We study how coupling to supergravity affects the phase structure of a system exhibiting dynamical supersymmetry breaking in a meta-stable vacuum. More precisely, we consider the Seiberg dual of SQCD coupled to supergravity at finite temperature. We show that the gravitational interactions decrease the critical temperature for the second order phase transition in the quark direction, that is also present in the global case. Furthermore, we find that, due to supergravity, a new second order phase transition occurs in the meson direction, whenever there is a nonvanishing constant term in the superpotential. Notably, this phase transition is a necessary condition for the fields to roll, as the system cools down, towards the meta-stable susy breaking vacuum, because of the supergravity-induced shift of the meta-stable minimum away from zero meson vevs. Finally, we comment on the phase structure of the KKLT model with uplifting sector given by the Seiberg dual of SQCD.

The small-scale structure of a string connecting a pair of static sources is explored for the weakly coupled anisotropic $\mathrm{SU}(2)$ Yang-Mills theory in ($2+1$) dimensions. A crucial ingredient in the formulation of the string Hamiltonian is the phenomenon of color smearing of the string constituents. The quark-antiquark potential is determined. We close with some discussion of the standard, fully Lorentz-invariant Yang-Mills theory.

Here we consider the nonlinear evolution of Alfvén waves that have been excited by gravitational waves from merging binary pulsars. We derive a wave equation for strongly nonlinear and dispersive Alfvén waves. Because of the weak dispersion of the Alfvén waves, significant wave steepening can occur, which in turn implies strong harmonic generation. We find that the harmonic generation is saturated due to dispersive effects, and use this to estimate the resulting spectrum. Finally we discuss the possibility of observing the above process.

We solve Einstein’s constraint equations in the conformal thin-sandwich decomposition to model thin shells of noninteracting particles in circular orbit about a nonrotating black hole. We use these simple models to explore the effects of some of the freely specifiable quantities in this decomposition on the physical content of the solutions. Specifically, we adopt either maximal slicing or Kerr-Schild slicing, and make different choices for the value of the lapse on the black hole horizon. For one particular choice of these quantities the resulting equations can be solved analytically; for all others we construct numerical solutions. We find that these different choices have no effect on our solutions when they are expressed in terms of gauge-invariant quantities.

We analyze how the spectrum of perturbations produced in a multicomponent modular inflation model proposed by Kadota and Stewart depends on couplings between the two moduli. Although some simple direct couplings give essentially the same results as the original model, $dn/d\ln k\propto n-1$, simple indirect couplings produce a power law spectrum, $n-1=\mathrm{\text{constant}}$, which can naturally be close to scale invariant.

There are evidences that the cosmic microwave background (CMB) large-angle anomalies imply a departure from statistical isotropy and hence from the standard cosmological model. We propose a $\Lambda \mathrm{CDM}$ model extension whose dark energy component preserves its nondynamical character but wields anisotropic vacuum pressure. Exact solutions for the cosmological scale factors are presented, upper bounds for the deformation parameter are evaluated and its value is estimated considering the elliptical universe proposal to solve the quadrupole anomaly. This model can be constructed from a Bianchi I cosmology with a cosmological constant from two different ways: (i) a straightforward anisotropic modification of the vacuum pressure consistently with energy-momentum conservation; (ii) a Poisson structure deformation between canonical momenta such that the dynamics remain invariant under scale factors rescalings.

Eventual signals of split supersymmetry in cosmic ray physics are analyzed in detail. The study focuses particularly on quasistable colorless $R$-hadrons originating from confinement of long-lived gluinos (with quarks, antiquarks, and gluons) produced in $pp$ collisions at astrophysical sources. Because of parton density requirements, the gluino has a momentum which is considerably smaller than the energy of the primary proton, and so production of heavy (mass $\sim 500\mathrm{GeV}$) $R$-hadrons requires powerful cosmic ray engines able to accelerate particles up to extreme energies, somewhat above ${10}^{13.6}\mathrm{GeV}$. Using a realistic Monte Carlo simulation with the AIRES engine, we study the main characteristics of the air showers triggered when one of these exotic hadrons impinges on a stationary nucleon of the Earth’s atmosphere. We show that $R$-hadron air showers present clear differences with respect to those initiated by standard particles. We use these shower characteristics to construct observables which may be used to distinguish long-lived gluinos at the Pierre Auger Observatory.

