We consider the implications of the condensation of a general local Becchi-Rouet-Stora-Tyutin invariant dimension two operator built out of the localizing ghost fields of the Gribov-Zwanziger Lagrangian which is a localized Lagrangian incorporating the Gribov problem in the Landau gauge. For different color tensor projections of the general operator, the properties of a frozen gluon propagator and unenhanced Faddeev-Popov ghost propagator, which are observed in lattice computations, can be reproduced. The alternative possibilities are distinguished by the infrared structure of the propagators of the spin-1 fields, other than those of the gluon and Faddeev-Popov ghost, for which there is no numerical simulation data to compare with yet.

We consider a series of massive scaling limits $m_1\to \infty$, $q\to 0$, $\lim m_{1}q={\Lambda }_3$ followed by $m_4\to \infty$, ${\Lambda }_3\to 0$, $\lim m_4{\Lambda }_3=({\Lambda }_2{)}^2$ of the $\beta$-deformed matrix model of Selberg type ($N_c=2$, $N_f=4$) which reduce the number of flavors to $N_f=3$ and subsequently to $N_f=2$. This keeps the other parameters of the model finite, which include $n=N_L$ and $N=n+N_R$, namely, the size of the matrix and the “filling fraction.” Exploiting the method developed before, we generate instanton expansion with finite $g_s$, ${ϵ}_{1,2}$ to check the Nekrasov coefficients ($N_f=3$, 2 cases) to the lowest order. The limiting expressions provide integral representation of irregular conformal blocks which contains a $2d$ operator $\lim \frac{1}{C(q)}\mathrm{\text{:}}{\mathrm{e}}^{(1/2){\alpha }_1\varphi (0)}\mathrm{\text{:}}({\int }_0^{q}dz\mathrm{\text{:}}{\mathrm{e}}^{b_E\varphi (z)}\mathrm{\text{:}}{)}^n\mathrm{\text{:}}{\mathrm{e}}^{(1/2){\alpha }_2\varphi (q)}\mathrm{\text{:}}$ and is subsequently analytically continued.

We derive a planar sector of the large $N$ nonsupersymmetric background of the quantum mechanical Hamiltonian of two Hermitian matrices coupled via a Yang-Mills interaction, in terms of the density of eigenvalues of one of the matrices. This background satisfies an implicit nonlinear integral equation, with a perturbative small coupling expansion and a solvable large coupling solution, which is obtained. The energy of system and the expectation value of several correlators are obtained in this strong coupling limit. They are free of infrared divergences.

Ultracompact minihalos (UCMHs) are dense dark matter structures, which can form from large density perturbations shortly after matter-radiation equality. If dark matter is in the form of weakly interacting massive particles (WIMPs), then UCMHs may be detected via their gamma-ray emission. We investigate how the Fermi satellite could constrain the abundance of UCMHs and place limits on the power spectrum of the primordial curvature perturbation. Detection by Fermi would put a lower limit on the UCMH halo fraction. The smallest detectable halo fraction $f_{\mathrm{UCMH}}\gtrsim {10}^{-7}$ is for $M_{\mathrm{UCMH}}\sim {10}^3{M}_{\odot }$. If gamma-ray emission from UCMHs is not detected, an upper limit can be placed on the halo fraction. The bound is tightest $f_{\mathrm{UCMH}}\lesssim {10}^{-5}$ for $M_{\mathrm{UCMH}}\sim {10}^5{M}_{\odot }$. The resulting upper limit on the power spectrum of the primordial curvature perturbation in the event of nondetection is in the range ${\mathcal{P}}_{\mathcal{R}}\lesssim {10}^{-6.5}–{10}^{-6}$ on scales $k\sim {10}^1–{10}^6{\mathrm{Mpc}}^{-1}$. This is substantially tighter than the existing constraints from primordial black hole formation on these scales; however, it assumes that dark matter is in the form of WIMPs, and UCMHs are not disrupted during the formation of the Milky Way halo.

