We discuss quantum radiation of a massless scalar field from a spherically symmetric nonsingular black hole with a finite lifetime. Namely, we discuss a sandwich black-hole model, where a black hole is originally created by a collapse of a null shell of mass $M$, and later, after some time $\mathrm{\Delta }V$, it is disrupted by the collapse of the other shell with negative mass $-M$. We assume that between the shells the metric is static and either coincides with the Hayward metric or with a special generalization of it. We show that in both cases for a sufficiently large parameter $\mathrm{\Delta }V$ the radiation after the formation of the black hole practically coincides with the Hawking result. We also calculate the radiation, emitted from the black hole interior. This radiation contains a peak at the moment when the second shell intersects the inner horizon. In the standard sandwich metric (with the Hayward interior) this outburst of energy is exponentially large. In the modified metric, which includes an additional nontrivial redshift parameter, this exponent is suppressed. This is a result of a significant decrease of the surface gravity of the inner horizon in the latter case. We discuss possible consequences of this result in the context of the self-consistency requirement for nonsingular models with quantum radiation.

We propose an interesting framework for asymmetric scalar dark matter (ADM), which has novel collider phenomenology in terms of an unstable ADM bound state (ADMonium) produced via Higgs portals. ADMonium is a natural consequence of the basic features of ADM: the (complex scalar) ADM is charged under a dark local $U(1{)}_d$ symmetry which is broken at a low scale and provides a light gauge boson $X$. The dark gauge coupling is strong and then ADM can annihilate away into $X$-pair effectively. Therefore, the ADM can form a bound state due to its large self-interaction via $X$ mediation. To explore the collider signature of ADMonium, we propose that ADM has a two-Higgs doublet portal. The ADMonium can have a sizable mixing with the heavier Higgs boson, which admits a large cross section of ADMonium production associated with $b\overline{b}$. The resulting signature at the LHC depends on the decays of $X$. In this paper we consider a case of particular interest: $pp\to b\overline{b}+\text{ADMonium}$ followed by $\text{ADMonium}\to 2X\to 2e^{+}{e}^{-}$ where the electrons are identified as (un)converted photons. It may provide a competitive explanation to heavy di-photon resonance searches at the LHC.

We discuss the cosmological implications of nonlocal modifications of general relativity containing tensorial structures. Assuming the presence of standard radiation- and matter-dominated eras, we show that, except in very particular cases, the nonlocal terms contribute a rapidly growing energy density. These models therefore generically do not have a stable cosmological evolution.

We study the magnetohydrodynamics of relativistic plasmas accounting for the chiral magnetic effect (CME). To take into account the evolution of the plasma velocity, obeying the Navier-Stokes equation, we approximate it by the Lorentz force accompanied by the phenomenological drag time parameter. On the basis of this ansatz, we obtain the contributions of both the turbulence effects, resulting from the dynamo term, and the magnetic field instability, caused by the CME, to the evolution of the magnetic field governed by the modified Faraday equation. In this way, we explore the evolution of the magnetic field energy and the magnetic helicity density spectra in the early Universe plasma. We find that the right-left electron asymmetry is enhanced by the turbulent plasma motion in a strong seed magnetic field compared to the pure CME case studied earlier for the hot Universe plasma in the same broken phase.

Cosmic strings are topological defects possibly formed in the early Universe, which may be observable due to their gravitational effects on the cosmic microwave background radiation or gravitational wave experiments. To this effect, it is important to quantitatively ascertain the network properties, including their density, velocity, or the number of strings present, at the various epochs in the observable Universe. Attempts to estimate these numbers often rely on simplistic approximations for the string parameters, such as assuming that the network is scaling. However, in cosmological models containing realistic amounts of radiation, matter, and dark energy, a string network is never exactly scaling. Here, we use the velocity-dependent one-scale model for the evolution of a string network to better quantify how these networks evolve. In particular, we obtain new approximate analytic solutions for the behavior of the network during the radiation-to-matter and matter-to-acceleration transitions (assuming, in the latter case, the canonical $\mathrm{\Lambda }$ cold dark matter model) and numerically calculate the relevant quantities for a range of possible dark energy models.

