A bstract The recent results from the Pulsar Timing Array (PTA) collaborations show first evidence for detection of a stochastic background gravitational waves at nHz frequencies. This discovery has profound implications physics both late and early Universe. In fact, together with interpretation in terms supermassive black hole binaries, many sources Universe can provide viable explanations as well. this paper, we study wave sourced by network axion-like-particle (ALP) domain walls...

We propose a simplified model of dark matter with scalar mediator to accommodate the di-photon excess recently observed by ATLAS and CMS collaborations. Decays resonance into can easily account for relatively large width resonance, while magnitude total combined constraint on relic density leads sharp predictions parameters Dark Sector. Under assumption rather width, predicts signal consistent ∼ 300 GeV particle 750 in channels missing energy. This prediction is not yet severely bounded LHC...

We derive a new bound on diphoton resonances using inclusive cross section measurements at the LHC, in so-far poorly constrained mass range between Upsilon and SM Higgs. This sets current best limit axion-like particles that couple to gluons photons, for masses 10 65 GeV. also estimate indicative sensitivities of dedicated LHC search same region, 7, 8 14 TeV. As byproduct our analysis, we comment particle interpretation CMS excesses low-mass dijet searches.

A bstract We assess the impact of searches at flavor factories for new neutral resonances that couple to both photons and gluons. These are well motivated by “heavy axion” solutions strong CP problem frameworks addressing Dark Matter Higgs hierarchy problem. use LHCb public diphoton data around B s mass derive current best limit on these masses between 4.9 6.3 GeV. estimate a future dedicated search would test an axion decay constant O (TeV) in few-to-tens GeV, being fully complementary low...

Abstract We study the early Universe evolution of axion-like particle (ALP) domain walls taking into account effect friction from particles in surrounding plasma, including case thermal equilibrium and frozen out species. characterize force interactions within ALP effective theory, providing new results for fermion contribution as well identifying simple conditions to be relevant during wall life time. When dominates, network departs standard scaling regime corresponding gravitational wave...

A bstract We study the LHC phenomenology of an Axion Like Particle (ALP) that couples only derivatively with top quark at tree level. inspect radiatively induced couplings SM fermions and (gauge) bosons associated production decay mechanisms ALP. focus on most challenging mass window remains open for a top-philic ALP, i.e., range between tens hundreds GeV. Not ALP processes but also virtual contributions to final states quarks are considered in detail. show how searches through resonant...

The Singlet-Doublet model of dark matter is a minimal extension the Standard Model with that mixture singlet and non-chiral pair electroweak doublet fermions. stability ensured by typical parity symmetry, and, similar to 'Bino-Higgsino' system, extra content improves gauge coupling unification. We revisit experimental constraints on model, combining most relevant bounds from direct (spin independent spin dependent) indirect searches. show such comprehensive analysis sets strong large part...

We study the effective theory of a generic class hidden sectors where supersymmetry is broken together with an approximate R-symmetry at low energy. The light spectrum contains gravitino and pseudo-Nambu-Goldstone boson R-symmetry, R-axion. derive new model-independent constraints on R-axion decay constant for masses ranging from GeV to TeV, which are relevance hadron colliders, lepton B factories. current bounds allow exciting possibility that first sign will be point out its most...

We present a novel baryogenesis mechanism in which the asymmetry is sourced from heavy particles either gain their mass or are created during bubble expansion strong first order phase transition. These then decay $CP$ and baryon number violating way inside bubble. The inherently out of equilibrium sufficiently dilute after wall crossing so third Sakharov condition easily met. Washout avoided provided reheat temperature below scale particles. relies on moderate supercooling relativistic walls...

Topological defects can act as local impurities that seed cosmological phase transitions. In this Letter, we study the case of domain walls and how they affect electroweak transition in singlet-extended standard model with a Z_{2}-symmetric potential. When occurs two steps, early breaking Z_{2} symmetry implies formation which then nucleation sites for second step. We develop method based on Kaluza-Klein decomposition to calculate rate catalyzed within 3D theory wall surface. By comparison...

We investigate the reach of LIGO/Virgo/KAGRA detectors in search for signatures first-order phase transitions early Universe. Utilizing data from first three observing runs, we derive constraints on parameters underlying gravitational-wave background, focusing characterized by strong supercooling. As an application our analysis, determine bounds parameter space two representative particle physics models. also comment expected third-generation probing supercooled transitions.

