With the enhancement mechanism provided by a noncanonical kinetic term with a peak, the amplitude of primordial curvature perturbations can be enhanced by seven orders of magnitude at small scales while keeping to be consistent with observations at large scales. The peak function and inflationary potential are not restricted in this mechanism. We use the Higgs model and T-model as examples to show how abundant primordial black hole dark matter with different mass and scalar induced secondary gravitational waves with different peak frequency are generated. We also show that the enhanced power spectrum for the primordial curvature perturbations and the energy density of the scalar induced secondary gravitational waves can have either a sharp peak or a broad peak. The primordial black holes with the mass around ${10}^{-14}-{10}^{-12}{M}_{\odot }$ produced with the enhancement mechanism can make up almost all dark matter, and the scalar induced secondary gravitational waves accompanied with the production of primordial black holes can be tested by the pulsar timing arrays and spaced based gravitational wave observatory. Therefore, the mechanism can be tested by primordial black hole dark matter and gravitational wave observations.

We show that axion stars formed from axions with nearly Planck-scale decay constants $f$ are unstable to decay and are unlikely to have phenomenological consequences. More generally, we show how results at smaller $f$ cannot be naïvely extrapolated to $f=\mathcal{O}(M_P)$ as, contrary to conventional wisdom, gravity and special relativity can both become relevant in the same regime. We clarify the rate of decay by reviewing and extending previous work on oscillons and axion stars, which imply a fast decay rate even for so-called dilute states at large $f$.

We investigate the implications of a hypothetical $2.5{\mathrm{M}}_{\odot }$ neutron star in regard to the possibility of a first order phase transition to quark matter. We use equations of state (EoS) of varying stiffness provided by a parametrizable relativistic mean field model transitioning to a constant speed of sound EoS. We find a strong connection between the discontinuity in energy density and the maximal neutron star mass. We demonstrate, that high maximal masses cannot be realized for large discontinuities. As a result visible mass gaps, i.e., twin stars, and masses of $M_{\max }\gtrsim 2.2M_{\odot }$ are mutually exclusive.

S stars in the Galactic Center are excellent testbeds of various general relativistic effects. While previous works focus on modeling their orbital motion around Sgr A*—the supermassive black hole in the Galactic Center—here we explore the possibility of using the rotation of S stars to test the de Sitter precession predicted by general relativity. We show that, by reorienting the rotation axes of S stars, de Sitter precession will change the apparent width of the absorption lines in the stellar spectra. Our numerical simulations suggest that the newly discovered S4714 and S62 are best suited for such a test because of their small pericenter distances relative to Sgr A*. Depending on the initial inclination of the star, the line width would vary by as much as $20–76\mathrm{km}{\mathrm{s}}^{-1}$ within a period of 20–40 years. Such a variation is comparable to the current detection limit. Since the precession rate is sensitive to the orbital eccentricity, monitoring the rotation velocities could also help us better constrain the orbital elements of the S stars.

We have systematically investigated the magnetic moments of spin-$\frac{1}{2}$ doubly charmed baryons in the framework of the heavy baryon chiral perturbation theory. In this paper, one loop corrections with intermediate spin-$\frac{1}{2}$ and spin-$\frac{3}{2}$ doubly charmed baryon states are considered. The numerical results are calculated to next-to-leading order: ${\mu }_{{\mathrm{\Xi }}_{cc}^{++}}=0.35{\mu }_N$, ${\mu }_{{\mathrm{\Xi }}_{cc}^{+}}=0.62{\mu }_N$, ${\mu }_{{\mathrm{\Omega }}_{cc}^{+}}=0.41{\mu }_N$. Our results may be useful for future experiment and chiral extrapolation of the lattice QCD.