We study the long wavelength shear modes (Tkachenko waves) of triangular lattices of singly quantized vortices in neutron star interiors taking into account the mutual friction between the superfluid and the normal fluid as well as the shear viscosity of the normal fluid. The set of Tkachenko modes that propagate in the plane orthogonal to the spin vector are weakly damped if the coupling between the superfluid and the normal fluid is small. In strong coupling, their oscillation frequencies are lower and are undamped for small and moderate shear viscosities. The periods of these modes are consistent with the observed $\sim 100–1000\mathrm{day}$ variations of spin for PSR 1828-11.

In the staggered fermion formulation of lattice QCD, we construct and classify the diquark operators to be embedded in the singly heavy baryons, $qqQ$. Along the same manner as in the staggered meson classifications given in [M. F. L. Golterman, Nucl. Phys. B273, 663 (1986).], we establish the group theoretical connections between continuum and lattice staggered diquark representations.

Under an assumption that the $2\leftrightarrow 3$ symmetry is broken only through phases, we give a systematic investigation of possible lepton mass matrix forms without referring to explicit parameter values. Two types of the $2\leftrightarrow 3$ symmetry are investigated: one is that the left- and right-handed fields $(f_L,f_R)$ obey the symmetry, and another one is that only $f_L$ obeys the symmetry. In the latter case, in spite of no $2\leftrightarrow 3$ symmetry in the Majorana mass matrix $M_R$ for ${\nu }_R$, the neutrino seesaw mass matrix still obeys the $2\leftrightarrow 3$ symmetry. Possible phenomenology is discussed.

We investigate the lattice index theorem and the localization of the zero modes for thick classical center vortices. For nonorientable spherical vortices, the index of the overlap Dirac operator differs from the topological charge although the traces of the plaquettes deviate only by a maximum of 1.5% from trivial plaquettes. This may be related to the fact that even in Landau gauge some links of these configuration are close to the nontrivial center elements.

We study the radiative leptonic decay, $B^{-}\to {\mu }^{-}{\overline{\nu }}_{\mu }\gamma$, in the framework of a relativistic independent quark model, based on the confining potential in the scalar-vector harmonic form. As expected, we find that the photon emission in this decay overcomes the so-called helicity suppression inevitable in the case of pure leptonic decay $(B^{-}\to {\mu }^{-}{\overline{\nu }}_{\mu })$. Our result for the branching ratio is $\mathcal{B}r(B^{-}\to {\mu }^{-}{\overline{\nu }}_{\mu }\gamma )=1.70\times {10}^{-6}$, which is comparable with other model predictions within the current experimental upper limit. The photon energy spectrum predicted in the model is slightly asymmetric with the peak value around 1.45 GeV, which should render it quite accessible to experimental analysis.

The photoproduction of quarkonium in coherent hadron-hadron ($pp/pA/AA$) interactions for LHC energies is an important tool to investigate the QCD dynamics at high energies. In this paper we estimate the integrated cross section and rapidity distribution for $J/\Psi$ and ${\rm Y}$ production using the color glass condensate (CGC) formalism. We predict large rates, implying that the experimental identification could be feasible at the LHC.

We study the heavy-heavy-light quark ($QQq$) system in a nonrelativistic potential model, and investigate the quark motional effect on the inter-two-quark potential in baryons. We adopt the Hamiltonian with the static three-quark potential which is obtained by the first-principle calculation of lattice QCD, rather than the two-body force in ordinary quark models. Using the renormalization-group inspired variational method in discretized space, we calculate the ground-state energy of $QQq$ systems and the light-quark spatial distribution. We find that the effective string tension between the two heavy quarks is reduced compared to the static three-quark case. This reduction of the effective string tension originates from the geometrical difference between the interquark distance and the flux-tube length, and is conjectured to be a general property for baryons.