We initiate a comprehensive investigation of the geometry amplituhedron, recently found geometric object whose volume calculates integrand scattering amplitudes in planar $$ \mathcal{N}=4 SYM theory. do so by introducing and studying its stratification, focusing on four-point amplitudes. The new stratification exhibits interesting combinatorial properties positivity is neatly captured permutations. As explicit examples, we find all boundaries for two three loop related geometries. recover...

A bstract Displaced vertices at colliders, arising from the production and decay of long-lived particles, probe dark matter candidates produced via freeze-in. If one assumes a standard cosmological history, these decays happen inside detector only if is very light because relic density constraint. Here, we argue how displaced events could well point to freeze-in within non-standard early universe history. Focusing on cosmology inflationary reheating, explore interplay between reheating...

A bstract We revisit the electroweak phase transition in scalar singlet extension of standard model with a ℤ 2 symmetry. In significant parts parameter space occurs two steps — including canonical benchmarks used experimental projections for gravitational waves. Domain walls produced first step seed final to vacuum, an effect which is typically neglected but leads exponentially enhanced tunnelling rate. improve previous results obtained seeded transition, made use thin-wall or high...

We study the impact of QCD axion strings on cosmological history electroweak (EW) symmetry breaking, focussing minimal KSVZ model. consider case pure SM Higgs potential as well a simple scenario with first order EW phase transition. capture effect Peccei-Quinn (PQ) sector within an effective-theory approach for field, where string core and heavy PQ states are integrated out. The relevant parameters in this effective theory controlled by size portal coupling between scalar, mass radial...

A bstract Axionic domain walls, as they move through the early universe plasma during their collapse, can generate a net baryon and lepton number mechanism of spontaneous baryogenesis, provided that there is coupling between axion or current. In this paper, we study systematically asymmetry produced by these walls (DWs) at annihilation, within different realisations L - B -violating sector, refer to process DW-genesis . We find maximised when DW network collapses approximately moment...

We present a gauge mediation principle for beyond standard model theories where exact UV scale invariance is broken in hidden sector. The relevant configurations are those which the and sector emanate from invariant pair of that communicate only via interactions. compute radiatively induced Higgs potential contains logarithmic mass-squared terms lead to unusual self-couplings. Its other couplings unchanged.

We investigate the general structure of mirror symmetry breaking in Twin Higgs scenario. show, using IR effective theory, that a significant gain fine tuning can be achieved if is broken hardly. emphasize weakly coupled UV completions naturally accommodate this analyze SUSY and present simple model with around 10% colored superpartners as heavy 2 TeV. The collider signatures models are discussed focus on extended sectors.

We investigate features of duality in three dimensional $ \mathcal{N} = 2 Chern-Simons matter theories conjectured to describe M2 branes at toric Calabi Yau four-fold singularities. For 3D with non-chiral 4D parents we propone a Seiberg-like which turns out be duality. chiral discuss the conditions under that leads comment on such without parents.

We consider two SUSY-breaking hidden sectors which decouple when their respective couplings to the visible particles are switched off. In such a scenario one expects find light fermions: Goldstino and pseudo-Goldstino. While former remains massless in rigid limit, latter becomes massive due radiative effects we analyze from several different points of view. This analysis is greatly facilitated by version Goldberger-Treiman relation, allows us write universal nonperturbative formula for mass....

The fundamental role of on-shell diagrams in quantum field theory has been recently recognized. On-shell diagrams, or equivalently bipartite graphs, provide a natural bridge connecting gauge to powerful mathematical structures such as the Grassmannian. We perform detailed investigation combinatorial and geometric objects associated these graphs. mainly focus on their relation polytopes toric geometry, Grassmannian its stratification. Our work extends current understanding connections along...

We study the Singlet-Doublet dark matter model in regime of feeble couplings, where abundance is obtained via freeze-in mechanism. As a consequence small heavier particles are long-lived with decay length at typical scales collider experiments. analyse signatures model, characterised by displaced $h$ and $Z$ bosons plus missing momentum, employing current LHC searches for vertices energy to significantly constrain parameter space model. also take into account cosmological bounds relevant our...