The study of entanglement in particle physics has been gathering pace the past few years. It is a new field that providing important results about possibility detecting and testing Bell inequality at colliders for final states as diverse top-quark, τ-lepton pairs Λ-baryons, massive gauge bosons vector mesons. In this review, after presenting definitions, tools basic are necessary understanding these developments, we summarize main findings—as published by beginning year 2024—including...

We scrutinise the evidences recently reported by ATLAS and CMS collaborations for compatible 750 GeV resonances which appear in di-photon channels of two experiments both 8 TeV 13 datasets. Similar di-boson, di-lepton, di-jet $t\bar t$ final states are instead not detected. After discussing properties compatibility signals, we study implications on physics beyond Standard Model with particular emphasis possible scalar extensions theory such as singlet Higgs doublet models. also analyse...

We study possible effects of a dark matter (DM) core on the maximum mass neutron star (NS), mass-radius relation and NS tidal deformability parameter $\mathrm{\ensuremath{\Lambda}}$. show that all these quantities would in general be reduced presence DM core. In particular, our calculations indicate with fraction $\ensuremath{\sim}5%$ could affect significantly interpretation data as constraints nuclear equation state (EOS), potentially excluding some EOS models basis measured PSR...

The recently claimed anomaly in the measurement of 21 cm hydrogen absorption signal by EDGES at $z\sim 17$, if cosmological, requires existence new physics. possible attempts to resolve rely on either (i) cooling gas via dark matter-hydrogen interactions or (ii) modifying soft photon background beyond standard CMB one, as possibly suggested also ARCADE~2 excess. We argue that solutions belonging first class are generally tension with cosmological matter probes once simple sector models...

Within the framework of scalar-tensor theories, we study conditions that allow single field inflation dynamics on small cosmological scales to significantly differ from large probed by observations cosmic microwave background. The resulting double scenario is characterised two consequent eras, usually separated a period where slow-roll approximation fails. At values inflaton dominated interplay between its non-minimal coupling gravity and radiative corrections self-coupling. For potential...

We provide further details on a recent proposal addressing the nature of dark sectors in cosmology and demonstrate that all current observations related to Dark Matter can be explained by presence heavy spin-2 particle. Massive fields their gravitational interactions are uniquely described ghost-free bimetric theory, which is minimal natural extension General Relativity. In this setup, largeness physical Planck mass naturally extremely weak couplings field baryonic matter therefore explains...

The EDGES experiment has recently measured an anomalous global 21-cm spectrum due to hydrogen absorptions at redshifts of about $z\sim 17$. Model independently, the unusually low temperature baryons probed by this observable sets strong constraints on any physical process that transfers energy into baryonic environment such redshifts. Here we make use derive bounds injection a possible population ${\cal O}(1-100) M_\odot$ primordial black holes, which induce wide radiation during accretion...

Motivated by the recent detection of gravitational wave signal emitted a binary neutron star merger, we analyse possible impact dark matter on such signals. We show that cores in merging stars may yield an observable supplementary peak power spectral density following which could be distinguished from features produced components.

There has been a steady interest in flavor anomalies and their global fits as ideal probes of new physics. If the are real, one promising explanation is Z′ gauge boson with flavor-changing coupling to bottom strange quarks flavor-conserving muons and, possibly, electrons. We point out that direct production such Z′, emerging from collision b s quarks, may offer complementary window into these phenomena because collider searches already provide competitive constraints. On top that, we analyze...

Observational evidence for the existence of Dark Matter is limited to its gravitational effects. The extensive program dedicated searches has yielded null results so far, challenging most popular models. Here we propose that this case because very cold a manifestation gravity itself. consistent bimetric theory gravity, only known ghost-free extension General Relativity involving massless and massive spin-2 field, automatically contains perfect candidate. We demonstrate particle can be heavy,...

Abstract Quantum entanglement of weak interaction gauge bosons produced at colliders can be explored by computing the corresponding polarization density matrix. To this end, we consider Higgs boson decays $$H\rightarrow W W^*$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>H</mml:mi> <mml:mo>→</mml:mo> <mml:mi>W</mml:mi> <mml:msup> <mml:mo>∗</mml:mo> </mml:msup> </mml:mrow> </mml:math> and Z Z^*$$ <mml:mi>Z</mml:mi> , in which $$W^*$$ $$Z^*$$ are off-shell...

We present a feasibility study to probe quantum entanglement and Bell inequality violation in the process <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi mathvariant="normal">e</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi mathvariant="normal">e</a:mi><a:mo>−</a:mo></a:msup><a:mo stretchy="false">→</a:mo><a:msup><a:mi>τ</a:mi><a:mo>+</a:mo></a:msup><a:msup><a:mi>τ</a:mi><a:mo>−</a:mo></a:msup></a:math> at center-of-mass energy of <f:math...

