We construct the $\mathcal{N}=2$ supersymmetric Grassmannian nonlinear sigma model for the massless case and extend it to a massive $\mathcal{N}=2$ model by adding an appropriate superpotential. We then study their Bogomol’nyi-Prasad-Sommerfield (BPS) equations leading to supersymmetric $Q$-lumps carrying both topological and Noether charges. These solutions are shown to be always time dependent even sometimes involving multiple frequencies. Thus we illustrate explicitly that the time dependence is consistent with remaining supersymmetries of solitons.

If the fundamental Planck scale is about a TeV and the cosmic neutrino flux is at the Waxman-Bahcall level, quantum black holes are created daily in the Antarctic ice cap. We reexamine the prospects for observing such black holes with the IceCube neutrino-detection experiment. To this end, we first revise the black hole production rate by incorporating the effects of inelasticty, i.e., the energy radiated in gravitational waves by the multipole moments of the incoming shock waves. After that we study in detail the process of Hawking evaporation accounting for the black hole’s large momentum in the lab system. We derive the energy spectrum of the Planckian cloud which is swept forward with a large, $\mathcal{O}({10}^6)$, Lorentz factor. (It is noteworthy that the boosted thermal spectrum is also relevant for the study of near-extremal supersymmetric black holes, which could be copiously produced at the Large Hadron Collider.) In the semiclassical regime, we estimate the average energy of the boosted particles to be less than 20% the energy of the $\nu$ progenitor. Armed with such a constraint, we determine the discovery reach of IceCube by tagging on soft (relative to what one would expect from charged current standard model processes) muons escaping the electromagnetic shower bubble produced by the black hole’s light descendants. The statistically significant $5\sigma$ excess extends up to a quantum gravity scale $\sim 1.3\mathrm{TeV}$.

Recent type Ia supernovae data seem to favor a dark energy model whose equation of state $w(z)$ crosses $-1$, which is a much more amazing problem than the acceleration of the universe. Either the case that $w(z)$ evolves from above $-1$ to below $-1$ or the case that $w(z)$ runs from below $-1$ to above $-1$, is consistent with present data. In this paper we show that it is possible to realize the crossing behaviors of both of the two cases by only a single scalar field in frame of Dvali-Gabadadze-Porrati braneworld. At the same time we prove that there does not exist scaling solution in a universe with dust.

Considering gravitino dark matter scenarios, we obtain the full gauge-invariant result for the relic density of thermally produced gravitinos to leading order in the standard model gauge couplings. For the temperatures required by thermal leptogenesis, we find gaugino mass bounds which will be probed at future colliders. We show that a conceivable determination of the gravitino mass will allow for a unique test of the viability of thermal leptogenesis in the laboratory.

We analyze leptogenesis in a supersymmetric triplet seesaw scenario that explains the observed neutrino masses, adopting a phenomenological approach where the decay branching ratios of the triplets and the amount of $CP$ violation in its different decay channels are assumed as free parameters. We find that the solutions of the relevant Boltzmann equations lead to a rich phenomenology, in particular, much more complex compared to the nonsupersymmetric case, mainly due to the presence of an additional Higgs doublet. Several unexpected and counter-intuitive behaviors emerge from our analysis: the amount of $CP$ violation in one of the decay channels can prove to be irrelevant to the final lepton asymmetry, leading to successful leptogenesis even in scenarios with a vanishing $CP$ violation in the leptonic sector; gauge annihilations can be the dominant effect in the determination of the evolution of the triplet density up to very high values of its mass, leading anyway to a sizeable final lepton asymmetry, which is also a growing function of the washout parameter $K\equiv {\Gamma }_d/H$, defined as usual as the ratio between the triplet decay amplitude ${\Gamma }_d$ and the Hubble constant $H$; on the other hand, cancellations in the Boltzmann equations may lead to a vanishing lepton asymmetry if in one of the decay channels both the branching ratio and the amount of $CP$ violation are suppressed, but not vanishing. The present analysis suggests that in the supersymmetric triplet seesaw model successful leptogenesis can be attained in a wide range of scenarios, provided that an asymmetry in the decaying triplets can act as a lepton-number reservoir.

