We study topological vortex solutions in a generalized Abelian Higgs model with nonpolynomial dielectric and potential functions. These quantities are chosen by requiring integrability of the self-dual limit of the theory for all values of the magnetic flux. All the vortex profiles are described by exact analytical expressions that solve the self-dual vortex equations. There is only a symmetry-breaking superconducting phase and the model sustains regular phenomenology.

We study quantum electrodynamics (QED) in the light-front dynamical form by using null-plane causal perturbation theory. We establish the equivalence with instant dynamics for the scattering processes, whose normalization allows one to construct the instantaneous terms of the usual null-plane QED Lagrangian density. Then we study vacuum polarization and normalize it by studying its insertions into Møller’s scattering process, obtaining the complete photon propagator, which turns out to be equivalent to the one of instant dynamics only when gauge invariance is taken into account.

We investigate the isodoublet vector leptoquark $V_2$ as a solution to the $B$ anomalies $R_{K,K^{*}}$ and $R_{D,D^{*}}$, as well as explaining the muon and electron anomalous magnetic moments and the very recent $W$-mass anomaly.

Dark photons are predicted by various new physics models and are being intensively studied in a variety of experiments. In the first part of this paper, we obtain partial wave unitarity constraints on the dark photon parameter space from the allowed $VV\to VV$ scattering processes in the limit of large center-of-mass energy, where $V=W$, $Z$. In the second part of the paper, searches are performed using the expected differential rates with a realistic detector simulation including a comprehensive set of background processes on dilepton and dilepton plus a photon events at the High Luminosity LHC. In these searches, sensitive differential distributions are used in an optimized way to determine the sensitivity to dark photon parameter space. It is shown that remarkable sensitivity to the dark photon model is achieved, and kinetic mixing strength can be probed down to $(1.4-10)\times {10}^{-4}$ for dark photon mass between 15 GeV to 2 TeV. We also investigate the sensitivity of a future muon collider suggested by the muon accelerator program (MAP) to the dark photon model at different center-of-mass energies. It is shown that a future muon collider is able to reach a sensitivity to kinetic mixing at the order of ${10}^{-4}$.

We present the first point-by-point extraction of a twist-3 PDF. The scalar PDF, $e(x)$, is accessed through the analysis of the data for the $\sin {\varphi }_R$-moment of the beam-spin asymmetry for dihadron production in semi-inclusive DIS off proton target at CLAS and CLAS12. The dihadron formalism allows for use of collinear framework, hence calling for a minimal set of approximations and hypotheses. The extracted PDF $e(x)$ carries insights into the physics of the largely-unexplored quark-gluon correlations, and its first Mellin moment is related to the marginally known scalar charge of the nucleon. We show that the proton flavor combination of the scalar PDF is nonzero at more than 74% probability.

We study the leading-twist time-reversal even transverse momentum-dependent parton distribution functions (TMDs) of light and heavy vector mesons, i.e., the $\rho$, $J/\psi$ and $\mathrm{\Upsilon }$. We employ the leading Fock-state light front wave functions (LF-LFWFs) of $\rho$ and $J/\psi$ from our recent study, and supplement with $\mathrm{\Upsilon }$’s LF-LFWFs. These LF-LFWFs are extracted from dynamically solved Bethe-Salpeter wave functions. The vector meson TMDs are then studied with the light front overlap representation at leading Fock-state. All the obtained TMDs are nonvanishing and evolve with current quark mass, in particular the tensor polarized TMDs $f_{1LT}$ and $f_{1TT}$ which undergo a sign flip. The $\rho$ TMDs are compared with other model studies and agreement is found, aside from $f_{1LT}$ and $f_{1TT}$. Finally, the collinear PDFs of vector mesons are studied. The $\rho$’s valence PDFs $f_{1,v}(x)$ and $g_{1L,v}(x)$ are evolved to the scale of 2.4 GeV, with their first three moments compared to the lattice QCD prediction. The qualitative behavior of tensor polarized PDF $f_{1LL}(x)$ in $\rho$ at large $x$ is also discussed.

A semiclassical approach is used to calculate radiation emission in the collision of an electron with an intense focused laser pulse. The results are benchmarked with numerical calculations of exact results in a plane wave and compared to predictions from the locally constant field and locally monochromatic approximations. It is found that simulations employing the semiclassical approach capture features in the energy spectra, such as subharmonics and bandwidth structure, which are beyond local approaches. The formation length is introduced as a diagnostic to select between approaches as the electron is propagated through the pulse.