We consider a nonminimal quartic inflation scenario in the minimal ${\mathrm{U}(1)}_X$ extension of the Standard Model (SM) with the classical conformal invariance, where the inflaton is identified with the ${\mathrm{U}(1)}_X$ Higgs field ($\varphi$). By virtue of the classically conformal invariance and the radiative ${\mathrm{U}(1)}_X$ symmetry breaking via the Coleman-Weinberg mechanism, the inflationary predictions (in particular, the tensor-to-scaler ratio $r$), the ${\mathrm{U}(1)}_X$ coupling $g_X$, and the ${\mathrm{U}(1)}_X$ gauge boson mass $m_{Z^{\prime }}$ are all determined by only two free parameters: the inflaton mass $m_{\varphi }$ and its mixing angle $\theta$ with the SM Higgs field. FASER can search for a long-lived scalar, which is the inflaton in our scenario, for the parameter ranges $0.1\lesssim m_{\varphi }[\mathrm{GeV}]\lesssim 4$ and ${10}^{-5}\lesssim \theta \lesssim {10}^{-3}$. Therefore, if such a scalar is discovered at FASER, both $m_{\varphi }$ and $\theta$ would be fixed, leading to the predictions for $r$, $g_X$, and $m_{Z^{\prime }}$ in our model. These predictions can be tested by future cosmological observations and LHC searches for the $Z^{\prime }$ boson resonance.

The cold dark matter (CDM) candidate with weakly interacting massive particles can successfully explain the observed dark matter relic density in cosmic scale and the large-scale structure of the Universe. However, a number of observations at the satellite galaxy scale seem to be inconsistent with CDM simulation. This is known as the small-scale problem of CDM. In recent years, it has been demonstrated that self-interacting dark matter (SIDM) with a light mediator offers a reasonable explanation for the small-scale problem. We adopt a simple model with SIDM and focus on the effects of Sommerfeld enhancement. In this model, the dark matter candidate is a leptonic scalar particle with a light mediator. We have found favored regions of the parameter space with proper masses and coupling strength generating a relic density that is consistent with the observed CDM relic density. Furthermore, this model satisfies the constraints of recent direct searches and indirect detection for dark matter as well as the effective number of neutrinos and the observed small-scale structure of the Universe. In addition, this model with the favored parameters can resolve the discrepancies between astrophysical observations and $N$-body simulations.

Within the framework of soft collinear effective theory, we present calculations of semi-inclusive jet functions and fragmenting jet functions at next-to-leading order for both quark- and gluon-initiated jets, for jet algorithms of $J_{E_T}^{(I)}$ and $J_{E_T}^{(II)}$ where one maximizes a suitable jet function. We demonstrate the consistency of the obtained results with the standard perturbative QCD calculations for the $J_{E_T}^{(I)}$ algorithm, while the results for fragmenting jet functions with the $J_{E_T}^{(II)}$ algorithm are new. The renormalization-group (RG) equations for both semi-inclusive jet functions and fragmenting jet functions are derived and shown to follow the timelike Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equations, independent of specific jet algorithms. The RG equation can be used to resum single logarithms of the jet size parameter $\beta$ for highly collimated jets in these algorithms where $\beta \gg 1$.

In this paper, we elaborate on a method to decompose multiloop multileg scattering amplitudes into Lorentz-invariant form factors, which exploits the simplifications that arise from considering four-dimensional external states. We propose a simple and general approach that applies to both fermionic and bosonic amplitudes and allows us to identify a minimal number of physically relevant form factors, which can be related one to one to the independent helicity amplitudes. We discuss explicitly its applicability to various four- and five-point scattering amplitudes relevant for LHC physics.

We investigate the influence of the Kondo effect, namely, the nonperturbative effect induced by heavy impurities, on the chiral separation effect (CSE) in quark matter. We employ a simple effective model incorporating the Kondo condensate made of a light quark and a heavy quark, and compute the response function of the axial current to the magnetic field in the static and dynamical limits. As a result, we find that the Kondo effect catalyzes the CSE in both of the limits, and in particular the CSE in the dynamical limit can be enhanced by a factor of approximately 3. Our findings clearly show that the presence of heavy impurities in quark matter can play an important role in the transport phenomena of light quarks induced by a magnetic field.

In the present work, we investigate the hidden-strangeness production process in the $S=+1$ channel via $K^{+}p\to K^{+}\varphi p$, focusing on the exotic pentaquark molecular $K^{*}\mathrm{\Sigma }$ bound-state, assigned by $P_s^{+}(2071,3/2^{-})$. For this purpose, we employ the effective Lagrangian approach in the tree-level Born approximation. Using the experimental and theoretical inputs for the exotic state and for the ground-state hadron interactions, the numerical results show a small but obvious peak structure from $P_s^{+}$ with the signal-to-background ratio $\approx 1.7\%$, and it is enhanced in the backward-scattering region of the outgoing $K^{+}$ in the center-of-mass frame. We also find that the contribution from the $K^{*}(1680,1^{-})$ meson plays an important role to reproduce the data. The proton-spin polarizations are taken into account to find a way to reduce the background. The effects of the possible 27-plet pentaquark ${\mathrm{\Theta }}_{27}^{++}$ is discussed as well.

