We study a generalization of the Skyrme model with the inclusion of a sixth-order term and a generalized mass term. We first analyze the model in a regime where the nonlinear $\sigma$ and Skyrme terms are switched to zero, which leads to well-behaved analytical Bogomol’nyi-Prasad-Sommerfeld–type solutions. Adding contributions from the rotational energy, we reproduce the mass of the most abundant isotopes to rather good accuracy. These BPS-type solutions are then used to compute the contributions from the nonlinear sigma and Skyrme terms when these are switched on. We then adjust the four parameters of the model using two different procedures and find that the additional terms only represent small perturbations to the system. We finally calculate the binding energy per nucleon and compare our results with the experimental values.

We consider the interpretation of the MiniBooNE low-energy anomaly and the gallium radioactive source experiments anomaly in terms of short-baseline electron neutrino disappearance in the framework of $3+1$ four-neutrino mixing schemes. The separate fits of MiniBooNE and gallium data are highly compatible, with close best-fit values of the effective oscillation parameters $\Delta m^2$ and ${sin}^{2}2\vartheta$. The combined fit gives $\Delta m^2\gtrsim 0.1{\mathrm{eV}}^2$ and $0.11\lesssim {sin}^{2}2\vartheta \lesssim 0.48$ at $2\sigma$. We consider also the data of the Bugey and Chooz reactor antineutrino oscillation experiments and the limits on the effective electron antineutrino mass in $\beta$ decay obtained in the Mainz and Troitsk tritium experiments. The fit of the data of these experiments limits the value of ${sin}^{2}2\vartheta$ below 0.10 at $2\sigma$. Considering the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data as a statistical fluctuation, we perform a combined fit which gives $\Delta m^2\simeq 2\mathrm{eV}$ and $0.01\lesssim {sin}^{2}2\vartheta \lesssim 0.13$ at $2\sigma$. Assuming a hierarchy of masses $m_1$, $m_2$, $m_3\ll m_4$, the predicted contributions of $m_4$ to the effective neutrino masses in $\beta$ decay and neutrinoless double-$\beta$ decay are, respectively, between about 0.06 and 0.49 and between about 0.003 and 0.07 eV at $2\sigma$. We also consider the possibility of reconciling the tension between the neutrino MiniBooNE and gallium data and the antineutrino reactor and tritium data with different mixings in the neutrino and antineutrino sectors. We find a $2.6\sigma$ indication of a mixing angle asymmetry.

Using a sample of $102\times {10}^6$ ${\rm Y}(1S)$ events collected with the Belle detector, we report on the first search for charge-parity-even charmonium and charmoniumlike states in ${\rm Y}(1S)$ radiative decays. No significant ${\chi }_{cJ}$ or ${\eta }_c$ signal is observed and 90% C.L. limits on $\mathcal{B}({\rm Y}(1S)\to \gamma {\chi }_{c0})<6.5\times {10}^{-4}$, $\mathcal{B}({\rm Y}(1S)\to \gamma {\chi }_{c1})<2.3\times {10}^{-5}$, $\mathcal{B}({\rm Y}(1S)\to \gamma {\chi }_{c2})<7.6\times {10}^{-6}$, and $\mathcal{B}({\rm Y}(1S)\to \gamma {\eta }_c)<5.7\times {10}^{-5}$ are obtained. The product branching fraction limits $\mathcal{B}({\rm Y}(1S)\to \gamma X(3872))\mathcal{B}(X(3872)\to {\pi }^{+}{\pi }^{-}J/\psi )<1.6\times {10}^{-6}$, $\mathcal{B}({\rm Y}(1S)\to \gamma X(3872))\mathcal{B}(X(3872)\to {\pi }^{+}{\pi }^{-}{\pi }^{0}J/\psi )<2.8\times {10}^{-6}$, $\mathcal{B}({\rm Y}(1S)\to \gamma X(3915))\mathcal{B}(X(3915)\to \omega J/\psi )<3.0\times {10}^{-6}$, and $\mathcal{B}({\rm Y}(1S)\to \gamma Y(4140))\mathcal{B}(Y(4140)\to \varphi J/\psi )<2.2\times {10}^{-6}$ are obtained at the 90% C.L. Furthermore, no evidence is found for excited charmonium states below $4.8\mathrm{GeV}/c^2$.

