We propose a left-right symmetric framework with a universal seesaw mechanism for the generation of masses of the Standard Model quarks and leptons. Heavy vectorlike singlet quarks and leptons are required for generation of Standard-Model-like quark and lepton masses through a seesaw mechanism. A softly broken $Z_2$ symmetry distinguishes the lepton sector and the quark sector of the model. This leads to the presence of some lepton-specific interactions that can produce unique collider signatures which can be explored at the current Large Hadron Collider run and also future colliders.

We present an extension of the standard model, containing a fermion dark matter candidate and two real scalar singlets, where the observed dark matter abundance is produced via freeze-out before the electroweak phase transition. We show that, in this case, the dark matter annihilation channels determining its freeze-out are different from those producing indirect detection signals. We present a benchmark model where the indirect annihilation cross section differs from the freeze-out one. The model also has a gravitational wave signature due to the first-order electroweak phase transition.

We analyze two consequences of the relationship between collinear factorization and $k_t$-factorization. First, we show that the $k_t$-factorization gives a fundamental justification for the choice of the hard scale $Q^2$ done in the collinear factorization. Second, we show that in the collinear factorization there is an uncertainty on this choice which will not be reduced by higher orders. This uncertainty is absent within the $k_t$-factorization formalism.

We explore jet physics in hadron collisions using the parton shower event generator Deductor. Of particular interest is the one jet inclusive cross section $d\sigma /d{P}_{\mathrm{T}}$ for jets of very high $P_{\mathrm{T}}$. Compared to the Born level, the cross section decreases substantially because of $P_{\mathrm{T}}$ loss from the jet during showering. We compare to the same effect in Pythia and Dire. The cross section then increases substantially because of the summation of threshold logarithms included in Deductor. We also study the cross section to have a gap with no jets between two hard jets that are widely separated in rapidity. Here we compare Atlas data to Deductor with virtuality based ordering and to Deductor with $k_{\mathrm{T}}$ ordering. We also compare with perturbation theory. In both cases, we check whether adding an underlying event and hadronization has a significant effect beyond that found with just a parton shower.

We consider idealized parton shower event generators that treat parton spin and color exactly, leaving aside the choice of practical approximations for spin and color. We investigate how the structure of such a parton shower generator is related to the structure of QCD. We argue that a parton shower with splitting functions proportional to ${\alpha }_{\mathrm{s}}$ can be viewed not just as a model, but as the lowest order approximation to a shower that is defined at any perturbative order. To support this argument, we present a formulation for a parton shower at order ${\alpha }_{\mathrm{s}}^k$ for any $k$. Since some of the input functions needed are specified by their properties but not calculated, this formulation does not provide a useful recipe for an order ${\alpha }_{\mathrm{s}}^k$ parton shower algorithm. However, in this formulation we see how the operators that generate the shower are related to operators that specify the infrared singularities of QCD.

We update a previous study of the effects of vector interactions in the Nambu–Jona-Lasinio model on the formation of inhomogeneous chiral symmetry breaking condensates. In particular, by properly considering a spatially modulated vector mean field associated with the quark number density of the system we show that, as the value of the vector coupling increases, a chiral density wave modulation can become thermodynamically favored over a real sinusoidal modulation. This behavior is found both via a Ginzburg-Landau analysis close to the Lifshitz point, as well as with a full numerical diagonalization of the mean-field Dirac Hamiltonian at vanishing temperature.

Latest measurements suggest that the $X(3872)$ mass lies less than 200 keV away from the $D^0{\overline{D}}^{0*}$ threshold, reenforcing its interpretation as a loosely bound mesonic molecule. This observation implies that in processes like $D^0{\overline{D}}^0{\pi }^0$ production, threshold effects could disguise the actual pole position of the $X(3872)$. We propose a new effective field theory with $D^0$, ${\overline{D}}^0$, and ${\pi }^0$ degrees of freedom for the $X(3872)$, considering Galilean invariance to be an exact symmetry. The $D^{0*}$ enters as a $D^0{\pi }^{0}p$-wave resonance, allowing for a comprehensive study of the influence of pion interactions on the $X(3872)$ width. We calculate relations between the mass of the $X(3872)$, its width, and its line shape in $D^0{\overline{D}}^0{\pi }^0$ production up to next-to-leading order. Our results provide a tool for the extraction of the $X(3872)$ pole position from the experimental data near threshold.

Very recently, Belle Collaboration reported observation of a narrow state called $\mathrm{\Omega }(2012)$ with mass $2012.4\pm 0.7(\mathrm{stat})\pm 0.6(\mathrm{syst})\mathrm{MeV}$ and width $6.4_{-2.0}^{+2.5}(\mathrm{stat})\pm 1.6(\mathrm{syst})\mathrm{MeV}$. We calculate the mass and residue of the $\mathrm{\Omega }(2012)$ state by employing the QCD sum rule method. Comparison of the obtained results with the experimental data allows us to interpret this state as a $1P$ orbital excitation of the ground state $\mathrm{\Omega }$ baryon, i.e., with quantum numbers $J^P={\frac{3}{2}}^{-}$.