Milani et al. recently have published careful and fundamental studies of the accuracy with which both gravitational physics information and the solar quadrupole moment can be obtained from Earth-Mercury distance data. To complement these results, a quite different analysis method is used in the present paper. We calculate the first-order corrections to the Keplerian motion of a single planet around the Sun due to the parameterized post-Newtonian theory parameters $\beta$, $\gamma$, ${\alpha }_1$, ${\alpha }_2$, and $\xi$, as well as corrections due to the solar quadrupole moment $J_2$ and a possible secular change in $G{M}_{\odot }$. The Nordtvedt parameter $\eta$ that is used in tests of the strong equivalence principle also is included in this analysis. The expected accuracies are given for 1 yr, 2 yr, and 8 yr mission durations, assuming that the planet-planet and asteroid-planet perturbations are accurately known. The “modified worst-case” error analysis method that we use is quite different from the usual covariance analysis method based on assumed uncorrelated random errors, plus a bias that is fixed or that changes in a prescribed way. We believe this is appropriate because systematic measurement errors are likely to be the main limitation on the accuracy of the results. Our final estimated uncertainties are one-third of the errors that would result if a 4.5-cm rms systematic error had the most damaging possible variation with time. We discuss the resulting uncertainties for several different subsets of orbital and relativity parameters.

We present a numerical method to compute path integrals in effective SU(2) Yang-Mills theories. The basic idea is to approximate the Yang-Mills path integral by summing over all gauge field configurations, which can be represented as a linear superposition of a small number of localized building blocks. With a suitable choice of building blocks many essential features of SU(2) Yang-Mills theory can be reproduced, particularly confinement. The analysis of our results leads to the conclusion that topological charge as well as extended structures are essential elements of confining gauge field configurations.

We address the problem of determining the type I, type II or borderline dual superconductor behavior in maximal Abelian gauge $SU(2)$ through the study of the dual Abrikosov vortex. We find that significant electric currents in the simulation data call into question the use of the dual Ginzburg-Landau Higgs model in interpreting the data. Further, two definitions of the penetration depth parameter take two different values. The splitting of this parameter into two is intricately connected to the existence of electric currents. It is important in our approach that we employ definitions of flux and electric and magnetic currents that respect Maxwell equations exactly for lattice averages independent of lattice spacings. Applied to specific Wilson loop sizes, our conclusions differ from those that use the dual GLH model.

We construct the $S$-wave part of the electromagnetic vector annihilation current to $\mathcal{O}({\alpha }_s{v}^2)$ on the lattice for heavy quarks whose dynamics are described by the NRQCD action, and $v$ is the nonrelativistic quark velocity inside the meson. The lattice vector current for $Q\overline{Q}$ annihilation is expressed as a linear combination of lattice operators with quantum numbers $L=0$, $J^P=1^{-}$, and the coefficients are determined by matching this lattice current to the corresponding continuum current in QCD to $O(v^2)$ at one-loop. The annihilation channel gives a complex amplitude and a proper choice for the contours of integration is needed; a simple Wick rotation is not possible. In this way, and with a careful choice of subtraction functions in the numerical integration, the Coulomb-exchange and infrared singularities appearing in the amplitudes are successfully treated. The matching coefficients are given as a function of the heavy quark mass $Ma$ in lattice units. An automated vertex generation program written in Python is employed, allowing us to use a realistic NRQCD action and an improved gluon lattice action. A change in the definition of either action is easily accommodated in this procedure. The final result, when combined with lattice simulation results, describes the electromagnetic decays of heavy quarkonia, notably the ${\rm Y}$ meson.

The PVLAS signal has led to the proposal of many experiments searching for light bosons coupled to photons. The coupling strength probed by these near-future searches is, however, far from the allowed region, if astrophysical bounds apply. But the environmental conditions for the production of axionlike particles in stars are very different from those present in laboratories. We consider the case in which the coupling and the mass of an axionlike particle depend on environmental conditions such as the temperature and matter density. This can relax astrophysical bounds by several orders of magnitude, just enough to allow for the PVLAS signal. This creates exciting possibilities for a detection in near-future experiments.