The components of the renormalized quantum energy-momentum tensor for a massive vector field coupled to the gravitational field configuration of static $3+1$ dimensional black strings in anti-de Sitter space are analytically evaluated using the Schwinger-DeWitt approximation. The general results are employed to investigate the pointwise energy conditions for the quantized matter field, and it is shown that they are violated at some regions of the space-time, in particular the horizon of the black hole.

In the original version of the minimal $SU(3{)}_C\times SU(3{)}_L\times U(1{)}_N$ model the masses of all quarks are correctly obtained by introducing three scalar triplets into the model; meanwhile the lepton mass generation requires the introduction of at least one scalar sextet. In this work we show that this scalar sextet is unable to yield the correct neutrino masses and mixing. In order to solve this puzzle in the most economical way, we evoke an additional $Z_3$ discrete symmetry, without including this sextet in the scalar spectrum, and propose a truly minimal 3-3-1 model capable of generating the correct masses and mixing of all fermions. Moreover, we show that our proposal leads to naturally light neutrinos with masses in the eV range, obtained with three scalar triplets only. Finally, the so-called minimal 3-3-1 model is also in danger due to the presence of undesirable effective operators that lead to proton decay unless they are suppressed by extremely small couplings or, as we choose to employ in this work, are eliminated by some discrete symmetry.

In this paper, incorporating the property of the vacuum negative pressure, namely, the bag constant, we present a new model of the equation of state (EOS) of quark matter at finite chemical potential and zero temperature. By comparing our EOS with Fraga et al.’s EOS and SQM1 model, one finds that our EOS is softer than Fraga et al.’s EOS and SQM1 model. The reason for this difference is analyzed. With these results we investigate the structure of a quark star. A comparison between our model of the quark star and other models is made. The obtained mass of the quark star is $1.3\sim 1.66M_{\odot }$ and the radius is $9.5\sim 14\mathrm{Km}$. One can see that our star’s compactness is smaller than that of the other two models.

Recent lattice results in pure glue $SU(3)$ theory at high temperatures have shown that the expectation value of the renormalized Polyakov loop approaches its asymptotic limit at high temperatures from above. We show that this implies that the “heavy quark free energy” obtained from the renormalized loop computed on the lattice does not behave like a true thermodynamic free energy. While this should be expected to occur in asymptotically free gauge theories such as QCD, we use the gauge/string duality to show that in a large class of strongly coupled gauge theories with nontrivial UV fixed points the Polyakov loop reaches its asymptotic value from above only if the dimension of the relevant operator used to deform the conformal field theory is greater than or equal to 3.

In the minimal formulation of gravity with Lifshitz-type anisotropic scaling, the gauge symmetries of the system are foliation-preserving diffeomorphisms of spacetime. Consequently, compared to general relativity, the spectrum contains an extra scalar graviton polarization. Here we investigate the possibility of extending the gauge group by a local $U(1)$ symmetry to “nonrelativistic general covariance.” This extended gauge symmetry eliminates the scalar graviton, and forces the coupling constant $\lambda$ in the kinetic term of the minimal formulation to take its relativistic value, $\lambda =1$. The resulting theory exhibits anisotropic scaling at short distances, and reproduces many features of general relativity at long distances.

In order to classify modified gravity models according to their physical properties, we analyze the cosmological linear perturbations for $f(R,\mathcal{G})$ theories ($R$ being the Ricci scalar and $\mathcal{G}$, the Gauss-Bonnet term) with a minimally coupled perfect fluid. For the scalar-type perturbations, we identify in general six degrees of freedom. We find that two of these physical modes obey the same dispersion relation as the one for a nonrelativistic de Broglie wave. This means that spacetime is either highly unstable or its fluctuations undergo a scale-dependent superluminal propagation. Two other modes correspond to the degrees of freedom of the perfect fluid, and propagate with the sound speed of such a fluid. The remaining two modes correspond to the entropy and temperature perturbations of the perfect fluid, and completely decouple from the other modes for a barotropic equation of state. We then provide a concise condition on $f(R,\mathcal{G})$ theories, which both $f(R)$ and $R+f(\mathcal{G})$ do fulfill, to avoid the de Broglie–type dispersion relation. For the vector-type perturbation, we find that the perturbations decay in time. For the tensor-type perturbation, the perturbations can be either superluminal or subluminal, depending on the model. No-ghost conditions are also obtained for each type of perturbation.