Measuring the volume-weighted peculiar velocity statistics from inhomogeneously and sparsely distributed galaxies/halos, by existing velocity assignment methods, suffers from a significant sampling artifact. As an alternative, the Kriging interpolation based on Gaussian processes was introduced and evaluated [Y. Yu, J. Zhang, Y. Jing, and P. Zhang, Phys. Rev. D 92, 083527 (2015)]. Unfortunately, the most straightforward application of Kriging does not perform better than the existing methods in the literature. In this work, we investigate two physically motivated extensions. The first takes into account of the anisotropic velocity correlations. The second introduces the nugget effect, on account of multistreaming of the velocity field. We find that the performance is indeed improved. For sparsely sampled data [$n_P\lesssim 6\times {10}^{-3}(h^{-1}\mathrm{Mpc}{)}^{-3}$] where the sampling artifact is the most severe, the improvement is significant and is two-fold: 1) The scale of reliable measurement of the velocity power spectrum is extended by a factor $\sim 1.6$, and 2) the dependence on the velocity correlation prior is weakened by a factor of $\sim 2$. We conclude that such extensions are desirable for accurate velocity assignment by Kriging.

Based on thermodynamics, we study the galactic clustering of an expanding Universe by considering the logarithmic and volume (quantum) corrections to Newton’s law along with the repulsive effect of a harmonic force induced by the cosmological constant ($\mathrm{\Lambda }$) in the formation of the large scale structure of the Universe. We derive the $N$-body partition function for extended-mass galaxies (galaxies with halos) analytically. For this partition function, we compute the exact equations of states, which exhibit the logarithmic, volume, and cosmological constant corrections. In this setting, a modified correlation (clustering) parameter (due to these corrections) emerges naturally from the exact equations of state. We compute a corrected grand canonical distribution function for this system. Furthermore, we obtain a deviation in differential forms of the two-point correlation functions for both the point-mass and extended-mass cases. The consequences of these deviations on the correlation function’s power law are also discussed.

We study the longitudinal, transverse, and normal polarization components of the tau lepton in the decays ${\overline{B}}^0\to D^{(*)}{\tau }^{-}{\overline{\nu }}_{\tau }$ and discuss their role in searching for new physics (NP) beyond the standard model (SM). Starting with a model-independent effective Hamiltonian including non-SM four-Fermi operators, we obtain experimental constraints on different NP scenarios and investigate their effects on the polarization observables. In the SM the longitudinal and transverse polarizations of the tau lepton differ substantially from the corresponding zero lepton mass values of $P_L=-1$ and $P_T=0$. In addition, $P_L$ and $P_T$ are very sensitive to NP effects. For the transverse polarization this holds true, in particular, for the effective tensor operator in the case of ${\overline{B}}^0\to D^{*}$ and for the scalar operator in the case of ${\overline{B}}^0\to D$. The $T$-odd normal polarization $P_N$, which is predicted to be negligibly small in the SM, can be very sizable assuming NP complex Wilson coefficients. We also discuss in some detail how the three polarization components of the tau lepton can be measured with the help of its subsequent leptonic and semihadronic decays.

Kinematic edges in the invariant mass distributions of different final state particles are typically a signal of new physics. In this work we propose a scenario wherein these edges could be utilized in discriminating between different classes of models. To this effect, we consider the resonant production of a heavy Higgs like resonance ($H_1$) as a case study. Such states are a characteristic feature of many new physics scenarios beyond the standard model (SM). In the event of a discovery, it is essential to identify the true nature of the underlying theory. In this work we propose a channel, $H_1\to t_{2}t$, where $t_2$ is a vectorlike gauge singlet top-partner that decays into $Wb$, $Zt$, $ht$. Invariant mass distributions constructed out of these final states are characterized by the presence of kinematic edges, which are unique to the topology under consideration. Further, since all the final state particles are SM states, the position in the edges of these invariant mass distributions can be used to exclusively determine the masses of the resonances. Observation of these features are meant to serve as a trigger, thereby mandating a more detailed analysis in a particular direction of parameter space. The absence of these edge like features, in the specific invariant mass distributions considered here, in minimal versions of supersymmetric models (MSSM) also serves as a harbinger of such non-MSSM-like scenarios.