The standard model augmented by the presence of gauge-singlet right-handed neutrinos proves to be an ideal scenario for accommodating nonzero neutrino masses. Among the new parameters of this “new standard model” are right-handed neutrino Majorana masses $M$. Theoretical prejudice points to $M$ much larger than the electroweak symmetry breaking scale, but it has recently been emphasized that all $M$ values are technically natural and should be explored. Indeed, $M$ around $1–10\mathrm{eV}$ can accommodate an elegant oscillation solution to the liquid scintillator neutrino detector (LSND) anomaly, while other $M$ values lead to several observable consequences. We consider the phenomenology of low-energy ($M\lesssim 1\mathrm{keV}$) seesaw scenarios. By exploring such a framework with three right-handed neutrinos, we can consistently fit all oscillation data—including those from LSND—while partially addressing several astrophysical puzzles, including anomalous pulsar kicks, heavy element nucleosynthesis in supernovae, and the existence of warm dark matter. In order to accomplish all of this, we find that a nonstandard cosmological scenario is required. Finally, low-energy seesaws—regardless of their relation to the LSND anomaly—can also be tested by future tritium beta-decay experiments, neutrinoless double-beta decay searches, and other observables. We estimate the sensitivity of such probes to $M$.

We present measurements of the total production rates and momentum distributions of the charmed baryon ${\mathit{\Lambda }}_c^{+}$ in $e^{+}{e}^{-}\to \mathrm{\text{hadrons}}$ at a center-of-mass energy of 10.54 GeV and in $\mathit{{\rm Y}}(4S)$ decays. In hadronic events at 10.54 GeV, charmed hadrons are almost exclusively leading particles in $e^{+}{e}^{-}\to c\overline{c}$ events, allowing direct studies of $c$-quark fragmentation. We measure a momentum distribution for ${\mathit{\Lambda }}_c^{+}$ baryons that differs significantly from those measured previously for charmed mesons. Comparing with a number of models, we find none that can describe the distribution completely. We measure an average scaled momentum of $⟨x_p⟩=0.574\pm 0.009$ and a total rate of $N_{\mathit{\Lambda }c}^{q\overline{q}}=0.057\pm 0.002(\exp .)\pm 0.015(\mathrm{BF}){\mathit{\Lambda }}_c^{+}$ per hadronic event, where the experimental error is much smaller than that due to the branching fraction into the reconstructed decay mode, $p{K}^{-}{\pi }^{+}$. In $\mathit{{\rm Y}}(4S)$ decays we measure a total rate of $N_{\mathit{\Lambda }c}^{\mathit{{\rm Y}}}=0.091\pm 0.006(\exp .)\pm 0.024(\mathrm{BF})$ per $\mathit{{\rm Y}}(4S)$ decay, and find a much softer momentum distribution than expected from $B$ decays into a ${\mathit{\Lambda }}_c^{+}$ plus an antinucleon and one to three pions.

Knowledge of the $B_s$ decay fraction of the ${\rm Y}(5S)$ resonance, $f_S$, is important for $B_s$ meson studies at the ${\rm Y}(5S)$ energy. Using a data sample collected by the CLEO III detector at CESR consisting of $0.423{\mathrm{fb}}^{-1}$ on the ${\rm Y}(5S)$ resonance, $6.34{\mathrm{fb}}^{-1}$ on the ${\rm Y}(4S)$ and $2.32{\mathrm{fb}}^{-1}$ in the continuum below the ${\rm Y}(4S)$, we measure $\mathcal{B}({\rm Y}(5S)\to \varphi X)=(13.8\pm {0.7}_{-1.5}^{+2.3})\%$ and $\mathcal{B}({\rm Y}(4S)\to \varphi X)=(7.1\pm 0.1\pm 0.6)\%$; the ratio of the two rates is ($1.9\pm {0.1}_{-0.2}^{+0.3}$). This is the first measurement of the $\varphi$ meson yield from the ${\rm Y}(5S)$. Using these rates, and a model dependent estimate of $\mathcal{B}(B_s\to \varphi X)$, we determine $f_S=(24.6\pm {2.9}_{-5.3}^{+11.0})\%$. We also update our previous independent measurement of $f_S$ made using the inclusive $D_s$ yields to now be $(16.8\pm {2.6}_{-3.4}^{+6.7})\%$, due to a better estimate of the number of hadronic events. We also report the total ${\rm Y}(5S)$ hadronic cross section above continuum to be $\sigma (e^{+}{e}^{-}\to {\rm Y}(5S))=(0.301\pm 0.002\pm 0.039)\mathrm{nb}$. This allows us to extract the fraction of $B$ mesons as $(58.9\pm 10.0\pm 9.2)\%$, equal to 1-$f_S$. Averaging the three methods gives a model dependent result of $f_S=({21}_{-3}^{+6})\%$.

