We show that natural supersymmetry can be embedded in a five-dimensional theory with supersymmetry breaking à la Scherk-Schwarz (SS). There is no “gluino-sucks” problem for stops localized in the four-dimensional brane and gluinos propagating in the full five-dimensional bulk, and sub-TeV stops are easily accommodated. The $\mu /B_{\mu }$ problem is absent as well; the SS breaking generates a Higgsino Dirac mass, and no bilinear Higgs mass parameter in the superpotential is required. Moreover, for nonmaximal SS twists leading to $\tan \beta \simeq 1$, the Higgs spectrum is naturally split, in agreement with LHC data. The 125 GeV Higgs mass and radiative electroweak symmetry breaking can be accommodated by minimally extending the Higgs sector with $Y=0$ $SU(2{)}_L$ triplets.

We compute masses of $D$ meson, $D_s$ meson, and charmonium states using $N_f=2+1+1$ Wilson twisted mass lattice QCD. All results are extrapolated to physical light quark masses, to physical strange and charm quark masses, and to the continuum. Our analysis includes states with spin $J=0$, 1, 2, parity $\mathcal{P}=-,+$, and in case of charmonium also charge conjugation $\mathcal{C}=-,+$. Computations are based on a large set of quark-antiquark meson creation operators. We investigate and quantify all sources of systematic errors, including fitting range uncertainties, finite volume effects, isospin breaking effects, and the choice of the fitting ansatz for the combined chiral and continuum extrapolation such that the resulting meson masses can be compared directly and in a meaningful way to experimental results. Within combined statistical and systematic errors, which are between below 2 per mille and 3%, our results agree with available experimental results for most of the states. In the few cases where we observe discrepancies, we discuss possible reasons.

We estimate the thermal width of a heavy quark-antiquark pair inside a strongly coupled plasma using a holographic AdS/QCD model. The imaginary part of the quark potential that produces the thermal width appears in the gravity dual from quantum fluctuations of the string world sheet in the vicinity of the horizon. The results, obtained using a soft wall background that involves an infrared mass scale, are consistent with a previous analysis where the mass scale was introduced by averaging over quark-antiquark states.

The astrophysical relevance of chaos for a test particle with spin moving in Schwarzschild spacetime was the objective of C. Verhaaren and E. W. Hirschmann in [Phys. Rev. D 81, 124034 (2010)]. Even if the results of the study might appear to be qualitatively in agreement with similar works, the study presented in their work suffers both from theoretical and technical issues. These issues are discussed in this comment.

We calculate some tree-level scattering amplitudes for a generalization of the protostring, which is a novel string model implied by the simplest string bit models. These bit models produce a light-cone world sheet which supports $s$ integer moded Grassmann fields. In the generalization we supplement this Grassmann world-sheet system with $d=24-s$ transverse coordinate world-sheet fields. The protostring corresponds to $s=24$ and the bosonic string to $s=0$. The interaction vertex is a simple overlap with no operator insertions at the break/join point. Assuming that $s$ is even we calculate the multistring scattering amplitudes by bosonizing the Grassmann fields, each pair equivalent to one compactified bosonic field, and applying Mandelstam’s interacting string formalism to a system of $s/2$ compactified and $d$ uncompactified bosonic world-sheet fields. We obtain all amplitudes for open strings with no oscillator excitations and for closed strings with no oscillator excitations and zero winding number. We then study in detail some simple special cases. Multistring processes with maximal helicity violation have much simpler amplitudes. We also specialize to general four-string amplitudes and discuss their high energy behavior. Most of these models are not covariant under the full Lorentz group $O(d+1,1)$. The exceptions are the bosonic string whose Lorentz group is $O(25,1)$ and the protostring whose Lorentz group is $O(1,1)$. The models in between only enjoy an $O(1,1)\times O(d)$ spacetime symmetry.