In the context of the recently proposed first-order thermodynamics of scalar-tensor gravity, we discuss the possibility of zero-temperature states of equilibrium other than Einstein gravity, including pathological Brans-Dicke theory, Palatini $f(R)$ gravity, and cuscuton gravity, all with nondynamical scalar fields. The formalism is extended to Nordström gravity, which contains only a scalar degree of freedom and has negative temperature relative to general relativity.

The thermal Sunyaev-Zel’dovich (tSZ) effect is the distortion generated in the cosmic microwave background (CMB) spectrum by the inverse-Compton scattering of CMB photons off free, energetic electrons, primarily located in the intracluster medium. Cosmic infrared background (CIB) photons from thermal dust emission in star-forming galaxies are expected to undergo the same process. In this work, we perform the first calculation of the resulting tSZ-like distortion in the CIB. Focusing on the CIB monopole, we use a halo model approach to calculate both the CIB signal and the Compton-$y$ field that generates the distortion. We self-consistently account for the redshift coevolution of the CIB and Compton-$y$ fields: they are (partially) sourced by the same dark matter halos, which introduces new aspects to the calculation as compared to the CMB case. We find that the inverse-Compton distortion to the CIB monopole spectrum has a positive (negative) peak amplitude of $\approx 4\mathrm{Jy}/\mathrm{sr}$ ($\approx -5\mathrm{Jy}/\mathrm{sr}$) at 2260 GHz (940 GHz). In contrast to the usual tSZ effect, the distortion to the CIB spectrum has two null frequencies, at approximately 196 and 1490 GHz. We perform a Fisher matrix calculation to forecast the detectability of this new distortion signal by future experiments. PIXIE would have sufficient instrumental sensitivity to detect the signal at $4\sigma$, but foreground contamination reduces the projected signal-to-noise by a factor of $\approx 70$. A future ESA Voyage 2050 spectrometer could detect the CIB distortion at $\approx 5\sigma$ significance, even after marginalizing over foregrounds. A measurement of this signal would provide new information on the star formation history of the Universe, and the distortion anisotropies may be accessible by near-future ground-based experiments.

One important global topological property of a spacetime manifold is orientability. It is widely believed that spatial orientability can only be tested by global journeys around the Universe to check for orientation-reversing closed paths. Since such global journeys are not feasible, theoretical arguments that combine universality of physical experiments with local arrow of time, $CP$ violation and $CPT$ invariance are usually offered to support the choosing of time- and space-orientable spacetime manifolds. The nonexistence of globally defined spinor fields on a nonorientable spacetime is another theoretical argument for orientability. However, it is conceivable that orientability can be put to test by local physical effects. In this paper, we show that it is possible to locally access spatial orientability of a spatially flat Friedmann-Robertson-Walker spacetime through quantum vacuum electromagnestic fluctuations. We argue that a putative nonorientability of the spatial sections of spatially flat Friedmann-Robertson-Walker spacetime can be ascertained by the study of the stochastic motions of a charged particle or a point electric dipole under quantum vacuum electromagnetic fluctuations. In particular, the stochastic motions of a dipole permit the recognition of a presumed nonorientability of three space in itself.

In trace-free Einstein gravity, the stress-energy tensor of matter is not necessarily conserved and so the theory offers a natural framework for interacting dark energy models where dark energy has a constant equation of state $w=-1$. We derive the equations of motion for linear cosmological perturbations in interacting dark energy models of this class, focusing on the scalar sector. Then, we consider a specific model where the energy-momentum transfer potential is proportional to the energy density of cold dark matter; this transfer potential has the effect of inducing an effective equation of state $w_{\mathrm{eff}}\ne 0$ for cold dark matter. We analyze in detail the evolution of perturbations during radiation domination on super-Hubble scales, finding that the well-known large-scale instability that affects a large class of interacting dark energy models is absent in this model. To avoid a gradient instability, energy must flow from dark matter to dark energy. Finally, we show that interacting dark energy models with $w=-1$ are equivalent to a class of generalized dark matter models.

