We present measurements of the masses and decay widths of the baryonic states ${\mathrm{\Sigma }}_c(2455{)}^{0/++}$ and ${\mathrm{\Sigma }}_c(2520{)}^{0/++}$ using a data sample corresponding to an integrated luminosity of $711{\mathrm{fb}}^{-1}$ collected with the Belle detector at the KEKB $e^{+}{e}^{-}$ asymmetric-energy collider operating at the $\mathrm{\Upsilon }(4S)$ resonance. We report the mass differences with respect to the ${\mathrm{\Lambda }}_c^{+}$ baryon $$\begin{gathered} M({\mathrm{\Sigma }}_c(2455{)}^0)-M({\mathrm{\Lambda }}_c^{+})=167.29\pm 0.01\pm 0.02\mathrm{MeV}/c^2, \\ M({\mathrm{\Sigma }}_c(2455{)}^{++})-M({\mathrm{\Lambda }}_c^{+})=167.51\pm 0.01\pm 0.02\mathrm{MeV}/c^2, \\ M({\mathrm{\Sigma }}_c(2520{)}^0)-M({\mathrm{\Lambda }}_c^{+})=231.98\pm 0.11\pm 0.04\mathrm{MeV}/c^2, \\ M({\mathrm{\Sigma }}_c(2520{)}^{++})-M({\mathrm{\Lambda }}_c^{+})=231.99\pm 0.10\pm 0.02\mathrm{MeV}/c^2, \end{gathered}$$and the decay widths $$\begin{gathered} \mathrm{\Gamma }({\mathrm{\Sigma }}_c(2455{)}^0)=1.76\pm 0.04_{-0.21}^{+0.09}\mathrm{MeV}/c^2, \\ \mathrm{\Gamma }({\mathrm{\Sigma }}_c(2455{)}^{++})=1.84\pm 0.04_{-0.20}^{+0.07}\mathrm{MeV}/c^2, \\ \mathrm{\Gamma }({\mathrm{\Sigma }}_c(2520{)}^0)=15.41\pm 0.41_{-0.32}^{+0.20}\mathrm{MeV}/c^2, \\ \mathrm{\Gamma }({\mathrm{\Sigma }}_c(2520{)}^{++})=14.77\pm 0.25_{-0.30}^{+0.18}\mathrm{MeV}/c^2, \end{gathered}$$where the first uncertainties are statistical and the second are systematic. The isospin mass splittings are measured to be $M({\mathrm{\Sigma }}_c(2455{)}^{++})-M({\mathrm{\Sigma }}_c(2455{)}^0)=0.22\pm 0.01\pm 0.01\mathrm{MeV}/c^2$ and $M({\mathrm{\Sigma }}_c(2520{)}^{++})-M({\mathrm{\Sigma }}_c(2520{)}^0)=0.01\pm 0.15\pm 0.03\mathrm{MeV}/c^2$. These results are the most precise to date.

We consider the QCD string as an effective string, whose action describes long-range stringy fluctuations. The leading infrared contribution to the ground state energy is given by the Alvarez-Arvis formula, usually derived using the Nambu-Goto action. Here we rederive it by a saddle-point calculation using the Polyakov formulation of the free string, where the world sheet metric and the target space coordinates are treated as independent variables. The next-order operator in the effective action which is relevant in the infrared limit is the extrinsic curvature term. We show that the spectrum does not change order by order in the inverse string length, but may change at intermediate distances.

In this paper, we study twist deformed quantum field theories obtained by combining the Wightman axiomatic approach with the idea of spacetime noncommutativity. We prove that the deformed fields with deformation parameters of opposite sign satisfy the condition of mutual asymptotic commutativity, which was used earlier in nonlocal quantum field theory as a substitute for relative locality. We also present an improved proof of the wedge localization property discovered for the deformed fields by Grosse and Lechner, and we show that the deformation leaves the asymptotic behavior of the vacuum expectation values in spacelike directions substantially unchanged.

In the context of the nonminimal Standard Model extension a special subset of the $CPT$-even higher-dimensional operators in the photon sector is discussed from a quantum field theoretical point of view. The modified dispersion laws, photon polarization vectors and the gauge field propagator are obtained and their properties are analyzed. It is demonstrated that for certain sectors of the modified theory a puzzle arises for the optical theorem at tree level. This is followed by a discussion of how it can be interpreted and resolved at first order Lorentz violation. Furthermore the commutator of two gauge fields that are evaluated at different spacetime points is obtained and discussed. The structure of the theory is shown to resemble the structure of the modification based on the corresponding dimension-4 operator. However some properties are altered due to the nonrenormalizable nature of the theory considered. The results provide more insight into the characteristics of Lorentz-violating quantum field theories that rest upon contributions of nonrenormalizable dimension.