Detecting dark matter as it streams through detectors on Earth relies on knowledge of its phase space density on a scale comparable to the size of our Solar System. Numerical simulations predict that our galactic halo contains an enormous hierarchy of substructures, streams and caustics, the remnants of the merging hierarchy that began with tiny Earth-mass microhalos. If these bound or coherent structures persist until the present time, they could dramatically alter signatures for the detection of weakly interacting elementary particle dark matter. Using numerical simulations that follow the coarse grained tidal disruption within the Galactic potential and fine grained heating from stellar encounters, we find that microhalos, streams, and caustics have a negligible likelihood of impacting direct detection signatures implying that dark matter constraints derived using simple smooth halo models are relatively robust. We also find that many dense central cusps survive, yielding a small enhancement in the signal for indirect detection experiments.

In this paper, the cosmological dynamics of Brans-Dicke (BD) theory in which there are fermions with a coupling to BD scalar field as well as a self-interaction potential is investigated. The conditions that there exists a solution which is stable and represents a late-time accelerated expansion of the Universe are found. The variable mass of fermions cannot vanish exactly during the evolution of the Universe once it exists initially. It is shown that the late-time acceleration depends completely on the self-interaction of the fermion field if our investigation is restricted to the theory with positive BD parameter $\omega$. Provided a negative $\omega$ is allowed, there will be another two classes of stable solutions describing the late-time accelerated expansion of the Universe.

In the delayed explosion scenario of core-collapse supernovae, the accretion phase shows pronounced convective overturns and a low-multipole hydrodynamic instability, the standing accretion shock instability. These effects imprint detectable fast time variations on the emerging neutrino flux. Among existing detectors, IceCube is best suited to this task, providing an event rate of $\sim 1000{\mathrm{ms}}^{-1}$ during the accretion phase for a fiducial SN distance of 10 kpc, comparable to what could be achieved with a megaton water Cherenkov detector. If the standing accretion shock instability activity lasts for several hundred ms, a Fourier component with an amplitude of 1% of the average signal clearly sticks out from the shot noise. We analyze in detail the output of axially symmetric hydrodynamical simulations that predict much larger amplitudes up to frequencies of a few hundred Hz. If these models are roughly representative for realistic SNe, fast time variations of the neutrino signal are easily detectable in IceCube or future megaton-class instruments. We also discuss the information that could be deduced from such a measurement about the physics in the SN core and the explosion mechanism of the SN.

We investigate the effect of the color-flavor locking pairing pattern on the adiabatic radial oscillations of pure self-bound quark stars using an equation of state in the framework of the MIT bag model. We integrate the equations of relativistic radial oscillations to determine the fundamental and the first excited oscillation modes for several parameterizations of the equation of state. For low mass stars we find that the period of the fundamental mode is typically $\sim 0.1\mathrm{ms}$ and has a small dependence on the parameters of the equation of state. For large mass stars the effect of color-flavor locking is related to the rise of the maximum mass with increasing $\Delta$. As for unpaired quark stars, the period of the fundamental mode becomes divergent at the maximum mass but now the divergence is shifted to large masses for large values of the pairing gap $\Delta$. As a consequence, the oscillation period is strongly affected by color superconductivity for stars with $M\gtrsim 1.5{\mathrm{M}}_{\odot }$. We fit the period of the fundamental mode with appropriate analytical functions of the gravitational redshift of the star and the pairing gap $\Delta$. We further discuss the excitation and damping of the modes and their potential detectability during violent transient phenomena.

We evaluate the flux of tau neutrinos produced from the decay of pair produced taus from incident muons using a cascade equation analysis. To solve the cascade equations, our numerical result for the tau production $Z$ moment is given. Our results for the flux of tau neutrinos produced from incident muons are compared to the flux of tau neutrinos produced via oscillations and the direct prompt atmospheric tau neutrino flux. Results are given for both downward and upward going neutrinos fluxes and higher zenith angles are discussed. We conclude that the direct prompt atmospheric tau neutrino flux dominates these other atmospheric sources of tau neutrinos for neutrino energies larger than a few TeV for upward fluxes, and over a wider range of energy for downward fluxes.