Abstract The Belle II collaboration has recently observed the rare decay $$B^+\rightarrow K^+ \nu \bar{\nu }$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:msup> <mml:mi>B</mml:mi> <mml:mo>+</mml:mo> </mml:msup> <mml:mo>→</mml:mo> <mml:mi>K</mml:mi> <mml:mi>ν</mml:mi> <mml:mover> </mml:mrow> <mml:mo>¯</mml:mo> </mml:mover> </mml:math> , finding an excess with respect to Standard Model prediction. We explore possibility that data entails long-distance interactions...

The violation of the Bell inequality is one hallmarks quantum mechanics and can be used to rule out local deterministic alternative descriptions. We utilize data analysis published by LHCb Collaboration on helicity amplitudes for decay <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi>B</a:mi><a:mn>0</a:mn></a:msup><a:mo stretchy="false">→</a:mo><a:mi>J</a:mi><a:mo>/</a:mo><a:mi>ψ</a:mi><a:msup><a:mi>K</a:mi><a:mo>*</a:mo></a:msup><a:mo...

Leptogenesis with heavy neutrino flavours is discussed within a density matrix formalism. We write the equation, describing generation of matter-antimatter asymmetry, for an arbitrary choice right-handed (RH) masses. For hierarchical RH masses lying in fully flavoured regimes, this reduces to multiple-stage Boltzmann equations. In case we recover and extend results previously derived quantum state collapse description. confirm generic existence phantom terms. However, taking into account...

Seemingly unrelated models of inflation that originate from different physical setups yield, in some cases, identical predictions for the currently constrained inflationary observables. In order to classify available models, we propose express slow-roll parameters and relevant observables terms frame reparametrization invariant quantities. The adopted formalism makes manifest redundancy afflicts current description dynamics offers a straightforward way identify classes which yield...

Thermal corrections in classically conformal models typically induce a strong first-order electroweak phase transition, thereby resulting stochastic gravitational wave background that could be detectable at observatories. After reviewing the basics of scenarios, this paper we investigate transition dynamics thermal environment and related phenomenology within framework scalar extensions Standard Model. We find minimal involving only one additional field struggle to reproduce correct once are...

In constant-roll inflation, the scalar field that drives accelerated expansion of Universe is rolling down its potential at a constant rate. Within this framework, we highlight relations between Hubble slow-roll parameters and ones, studying in detail case single-field Coleman-Weinberg model characterised by non-minimal coupling inflaton to gravity. With respect exact predictions, find assuming an approximate behaviour yields difference Δ r = 0.001 tensor-to-scalar ratio prediction. Such...

The negative outcomes of laboratory searches, juxtaposed with cosmological observations, may indicate that dark matter has a gravitational origin. We show coherent oscillations massive spin-2 field emerging from bimetric theory can easily account for the observed abundance. framework, based on only known consistent extension general relativity to interacting fields, is testable in precision measurements electric charge variation by means atomic clocks, molecular systems, dedicated resonant...

A bstract Quantum tomography provides the full reconstruction of density matrix a state. We use it to study Higgs boson decay into weak gauge bosons. Anomalous couplings beyond Standard Model can be constrained by means observables easily defined in terms polarization matrix. describe strategy based on three that together provide most stringent limits. Two these are linked entanglement between polarizations two bosons, other is CP-odd combinations one momentum and polarizations. find for Z...

Within classically conformal models, the spontaneous breaking of scale invariance is usually associated to a strong first order phase transition that results in gravitational wave background within reach future space-based interferometers. In this paper we study case gauged B-L model, analysing impact minimal extension Standard Model on dynamics electroweak symmetry and derive its signature. Particular attention paid problem vacuum stability role QCD transition, which prove responsible for...

Abstract We study the evolution of light spectator fields in an asymmetric polynomial potential. During inflation, stochastic fluctuations displace field from global minimum its potential, populating false vacuum state and thereby allowing for formation bubbles. By using a lattice simulation, we show that these bubbles begin to contract once they re-enter horizon and, if sufficiently large, collapse into black holes. This process generally results primordial holes, which, due specific shape...

The experimental data on the helicity amplitudes of charmonium decays allow us to measure entanglement in final state spin correlations and test possible violations Bell inequality. We find that inequality is violated with a significance <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mn>5</a:mn><a:mi>σ</a:mi></a:mrow></a:math> or more <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"...

We study whether the hinted 750 GeV resonance at LHC can be a Coleman-Weinberg inflaton which is non-minimally coupled to gravity. Since must couple new charged and coloured states reproduce diphoton signature, same interaction generate its effective potential trigger electroweak symmetry breaking via portal coupling Higgs boson. This inflationary scenario predicts lower bound on tensor-to-scalar ratio of r ≳ 0.006, where minimal value corresponds measured spectral index n s ≃ 0.97. However,...