We constrain the parameterized post-Einsteinian framework with binary pulsar observations of orbital period decay due to gravitational wave emission. This framework proposes to enhance the amplitude and phase of gravitational waveform templates through post-Einsteinian parameters to search for generic deviations from general relativity in gravitational wave data. Such enhancements interpolate between general relativity and alternative theory predictions, but their magnitude must be such as to satisfy all current experiments and observations. The data that currently constrains the parameterized post-Einsteinian framework the most is the orbital period decay of binary pulsars. We use such observations to bound the magnitude of post-Einsteinian parameters, which will be critical when gravitational waves are detected and this framework is implemented.

We have considered a supersymmetric scenario in which the minimal supersymmetric standard model is augmented with a right-chiral neutrino superfield for each generation. Such a scenario can have a lightest supersymmetric particle (LSP) dominated by the right-chiral sneutrino state and the lighter stau as the next-to-lightest supersymmetric particle (NLSP). This can easily be motivated by assuming a high-scale framework of supersymmetry breaking like minimal supergravity (mSUGRA). Because of the extremely small neutrino Yukawa coupling, the decay of the NLSP to the LSP is suppressed and, consequently, the NLSP—here the lighter stau mass eigenstate—becomes stable at the length scale of the detector. The collider signal in this case consists of charged tracks of massive stable particles in the muon chamber. Following up on our earlier studies on neutralino and chargino reconstruction in such a scenario, we have shown that the kinematical information obtained from these charged tracks allows us to reconstruct the left-chiral tau sneutrino as well over a significant region of the mSUGRA parameter space. Two methods for reconstruction are suggested and their relative merits are discussed.

We propose a dark matter model in which the signal in direct detection experiments arises from electromagnetic, not nuclear, energy deposition. This can provide a novel explanation for the DAMA result while avoiding many direct detection constraints. The dark matter state is taken nearly degenerate with another state. These states are naturally connected by a dipole moment operator, which can give both the dominant scattering and decay modes between the two states. The signal at DAMA then arises from dark matter scattering in the Earth into the excited state and decaying back to the ground state through emission of a single photon in the detector. This model has unique signatures in direct detection experiments. The density and chemical composition of the detector is irrelevant—only the total volume affects the event rate. In addition, the spectrum is a monoenergetic line, which can fit the DAMA signal well. This model is readily testable at experiments such as CDMS and XENON100 if they analyze their low-energy, electronic recoil events.

We continue our numerical Monte Carlo simulation of a gas of closed loops on a 3 dimensional lattice, however, now in the presence of a topological term added to the action which corresponds to the total linking number between the loops. We compute the linking number using a novel approach employing certain notions from knot theory. Adding the topological term converts the particles into anyons. Interpreting the model as an effective theory that describes the $2+1$-dimensional Abelian Higgs model in the asymptotic strong-coupling regime, the topological linking number simply corresponds to the addition to the action of the Chern-Simons term. The system continues to exhibit a phase transition as a function of the vortex mass as it becomes small. We find the following new results. The Chern-Simons term has no effect on the Wilson loop. On the other hand, it does effect the ’t Hooft loop of a given configuration, adding the linking number of the ’t Hooft loop with all of the dynamical vortex loops. We find the unexpected result that both the Wilson loop and the ’t Hooft loop exhibit a perimeter law even though there are no massless particles in the theory, in both phases of the theory. It should be noted that our method suffers from numerical instabilities if the coefficient of the Chern-Simons term is too large; thus, we have restricted our results to small values of this parameter. Furthermore, interpreting the lattice loop gas as an effective theory describing the Abelian Higgs model is only known to be true in the infinite coupling limit; for strong but finite coupling this correspondence is only a conjecture, the validity of which is beyond the scope of this article.