The photon contribution to the divergences and conformal anomaly in the theory with Lorentz and $CPT$-violating terms is evaluated. We calculate one-loop counterterms coming from the integration over the electromagnetic field and check that they possess local conformal invariance. Furthermore, conformal anomaly and the anomaly-induced effective action are calculated. It turns out that the new terms do not affect the dynamics of the conformal factor in the anomaly-driven inflation (Starobinsky model) and its extensions. At the same time, one can expect these terms to affect the gravitational wave equation and, in general, cosmic perturbations.

This short note is devoted to Hamiltonian analysis of three-dimensional gravity action that was proposed recently in [O. Andreev, M. Haack, and S. Hofmann, Phys. Rev. D 89, 064012 (2014)]. We perform this analysis and determine the number of physical degrees of freedom.

Black holes emit high energy particles which induce a finite density potential for any scalar field $\varphi$ coupling to the emitted quanta. Due to energetic considerations, $\varphi$ evolves locally to minimize the effective masses of the outgoing states. In theories where $\varphi$ resides at a metastable minimum, this effect can drive $\varphi$ over its potential barrier and classically catalyze the decay of the vacuum. Because this is not a tunneling process, the decay rate is not exponentially suppressed and a single black hole in our past light cone may be sufficient to activate the decay. Moreover, decaying black holes radiate at ever higher temperatures, so they eventually probe the full spectrum of particles coupling to $\varphi$. We present a detailed analysis of vacuum decay catalyzed by a single particle, as well as by a black hole. The former is possible provided large couplings or a weak potential barrier. In contrast, the latter occurs much more easily and places new stringent limits on theories with hierarchical spectra. Finally, we comment on how these constraints apply to the standard model and its extensions, e.g. metastable supersymmetry breaking.

We propose a novel first-order formalism for a type of $K$-brane system. An example solution is presented and studied. We illustrate how the deviation parameter affects the properties of the model, such as the stability of the solutions and the localization of fermions and gravitons. We argue that our solution is stable against linear perturbations. The tensor zero mode of a graviton can be localized on the brane while the scalar zero mode cannot. The localization condition for fermion is also discussed.

We adopt a reference-metric approach to generalize a covariant and conformal version of the Z4 system of the Einstein equations. We refer to the resulting system as “fully covariant and conformal,” or fCCZ4 for short, since it is well suited for curvilinear as well as Cartesian coordinates. We implement this fCCZ4 formalism in spherical polar coordinates under the assumption of spherical symmetry using a partially implicit Runge-Kutta method and show that our code can evolve both vacuum and nonvacuum spacetimes without encountering instabilities. Our method does not require regularization of the equations to handle coordinate singularities, nor does it depend on constraint-preserving outer boundary conditions. It also does not need any modifications of the equations for evolutions of black holes. We perform several tests and compare the performance of the fCCZ4 system, for different choices of certain free parameters, with that of BSSN. Confirming earlier results we find that, for an optimal choice of these parameters and for neutron-star spacetimes, the violations of the Hamiltonian constraint can be between 1 and 3 orders of magnitude smaller in the fCCZ4 system than in the BSSN formulation. For black hole spacetimes, on the other hand, any advantages of fCCZ4 over BSSN are less evident.

Fundamental fields are a natural outcome in cosmology and particle physics and might therefore serve as a proxy for more complex interactions. The equivalence principle implies that all forms of matter gravitate, and one therefore expects relevant, universal imprints of new physics in strong field gravity, such as that encountered close to black holes. Fundamental fields in the vicinities of supermassive black holes give rise to extremely long-lived, or even unstable, configurations, which slowly extract angular momentum from the black hole or simply evolve nonlinearly over long time scales, with important implications for particle physics and gravitational-wave physics. Here, we perform a fully nonlinear study of scalar-field condensates around rotating black holes. We provide novel ways to specify initial data for the Einstein—Klein—Gordon system, with potential applications in a variety of scenarios. Our numerical results confirm the existence of long-lived bar modes, which act as lighthouses for gravitational wave emission: the scalar field condenses outside the black hole geometry and acts as a constant frequency gravitational-wave source for very long time scales. This effect could turn out to be a potential signature of beyond standard model physics and also a promising source of gravitational waves for future gravitational-wave detectors.

We study the near-horizon geometry of generic Killing horizons constructing suitable coordinates and taking the appropriate scaling limit. We are able to show that the geometry will always show an enhancement of symmetries, and, in the extremal case, will develop a causally disconnected “throat” as expected. We analyze the implications of this to the Kerr/CFT conjecture and the attractor mechanism. We are also able to construct a set of special (pure) spinors associated with the horizon structure using their interpretation as maximally isotropic planes. The structure generalizes the usual reduced holonomy manifold in an interesting way and may be fruitful to the search of new types of compactification backgrounds.