We explore an electroweak symmetry breaking (EWSB) scenario based on the mixture of a fundamental Higgs doublet and an SU(4)/Sp(4) composite pseudo-Nambu-Goldstone doublet—a particular manifestation of bosonic technicolor/induced EWSB. Taking the fundamental Higgs mass parameter to be positive, EWSB is triggered by the mixing of the doublets. This setup has several attractive features and phenomenological consequences, which we highlight: (i) Unlike traditional bosonic technicolor models, the hierarchy between ${\mathrm{\Lambda }}_{\mathrm{TC}}$ and the electroweak scale depends on vacuum (mis)alignment and can be sizable, yielding an attractive framework for natural EWSB; (ii) As the strong sector is based on SU(4)/Sp(4), a fundamental (UV-complete) description of the strong sector is possible, that is informed by the lattice; (iii) The lightest vector resonances occur in the 10-plet, 5-plet and singlet of Sp(4). Misalignment leads to a 10-plet “parity-doubling” cancellation in the $S$ parameter, and a suppressed 5-plet contribution; (iv) Higgs coupling deviations are typically of $\mathcal{O}(1\%)$; (v) The 10-plet isotriplet resonances decay dominantly to a massive technipion and a gauge boson, or to technipion pairs, rather than to gauge boson or fermion pairs; moreover, their couplings to fermions are small. Thus, the bounds on this setup from conventional heavy-vector-triplet searches are weak. A supersymmetric $U(1{)}_R$ symmetric realization is briefly described.

Two-Higgs-doublet extensions of the standard model, such as supersymmetry, predict the existence of charged Higgs bosons. We explore the reach for TeV-scale charged Higgs bosons through their associated production with top quarks, and their decay to boosted top jets and ${\mu }_x$-tagged boosted bottom jets, at a 14 TeV CERN Large Hadron Collider and at a 100 TeV Future Circular Collider. In particular, we show the moderate $\tan \beta$ “wedge” region of parameter space cannot be probed at the Large Hadron Collider for TeV-scale $H^{\pm }$ because the cross section is too small. However, a 100 TeV future proton collider can close the wedge region below 2 TeV, and search for $H^{\pm }$ up to 6 TeV.

We discuss contributions to neutrinoless double beta ($0\nu \beta \beta$) decay involving vector bosons. The starting point is a list of all possible vector representations that may contribute to $0\nu \beta \beta$ decay via $d=9$ or $d=11$ operators at tree level. We then identify gauge groups which contain these vectors in the adjoint representation. Even though the complete list of vector fields that can contribute to $0\nu \beta \beta$ up to $d=11$ is large (a total of 46 vectors), only a few of them can be gauge bosons of phenomenologically realistic groups. These latter cases are discussed in some more detail, and lower (upper) limits on gauge boson masses (mixing angles) are derived from the absence of $0\nu \beta \beta$ decay.

