We examine indirect signals produced by neutralino self-annihilations, in the galactic halo or inside celestial bodies, in the frame of an effective minimal supersymmetric standard model without gaugino-mass unification at a grand unification scale. We compare our theoretical predictions with current experimental data of gamma rays and antiprotons in space and of upgoing muons at neutrino telescopes. Results are presented for a wide range of the neutralino mass, although our discussions are focused on light neutralinos. We find that only the antiproton signal is potentially able to set constraints on very low-mass neutralinos, below 20 GeV. The gamma-ray signal, both from the galactic center and from high galactic latitudes, requires significantly steep profiles or substantial clumpiness in order to reach detectable levels. The upgoing muon signal is largely below experimental sensitivities for the neutrino flux coming from the Sun; for the flux from the Earth an improvement of about one order of magnitude in experimental sensitivities (with a low energy threshold) can make accessible neutralino masses close to O, Si and Mg nuclei masses, for which resonant capture is operative.

We study finite volume effects in heavy quark systems in the framework of heavy meson chiral perturbation theory for full, quenched, and partially quenched QCD. A novel feature of this investigation is the role played by the scales ${\Delta }_{*}$ and ${\delta }_s,$ where ${\Delta }_{*}$ is the mass difference between the heavy-light vector and pseudoscalar mesons of the same quark content, and ${\delta }_s$ is the mass difference due to light flavor $\mathrm{SU}\left(3\right)\mathrm{}$ breaking. The primary conclusion of this work is that finite volume effects arising from the propagation of Goldstone particles in the effective theory can be altered by the presence of these scales. Since ${\Delta }_{*}$ varies significantly with the heavy quark mass, these volume effects can be amplified in both heavy and light quark mass extrapolations (interpolations). As an explicit example, we present results for B parameters of neutral B meson mixing matrix elements and heavy-light decay constants to one-loop order in finite volume heavy meson chiral perturbation theory for full, quenched, and $N_f=2+1\mathrm{}$ partially quenched QCD. Our calculation shows that for high-precision determinations of the phenomenologically interesting $\mathrm{SU}\left(3\right)\mathrm{}$ breaking ratios, finite volume effects are significant in quenched and not negligible in partially quenched QCD, although they are generally small in full QCD.

We investigate four-body states with only charm quarks. Working in a large but finite oscillator basis, we present a net binding analysis to determine if the resulting states are stable against breakup into a pair of $c\overline{c}$ mesons. We find several close-lying bound states in the two models we examine.

We consider 3 types of processes pertinent to the phenomenology of an H dibaryon: conversion of two Λ’s in a doubly strange hypernucleus to an H, decay of the H to two baryons, and—if the H is light enough—conversion of two nucleons in a nucleus to an H. We compute the spatial wave function overlap using the Isgur-Karl, Miller-Spencer and Bethe-Goldstone wave functions, and treat the weak interactions phenomenologically. The observation of $\Lambda$ decays from doubly strange hypernuclei puts a constraint on the H wave function which is plausibly satisfied. Imposing this constraint, we obtain model-independent lower limits on the H lifetime; if $m_H<m_N{+m}_{\Lambda },$ the H lifetime can be of the order of or longer than the age of the Universe. We discuss limits on a long-lived or stable H, and point out how experiments can improve the constraints.

Dihadron fragmentation functions and their evolution are studied in the process of $e^{+}{e}^{-}$ annihilation. Under the collinear factorization approximation and facilitated by the cut-vertex technique, the two hadron inclusive cross section at leading order is shown to factorize into a short distance parton cross section and a long distance dihadron fragmentation function. We provide the definition of such a dihadron fragmentation function in terms of parton matrix elements and derive its Dokshitzer-Gribov-Lipatov-Altarelli-Parisi evolution equation at leading log. The evolution equation for the nonsinglet quark fragmentation function is solved numerically with a simple ansatz for the initial condition and results are presented for cases of physical interest.