It has been conjectured that the speed of sound in holographic models with UV fixed points has an upper bound set by the value of the quantity in conformal field theory. If true, this would set stringent constraints for the presence of strongly coupled quark matter in the cores of physical neutron stars, as the existence of two-solar-mass stars appears to demand a very stiff equation of state. In this article, we present a family of counterexamples to the speed of sound conjecture, consisting of strongly coupled theories at finite density. The theories we consider include $\mathcal{N}=4$ super Yang-Mills at finite $R$-charge density and nonzero gaugino masses, while the holographic duals are Einstein-Maxwell theories with a minimally coupled scalar in a charged black hole geometry. We show that for a small breaking of conformal invariance, the speed of sound approaches the conformal value from above at large chemical potentials.

We calculate the value of the coupling at the infrared zero of the beta function of an asymptotically free SU(3) gauge theory at the five-loop level as a function of the number of fermions. Both a direct analysis of the beta function and analyses of Padé approximants are used for this purpose. We then calculate the value of the five-loop anomalous dimension, ${\gamma }_m$, of the fermion bilinear at this IR zero of the beta function.

In this paper, we study rotating boson stars in the large coupling limit as well as in the Newtonian limit. We investigate the equilibrium solutions in four and five dimensions by adopting some analytical approximations. We show that the relations among the radius, angular momentum, Newtonian energy, and quadrupole moment (for the four-dimensional solution) of the boson star can be qualitatively realized for the minimal number of boson-star parameters.

We show that a particle detector can distinguish the interior of a hollow shell from flat space for switching times much shorter than the light-crossing time of the shell, even though the local metrics are indistinguishable. This shows that a particle detector can read out information about the nonlocal structure of spacetime even when switched on for scales much shorter than the characteristic scale of the nonlocality.

We establish the existence and find the necessary and sufficient conditions for a new class of solutions of locally rotationally symmetric spacetimes that have nonvanishing rotation and spatial twist simultaneously. We transparently show that the existence of such solutions demands nonvanishing and bounded heat flux and these solutions are self-similar. We provide a brief algorithm indicating how to solve the system of field equations with the given Cauchy data on an initial spacelike Cauchy surface. Finally we argue that these solutions can be used as a first approximation from spherical symmetry to study rotating, inhomogeneous, dynamic and radiating astrophysical stars.

We consider a particular truncation of the generalized Proca field theory in four dimensions for which we construct static and axisymmetric rotating black hole “stealth solutions,” namely solutions with (anti) de Sitter or Kerr metric but nontrivial vector field. The static configuration is promoted to a backreacting black hole with asymptotic (anti) de Sitter behavior by turning on a nonlinear electrodynamic source given as a fixed power of the Maxwell invariant. Finally we extend our solutions to arbitrary dimensions.

General nonsingular accelerating cosmological solutions for an initial cosmic period of pure vacuum birth era are derived. This vacuum era is described by a varying cosmological “constant” suggested by the renormalization group flow of asymptotic safety scenario near the ultraviolet fixed point. In this scenario, a natural exit from inflation to the standard decelerating cosmology occurs when the energy scale lowers and the cosmological constant becomes insignificant. In the following period where matter is also present, cosmological solutions with characteristics similar to the vacuum case are generated. Remarkably the set of equations allows for particle production and entropy generation. Alternatively, in the case of nonzero bulk viscosity, entropy production and reheating is found. As for the equations of motion, they modify Einstein equations by adding covariant kinetic terms of the cosmological constant which respect the Bianchi identities. An advance of the proposed framework is that it ensures a consistent description of both a quantum vacuum birth of the universe and a subsequent cosmic era in the presence of matter.