We present a new analysis of the diffuse soft $\gamma$-ray emission toward the inner Galaxy as measured by the spectrometer aboard the INTEGRAL satellite (SPI) with 16 years of data taking. The analysis implements a spatial template fit of SPI data and an improved instrumental background model. We characterize the contribution of primordial black holes (PBH) as dark matter (DM) candidates evaporating into $\mathcal{O}(1)\mathrm{MeV}$ photons by including, for the first time to our knowledge, the spatial distribution of their signal into the fitting procedure. No PBH signal is detected, and we set the strongest limit on PBH DM for masses up to $4\times {10}^{17}\mathrm{g}$, significantly closing in to the so-called asteroid mass range.

We consider the evolution equations for the bulk viscous pressure, diffusion current, and shear tensor derived within second-order relativistic dissipative hydrodynamics from kinetic theory. By matching the higher-order moments directly to the dissipative quantities, all terms which are of second order in the Knudsen number Kn vanish, leaving only terms of order $\mathcal{O}({\mathrm{Re}}^{-1}\mathrm{Kn})$ and $\mathcal{O}({\mathrm{Re}}^{-2})$ in the relaxation equations, where ${\mathrm{Re}}^{-1}$ is the inverse Reynolds number. We therefore refer to this scheme as the inverse-Reynolds-dominance (IReD) approach. The remaining (nonvanishing) transport coefficients can be obtained exclusively in terms of the inverse of the collision matrix. This procedure fixes unambiguously the relaxation times of the dissipative quantities, which are no longer related to the eigenvalues of the inverse of the collision matrix. In particular, we find that the relaxation times corresponding to higher-order moments grow as their order increases, thereby contradicting the separation of scales paradigm. The formal (up to second order) equivalence with the standard DNMR approach is proven and the connection between the IReD transport coefficients and the usual DNMR ones is established.

A dark $Z$ is a massive Abelian gauge boson which is coupled to the Standard Model through both kinetic and mass mixing with the electroweak sector. We study the phenomenology of the dark $Z$ at an energy-frontier $e^{+}{e}^{-}$ collider, such as the proposed International Linear Collider (ILC). We show that precision electroweak constraints and the current bounds from the hadron colliders allow a dark $Z$ that is kinematically accessible at the ILC with 250 or 500 GeV center-of-mass energy. Further, the reach of the ILC searches for a dark $Z$ significantly exceeds the expected reach of the high luminosity LHC. If a signal consistent with a dark-$Z$ is discovered, it would motivate a dedicated run of the ILC at the center-of-mass energy matching the dark-$Z$ mass. We demonstrate that a short one month run at design luminosity could measure the dark-$Z$ chiral couplings to fermions with percent precision. This measurement can be used to discriminate between competing theoretical models of the resonance: for example, the dark $Z$ can be distinguished from a dark photon with purely kinetic mixing.

We investigate the phenomenological viability of real spin half, zero, and one dark matter candidates, which interact predominantly with third-generation heavy quarks and gluons via the 28 gauge invariant higher-dimensional effective operators. The corresponding Wilson coefficients are constrained one at a time from the relic density ${\mathrm{\Omega }}^{\mathrm{DM}}{h}^2\approx 0.1198$. Their contributions to the thermally-averaged annihilation cross sections are shown to be consistent with the FermiLAT and H.E.S.S. experiments’ projected upper bound on the annihilation cross section in the $b\overline{b}$ mode. The tree-level gluonphilic and one-loop induced heavy-quarkphilic dark matter (DM) nucleon direct detection cross sections are analyzed. The nonobservation of any excess over expected background in the case of recoiled Xe nucleus events for spin-independent DM-nucleus scattering in XENON-1T sets the upper limits on the 18 Wilson coefficients. Our analysis validates the real DM candidates for the large range of accessible mass spectrum below 2 TeV for all but one interaction induced by the said operators.

The existence of a strongly coupled ultraviolet fixed point in four-dimensional lattice models as they cross into the conformal window has long been hypothesized. The SU(3) gauge system with eight fundamental fermions is a good candidate to study this phenomenon as it is expected to be very close to the opening of the conformal window. I study the system using staggered lattice fermions in the chiral limit. My numerical simulations employ improved lattice actions that include heavy Pauli-Villars (PV) type bosons. This modification does not affect the infrared dynamics but greatly reduces the ultraviolet fluctuations, thus allowing the study of stronger renormalized couplings than previously possible. I consider two different PV actions and find that both show an apparent continuous phase transition in the eight-flavor system. I investigate the critical behavior using finite size scaling of the renormalized gradient flow coupling. The finite size scaling curve-collapse analysis predicts a first-order phase transition consistent with discontinuity exponent $\nu =1/4$ in the system without PV bosons. The scaling analysis with the PV boson actions is not consistent with a first-order phase transition. The numerical data are well described by “walking scaling” corresponding to a renormalization group $\beta$ function that just touches zero, $\beta (g^2)\sim (g^2-g_{\star }^2{)}^2$, though second-order scaling cannot be excluded. Walking scaling could imply that the eight-flavor system is the opening of the conformal window, an exciting possibility that could be related to ’t Hooft anomaly cancellation of the system.

