The scalar singlet model extends the Standard Model with the addition of a new gauge singlet scalar. We reexamine the limits on the new scalar from oblique parameter fits and from a global fit to precision electroweak observables and present analytic expressions for our results. For the case when the new scalar is much heavier than the weak scale, we map the model onto the dimension-six Standard Model effective field theory and review the allowed parameter space from unitarity considerations and from the requirement that the electroweak minimum be stable. A global fit to precision electroweak data, along with LHC observables, is used to constrain the parameters of the high scale singlet model, and we determine the numerical effects of performing the matching at both tree level and one loop.

We compute the composition of the bottomonium $\mathrm{\Upsilon }(nS)$ states [including $\mathrm{\Upsilon }(10860)$] and the new $\mathrm{\Upsilon }(10753)$ resonance reported by Belle in terms of quarkonium and meson-meson components. We use a recently developed novel approach utilizing lattice QCD string breaking potentials for the study of resonances. This approach is based on the diabatic extension of the Born-Oppenheimer approximation and the unitary emergent wave method and allows us to compute the poles of the $\mathrm{S}$ matrix. We focus on $I=0$ bottomonium $S$ wave bound states and resonances, where the Schrödinger equation is a set of coupled differential equations. One of the channels corresponds to a confined heavy quark-antiquark pair $\overline{b}b$, and the others correspond to pairs of heavy-light mesons. In a previous study, only one meson-meson channel ${\overline{B}}^{(*)}{B}^{(*)}$ was considered. Now, we also include the closed strangeness channel ${\overline{B}}_s^{(*)}{B}_s^{(*)}$, extending our formalism significantly to have a more realistic description of bottomonium. We confirm the new Belle resonance $\mathrm{\Upsilon }(10753)$ as a dynamical meson-meson resonance with around 76% meson-meson content. Moreover, we identify $\mathrm{\Upsilon }(4S)$ and $\mathrm{\Upsilon }(10860)$ as states with both sizable quarkonium and meson-meson contents. With these results, we contribute to the clarification of ongoing controversies in the vector bottomonium spectrum.

We investigate the axial $U(1)$ anomaly of two-flavor QCD at temperatures 190–330 MeV. In order to preserve precise chiral symmetry on the lattice, we employ the Möbius domain-wall fermion action as well as overlap fermion action implemented with a stochastic reweighting technique. Compared to our previous studies, we reduce the lattice spacing to 0.07 fm, simulate larger multiple volumes to estimate finite size effect, and take more than four quark mass points, including one below physical point to investigate the chiral limit. We measure the topological susceptibility, axial $U(1)$ susceptibility, and examine the degeneracy of $U(1)$ partners in meson/baryon correlators. All the data above the critical temperature indicate that the axial $U(1)$ violation is consistent with zero within statistical errors. The quark mass dependence suggests disappearance of the $U(1)$ anomaly at a rate comparable to that of the $SU(2{)}_L\times SU(2{)}_R$ symmetry breaking.

The massive screened expansion for pure SU(3) Yang-Mills theory is extended to finite temperature in the Landau gauge. All thermal integrals are evaluated analytically up to an external one-dimensional integration, yielding explicit integral representations of analytic functions that can be continued to the whole complex plane. The gluon propagator is first explored in the Euclidean space by making use of parameters obtained from first principles, which were already found to accurately reproduce the lattice data at zero temperature. Within such a scheme, the agreement with the lattice at $T\ne 0$ turns out to be only qualitative. The description improves provided that the parameters are tuned in a temperature-dependent way by a fit to the data, carried out separately for each component of the propagator; in particular, the transverse component closely follows the lattice data, while the agreement of the longitudinal component with the data is poor at small momenta and moderately high temperatures. The dispersion relations of the quasi-gluon are then extracted from the pole trajectory in the complex plane using the fitted parameters. A crossover is found for the mass, suppressed by temperature like an order parameter in the confined phase, while increasing like an ordinary thermal mass in the deconfined phase.

We study exclusive ${\pi }^{+}{\pi }^{-}$ pair production near ${\rho }^0$ resonance peak in ultraperipheral heavy ion collisions. A pion pair can either be produced via two photon fusion process or from the decay of ${\rho }^0$ in photon-nuclear reaction. At very low pair transverse momentum, the electromagnetic and nuclear amplitudes become comparable. We show that the Coulomb nuclear interference amplitude gives rise to sizable $\cos \varphi$ and $\cos 3\varphi$ azimuthal asymmetries, which can be used to constrain the phase of the dipole-nucleus scattering amplitude.