We consider an extended Nambu–Jona-Lasinio model including both $\left(q\overline{q}\right)$ and (qq) interactions with two light-quark flavors in the presence of a single (quark density) chemical potential. In the color superconducting phase of the quark matter the color ${\mathrm{SU}}_c\mathrm{}\left(3\right)\mathrm{}$ symmetry is spontaneously broken down to ${\mathrm{SU}}_c\mathrm{}\left(2\right).$ If the usual counting of Goldstone bosons would apply, five Nambu-Goldstone (NG) bosons corresponding to the five broken color generators should appear in the mass spectrum. Unlike that expectation, we find only three gapless diquark excitations of quark matter. One of them is an ${\mathrm{SU}}_c\mathrm{}\left(2\right)\mathrm{}$ singlet; the remaining two form an ${\mathrm{SU}}_c\mathrm{}\left(2\right)\mathrm{}$ (anti)doublet and have a quadratic dispersion law in the small momentum limit. These results are in agreement with the Nielsen-Chadha theorem, according to which NG bosons in Lorentz-noninvariant systems, having a quadratic dispersion law, must be counted differently. The origin of the abnormal number of NG bosons is shown to be related to a nonvanishing expectation value of the color charge operator $Q_8$ reflecting the lack of color neutrality of the ground state. Finally, by requiring color neutrality, two massive diquarks are argued to become massless, resulting in a normal number of five NG bosons with the usual linear dispersion laws.

We calculate the amplitudes and the cross sections of the charm dissociation processes $J/\psi +\overrightarrow{\pi }D\overline{D}{,D}^{*}\overline{D}(\overline{D^{*}}{D),D}^{*}\overline{D^{*}}$ within a relativistic constituent quark model. We consistently account for the contributions coming from both the box and triangle diagrams that contribute to the dissociation processes. The cross section is dominated by the $D^{*}\overline{D}$ and $D^{*}\overline{D^{*}}$ channels. When summing up the four channels we find a maximum total cross section of about 2.3 mb at $\sqrt{s}\approx 4.1\mathrm{GeV}.$ We compare our results to the results of other model calculations.

A charged lepton contribution to the solar neutrino mixing induces a contribution to ${\theta }_{13},$ barring cancellations or correlations, which is independent of the model building options in the neutrino sector. We illustrate two robust arguments for that contribution to be within the expected sensitivity of high intensity neutrino beam experiments. We find that the case in which the neutrino sector gives rise to a maximal solar angle (the natural situation if the hierarchy is inverse) leads to a ${\theta }_{13}$ close to or exceeding the experimental bound depending on the precise values of ${\theta }_{12},$ ${\theta }_{23},$ an unknown phase and possible additional contributions. We finally discuss the possibility that the solar angle originates predominantly in the charged lepton sector. We find that the construction of a model of this sort is more complicated. We comment on a recent example of natural model of this type.

The phenomenology of the little-flavon model is discussed. Flavor changing neutral current and lepto-quark compositeness set the most stringent bounds to the lowest possible value for the scale at which the flavons arise as pseudo-Goldstone bosons.

Using events in which one of two neutral B mesons from the decay of an ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}$ resonance is fully reconstructed, we set limits on the difference between the decay rates of the two neutral B mass eigenstates and on CP, T, and CPT violation in $B^0{B}^0$ mixing. The reconstructed decays, comprising both CP and flavor eigenstates, are obtained from 88 million ${\rm Y}\mathrm{}\left(4S\right)\mathrm{}\to B\overline{B}$ decays collected with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC. We determine six independent parameters governing oscillations $(\Delta m,\Delta \Gamma /\Gamma ),$ CPT and CP violation $(\mathrm{Re}\mathsf{z},\mathrm{Im}\mathsf{z}),$ and CP and T violation $(\mathrm{Im}{\lambda }_{\mathrm{CP}},|q/p|),$ where ${\lambda }_{\mathrm{CP}}$ characterizes $B^0$ and $B^0$ decays to states of charmonium plus $K_S^0$ or $K_L^0.$ The results are $\mathrm{sgn}\left(\mathrm{Re}{\lambda }_{\mathrm{CP}}\right)\Delta \Gamma /\Gamma =-0.008\pm 0.037(\mathrm{stat}.\mathrm{})\pm 0.018(\mathrm{syst}.\mathrm{})[-0.084,0.068],$$|q/p|=1.029\mathrm{}\pm 0.013(\mathrm{stat}.\mathrm{})\pm 0.011(\mathrm{syst}.\mathrm{})[1.001,1.057],$$(\mathrm{Re}{\lambda }_{\mathrm{CP}}/|{\lambda }_{\mathrm{CP}}|)\mathrm{Re}\mathrm{z}=0.014\mathrm{}\pm 0.035(\mathrm{stat}.\mathrm{})\pm 0.034(\mathrm{syst}.\mathrm{})[-0.072,0.101],$$\mathrm{Im}\mathrm{z}=0.038\mathrm{}\pm 0.029(\mathrm{stat}.\mathrm{})\pm 0.025(\mathrm{syst}.\mathrm{})[-0.028,0.104].$The values inside square brackets indicate the 90% confidence-level intervals. The values of $\mathrm{Im}{\lambda }_{\mathrm{CP}}$ and $\Delta m$ are consistent with previous analyses and are used as cross checks. These measurements are in agreement with standard model expectations.