We present calculation on the azimuthal spin asymmetries for pion pair production in semi-inclusive deep inelastic scattering (SIDIS) process at both HERMES and COMPASS kinematics, with transversely polarized proton, deuteron, and neutron targets. We calculate the asymmetry by adopting a set of parametrization of the interference fragmentation functions and two different models for the transversity. We find that the result for the proton target is insensitive to the approaches of the transversity but more helpful to understand the interference fragmentation functions. However, for the neutron target, which can be obtained through using deuteron and ${}^3\mathrm{He}$ targets, we find different predictions for different approaches to the transversity. Thus probing the two pion interference fragmentation from the neutron can provide us more interesting information on the transversity.

We propose a new texture for the light neutrino mass matrix. The proposal is based upon imposing a zero-trace condition on the two-by-two submatrices of the complex symmetric Majorana mass matrix in the flavor basis where the charged lepton mass matrix is diagonal. Restricting the mass matrix to have two traceless submatrices may be found sufficient to describe the current data. Eight out of 15 independent possible cases are found to be compatible with current data. Numerical and some approximate analytical results are presented.

We present a measurement of the time-dependent $CP$-violating asymmetries in $B^0\to K_S^0{\pi }^0$ decays based on $383\times {10}^6$ $\mathit{{\rm Y}}(4S)\to B\overline{B}$ events collected by the BABAR experiment at the PEP-II asymmetric-energy $B$ Factory at the Stanford Linear Accelerator Center. We measure the direct $CP$-violating asymmetry $C_{K_S^0{\pi }^0}=0.24\pm 0.15\pm 0.03$ and the $CP$-violating asymmetry in the interference between mixing and decay $S_{K_S^0{\pi }^0}=0.40\pm 0.23\pm 0.03$, where the first errors are statistical and the second are systematic. On the same sample, we measure the decay branching fraction, obtaining $\mathcal{B}(B^0\to K^0{\pi }^0)=(10.3\pm 0.7\pm 0.6)\times {10}^{-6}$.

We present a measurement of the cross section for $W$-boson production in association with jets in $p\overline{p}$ collisions at $\sqrt{s}=1.96\mathrm{TeV}$. The analysis uses a data sample corresponding to an integrated luminosity of $320{\mathrm{pb}}^{-1}$ collected with the CDF II detector. $W$ bosons are identified in their electron decay channel and jets are reconstructed using a cone algorithm. For each $W+\ge n\mathrm{\text{−}}\mathrm{\text{jet}}$ sample ($n=1-4$) we measure the differential cross section $d\sigma (p\overline{p}\to W+\ge n\mathrm{\text{−}}\mathrm{\text{jet}})/d{E}_T^{\mathrm{nth}\mathrm{\text{−}}\mathrm{jet}}\times \mathcal{B}(W\to e\nu )$ with respect to the transverse energy $E_T$ of the $n$th-highest $E_T$ jet above 20 GeV, and the total cross section $\sigma (p\overline{p}\to W+\ge n\mathrm{\text{−}}\mathrm{\text{jet}};E_T^{\mathrm{nth}\mathrm{\text{−}}\mathrm{jet}}>25\mathrm{GeV})\times \mathcal{B}(W\to e\nu )$, for a restricted $W\to e\nu$ decay phase space. The cross sections, corrected for all detector effects, can be directly compared to particle level $W+\mathrm{\text{jet}}(\mathrm{s})$ predictions. We present here comparisons to leading order and next-to-leading order predictions.

We refine and update the metastability constraint on the standard model (SM) top and Higgs masses by analytically including gravitational corrections to the vacuum decay rate. Present best-fit ranges of the top and Higgs masses mostly lie in the narrow metastable region. Furthermore, we show that the SM potential can be fine-tuned in order to be made suitable for inflation. However, SM inflation results in a power spectrum of cosmological perturbations not consistent with observations.

We point out that in nonsupersymmetric grand unified theories, in which the $SU(5)$ gauge symmetry is broken down to the standard model gauge group by a $\mathbf{24}$ Higgs multiplet the Appelquist-Carazzone decoupling is violated. This is because the $SU(2{)}_L$ Higgs triplet contained in the $\mathbf{24}$ acquires a dimension-full coupling to the $SU(2{)}_L$ Higgs doublets which is proportional to the grand unified symmetry breaking vacuum expectation value. As a result, at one-loop heavy gauge and Higgs fields contribution to tadpoles generates a vacuum expectation value of the triplet which is not suppressed for $V\to \infty$ and violates the custodial symmetry.