The low-lying $sQ\overline{q}\overline{q}$ ($q=u$, $d$, $Q=c$, $b$) tetraquark states with $J^P=0^{+}$, $1^{+}$, and $2^{+}$, and in the isoscalar and isovector sectors, are systematically investigated in the framework of the real- and complex-scaling range of a chiral quark model, whose parameters are fixed in advance describing hadron, hadron-hadron, and multiquark phenomenology, and thus, all results presented here are pure predictions. Each tetraquark configuration compatible with the quantum numbers studied is taken into account; this includes meson-meson, diquark-antidiquark, and K-type arrangements of quarks with all possible color wave functions in the four-body sector. Among the different numerical techniques to solve the Schrödinger-like four-body bound-state equation, we use a variational method in which the trial wave function is expanded in complex-range Gaussian basis functions because of its simplicity and flexibility. Several compact bound states and narrow resonances are found in both charm-strange $cs\overline{q}\overline{q}$ and bottom-strange $bs\overline{q}\overline{q}$ tetraquark sectors, most of them as a product of the strong coupling between the different channels. In regard to the so-called $X_{0,1}(2900)$ structures recently discovered with good statistical significance by the LHCb Collaboration, whose properties point out to be $cs\overline{u}\overline{d}$ tetraquarks, we find that they are unstable in our formalism with several candidates in the single-channel computations. We distinguish four cases with $I(J^P)=0(0^{+})$ quantum numbers: three K-type configurations with masses at 2.89, 2.96, and 2.97 GeV, and one hidden-color coupled-channel calculation delivering a mass 2.86 GeV. With quantum numbers $I(J^P)=0(1^{+})$, only one candidate can be found in the hidden-color coupled-channel calculation with mass 2.94 GeV.

The dependence of the production of the $X(3872)$ meson on the hadron multiplicity in $pp$ collisions has been used as evidence against $X$ being a charm-meson molecule. The argument is based in part on the incorrect assumption that the cross section for the breakup of $X$ by scattering with comovers can be approximated by a geometric cross section inversely proportional to the binding energy of $X$. The breakup cross section should instead be approximated by the probability-weighted sum of the cross sections for the scattering of comoving pions from the charm-meson constituents of $X$, which is insensitive to the binding energy. A simple modification of the comover interaction model gives excellent fits to the data from the LHCb Collaboration on the multiplicity dependence of the production of $X$ and $\psi (2S)$ using parameters compatible with $X$ being a loosely bound charm-meson molecule.

This paper aims at giving a novel approach to investigate the behavior of the renormalization group flow for tensorial group field theories to all order of the perturbation theory. From an appropriate choice of the kinetic kernel, we build an infinite family of just-renormalizable models, for tensor fields with arbitrary rank $d$. Investigating the large $d$-limit, we show that the self-energy melonic amplitude is decomposed as a product of loop-vertex functions depending only on dimensionless mass. The corresponding melonic amplitudes may be mapped as trees in the so-called Hubbard-Stratonivich representation, and we show that only trees with edges of different colors survive in the large $d$-limit. These two key features allow to resum the perturbative expansion for self energy, providing an explicit expression for arbitrary external momenta in terms of Lambert function. Finally, inserting this resummed solution into the Callan-Symanzik equations, and taking into account the strong relation between two and four point functions arising from melonic Ward-Takahashi identities, we then deduce an explicit expression for relevant and marginal $\beta$-functions, valid to all orders of the perturbative expansion. By investigating the solutions of the resulting flow, we conclude about the nonexistence of any fixed point in the investigated region of the full phase space.

We show that the correlator of three large charge operators with minimal scaling dimension can be computed semiclassically in conformal field theories (CFTs) with a $U(1)$ symmetry for arbitrary fixed values of the ratios of their charges. We obtain explicitly the operator product expansion coefficient from the numerical solution of a nonlinear boundary value problem in the conformal superfluid effective field theory in $3d$. The result applies in all three-dimensional CFTs with a $U(1)$ symmetry whose large charge sector is a superfluid.

The Standard-Model Extension (SME) is an effective-field-theoretic framework that catalogs all Lorentz-violating field operators. The anisotropic correction from the minimal gravitational SME to Newtonian gravitational energy for spheroids is studied, and the rotation of rigid spheroids is solved with the perturbation method and numerical approach. The well-known forced precession solution given by Nordtvedt in the parametrized post-Newtonian formalism is recovered and applied to two observed solitary millisecond pulsars to set bounds on the coefficients for Lorentz violation in the SME framework. A different solution, which describes the rotation of an otherwise free-precessing star in the presence of Lorentz violation, is found, and its consequences on pulsar signals and continuous gravitational waves emitted by neutron stars (NSs) are investigated. The study provides new possible tests of Lorentz violation once free-precessing NSs are firmly identified in the future.

