Modern Physics Letters A

Events featuring high energy jets and a large amount of missing transverse energy constitute a key signature for a wide spectrum of new physics models. In this review, the results of two searches with such signatures are presented. The benefits of performing these searches in a model-independent way are discussed and data-driven techniques used to estimate Standard Model backgrounds are described in detail. These data-driven techniques will be an important part of searches for new physics at the LHC, especially in the early data-taking period.

Strong interactions are described by the Quantum Field Theory due to Heisenberg–Pauli. We postulate that the one particle physical states with appropriate quantum numbers (fermions and bosons) must be expressed by the normalized Fock space state vectors, which can conveniently be (and approximately) calculated in their rest frame, using Tamm–Dancoff variational method. Interactions between two physical particles can be analyzed by the same Hamiltonian as for each physical particle state, similar to analyzing nucleus–nucleus collisions. Our theories are free from any ultraviolet divergency. Our one physical particle state is similar to bound state in quantum mechanics.

Integration over connection type variables in the path integral for the discrete form of the first-order formulation of general relativity theory is studied. The result (a generalized function of the rest of variables of the type of tetrad or elementary areas) can be defined through its moments, i.e. integrals of it with the area tensor monomials. In our previous paper these moments have been defined by deforming integration contours in the complex plane as if we had passed to a Euclidean-like region. In this paper we define and evaluate the moments in the genuine Minkowski region. The distribution of interest resulting from these moments in this non-positively defined region contains the divergences. We prove that the latter contribute only to the singular (δ-function like) part of this distribution with support in the non-physical region of the complex plane of area tensors while in the physical region this distribution (usual function) confirms that defined in our previous paper which decays exponentially at large areas.

Besides that, we evaluate the basic integrals over which the integral over connections in the general path integral can be expanded.

Following Ref. 10, we explore the parameter space of the case when the supersymmetry (SUSY) breaking scale is lower, for example, in gauge mediated SUSY breaking model. During inflation, the form of the potential is V₀ plus MSSM (or A-term) inflation. We show that the model works for a wide range of the potential V₀ with the soft SUSY breaking mass m ~ O(1) TeV. The implication to MSSM (or A-term) inflation is that the flat directions which is lifted by the non-renormalizable terms described by the superpotential with p = 4 and p = 5 are also suitable to be an inflaton field for λ_p = O(1) provided there is an additional false vacuum term V₀ with appropriate magnitude. The flat directions correspond to p = 6 also works for .

According to a usual reading, decoherence is a process resulting from the interaction between a small system and its large environment where information and energy are dissipated. The particular models treated in the literature on the subject reinforce this idea since, in general, the behavior of a particle immersed in a large "bath" composed by many particles is studied. The aim of this letter is to warn against this usual simplified reading. By means of the analysis of a well-known model, we will show that decoherence may occur in a system interacting with an environment consisting of only one particle.

In this paper, the holographic dark energy in Brans–Dicke theory is confronted by cosmic observations from SN Ia, BAO, OHD and CMB via Markov-Chain Monte-Carlo (MCMC) method. The best fit parameters are found in 1σ region: and (equivalently ω = 2415.653 which is less than the solar system bound and consistent with other constraint results). With these best fit values of the parameters, it is found that the universe is undergoing accelerated expansion, and the current value of equation of state of holographic dark energy which is phantom like in Brans–Dicke theory. The effective Newton's constant decreases with the expansion of our universe for the negative value of model parameter α.

Considering plane gravitational waves propagating through flat spacetime, it is shown that curvatures experienced both in the starting point and during their arrival at the earth can cause a considerable shift in the frequencies as measured by earth and space-based detectors. In particular for the case of resonant bar detectors this shift can cause noise-filters to smother the signal.