Large field inflation models are favored by the recent BICEP2 that has detected gravitational wave modes generated during inflation. We study general large field inflation models for which the potential contains (constant) quadratic and quartic terms of inflaton field. We show, in this framework, those inflation models can generate the fluctuation with the tensor-to-scalar ratio of 0.2 as well as the scalar spectral index of 0.96; those are very close to the center value of the tensor-to-scalar ratio reported by BICEP2 as well as Planck. Finally, we briefly discuss the particle physics model building of inflation.

We show that the relativistic effects are negligibly small in the nonlinear density and velocity bispectra. Although the nonlinearities of the Einstein equation introduce additional nonlinear terms to the Newtonian fluid equations, the corrections to the bispectrum only show up on superhorizon scales. We show this with the next-to-leading order nonlinear bispectrum for a pressureless fluid in a flat Friedmann-Robertson-Walker background by calculating the density and velocity fields up to fourth order. We work in the comoving gauge, where the dynamics is identical to the Newtonian up to second order. We also discuss the leading order matter bispectrum in various gauges, and show yet another relativistic effect near horizon scales that the matter bispectrum strongly depends on the gauge choice.

Recent observations of magnetic fields in intergalactic void regions and in high redshift galaxies may indicate that large scale magnetic fields have a primordial origin. If primordial magnetic fields were present soon after the recombination epoch, they would have induced density fluctuations on the one hand and dissipated their energy into the primordial gas on the other, and thereby significantly altered the thermal history of the Universe. Here we consider both the effects and calculate the brightness temperature fluctuations of the 21 cm line using simple Monte Carlo simulations. We find that the fluctuations of the 21 cm line from the energy dissipation appear only on very small scales and those from the density fluctuations always dominate on observationally relevant angular scales.

The experimental fact that the energy density in dark matter (DM) and in baryons is of the same order is one of the most puzzling in cosmology. In this work we suggest a new mechanism able to explain this coincidence in the context of out-of-equilibrium baryogenesis with DM production á la SuperWIMP starting from the same initial particle. Two simple implementations of this scenario within supersymmetric models with gravitino DM are discussed.

Signatures of the $\mathrm{SO}(5)\times \mathrm{U}(1)$ gauge-Higgs unification at LHC and future colliders are explored. The Kaluza-Klein (KK) mass spectra of $\gamma ,Z,Z_R$ and the Higgs self-couplings obey universality relations with the Aharonov-Bohm phase ${\theta }_H$ in the fifth dimension. The current data at low energies and at LHC indicate ${\theta }_H<0.2$. Couplings of quarks and leptons to KK gauge bosons are determined. Three neutral gauge bosons, the first KK modes $Z_R^{(1)}$, $Z^{(1)}$, and ${\gamma }^{(1)}$, appear as $Z^{\prime }$ bosons in dilepton events at LHC. For ${\theta }_H=0.114$, the mass and decay width of $Z_R^{(1)}$, $Z^{(1)}$, and ${\gamma }^{(1)}$ are (5.73, 482), (6.07, 342), and (6.08 TeV, 886 GeV), respectively. For ${\theta }_H=0.073$ their masses are $8.00\sim 8.61\mathrm{TeV}$. An excess of events in the dilepton invariant mass should be observed in the $Z^{\prime }$ search at the upgraded LHC at 14 TeV.

We present a precise calculation of the dilepton invariant-mass spectrum and the decay rate for $B^{\pm }\to {\pi }^{\pm }{\ell }^{+}{\ell }^{-}$ (${\ell }^{\pm }=e^{\pm },{\mu }^{\pm }$) in the Standard Model (SM) based on the effective Hamiltonian approach for the $b\to d{\ell }^{+}{\ell }^{-}$ transitions. With the Wilson coefficients already known in next-to-next-to-leading logarithmic (NNLL) accuracy, the remaining theoretical uncertainty in the short-distance contribution resides in the form factors $f_{+}(q^2)$, $f_0(q^2)$ and $f_T(q^2)$. Of these, $f_{+}(q^2)$ is well measured in the charged-current semileptonic decays $B\to \pi \ell {\nu }_{\ell }$, and we use the $B$-factory data to parametrize it. The corresponding form factors for the $B\to K$ transitions have been calculated in the lattice QCD approach for large $q^2$ and extrapolated to the entire $q^2$ region using the so-called $z$ expansion. Using an $SU(3{)}_F$-breaking ansatz, we calculate the $B\to \pi$ tensor form factor, which is consistent with the recently reported lattice $B\to \pi$ analysis obtained at large $q^2$. The prediction for the total branching fraction $\mathcal{B}(B^{\pm }\to {\pi }^{\pm }{\mu }^{+}{\mu }^{-})=(1.88_{-0.21}^{+0.32})\times {10}^{-8}$ is in good agreement with the experimental value obtained by the LHCb Collaboration. In the low-$q^2$ region, heavy-quark symmetry (HQS) relates the three form factors with each other. Accounting for the leading-order symmetry-breaking effects, and using data from the charged-current process $B\to \pi \ell {\nu }_{\ell }$ to determine $f_{+}(q^2)$, we calculate the dilepton invariant-mass distribution in the low-$q^2$ region in the $B^{\pm }\to {\pi }^{\pm }{\ell }^{+}{\ell }^{-}$ decay. This provides a model-independent and precise calculation of the partial branching ratio for this decay.