The curvature of a spacetime, either in a topological sense, or averaged over superhorizon-sized patches, is often equated with the global curvature term that appears in Friedmann’s equation. In general, however, the Universe is inhomogeneous, and gravity is a nonlinear theory, thus any curvature perturbations violate the assumptions of the Friedmann-Lemaïtre-Robertson-Walker model; it is not necessarily true that local curvature, averaged over patches of constant-time surfaces, will reproduce the observational effects of global symmetry. Further, the curvature of a constant-time hypersurface is not an observable quantity, and can only be inferred indirectly. Here, we examine the behavior of curvature modes on hypersurfaces of an inhomogeneous spacetime nonperturbatively in a numerical relativistic setting, and how this curvature corresponds with that inferred by observers. We also note the point at which observations become sensitive to the impact of curvature sourced by inhomogeneities on inferred average properties, finding general agreement with past literature.

In this paper we present a class of potentials derived by no-scale supergravity in order to explain the production of primordial black holes (PBHs) in the Universe. By breaking the $\mathrm{SU}(2,1)/\mathrm{SU}(2)\times \mathrm{U}(1)$ symmetry we fix one of the two chiral fields and we derive effective scalar potentials which are capable of generating PBHs. Specifically, we modify well-known superpotentials, which reduce to Starobinsky-like effective scalar potentials. Thus, we derive scalar potentials which, on the one hand, explain the production of PBHs and, on the other hand, they conserve the transformation laws, which yield from the parametrization of the coset $\mathrm{SU}(2,1)/\mathrm{SU}(2)\times \mathrm{U}(1)$. Moreover, we generate PBHs by modifying the kinetic term of the Langrangian (or the Kähler potential) and we keep the superpotentials unmodified. In all cases we evaluate the fractional abundances of PBHs by comparing Press–Schechter approach and peak theory, while focusing on explaining the dark matter in the Universe. All models are in complete consistence with Planck constraints.

In this paper we introduce the fractional dark energy model, in which the accelerated expansion of the Universe is driven by a nonrelativistic gas (composed by either fermions or bosons) with a noncanonical kinetic term. The kinetic energy is inversely proportional to the cube of the absolute value of the momentum for a fluid with an equation of state parameter equal to minus one, and whose corresponding energy density mimics the one of the cosmological constant. In the general case, the dark energy equation of state parameter (times three) is precisely the exponent of the momentum in the kinetic term. We show that this inverse momentum operator appears in fractional quantum mechanics and it is the inverse of the Riesz fractional derivative. The observed vacuum energy can be obtained through the integral of the Fermi-Dirac (or Bose-Einstein) distribution and the lowest allowed energy of the particles. Finally, a possible thermal production and fate of fractional dark energy is investigated.

We perform binary neutron star merger simulations using a newly derived set of finite-temperature equations of state in the Brueckner-Hartree-Fock approach. We point out the important and opposite roles of finite temperature and rotation for stellar stability and carry out a detailed study about the gravitational-wave properties, matter distribution, and ejecta properties in the postmerger phase for the different cases. The validity of several universal relations is also examined and the most suitable equations of state are identified.

All results of the neutron lifetime measurements performed in the last 20 years with the ultracold neutron storage method are in a good agreement. These results are also consistent with the latest most accurate measurements of the neutron decay asymmetry within the Standard Model. However, there is a significant discrepancy at the $3.6\sigma$ (1% of the decay probability) level between the averaged result of the storage method experiments and the most accurate measurements performed with the beam method. This article addresses the possible causes of the neutron lifetime discrepancy. We focused on finding the spectrum of possible systematic corrections in the beam experiment. Four separate sources of the systematic errors that had not been properly addressed in articles dedicated to the beam technique were considered. Two of those sources are related to the motion of protons in an electromagnetic field and the elastic scattering by the residual gas. These problems are associated with the geometrical configuration of the setup and the proton detector size. The Monte Carlo simulation shows that these effects are negligible and do not affect measurement results. The third error concerns proton loss in the dead layer of the detector. It is shown that the correction for the dead layer requires a more detailed analysis than that given in the papers describing the beam measurement method. The fourth source of the systematic error is the charge exchange process on the residual gas. The influence of the residual gas was neglected in the beam method experiments. We present arguments showing that careful analysis of this issue is necessary since the proposed proton losses correction decreases the measured lifetime, bringing it closer to the storage method results. For the problem of proton charge exchange on a residual gas, the spectrum of possible corrections is investigated. It is shown that for an accurate calculation of the correction, it is necessary to directly measure the concentration and composition of the residual gas inside the proton trap. The analysis reveals that even the presence of only ${\mathrm{H}}_2$ molecules inside the proton trap can lead to the significant correction, which is the most probable explanation of the neutron anomaly.