The full ATLAS run 2 dataset with a time-integrated luminosity of $139{\mathrm{fb}}^{-1}$ in the diboson and dilepton channels is used to probe benchmark models with extended gauge sectors: the $E_6$-motivated grand unification models, the left-right symmetric model, and the sequential standard model [extended gauge model (EGM)]. These all predict neutral $Z^{\prime }$ vector bosons, decaying into lepton pairs $\ell \ell$ or into electroweak gauge boson pairs $WW$, where one $W$ in turn decays semileptonically. The 95% C.L. exclusion limits on the $Z^{\prime }$ resonance production cross section times the branching ratio to electroweak gauge boson pairs and to lepton pairs in the mass range of $\sim 1$ to 6 TeV are converted to constraints on the $Z\text{−}{Z}^{\prime }$ mixing parameter and the heavy resonance mass. We present exclusion regions on the parameter space of the $Z^{\prime }$ which are significantly extended compared to those obtained from the previous analyses performed with LHC data collected at 7 and 8 TeV in run 1 as well as at 13 TeV in run 2 at a time-integrated luminosity of $36.1{\mathrm{fb}}^{-1}$ and are the most stringent bounds to date. Also presented, from a similar analysis of electrically charged $W^{\prime }$ bosons arising in the EGM, which can decay through $W^{\prime }\to WZ$ and $W^{\prime }\to \ell \nu$, are limits on the $W\text{−}{W}^{\prime }$ mixing parameter and the charged $W^{\prime }$ vector boson mass.

We report the measurement of branching fractions and $CP$-violation asymmetries in $B\to \varphi \varphi K$ decays based on a $711{\mathrm{fb}}^{-1}$ data sample containing $772\times {10}^{6}B\overline{B}$ events. The data were recorded at the $\mathrm{\Upsilon }(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy $e^{+}{e}^{-}$ collider. For $B^{+}\to \varphi \varphi K^{+}$, the branching fraction and $CP$-violation asymmetry measured below the ${\eta }_c$ threshold ($m_{\varphi \varphi }<2.85\mathrm{GeV}/c^2$) are $[3.43_{-0.46}^{+0.48}(\mathrm{stat})\pm 0.22(\mathrm{syst})]\times {10}^{-6}$ and $-0.02\pm 0.11(\mathrm{stat})\pm 0.01(\mathrm{syst})$, respectively. Similarly, the branching fraction obtained for $B^0\to \varphi \varphi K^0$ below the ${\eta }_c$ threshold is $[3.02_{-0.66}^{+0.75}(\mathrm{stat})\pm 0.20(\mathrm{syst})]\times {10}^{-6}$. We also measure the $CP$-violation asymmetry for $B^{+}\to \varphi \varphi K^{+}$ within the ${\eta }_c$ region ($m_{\varphi \varphi }\in [2.94,3.02]\mathrm{GeV}/c^2$) to be $+0.12\pm 0.12(\mathrm{stat})\pm 0.01(\mathrm{syst})$.

In this work, we classify all the effective $U(1)$ symmetries and their associated Noether charges in the standard model (SM) and its minimal supersymmetric extension (MSSM) from the highest scale after inflation down to the weak scale. We then demonstrate that the discovery of the violation of baryon minus lepton number ($B-L$), which pinpoints to its violation in the primordial Universe at any cosmic temperature above 30 TeV, will open up a new window of baryogenesis in these effective charges above this scale. While the fast SM baryon number violation in the early Universe could be the first piece to solve the puzzle of cosmic baryon asymmetry, ($B-L$) violation could be the second important piece. In the background of an expanding Universe, there is ample opportunity for out-of-equilibrium processes to generate an asymmetry in the numerous effective charges in the SM or the MSSM, making a baryon-asymmetric Universe almost unavoidable. Finally, we provide examples in the SM and the MSSM where baryogenesis can proceed through out-of-equilibrium dynamics without explicitly breaking baryon or lepton number.