We calculate the decay widths of both the second and the third radial excitations of $\eta$ and ${\eta }^{\prime }$ within the framework of the ${}^{3}P_0$ model. After comparing the theoretical decay widths and decay patterns with the available experimental data of $\eta (1760)$, $X(1835)$, $X(2120)$, and $X(2370)$, we find that the interpretation of $\eta (1760)$ and $X(1835)$ as the second radial excitation of $\eta$ and ${\eta }^{\prime }$ crucially depends on the measured mass and width of $\eta (1760)$, which is still controversial experimentally. We suggest that there may be sizable $p\overline{p}$ content in $X(1835)$. $X(2120)$ and $X(2370)$ cannot be understood as the third radial excitations of $\eta$ and ${\eta }^{\prime }$. $X(2370)$ is probably a mixture of ${\eta }^{\prime }(4{}^{1}S_0)$ and glueball.

The heaviest members of the standard model—the gauge bosons $W$, $Z$ and the top quarks and antiquarks—may form collective baglike excitations of the Higgs vacuum provided their number is large enough, at both zero and finite temperatures. Since the Higgs vacuum expectation value is significantly modified inside them, they are called “bags.” In this work we argue that creation of such objects can explain certain numerical studies of cosmological baryogenesis. Using as an example a hybrid model combining inflationary preheating with cold electroweak transition, we identify “spots of unbroken phase” found in numerical studies of this scenario with such $W\mathrm{\text{−}}Z$ bags. We argue that the baryon number violation should happen predominantly inside these objects, and we show that the rates calculated in numerical simulations can be analytically explained using finite-size, pure gauge sphaleron solutions, developed previously in the QCD context by Carter, Ostrovsky, and Shuryak. Furthermore, we point out significant presence of the top quarks/antiquarks in these bags (which were not included in those numerical studies). Although the basic sphaleron exponent remains unchanged by the tops’ presence, we find that tops help to stabilize them for a longer time. Another enhancement of the transition rate comes from the “recycling” of the tops in the topological transition. Inclusion of the fermions (tops) enhances the sphaleron rate by up to 2 orders of magnitude. Finally, we discuss the magnitude of the $CP$ violation needed to explain the observed baryonic asymmetry of the Universe and give arguments that the difference in the top-antitop population in the bag of the right magnitude can arise both from $CP$ asymmetries in the top decays and in top propagation into the bags, due to the Farrar-Shaposhnikov effect.

We discuss a new family of multiquanta-bound states in the standard model which exist due to the mutual Higgs-based attraction of the heaviest members of the standard model, namely, gauge quanta $W$, $Z$, and (anti)top quarks, $\overline{t}$, $t$. We use a self-consistent mean-field approximation, up to a rather large particle number $N$. In this paper we do not focus on weakly bound, nonrelativistic bound states, but rather on “bags” in which the Higgs vacuum expectation value is significantly modified or depleted. The minimal number $N$ above which such states appear strongly depends on the ratio of the Higgs mass to the masses of $W$, $Z$, $\overline{t}$, $t$: For a light Higgs mass, $m_H\sim 50\mathrm{GeV}$, bound states start from $N\sim O(10)$, but for a “realistic” Higgs mass, $m_H\sim 100\mathrm{GeV}$, one finds metastable/bound $W$, $Z$ bags only for $N\sim O(1000)$. We also found that in the latter case pure top bags disappear for all $N$, although top quarks can still be well bound to the $W$ bags. Anticipating the cosmological applications (discussed in the following Article [Phys. Rev. D 82, 073019]) of these bags as “doorway states” for baryosynthesis, we also consider here the existence of such metastable bags at finite temperatures, when standard-model parameters such as Higgs, gauge, and top masses are significantly modified.

We consider the effects of a fourth generation of chiral fermions within the MSSM (minimal supersymmetric standard model). Such a model offers the possibility of having the lightest neutral Higgs boson significantly heavier than in the three generation MSSM. The model is highly constrained by precision electroweak data, along with Higgs searches at the Tevatron. In addition, the requirements of perturbative unitarity and direct searches for heavy quarks imply that the four generation MSSM is only consistent for $\tan \beta \sim 1$ and highly tuned 4th generation fermion masses.