We investigate the effect of the dimuon $CP$ asymmetry from the $B$ decay modes, recently observed at $3.2\sigma$ deviation from the standard model (SM) by the D0 Collaboration, in the context of SU(5) and SO(10) grand unified theory models. We exhibit that a large amount of flavor violation between the second and the third generation is generated due to the large neutrino atmospheric mixing angle and this flavor violation can be responsible for the large $CP$ asymmetry, i.e., $a_{\mathrm{sl}}^s=(-12.7\pm 5.0)\times {10}^{-3}$ (assuming $2\sigma$ error in the prediction of the standard model value of ${\Gamma }_{12}^s/M_{12}^s$ and error in the lattice measurements of $B_{B_s}{f}_{B_s}^2$) due to the presence of new phases which are not present in the Cabibbo-Kobayashi-Maskawa matrix in the Yukawa couplings. We also study the implication of the parameter space in these grand unified theory models with large $CP$ violating lepton asymmetry for different phenomenologies, e.g., $\mathrm{Br}(\tau \to \mu \gamma )$, $\mathrm{Br}(B_s\to \mu \mu )$ at the Fermilab, direct detection of dark matter in the ongoing detectors, and measurement of muon flux from solar neutrinos at the IceCube experiment.

We have measured the running coupling constant of SU(3) gauge theory coupled to $N_f=2$ flavors of symmetric representation fermions, using the Schrödinger functional scheme. Our lattice action is defined with hypercubic smeared links which, along with the larger lattice sizes, bring us closer to the continuum limit than in our previous study. We observe that the coupling runs more slowly than predicted by asymptotic freedom, but we are unable to observe fixed point behavior before encountering a first order transition to a strong coupling phase. This indicates that the infrared fixed point found with the thin-link action is a lattice artifact. The slow running of the gauge coupling permits an accurate determination of the mass anomalous dimension for this theory, which we observe to be small, ${\gamma }_m\lesssim 0.6$, over the range of couplings we can reach. We also study the bulk and finite-temperature phase transitions in the strong coupling region.

We examine the dependence of parton distribution functions (PDFs) on the value of the QCD coupling strength ${\alpha }_s(M_Z)$. We explain a simple method that is rigorously valid in the quadratic approximation normally applied in PDF fitting, and fully reproduces the correlated dependence of theoretical cross sections on ${\alpha }_s$ and PDF parameters. This method is based on a statistical relation that allows one to add the uncertainty produced by ${\alpha }_s$, computed with some special PDF sets, in quadrature with the PDF uncertainty obtained for the fixed ${\alpha }_s$ value (such as the CTEQ6.6 PDF set). A series of four CTEQ6.6AS PDFs realizing this approach, for ${\alpha }_s$ values in the interval $0.116\le {\alpha }_s(M_Z)\le 0.120$, is presented. Using these PDFs, the combined ${\alpha }_s$ and PDF uncertainty is assessed for theoretical predictions at the Fermilab Tevatron and Large Hadron Collider.

We further study a predictive model for the masses and mixing matrix of three Majorana neutrinos. At zeroth order the model yielded degenerate neutrinos and a generalized tribimaximal mixing matrix. At first order the mass splitting was incorporated and the tribimaximal mixing matrix emerged with very small corrections but with a zero value for the parameter $s_{13}$. In the present paper a different, assumed weaker, perturbation is included which gives a nonzero value for $s_{13}$ and further corrections to other quantities. These corrections are worked out and their consequences discussed under the simplifying assumption that the conventional $CP$ violation phase vanishes. It is shown that the existing measurements of the parameter $s_{23}$ provide strong bounds on $s_{13}$ in this model.

We analyze the power of the Tevatron data set to exclude or discover fourth generation neutrinos. In a general framework, one can have mixed left- and right-handed neutrinos, with Dirac and Majorana neutrinos as extreme cases. We demonstrate that a single Tevatron experiment can make powerful statements across the entire mixing space, extending LEP’s mass limits of 60–80 GeV up to 150–175 GeV, depending on the mixing.