m_5 < 200$ GeV. In this paper we propose a new "low-$m_5$" benchmark for the GM model, defined for $m_5 \in (50, 550)$ GeV, and characterize its properties. We apply all existing experimental constraints and summarize the phenomenology of the surviving parameter space. We show that the benchmark populates almost the entirety of the relevant allowed parameter plane for $m_5$ below 200 GeV and satisfies the constraints from the 125 GeV Higgs boson signal strengths. We compute the 125 GeV Higgs boson's couplings to fermion and vector boson pairs and show that they are always enhanced in the benchmark relative to those in the Standard Model. We also compute the most relevant production cross sections for $H_5$ at the LHC, including Drell-Yan production of $H_5$ pairs. The process $pp \to H \to H_5 H_5$ contributes in a small region of parameter space, but is small compared to the Drell-Yan production cross section. Finally we compute the branching ratios of $H_5^0 \to \gamma\gamma$ and $H_5^{\pm} \to W^{\pm} \gamma$. The width-to-mass ratio of each of the $H_5$ states is below 1\% over the entire benchmark, so that the narrow-width approximation is well justified.

We propose a CP-violating source in the charged Higgs sector of a 3-Higgs Doublet Model (3HDM) that will contribute to three CP-asymmetry observables for low energy processes. In the context of such a 3HDM, a measurement of one of the specific asymmetry observables (i.e., B̅→ X_s+dγ) could obtain up to 2.5 Beyond the SM (BSM) from the full BELLE II data set. In addition to these CP-violating observables, the current measurements of Electron Dipole Moments (EDMs) constrain the available parameter region of the CP-violating 3HDM. In this work, we perform a thorough analysis of the parameter space of it to find the regions that satisfy EDMs, B̅→ X_s γ, direct collider searches for charged Higgs bosons as well as theoretical bounds.

Abstract We demonstrate a new type of cancellation of contributions to the electron and neutron electric dipole moments (EDMs) that occurs in three Higgs doublet models (3HDMs) when CP violation appears in the charged Higgs sector. The cancellation becomes exact when the two physical charged Higgs bosons in the model are degenerate in mass. Depending on the model parameters, degeneracies at the 10% level are however sufficient to evade current bounds on the electron and neutron EDMs. We demonstrate that viable parameter space remains with both charged Higgs bosons lighter than 500 GeV and large CP-violating phases while also satisfying theoretical constraints from perturbativity and experimental ones from $$ \overline{B} $$ B ¯ → Xsγ and direct searches.

A bstract We discuss the vacuum structure of a version of the Georgi-Machecek model with an exact ℤ 2 symmetry acting on the triplet fields. Besides the usual custodial-symmetric model, with ρ = 1 at tree-level, a model with a dark matter candidate is also viable. The other phases of the model lead to electric charge breaking, a wrong pattern of electroweak symmetry breaking or to ρ ≠ 1 at tree-level. We derive conditions to have an absolute minimum in each of the two viable phases, the custodial and the dark matter phases.

We study the experimental constraints on CP violation originating in a dark sector that communicates with the Standard Model through a Higgs portal coupling H(dagger)HZ'(mu nu)(Z) over tilde'(mu nu), where the Z' is from a new U(1) gauge symmetry which is assumed to couple to lepton number. We compute explicitly the leading two-loop contribution of this effective operator to the electron electric dipole moment (EDM) and show that the resulting constraints arc comparable to those from direct Z' searches at electron-positron colliders when the effective operator is generated at tree level. We also examine an explicit UV completion for this effective operator that was first introduced to achieve electroweak baryogenesis and show that collider constraints from B factories already exclude viable baryogenesis for Z' masses below 10 GeV, and that future electronpositron Higgs factories will exclude viable baryogenesis for Z' masses up to the e(+)e(-) center-of-mass energy if anticipated luminosities are achieved. For higher Z' masses, the full viable baryogenesis parameter space lies within 6 orders of magnitude of the current upper bound on the electron EDM.

Evidence for dark matter self-interactions has recently been reported based on the observation of a spatial offset between the dark matter halo and the stars in a galaxy in the cluster Abell 3827. Interpreting the offset as due to dark matter self-interactions leads to a cross section measurement of sigma_DM/m ~ (1-1.5) cm^2/g, where m is the mass of the dark matter particle. We use this observation to constrain singlet scalar dark matter coupled to the Standard Model and to two-Higgs-doublet models. We show that the most natural scenario in this class of models is very light dark matter, below about 0.1 GeV, whose relic abundance is set by freeze-in, i.e., by slow production of dark matter in the early universe via extremely tiny interactions with the Higgs boson, never reaching thermal equilibrium. We also show that the dark matter abundance can be established through the usual thermal freeze-out mechanism in the singlet scalar extension of the Yukawa-aligned two-Higgs-doublet model, but that it requires rather severe fine tuning of the singlet scalar mass.

We study the effects of custodial symmetry violation in the Georgi-Machacek (GM) model. The GM model adds isospin-triplet scalars to the Standard Model in a way that preserves custodial symmetry at tree level; however, this custodial symmetry has long been known to be violated at the one-loop level by hypercharge interactions. We consider the custodial-symmetric GM model to arise at some high scale as a result of an unspecified ultraviolet completion, and quantify the custodial symmetry violation induced as the model is run down to the weak scale. The measured value of the eletroweak rho parameter (along with unitarity considerations) lets us constrain the scale of the ultraviolet completion to lie below tens to hundreds of TeV. Subject to this constraint, we quantify the size of other custodial-symmetry-violating effects at the weak scale, including custodial symmetry violation in the couplings of the 125 GeV Higgs boson to W and Z boson pairs and mixings and mass splittings among the additional Higgs bosons in the theory. We find that these effects are small enough that they are unlikely to be probed by the Large Hadron Collider, but may be detectable at a future e+e- collider.

We study the experimental constraints on the Georgi-Machacek model from direct searches for the new Higgs bosons and measurements of the properties of the discovered 125 GeV Higgs boson. We apply these by interfacing the public codes HiggsBounds 5.2.0 and HiggsSignals 2.2.1, which implement a large collection of direct-search constraints on extra Higgs bosons and measurements of the properties of the 125 GeV state to the model calculator GMCALC. We also implement constraints involving searches for doubly-charged Higgs bosons and Drell-Yan production of a neutral Higgs with decays to photon pairs directly into GMCALC; these channels are not included in HiggsBounds but provide important constraints on the model, especially at low mass. We identify new constraints on the model from $H_3^0 \to Z h$ and $H \to hh$ and point out that these channels remain promising. We also determine the allowed range of couplings of the SM-like Higgs boson after all experimental constraints are applied and show that the direct searches for additional Higgs bosons are generally more constraining than the measurements of the 125 GeV Higgs boson couplings. The updated GMCALC code will be released as version 1.5.0.