Using the exactly solvable Gross-Neveu model as theoretical laboratory, we analyze in detail the relationship between a relativistic quantum field theory at real and imaginary chemical potential. We find that one can retrieve the full information about the phase diagram of the theory from an imaginary chemical potential calculation. The prerequisite is to evaluate and analytically continue the effective potential for the chiral order parameter, rather than thermodynamic observables or phase boundaries. In the case of an inhomogeneous phase, one needs to compute the full effective action, a functional of the space-dependent order parameter, at imaginary chemical potential.

We study some effects when a probe light pulse propagates in the spacetime curved by the gravitational field of high-power laser pulses. The gravitational field produced by a high-power laser is calculated by using the linearized Einstein field equation under the weak field approximation. It is found that the gravitational modification of the photon Berry phase occurs when the probe light pulse transports in a uniform winding fiber in this gravitational background. We also find the gravitational redshifting and defocusing for the probe pulse caused by the gravitational field of the high-power lasers.

In this paper two things are done. First it is shown how a four-dimensional gauged Wess-Zumino-Witten term arises from the five-dimensional Einstein-Hilbert plus Gauss-Bonnet Lagrangian with a special choice of the coefficients. Second, the way in which the equations of motion of four-dimensional General Relativity arise is exhibited.

The large-angle (low-$\ell$) correlations of the cosmic microwave background (CMB) as reported by the Wilkinson Microwave Anisotropy Probe (WMAP) after their first year of observations exhibited statistically significant anomalies compared to the predictions of the standard inflationary big-bang model. We suggested then that these implied the presence of a solar system foreground, a systematic correlated with solar system geometry, or both. We reexamine these anomalies for the data from the first three years of WMAP’s operation. We show that, despite the identification by the WMAP team of a systematic correlated with the equinoxes and the ecliptic, the anomalies in the first-year internal linear combination (ILC) map persist in the three-year ILC map, in all-but-one case at similar statistical significance. The three-year ILC quadrupole and octopole therefore remain inconsistent with statistical isotropy—they are correlated with each other (99.6% C.L.), and there are statistically significant correlations with local geometry, especially that of the solar system. The angular two-point correlation function at scales $>60\mathrm{deg}$ in the regions outside the (kp0) galactic cut, where it is most reliably determined, is approximately zero in all wavebands and is even more discrepant with the best-fit $\Lambda \mathrm{CDM}$ inflationary model than in the first-year data—99.97% C.L. for the new ILC map. The full-sky ILC map, on the other hand, has a nonvanishing angular two-point correlation function, apparently driven by the region inside the cut, but which does not agree better with $\Lambda \mathrm{CDM}$. The role of the newly-identified low-$\ell$ systematics is more puzzling than reassuring.

We apply the soft-collinear effective theory to deep inelastic scattering near the endpoint region. The forward scattering amplitude and the structure functions are shown to factorize as a convolution of the Wilson coefficients, the jet functions, and the parton distribution functions. The behavior of the parton distribution functions near the endpoint region is considered. It turns out that it evolves with the Altarelli-Parisi kernel even in the endpoint region, and the parton distribution function can be factorized further into a collinear part and the soft Wilson line. The factorized form for the structure functions is obtained by the two-step matching, and the radiative corrections or the evolution for each factorized part can be computed in perturbation theory. We present the radiative corrections of each factorized part to leading order in ${\alpha }_s$, including the zero-bin subtraction for the collinear part.

We extend the $1/N_c$ expansion meson-baryon scattering formalism to cases in which the final state contains more than two particles. We first show that the leading-order large $N_c$ processes proceed through resonant intermediate states (e.g., $\rho N$ or $\pi \Delta$). We then tabulate linear amplitude expressions for relevant processes and find that the pole structure of baryon resonances can be uniquely identified by their (non)appearance in $\eta N$ or mixed partial-wave $\pi \Delta$ final states. We also show that quantitative predictions of $\pi N$ to $\pi \Delta$ branching ratios predicted at leading order alone do not agree with measurements, but the inclusion of $1/N_c$ corrections is ample to explain the discrepancies.

An empirical principle for the construction of a linear relationship between the total angular momentum and squared-mass of baryons is proposed. In order to examine linearity of the trajectories, a rigorous least-squares regression analysis was performed. Unlike the standard Regge-Chew-Frautschi approach, the constructed trajectories do not have nonlinear behavior. A similar regularity may exist for lowest-mass mesons. The linear baryonic trajectories are well described by a semiclassical picture based on a spinning relativistic string with tension. The obtained numerical solution of this model was used to extract the (di)quark masses.