In the $SO(5)\times U(1)$ gauge-Higgs unification (GHU), Kaluza-Klein (KK) excited states of charged and neutral vector bosons, $W^{(1)}$, $W_R^{(1)}$, $Z^{(1)}$, ${\gamma }^{(1)}$, and $Z_R^{(1)}$, can be observed as $W^{\prime }$ and $Z^{\prime }$ signals in collider experiments. In this paper we evaluate the decay rates of the $W^{\prime }$ and $Z^{\prime }$, and $s$-channel cross sections mediated by $W^{\prime }$ and $Z^{\prime }$ bosons with final states involving the standard model (SM) fermion pair ($\ell \nu$, $\ell \overline{\ell }$, $q{\overline{q}}^{\prime }$), $WH$, $ZH$, $WW$, and $WZ$. $W^{\prime }$ and $Z^{\prime }$ resonances appear around 6.0 TeV (8.5 TeV) for ${\theta }_H=0.115$ (0.0737) where ${\theta }_H$ is the Aharonov-Bohm phase in the fifth dimension in GHU. For decay rates we find $\mathrm{\Gamma }(W^{\prime }\to WH)\simeq \mathrm{\Gamma }(W^{\prime }\to WZ)$ ($W^{\prime }=W^{(1)}$, $W_R^{(1)}$), $\mathrm{\Gamma }(W^{(1)}\to WH,WZ)\sim \mathrm{\Gamma }(W_R^{(1)}\to WH,WZ)$, $\mathrm{\Gamma }(Z^{(1)}\to ZH)\simeq \sum _{Z^{\prime }=Z^{(1)},{\gamma }^{(1)}}\mathrm{\Gamma }(Z^{\prime }\to WW)$, and $\mathrm{\Gamma }(Z_R^{(1)}\to ZH)\simeq \mathrm{\Gamma }(Z_R^{(1)}\to WW)$. $W^{\prime }$ and $Z^{\prime }$ signals of GHU can be best found at the LHC experiment in the processes $pp\to W^{\prime }(Z^{\prime })+X$ followed by $W^{\prime }\to t\overline{b}$, $WH$, and $Z^{\prime }\to e^{+}{e}^{-}$, ${\mu }^{+}{\mu }^{-},ZH$ near the $W^{\prime }$ and $Z^{\prime }$ resonances. For the lighter $Z^{\prime }$ (${\theta }_H=0.115$) case, with forthcoming $30{\mathrm{fb}}^{-1}$ data of the 13 TeV LHC experiment we expect about ten ${\mu }^{+}{\mu }^{-}$ events for the invariant mass range 3000 to 7000 GeV, though the number of the events becomes much smaller when ${\theta }_H=0.0737$. In the process with $WZ$ in the final state, it is confirmed that the leading contributions in the amplitude from the longitudinal polarizations of $W$ and $Z$ in the $s$-, $t$-, and $u$-channels cancel with each other so that the unitarity is preserved, provided that all KK excited states in the intermediate states are taken into account. Deviation of the $WWZ$ coupling from the SM is very tiny. Exotic partners $t_T^{(1)}$ and $b_Y^{(1)}$ of the top and bottom quarks with electric charge $+5/3$ and $-4/3$ have mass $M_{t_T^{(1)},b_Y^{(1)}}=4.6\mathrm{TeV}$ (5.4 TeV) for ${\theta }_H=0.115$ (0.0737), becoming the lightest non-SM particles in GHU which can be singly produced in collider experiments.

We employ chiral perturbation theory to calculate the nucleon-pion-state contribution to the 3-point correlation functions measured in lattice QCD to compute various moments of parton distribution functions (quark momentum fraction, helicity and transversity moment). We estimate the impact of the nucleon-pion-state contribution on the plateau method for lattice simulations with a physical pion mass. The nucleon-pion-state contribution results in an overestimation of all three moments. The overestimation is at the 5–20% level for source-sink separations of about 1.5 fm.