Recently we have presented an analysis of flavor changing neutral coupling mediated radiative top quark decays at next-to-leading order in QCD. In the present paper we provide the details of the calculation of QCD corrections to $t\to q\gamma$ and $t\to qZ$ decays within the effective theory approach including operator mixing. In particular, we calculate virtual matrix element corrections and the corresponding bremsstrahlung contributions. In the case of $t\to q\gamma$ we study the effects of kinematic cuts on the extracted branching ratios. Analytical formulas are given at all stages of the calculation. We find that the $t\to q\gamma$ decay can be used to probe also the effective operators mediating $t\to qg$ processes, since these can naturally contribute 10% or more to the radiative decay, given typical experimental cuts on the decay kinematics at hadron colliders. Conversely, we argue that any positive experimental signal of the $t\to qg$ process would indicate a natural lower bound on $t\to q\gamma$ decay rate.

We analyze the parallel hybrid texture structures in the charged lepton and the neutrino sector. These parallel hybrid texture structures have physical implications as they cannot be obtained from arbitrary lepton mass matrices through weak basis transformations. The total 60 parallel hybrid texture structures can be grouped into 12 classes, and all the hybrid textures in the same class have identical physical implications. We examine all 12 classes under the assumption of nonfactorizable phases in the neutrino mass matrix. Five out of the total 12 classes are found to be phenomenologically disallowed. We study the phenomenological implications of the allowed classes for 1–3 mixing angle, Majorana and Dirac-type $CP$ violating phases. Interesting constraints on effective Majorana mass are obtained for all the allowed classes.

We assume that the early universe is homogeneous, anisotropic, and is dominated by the mutually Bogomol’nyi-Prasad-Sommerfeld ${22}^{\prime }{55}^{\prime }$ intersecting branes of M theory. The spatial directions are all taken to be toroidal. Using analytical and numerical methods, we study the evolution of such an universe. We find that, asymptotically, three spatial directions expand to infinity and the remaining spatial directions reach stabilized values. Any stabilized values can be obtained by a fine-tuning of initial brane densities. We give a physical description of the stabilization mechanism. Also, from the perspective of four-dimensional spacetime, the effective four-dimensional Newton’s constant $G_4$ is now time varying. Its time dependence will follow from explicit solutions. We find in the present case that, asymptotically, $G_4$ exhibits characteristic log periodic oscillations.

Application of the AdS/CFT correspondence to the Randall-Sundrum models may predict that there is no static solution for black holes with a radius larger than the bulk curvature scale. When the black hole has an extremal horizon, however, the correspondence suggests that the black hole can stay static. We focus on the effects of cosmological constant on the brane on such extremal brane-localized black holes. We observe that the positive cosmological constant restricts the black hole size on the brane as in ordinary four-dimensional general relativity. The maximum black hole size differs from that in four-dimensional general relativity case due to the nonlinear term in the effective Einstein equation. In the negative cosmological constant case, we obtain an implication on the Newton constant in the Karch-Randall model.

Nonlocal field theories which arise from $p$-adic string theories have vacuum soliton solutions. We find the soliton solutions at finite temperature. These solutions become important for the partition function when the temperature exceeds $m_s/g_o^2$, where $m_s$ is the string mass scale and $g_o$ is the open string coupling.

We analyze the definition of quasilocal energy in general relativity based on a Hamiltonian analysis of the Einstein-Hilbert action initiated by Brown-York. The role of the constraint equations, in particular, the Hamiltonian constraint on the timelike boundary, neglected in previous studies, is emphasized here. We argue that a consistent definition of quasilocal energy in general relativity requires, at a minimum, a framework based on the (currently unknown) geometric well-posedness of the initial boundary value problem for the Einstein equations.

We analyze a scalar potential of the minimal supersymmetric standard model (MSSM) with neutrino mass operators along unbounded-from-below and color and/or charged breaking directions. We show necessary conditions to avoid the potential minima which can be deeper than the realistic vacuum. These conditions would constrain more strongly than conditions in the MSSM without taking into account neutrino mass operators and can improve the predictive power of supersymmetric models with neutrino mass operators.