The nonperturbative behavior of strings in type IIA pp wave backgrounds with a compact lightlike direction is investigated using matrix string theory. At small string coupling, $g_s\ll 1,$ the behavior is determined by the combination ${\mathrm{Mg}}_s$ where M is a dimensionless parameter proportional to the strength of the Ramond-Ramond background. For ${\mathrm{Mg}}_s\ll 1,$ the matrix string theory is conventional; only the degrees of freedom in the Cartan subalgebra contribute, and the theory reduces to copies of the perturbative string. For ${\mathrm{Mg}}_s\gg 1,$ the theory admits degenerate vacua representing fundamental strings blown up into fuzzy spheres with nonzero light-cone momenta. We determine the spectrum of small fluctuations around these vacua. Around such a vacuum all $N^2$ degrees of freedom are excited with comparable energies. The spectrum of masses has a spacing that is independent of the radius of the fuzzy sphere, in agreement with the expected behavior of continuum giant gravitons. For “reducible” vacua we find that the momenta of fluctuations are generically irrational multiples of the inverse radius of the compact direction, showing that these blown up strings never close.

We consider a massive scalar field theory in anti–de Sitter space, in both minimally and non-minimally coupled cases. We introduce a relevant double-trace perturbation at the boundary, by carefully identifying the correct source and generating functional for the corresponding conformal operator. We show that such a relevant double-trace perturbation introduces changes in the coefficients in the boundary terms of the action, which in turn govern the existence of a bound state in the bulk. For instance, we show that the usual action, containing no additional boundary terms, gives rise to a bound state, which can be avoided only through the addition of a proper boundary term. Another notorious example is that of a conformally coupled scalar field, supplemented by a Gibbons-Hawking term, for which there is no associated bound state. In general, in both minimally and non-minimally coupled cases, we explicitly compute which boundary terms give rise to a bound state, and which ones do not. In the non-minimally coupled case, and when the action is supplemented by a Gibbons-Hawking term, this also fixes the allowed values of the coupling coefficient to the metric. We interpret our results to indicate that the requirement to satisfy the Breitenlohner-Freedman bound does not suffice to prevent tachyonic behavior from existing in the bulk, as it must be supplemented by additional conditions on the coefficients in the boundary terms of the action.

We continue with the program of paper I [Phys. Rev. D 70, 025009 (2004)] to implement open-closed string duality on free gauge field theory (in the large-N limit). In this paper we consider correlators such as $〈{\prod }_{i=1\mathrm{}}^n\mathrm{Tr}{\Phi }^{J_i}{(x}_i)〉.$ The Schwinger parametrization of this n-point function exhibits a partial gluing up into a set of basic skeleton graphs. We argue that the moduli space of the planar skeleton graphs is exactly the same as the moduli space of genus zero Riemann surfaces with n holes. In other words, we can explicitly rewrite the n-point (planar) free-field correlator as an integral over the moduli space of a sphere with n holes. A preliminary study of the integrand also indicates compatibility with a string theory on AdS space. The details of our argument are quite insensitive to the specific form of the operators and generalize to diagrams of a higher genus as well. We take this as evidence of the field theory’s ability to reorganize itself into a string theory.

Free $\mathcal{N}=4\mathrm{}$ super Yang-Mills theory (in the large-N limit) is dual to an, as yet, intractable closed string theory on ${\mathrm{AdS}}_5\times {\mathrm{S}}^5.$ We aim to implement open-closed string duality in this system and thereby recast the free-field correlation functions as amplitudes in AdS space. The basic strategy is to implement this duality directly on planar field theory correlation functions in the worldline (or first quantized) formulation. The worldline loops (remnants of the worldsheet holes) close to form tree diagrams. These tree diagrams are then to be manifested as tree amplitudes in AdS space by a change of variables on the worldline moduli space (i.e., Schwinger parameter space). Restricting to twist-2 operators, we are able to carry through this program for two- and three-point functions. However, it appears that this strategy can be implemented for four- and higher-point functions as well. An analogy to electrical networks is very useful in this regard.