The STAR collaboration reports a measurement of the transverse single-spin asymmetries, $A_N$, for neutral pions produced in polarized proton collisions with protons ($pp$), with aluminum nuclei ($p\mathrm{Al}$) and with gold nuclei ($p\mathrm{Au}$) at a nucleon-nucleon center-of-mass energy of 200 GeV. Neutral pions are observed in the forward direction relative to the transversely polarized proton beam, in the pseudorapidity region $2.7<\eta <3.8$. Results are presented for ${\pi }^0\mathrm{s}$ observed in the STAR forward meson spectrometer electromagnetic calorimeter in narrow Feynman x ($x_F$) and transverse momentum ($p_T$) bins, spanning the range $0.17<x_F<0.81$ and $1.7<p_T<6.0\mathrm{GeV}/c$. For fixed $x_F<0.47$, the asymmetries are found to rise with increasing transverse momentum. For larger $x_F$, the asymmetry flattens or falls as $p_T$ increases. Parametrizing the ratio $r(A)\equiv A_N(pA)/A_N(pp)=A^P$ over the kinematic range, the ratio $r(A)$ is found to depend only weakly on $A$, with $⟨P⟩=-0.027\pm 0.005$. No significant difference in $P$ is observed between the low-$p_T$ region, $p_T<2.5\mathrm{GeV}/c$, where gluon saturation effects may play a role, and the high-$p_T$ region, $p_T>2.5\mathrm{GeV}/c$. It is further observed that the value of $A_N$ is significantly larger for events with a large-$p_T$ isolated ${\pi }^0$ than for events with a nonisolated ${\pi }^0$ accompanied by additional jetlike fragments. The nuclear dependence $r(A)$ is similar for isolated and nonisolated ${\pi }^0$ events.

Nongeometric flux compactifications with frozen complex structure moduli have been recently studied for several phenomenological purposes. In this context, we analyze the possibility of realizing de Sitter solutions in the context of $\mathcal{N}=1$ type II nongeometric flux compactifications using the ${\mathbb{T}}^6/({\mathbb{Z}}_3\times {\mathbb{Z}}_3)$ toroidal orientifolds. For the type IIB case, we observe that the Bianchi identities are too strong to simultaneously allow both the NS-NS three-form flux ($H_3$) and the nongeometric ($Q$) flux to take nonzero values, which makes this model irrelevant for phenomenology due to the no-scale structure. For the type IIA case, we find that all the (nongeometric) flux solutions satisfying the Bianchi identities result in de Sitter no-go scenarios except for one case in which the no-go condition can be evaded. However for this case also, in our (limited) numerical investigation we do not find any de Sitter vacua using the integer fluxes satisfying all the Bianchi identities.

We study the $T$-dual completion of the four-dimensional $\mathcal{N}=1$ type II effective potentials in the presence of (non)geometric fluxes. First, we invoke a cohomology version of the $T$-dual transformations among the various moduli, axions, and fluxes appearing in the type IIA and type IIB effective supergravities. This leads to some useful observations about a significant mixing of the standard NS-NS fluxes with the (non)geometric fluxes on the mirror side. Further, using our $T$-duality rules, we establish an explicit mapping among the $F$ terms, $D$ terms, tadpole conditions, and Bianchi identities of the two theories. Second, we propose what we call a set of “axionic flux polynomials,” which depend on all of the axionic moduli and the fluxes. This subsequently helps to present the two scalar potentials in a concise and manifestly $T$-dual form, which can be directly utilized for various phenomenological purposes, as we illustrate in a couple of examples.

We study the correspondence between ${\mathrm{AdS}}_3$ massive IIA supergravity vacua and two-dimensional $\mathcal{N}=(0,4)$ quiver quantum field theories. After categorizing all kinds of gravity solutions, we demystify the ones that seem to reflect anomalous gauge theories. In particular, we prove that there are bound states of D-branes on the boundary of the space that provide the dual quiver theory with exactly the correct amount of flavor symmetry in order to cancel its gauge anomalies. Then we propose that the structure of the field theory should be complemented with additional bifundamental matter, which we argue may only be $\mathcal{N}=(4,4)$ hypermultiplets. Finally, we construct a Bogomol’nyi-Prasad-Sommerfield (BPS) string configuration and use the old and new supersymmetric matter to build its dual ultraviolet operator. During this holographic synthesis, we uncover some interesting features of the quiver superpotential and associate the proposed operator with the same classical mass of its dual BPS string.