We present results on the renormalization functions of the quark field and fermion bilinears with up to one covariant derivative. For the fermion part of the action, we employ the twisted mass formulation with $N_f=2$ and $N_f=4$ degenerate dynamical quarks, while in the gluon sector, we use the Iwasaki-improved action. The simulations for $N_f=4$ have been performed for pion masses in the range of 390–760 MeV and at three values of the lattice spacing, $a$, corresponding to $\beta =1.90$, 1.95, 2.10. The $N_f=2$ action includes a clover term with $c_{\mathrm{sw}}=1.57551$ at $\beta =2.10$, and three ensembles at different values of $m_{\pi }$. The evaluation of the renormalization functions is carried out in the ${\mathrm{RI}}^{\prime }$ scheme using a momentum source. The nonperturbative evaluation is complemented with a perturbative computation, which is carried out at one-loop level and to all orders in the lattice spacing, $a$. For each renormalization function computed nonperturbatively, we subtract the corresponding lattice artifacts to all orders in $a$, so that a large part of the cutoff effects is eliminated. The renormalization functions are converted to the $\overline{\mathrm{MS}}$ scheme at a reference energy scale of $\mu =2\mathrm{GeV}$ after taking the chiral limit.

We study the possibility of probing the unpolarized and linearly polarized transverse momentum-dependent gluon distributions in unpolarized $pp$ collision in charmonium and bottomonium production, employing the nonrelativistic QCD-based color octet model within transverse momentum-dependent factorization framework. The transverse momentum ($p_T$) and rapidity distributions of $J/\psi$ and $\mathrm{\Upsilon }(1\mathrm{S})$ at the LHCb, Relativistic Heavy Ion Collider (RHIC), and A Fixed Target Experiment (AFTER) energies are estimated. Significant modulations in the transverse-momentum spectrum of quarkonium in the low-$p_T$ region are obtained when contributions of linearly polarized gluons inside an unpolarized proton are taken into account. The results of quarkonium production in the color octet model and color evaporation model are compared.

The $J/\psi$ meson has negative $G$ parity so that, in the limit of isospin conservation, its decay into ${\pi }^{+}{\pi }^{-}$ should be purely electromagnetic. However, the measured branching fraction $\mathcal{B}(J/\psi \to {\pi }^{+}{\pi }^{-})$ exceeds by more than 4.5 standard deviations the expectation computed according to BABAR data on the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section. The possibility that the two-gluon plus one-photon decay mechanism is not suppressed by $G$-parity conservation is discussed, even by considering other multipion decay channels. As also obtained by phenomenological computation, such a decay mechanism could be responsible for the observed discrepancy. Finally, we notice that the BESIII experiment, having the potential to perform an accurate measurement of the $e^{+}{e}^{-}\to {\pi }^{+}{\pi }^{-}$ cross section in the $J/\psi$ mass energy region, can definitely prove or disprove this strong $G$-parity-violating mechanism by confirming or confuting the BABAR data.

We compute couplings between the $\rho$-meson and $D$ and $D^{*}$ mesons—$D^{(*)}\rho D^{(*)}$—that are relevant to phenomenological meson-exchange models used to analyze nucleon–$D$-meson scattering and explore the possibility of exotic charmed nuclei. Our framework is built from elements constrained by Dyson-Schwinger equation studies in QCD, and therefore expresses a simultaneous description of light- and heavy-quarks and the states they constitute. We find that all interactions, including the three independent $D^{*}\rho D^{*}$ couplings, differ markedly amongst themselves in strength and also in range, as measured by their evolution with $\rho$-meson virtuality. As a consequence, it appears that one should be cautious in using a single coupling strength or parametrization for the study of interactions between $D^{(*)}$ mesons and matter.

We examine the phase shifts and inelasticities associated with the $N^{*}(1440)$ Roper resonance, and we connect these infinite-volume observables to the finite-volume spectrum of lattice QCD using Hamiltonian effective field theory. We explore three hypotheses for the structure of the Roper resonance. All three hypotheses are able to describe the scattering data well. In the third hypothesis the Roper resonance couples the low-lying bare basis-state component associated with the ground-state nucleon with the virtual meson-baryon contributions. Here the nontrivial superpositions of the meson-baryon scattering states are complemented by bare basis-state components, explaining their observation in contemporary lattice QCD calculations. The merit of this scenario lies in its ability to not only describe the observed nucleon energy levels in large-volume lattice QCD simulations but also explain why other low-lying states have been missed in today’s lattice QCD results for the nucleon spectrum.