We compare results of exact calculations of single-parton scattering (SPS) and double-parton scattering (DPS) for production of $c\overline{c}c\overline{c}$ and for $D$ meson correlations. The SPS calculations are performed in collinear approximation with exact matrix element for $gg\to c\overline{c}c\overline{c}$ and $q\overline{q}\to c\overline{c}c\overline{c}$ subprocesses. It is shown that the contribution of gluon-gluon subprocess is about factor 50 larger than that for quark-antiquark annihilation. The new results are compared with results of previous calculation with the approximate matrix element for $gg\to c\overline{c}c\overline{c}$ in the high-energy approximation. The cross section for the present exact calculation is bigger only at small invariant masses and small rapidity difference between two $c$ quarks (or two $\overline{c}$ antiquarks). We compare correlations in rapidities of two $c$ (or two $\overline{c}$) for DPS and SPS contributions. Finally, we compare our predictions for $D$ mesons with recent results of the LHCb Collaboration for invariant mass, rapidity distance between mesons and dimeson invariant mass. The predicted shapes are similar to the measured ones, however, we still underpredict the experimental cross sections. Our new calculations clearly confirm the dominance of DPS in the production of events with double charm.

The presently available high-statistics data of the $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ processes measured by the Belle and BABAR collaborations are analyzed within a quasi-two-body factorization framework. Starting from the weak effective Hamiltonian, tree and annihilation amplitudes build up the $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ decay amplitude. Two of the three final-state mesons are assumed to form a single scalar, vector or tensor state originating from a quark-antiquark pair so that the factorization hypothesis can be applied. The meson-meson final state interactions are described by $K\pi$ and $\pi \pi$ scalar and vector form factors for the $S$ and $P$ waves and by relativistic Breit-Wigner formulas for the $D$ waves. A combined ${\chi }^2$ fit to a Belle Dalitz plot density distribution, to the total experimental branching fraction and to the ${\tau }^{-}\to K_S^0{\pi }^{-}{\nu }_{\tau }$ decay data, is carried out to fix the 33 free parameters. These are mainly related to the strengths of the scalar form factors and to unknown meson to meson transition form factors at a large momentum transfer squared equal to the $D^0$ mass squared. A good overall agreement to the Belle Dalitz plot density distribution is achieved. Another set of parameters fits equally well the BABAR collaboration Dalitz plot model. The parameters of both fits are close, following from similar Dalitz density distribution data for both collaborations. The corresponding one-dimensional effective mass distributions display the contributions of the ten quasi-two-body channels entering our $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ decay amplitude. The branching fractions of the dominant channels compare well with those of the isobar Belle or BABAR models. The lower-limit values of the branching fractions of the annihilation amplitudes are significant. Built upon experimental data from other processes, the unitary $K\pi$ and $\pi \pi$ scalar form factors, entering our decay amplitude and satisfying analyticity and chiral symmetry constraints, are furthermore constrained by the present Dalitz plot analysis. Our $D^0\to K_S^0{\pi }^{+}{\pi }^{-}$ decay amplitude could be a useful input for determinations of $D^0\text{−}{\overline{D}}^0$ mixing parameters and of the Cabibbo-Kobayashi-Maskawa angle $\gamma$ (or ${\varphi }_3$).

We consider a toy model of dark matter with a gauge singlet Dirac fermion that has contact interactions to quarks that differ for right-handed up and down quarks. This is motivated by the isospin-violating dark matter scenario that was proposed to reconcile reported hints of direct dark matter detection with bounds from nonobservation of the signal in other experiments. We discuss how the effects of isospin violation in these couplings can be observed at the LHC. By studying events with large missing transverse momentum (${\cancel{E}}_{\mathrm{T}}$), we show that the ratio of monophoton and monojet events is sensitive to the ratio of the absolute values of the couplings to the up and down quarks, while a dedicated study of dijet plus ${\cancel{E}}_{\mathrm{T}}$ events can reveal their relative sign. We also consider how our results are modified if, instead of a contact interaction, a particle that mediates the interaction is introduced. Our methods have broad applicability to new physics that involves unequal couplings to up and down quarks.