We compute the supergravity loop contributions to the visible sector scalar masses in the simplest five-dimensional (5D) “brane-world” model. Supersymmetry is assumed to be broken away from the visible brane and the contributions are UV finite due to 5D locality. We perform the calculation with $\mathcal{N}=1\mathrm{}$ supergraphs, using a formulation of 5D supergravity in terms of $\mathcal{N}=1\mathrm{}$ superfields. We compute contributions to the 4D effective action that determine the visible scalar masses, and we find that the mass-squared terms are negative.

We establish that the Einstein tensor takes on a highly symmetric form near the Killing horizon of any stationary but nonstatic (and nonextremal) black hole spacetime. [This follows up on a recent article by the current authors (gr-qc/0402069), which considered static black holes.] Specifically, at any such Killing horizon—irrespective of the horizon geometry—the Einstein tensor block-diagonalizes into “transverse” and “parallel” blocks, and its transverse components are proportional to the transverse metric. Our findings are supported by two independent procedures, one based on the regularity of the on-horizon geometry and another that directly utilizes the elegant nature of a bifurcate Killing horizon. It is then argued that geometrical symmetries will severely constrain the matter near any Killing horizon. We also speculate on how this may be relevant to certain calculations of the black hole entropy.

The LISA time-delay-interferometry responses to a gravitational wave signal are rewritten in a form that accounts for the motion of the LISA constellation around the Sun; the responses are given in closed analytic forms valid for any frequency in the band accessible to LISA. We then present a complete procedure, based on the principle of maximum likelihood, to search for stellar-mass binary systems in the LISA data. We define the required optimal filters, the amplitude-maximized detection statistic (analogous to the $\mathcal{F}$ statistic used in pulsar searches with ground-based interferometers), and discuss the false-alarm and detection probabilities. We then test the procedure in numerical simulations of gravitational-wave detection.

A Dalitz-plot analysis of $B_d^0\mathrm{}\left(t\right)\mathrm{}\to \rho \overrightarrow{\pi }{\pi }^{+}{\pi }^{-}{\pi }^0$ decays allows one to obtain the CP-violating phase $\alpha .$ In addition, one can extract the various tree (T) and penguin (P) amplitudes contributing to these decays. By comparing the measured value of $|P/T|$ with the theoretical prediction, one can detect the presence of physics beyond the standard model.

The mechanism of electroweak symmetry breaking in little Higgs models is analyzed in an effective field theory approach. This enables us to identify observable effects irrespective of the specific structure and content of the heavy degrees of freedom. We parametrize these effects in a common operator basis and present the complete set of anomalous contributions to gauge boson, Higgs boson, and fermion couplings. If the hypercharge assignments of the model retain their standard form, electroweak precision data are affected only via the S and T parameters and by contact interactions. As a proof of principle, we apply this formalism to the minimal model and consider the current constraints on the parameter space. Finally, we show how the interplay of measurements at the CERN LHC and a linear collider could reveal the structure of these models.

Using $\gamma \gamma J/\psi ,J/\overrightarrow{\psi }{e}^{+}{e}^{-}$ and ${\mu }^{+}{\mu }^{-}$ events from a sample of $14.0\times {10}^6$ $\psi \mathrm{}\left(2S\right)\mathrm{}$ decays collected with the BESII detector, the branching fractions for $\psi \mathrm{}\left(2S\right)\mathrm{}\to {\pi }^{0}J/\psi ,$ $\eta J/\psi ,$ and $\psi \mathrm{}\left(2S\right)\mathrm{}\to \gamma {\chi }_{c1\mathrm{}},\gamma {\chi }_{c2\mathrm{}}\to \gamma \gamma J/\psi$ are measured to be $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to {\pi }^{0}J/\psi ]=(1.43\mathrm{}\pm 0.14\pm 0.12)\times {10}^{-3},$ $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \eta J/\psi ]=(2.98\mathrm{}\pm 0.09\pm 0.23)\%,$ $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \gamma {\chi }_{c1\mathrm{}}\to \gamma \gamma J/\psi ]=(2.81\mathrm{}\pm 0.05\pm 0.23)\%,$ and $B\left[\psi \mathrm{}\right(2S)\mathrm{}\to \gamma {\chi }_{c2\mathrm{}}\to \gamma \gamma J/\psi ]=(1.62\mathrm{}\pm 0.04\pm 0.12)\%.$