We present results from a search for gravitational-wave bursts coincident with two core-collapse supernovae observed optically in 2007 and 2011. We employ data from the Laser Interferometer Gravitational-wave Observatory (LIGO), the Virgo gravitational-wave observatory, and the GEO 600 gravitational-wave observatory. The targeted core-collapse supernovae were selected on the basis of (1) proximity (within approximately 15 Mpc), (2) tightness of observational constraints on the time of core collapse that defines the gravitational-wave search window, and (3) coincident operation of at least two interferometers at the time of core collapse. We find no plausible gravitational-wave candidates. We present the probability of detecting signals from both astrophysically well-motivated and more speculative gravitational-wave emission mechanisms as a function of distance from Earth, and discuss the implications for the detection of gravitational waves from core-collapse supernovae by the upgraded Advanced LIGO and Virgo detectors.

We reexamine the discovery potential at hadron colliders of high-mass right-handed (RH) gauge bosons $W_R$—an inherent ingredient of left-right symmetric models (LRSM). We focus on the regime where the $W_R$ is very heavy compared to the heavy Majorana neutrino $N$, and we investigate an alternative signature for $W_R\to N$ decays. The produced neutrinos are highly boosted in this mass regime. Subsequently, their decays via off-shell $W_R$ bosons to jets, i.e., $N\to {\ell }^{\pm }jj$, are highly collimated, forming a single neutrino jet $(j_N)$. The final-state collider signature is then ${\ell }^{\pm }{j}_N$, instead of the widely studied ${\ell }^{\pm }{\ell }^{\pm }jj$. Present search strategies are not sensitive to this hierarchical mass regime due to the breakdown of the collider signature definition. We take into account QCD corrections beyond next-to-leading order (NLO) that are important for high-mass Drell-Yan processes at the 13 TeV Large Hadron Collider (LHC). For the first time, we evaluate $W_R$ production at NLO with threshold resummation at next-to-next-to-leading logarithm (NNLL) matched to the threshold-improved parton distributions. With these improvements, we find that a $W_R$ of mass $M_{W_R}=3(4)[5]\mathrm{TeV}$ and mass ratio of $(m_N/M_{W_R})<0.1$ can be discovered with a $5–6\sigma$ statistical significance at 13 TeV after $10(100)[2000]{\mathrm{fb}}^{-1}$ of data. Extending the analysis to the hypothetical 100 TeV Very Large Hadron Collider (VLHC), $5\sigma$ can be obtained for $W_R$ masses up to $M_{W_R}=15(30)$ with approximately $100{\mathrm{fb}}^{-1}$ ($10{\mathrm{ab}}^{-1}$). Conversely, with $0.9(10)[150]{\mathrm{fb}}^{-1}$ of 13 TeV data, $M_{W_R}<3(4)[5]\mathrm{TeV}$ and $(m_N/M_{W_R})<0.1$ can be excluded at 95% C.L.; with $100{\mathrm{fb}}^{-1}$ ($2.5{\mathrm{ab}}^{-1}$) of 100 TeV data, $M_{W_R}<22(33)\mathrm{TeV}$ can be excluded.

The magnetic moment of a baryon state is an equally important dynamical observable as its mass, which encodes crucial information of its underlying structure. According to the different color-flavor structure, we have calculated the magnetic moments of the hidden-charm pentaquark states with the isospin $(I,I_3)=(\frac{1}{2},\frac{1}{2})$ and $J^P={\frac{1}{2}}^{\pm }$, ${\frac{3}{2}}^{\pm }$, ${\frac{5}{2}}^{\pm }$, ${\frac{7}{2}}^{+}$ in the molecular model, the diquark-triquark model, and the diquark-diquark-antiquark model, respectively. Although a good description for the pentaquark mass spectrum and decay patterns has been obtained in all three models, different color-flavor structures lead to different magnetic moments, which can be used to pin down their inner structures and distinguish various models.