The chirally symmetric baryon parity-doublet model can be used as an effective description of the baryon-like objects in the chirally symmetric phase of QCD. Recently it has been found that above the critical temperature, higher chiral spin symmetries emerge in QCD. It is demonstrated here that the baryon parity-doublet Lagrangian is manifestly chiral spin invariant. We construct nucleon interpolators with fixed chiral spin transformation properties that can be used in lattice studies at high T.

Measurements are made of differential cross-sections of highly boosted pair-produced top quarks as a function of top-quark and $t\overline{t}$ system kinematic observables using proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13\mathrm{TeV}$. The data set corresponds to an integrated luminosity of $36.1{\mathrm{fb}}^{-1}$, recorded in 2015 and 2016 with the ATLAS detector at the CERN Large Hadron Collider. Events with two large-radius jets in the final state, one with transverse momentum $p_{\mathrm{T}}>500\mathrm{GeV}$ and a second with $p_{\mathrm{T}}>350\mathrm{GeV}$, are used for the measurement. The top-quark candidates are separated from the multijet background using jet substructure information and association with a $b$-tagged jet. The measured spectra are corrected for detector effects to a particle-level fiducial phase space and a parton-level limited phase space, and are compared to several Monte Carlo simulations by means of calculated ${\chi }^2$ values. The cross-section for $t\overline{t}$ production in the fiducial phase-space region is $292\pm 7(\mathrm{stat})\pm 71(\mathrm{syst})\mathrm{fb}$, to be compared to the theoretical prediction of $384\pm 36\mathrm{fb}$.

We study the dependence on field parametrization of the functional renormalization group equation in the $f(R)$ truncation for the effective average action. We perform a systematic analysis of the dependence of fixed points and critical exponents in polynomial truncations. We find that, beyond the Einstein-Hilbert truncation, results are qualitatively different depending on the choice of parametrization. In particular, we observe that there are two different classes of fixed points, one with three relevant directions and the other with two. The computations are performed in the background approximation. We compare our results with the available literature and analyze how different schemes in the regularizations can affect the fixed point structure.

We deal with the presence of magnetic monopoles in a non-Abelian model that generalizes the standard ’t Hooft–Polyakov model in three spatial dimensions. We investigate the energy density of the static and spherically symmetric solutions to find first order differential equations that solve the equations of motion. The system is further studied and two distinct classes of solutions are obtained, one that can also be described by analytical solutions and is called a small monopole, since it is significantly smaller than the standard ’t Hooft–Polyakov monopole. The other type of structure is the hollow monopole, since the energy density is endowed with a hole at its core. The hollow monopole can be smaller or larger than the standard monopole, depending on the value of the parameter that controls the magnetic permeability of the model.

We investigate the weak lensing corrections to the cosmic microwave background temperature and polarization anisotropies. We consider all the effects beyond the leading order: post-Born corrections, LSS corrections, and, for the polarization anisotropies, the correction due to the rotation of the polarization direction between the emission at the source and the detection at the observer. We show that the full next-to-leading order correction to the B-mode polarization is not negligible on small scales and is dominated by the contribution from the rotation; this is a new effect not taken into account in previous works. Considering vanishing primordial gravitational waves, the B-mode correction due to rotation is comparable to cosmic variance for $\ell \gtrsim 3500$, in contrast to all other spectra where the corrections are always below that threshold for a single multipole. Moreover, the sum of all the effects is larger than cosmic variance at high multipoles, showing that higher-order lensing corrections to B-mode polarization are in principle detectable.

Reconstructed maps of the lensing convergence of the cosmic microwave background (CMB) will play a major role in precision cosmology in coming years. CMB lensing maps will enable calibration of the masses of high-redshift galaxy clusters and will yield precise measurements of the growth of cosmic structure through cross correlations with galaxy surveys. During the next decade, CMB lensing reconstruction will rely heavily on temperature data, rather than polarization, thus necessitating a detailed understanding of biases due to extragalactic foregrounds. In the near term, the most significant bias among these is that due to the thermal Sunyaev-Zel’dovich (tSZ) effect. Moreover, high-resolution observations will be available at only a few frequencies, making full foreground cleaning challenging. In this paper, we demonstrate a solution to the foreground bias problem that involves cleaning only the large-scale gradients of the CMB temperature map. We show that the data necessary for tSZ-bias-free CMB lensing maps already exist in the form of large-scale measurements of the CMB across multiple frequencies by the Planck and WMAP satellite experiments. Specifically, we show that the bias to halo masses inferred from CMB lensing is eliminated by the utilization of clean gradients obtained from multifrequency component separation involving Planck and WMAP data, and that special lensing maps for galaxy cross correlations can be prepared with only a small penalty in signal-to-noise while requiring no masking, in-painting, modeling, or simulation effort for the tSZ bias. While we focus on cross correlations, we also show that gradient cleaning can mitigate biases to the CMB lensing autospectrum that arise from the presence of foregrounds in temperature and polarization with minimal loss of signal-to-noise.