We present a calculation of the proton momentum and angular momentum decompositions using overlap fermions on a $2+1$-flavor RBC/UKQCD domain-wall lattice at 0.143 fm with a pion mass of 171 MeV which is close to the physical one. A complete determination of the momentum and angular momentum fractions carried by up, down, strange, and glue inside the proton has been done with valence pion masses varying from 171 to 391 MeV. We have utilized fast Fourier transform on the stochastic-sandwich method for connected-insertion parts and the cluster-decomposition error reduction technique technique for disconnected-insertion parts has been used to reduce statistical errors. The full nonperturbative renormalization and mixing between the quark and glue operators are carried out. The final results are normalized with the momentum and angular momentum sum rules and reported at the physical valence pion mass at $\overline{\mathrm{MS}}(\mu =2\mathrm{GeV})$. The renormalized momentum fractions for the quarks and glue are $⟨x{⟩}^q=0.491(20)(23)$ and $⟨x{⟩}^g=0.509(20)(23)$, respectively, and the renormalized total angular momentum fractions for quarks and glue are $2J^q=0.539(22)(44)$ and $2J^g=0.461(22)(44)$, respectively. The quark spin fraction is $\mathrm{\Sigma }=0.405(25)(37)$ from our previous work and the quark orbital angular momentum fraction is deduced from $2L^q=2J^q-\mathrm{\Sigma }$ to be 0.134(22)(44).

We investigate the structure $X(4630)$ discovered by the LHCb Collaboration in the process $B^{+}\to J/\psi \varphi K^{+}$ as a resonance in the $J/\psi \varphi$ mass distribution. We explore this resonance as a diquark-antidiquark state $X=[cs][\overline{c}\overline{s}]$ with spin-parities $J^{\mathrm{PC}}=1^{-+}$. Its mass and current coupling are calculated using the QCD two-point sum rule method by taking into account vacuum condensates up to dimension 10. We also study decays of this tetraquark to mesons $J/\psi \varphi$, ${\eta }_c{\eta }^{(\prime )}$ and ${\chi }_{c1}{\eta }^{(\prime )}$, and compute partial widths of these channels. To this end, we employ the light-cone sum rule approach and technical methods of soft-meson approximation to extract strong coupling at relevant tetraquark-meson-meson vertices. Our predictions for the mass $m=(4632\pm 60)\mathrm{MeV}$ and width $\mathrm{\Gamma }=(159\pm 31)\mathrm{MeV}$ of $X$ are in a very nice agreement with recent measurements of the LHCb Collaboration. These results allow us to interpret the resonance $X(4630)$ as the tetraquark $X$ with spin-parities $J^{\mathrm{PC}}=1^{-+}$.

We discuss up-to-date constraints on the Majorana neutrino mass $m_{\beta \beta }$ from neutrinoless double beta decay ($0\nu \beta \beta$) searches in experiments using different isotopes: KamLAND-Zen and EXO (${}^{136}\mathrm{Xe}$), GERDA and MAJORANA (${}^{76}\mathrm{Ge}$) and CUORE (${}^{130}\mathrm{Te}$). Best fits and upper bounds on $m_{\beta \beta }$ are explored in the general landscape of nuclear matrix elements (NME), as well as for specific NME values obtained in representative nuclear models. By approximating the likelihood of $0\nu \beta \beta$ signals through quadratic forms, the analysis of separate and combined isotope data becomes exceedingly simple, and allows us to clarify various aspects of multi-isotope data combinations. In particular, we analyze the relative impact of different data in setting upper bounds on $m_{\beta \beta }$, as well as the conditions leading to nonzero $m_{\beta \beta }$ at best fit, for variable values of the NMEs. Detailed results on $m_{\beta \beta }$ from various combinations of data are reported in graphical and numerical form. Implications for future $0\nu \beta \beta$ data analyses and NME calculations are briefly discussed.