We examine the four-quark structure of the recently discovered charged $Z_c(3900)$, $Z(4430)$, and $X_b(5568)$ states. We calculate the widths of the strong decays $Z_c^{+}\to J/\psi {\pi }^{+}$ (${\eta }_c{\rho }^{+}$, ${\overline{D}}^0{D}^{*+}$, ${\overline{D}}^{*0}{D}^{+}$), $Z(4430{)}^{+}\to J/\psi {\pi }^{+}$ ($\psi (2s){\pi }^{+}$), and $X_b^{+}\to B_s{\pi }^{+}$ within a covariant quark model previously developed by us. We find that the tetraquark-type current widely used in the literature for the $Z_c(3900)$ leads to a significant suppression of the $\overline{D}{D}^{*}$ and ${\overline{D}}^{*}D$ modes. Contrary to this a molecular-type current provides an enhancement by a factor of 6–7 for the $\overline{D}{D}^{*}$ modes compared with the $Z_c^{+}\to J/\psi {\pi }^{+}$, ${\eta }_c{\rho }^{+}$ modes in agreement with recent experimental data from the BESIII Collaboration. In the case of the $Z(4430)$ state we test a sensitivity of the ratio $R_Z$ of the $Z(4430{)}^{+}\to \psi (2s){\pi }^{+}$ and $Z(4430{)}^{+}\to J/\psi {\pi }^{+}$ decay rates to a choice of the size parameter ${\mathrm{\Lambda }}_{Z(4430)}$ of the $Z(4430)$. Using the upper constraint for the sum of these two modes deduced from the LHCb Collaboration data we find that $R_Z$ varies from 4.64 to 4.08 when ${\mathrm{\Lambda }}_{Z(4430)}$ changes from 2.2 to 3.2 GeV. Also we make the prediction for the $Z(4430{)}^{+}\to D^{*+}{\overline{D}}^{*0}$ decay rate.

We consider quark-photon correlations that have been proposed as a source for single-spin asymmetries in inclusive deep inelastic scattering. A new sum rule for these correlators is derived and its phenomenological consequences are discussed. The results are interpreted within the context of an intuitive “electrodynamic lensing” picture.

A symmetry-preserving truncation of the two-body light-quark bound-state problem in relativistic quantum field theory is used to calculate the leading-twist parton distribution amplitudes (PDAs) of scalar systems, both ground-state and radial excitations, and the radial excitations of vector mesons. Owing to the fact that the scale-independent leptonic decay constant of a scalar meson constituted from equal-mass valence constituents vanishes, it is found that the PDA of a given scalar system possesses one more zero than that of an analogous vector meson. Consequently, whereas the mean light-front relative momentum of the valence constituents within a vector meson is zero, that within a scalar meson is large, an outcome which hints at a greater role for light-front angular momentum in systems classified as $P$-wave in quantum mechanical models. Values for the scale-dependent decay constants of ground-state scalar and vector systems are a by-product of this analysis, and they turn out to be roughly equal, viz. $\simeq 0.2\mathrm{GeV}$ at an hadronic scale. In addition, it is confirmed that the dilation characterizing ground-state PDAs is manifest in the PDAs of radial excitations too. The impact of $SU(3)$-flavor symmetry breaking is also considered. When compared with pseudoscalar states, it is a little stronger in scalar systems, but the size is nevertheless determined by the flavor dependence of dynamical chiral symmetry breaking and the PDAs are still skewed toward the heavier valence quark in asymmetric systems.

Using a sample of $(470.9\pm 2.8)\times 10^{6}B\overline{B}$ pairs, we measure the decay branching fraction $\mathcal{B}(B^0\to D^{*-}{\pi }^{+}{\pi }^{-}{\pi }^{+})=(7.26\pm 0.11\pm 0.31)\times {10}^{-3}$, where the first uncertainty is statistical and the second is systematic. Our measurement will be helpful in studies of lepton universality by measuring $\mathcal{B}(B^0\to D^{*-}{\tau }^{+}{\nu }_{\tau })$ using ${\tau }^{+}\to {\pi }^{+}{\pi }^{-}{\pi }^{+}{\overline{\nu }}_{\tau }$ decays, normalized to $\mathcal{B}(B^0\to D^{*-}{\pi }^{+}{\pi }^{-}{\pi }^{+})$.