We study supersymmetric solutions in four-dimensional $N=6$ gauged supergravity with the $SO(6)$ gauge group. There is a unique $N=6$ supersymmetric ${\mathrm{AdS}}_4$ vacuum with $SO(6)$ symmetry dual to an $N=6$ superconformal field theory (SCFT) in three dimensions. We find a number of domain walls interpolating between this ${\mathrm{AdS}}_4$ vacuum and singular geometries in the IR with $SO(2)\times SO(4)$, $U(3)$, $SO(3)$, and $SO(2)\times SO(2)\times SO(2)$ symmetries. The $SO(3)$ case admits $N=6$ or $N=2$ solutions depending on whether the pseudoscalars are present or not. On the other hand, all the remaining solutions preserve $N=6$ supersymmetry. These solutions describe renormalization-group (RG) flows from the $N=6$ SCFT to nonconformal field theories driven by mass deformations. In particular, the $SO(2)\times SO(4)$ solution is in agreement with the previously known mass deformations of the dual $N=6$ SCFT. We also give a supersymmetric Janus solution with $SO(2)\times SO(4)$ symmetry, describing two-dimensional conformal defects in the $N=6$ SCFT with unbroken $N=(4,2)$ supersymmetry. Finally, we find an $N=2$ supersymmetric ${\mathrm{AdS}}_2\times H^2$ solution with $SO(2)\times SO(4)$ symmetry and the corresponding domain wall interpolating between this fixed point and the ${\mathrm{AdS}}_4$ vacuum. The solution describes an ${\mathrm{AdS}}_4$ black hole with a magnetic charge and is dual to a twisted compactification of the $N=6$ SCFT on a hyperbolic space $H^2$. We also give a domain wall interpolating between a locally supersymmetric ${\mathrm{AdS}}_4$ and a curved domain wall with $SO(2)\times SO(2)\times SO(2)$ symmetry dual to an RG flow across dimensions from the $N=6$ SCFT to a supersymmetric quantum mechanics.

In this work, we study finite density effects in spontaneous chiral symmetry breaking as well as chiral phase transition under the influence of a background magnetic field in $2+1$ dimensions. For this purpose, we use an improved holographic soft wall model based on an interpolated dilaton profile. We find inverse magnetic catalysis at finite density. We observe that the chiral condensate decreases as the density increases, and the two effects (addition of magnetic field and chemical potential) sum up, decreasing even more the chiral condensate.

We consider 3- and 6-vector deformations of 11-dimensional supergravity backgrounds of the form $M_5\times M_6$ admitting at least three Killing vectors. Using flux formulation of the ${\mathrm{E}}_{6(6)}$ exceptional field theory, we derive (sufficient) conditions for the deformations to generate a solution. In the group manifold case, these generalizations of the classical Yang-Baxter equation for the case of r-matrices with three and six indices are shown to reproduce those obtained from exceptional Drinfeld algebra for ${\mathrm{E}}_{6(6)}$. In general, we see an additional constraint, which might be related to higher exceptional Drinfeld algebras.

We show that the one-loop Euler-Heisenberg QED effective Lagrangian in a constant background field acquires a very different nonperturbative trans-series structure at two-loop and higher-loop order in the fine structure constant. Beyond one-loop, virtual particles interact, causing fluctuations about the instantons, whereby the simple poles of the one-loop Borel transform become branch points. We illustrate this in detail at two-loop order using Ritus’s seminal result for the renormalized two-loop effective Lagrangian as an exact double-integral representation, and propose a possible new approach to computations at higher loop order. Our methods yield remarkably accurate extrapolations from weak-field to strong-field, and from magnetic to electric background field, at both one-loop and two-loop order, based on surprisingly little perturbative input.

We consider an entanglement harvesting protocol between two Unruh-deWitt detectors in quantum superpositions of static trajectories in the static de Sitter and thermal Minkowski spacetimes. We demonstrate for the first time that the spatial superposition of each detector’s path allows entanglement to be harvested from the quantum field in regimes where it would be otherwise impossible for detectors on classical trajectories. Surprisingly, for detectors on sufficiently delocalized trajectories in a thermal bath, the amount of harvested entanglement grows with the temperature of the field, violating a no-go theorem derived by Simidzija et al. [Phys. Rev. D 98, 085007]. We also discover interesting effects for mutual information harvesting, which depends sensitively on the nonlocal correlations between the superposed trajectories between the paths of the respective detectors.