The clockwork mechanism can explain interactions which are dimensionally very weak without the need for very large mass scales. We present a model in which the clockwork mechanism generates the very small Higgs portal coupling and dark matter particle mass necessary to explain cold dark matter via the freeze-in mechanism. We introduce a TeV-scale scalar clockwork sector which couples to the Standard Model via the Higgs portal. The dark matter particle is the lightest scalar of the clockwork sector. We show that the freeze-in mechanism is dominated by decay of the heavy clockwork scalars to light dark matter scalars and Higgs bosons. In the model considered, we find that freeze-in dark matter is consistent with the clockwork mechanism for global charge $q$ in the range $2\lesssim q\lesssim 4$ when the number of massive scalars is in the range $10\le N\le 20$. The dark matter scalar mass and portal coupling are independent of $q$ and $N$. For a typical TeV-scale clockwork sector, the dark matter scalar mass is predicted to be of the order of a MeV.

We study the postinflationary dynamics of the Standard Model (SM) Higgs field in the presence of a nonminimal coupling $\xi |\mathrm{\Phi }{|}^{2}R$ to gravity, both with and without the electroweak gauge fields coupled to the Higgs field. We assume a minimal scenario in which inflation and reheating are caused by chaotic inflation with a quadratic potential, and no additional new physics is relevant below the Planck scale. By using classical real-time lattice simulations with a renormalization group improved effective Higgs potential and by demanding the stability of the Higgs vacuum after inflation, we obtain upper bounds for $\xi$, taking into account the experimental uncertainty of the top-Yukawa coupling. We compare the bounds in the absence and presence of the electroweak gauge bosons and conclude that the addition of gauge interactions has a rather minimal impact. In the unstable cases, we parametrize the time when such instability develops. For a top-quark mass $m_t\approx 173.3\mathrm{GeV}$, the Higgs vacuum instability is triggered for $\xi \gtrsim 4–5$, although a slightly lower mass of $m_t\approx 172.1\mathrm{GeV}$ pushes up this limit to $\xi \gtrsim 11–12$. This, together with the estimation $\xi \gtrsim 0.06$ for stability during inflation, provides tight constraints to the Higgs field-curvature coupling within the SM.

Warm inflation is analyzed in the context of loop quantum cosmology (LQC). The bounce in LQC provides a mean through which a Liouville measure can be defined, which has been used previously to characterize the a priori probability for inflation in LQC. Here we take advantage of the tools provided by LQC to study instead the a priori probability for warm inflation dynamics in the context of a monomial quartic inflaton potential. We study not only the question of how a general warm inflation dynamics can be realized in LQC with an appropriate number of e-folds, but also how such dynamics is constrained to be in agreement with the latest cosmic microwave background radiation data from Planck. The fraction of warm inflation trajectories in LQC that gives both the required minimum amount e-folds of expansion and also passes through the observational window of allowed values for the tensor-to-scalar ratio and the spectral tilt is explicitly obtained. We find that the probability of warm inflation with a monomial quartic potential in LQC is higher than that of cold inflation in the same context. Furthermore, we also obtain that the a priori probability gets higher as the inherent dissipation of the warm inflation dynamics increases.

Primordial black holes (PBHs) can form in the radiation dominated early Universe from the collapse of large density perturbations produced by inflation. A power-law parametrization of the primordial power spectrum is often used to extrapolate from cosmological scales, where the amplitude of the perturbations is well measured by the cosmic microwave background and large scale structure observations, down to the small scales on which PBHs may form. We show that this typically leads to large errors in the amplitude of the fluctuations on small scales, and hence extremely inaccurate calculations of the abundance of PBHs are formed.

In this paper, we construct the complete set of minimal 3-point vertices for the massive Standard Model (SM) based purely on symmetry principles, mass dimension and high-energy behavior and without any recourse to field theory, gauge symmetries or Feynman rules. Because the gravitational vertices are no more challenging than any other vertices in this constructive method, we include them as well. We also calculate the high-energy behavior of these vertices and compare with the well-known massless vertices, both as a check and as a way to pin down the normalization constants. We include all these vertices in tables as a reference for future investigations.

We reconsider the criticality of the Ising model on two-dimensional dynamical triangulations based on the $N\times N$ Hermitian two-matrix model with the introduction of a loop-counting parameter and linear terms in the potential. We show that in the large-$N$ limit even though the Ising model is classical, the critical temperature can reach absolute zero by tuning the loop-counting parameter, and the corresponding continuum theory turns out to be the quantized theory of neither pure gravity nor gravity coupled to conformal matter with central charge being $1/2$.