International Journal of Modern Physics A

We review the color glass condensate effective theory, that describes the gluon content of a high energy hadron or nucleus, in the saturation regime. The emphasis is put on applications to high energy heavy ion collisions. After describing initial state factorization, we discuss the glasma phase, that precedes the formation of an equilibrated quark–gluon plasma. We end this review with a presentation of recent developments in the study of the isotropization and thermalization of the quark–gluon plasma.

The August 2011 Higgs mass prediction was based on an ongoing six-year project studying M-theory compactified on a manifold of G₂ holonomy, with significant contributions from Jing Shao, Eric Kuflik and others and particularly co-led by Bobby Acharya and Piyush Kumar. The M-theory results include stabilization of all moduli in a de Sitter vacuum, gauge coupling unification, derivation of TeV scale physics (solving the hierarchy problem), the derivation that generically scalar masses are equal to the gravitino mass which is larger than about 30 TeV, derivation of the Higgs mechanism via radiative electroweak symmetry breaking, absence of the flavor and CP problems, and the accommodation of string axions. The tanβ and the μ parameter are part of the theory and are approximately calculated; as a result, the little hierarchy problem is greatly reduced. The heavy scalars imply that decoupling rare decays such as B_s →μ⁺ μ^- should not deviate from their Standard Model values. This paper summarizes the results relevant to the Higgs mass prediction. A recent review [Int. J. Mod. Phys. A27, 1230012 (2012)] describes the program more broadly. Some of the results such as the scalar masses being equal to the gravitino mass and larger than about 30 TeV, derived early in the program, hold generically for compactified string theories as well as for compactified M-theory, while some other results may or may not. If the world is described by M-theory compactified on a G₂ manifold and has a Higgs mechanism (so it could be our world) then M_h was predicted to be 126±2 GeV before the measurement. The derivation has some assumptions not related to the Higgs mass, but involves no free parameters.

We investigate the effects of light-cone fluctuations over the renormalized vacuum expectation value of the stress–energy tensor of a real massless minimally coupled scalar field defined in a (d+1)-dimensional flat space–time with topology . For modeling the influence of light-cone fluctuations over the quantum field, we consider a random Klein–Gordon equation. We study the case of centered Gaussian processes. After taking into account all the realizations of the random processes, we present the correction caused by random fluctuations. The averaged renormalized vacuum expectation value of the stress–energy associated with the scalar field is presented.

In this paper, the hadronic decay has been analyzed in naive and QCD factorization methods. The simplest approach to obtain the amplitude of the hadronic B decays is naive factorization, where the matrix elements have been parametrized into products of decay constant and form factors. We have calculated the factorizable amplitudes and nonfactorizable contributions corresponding to the vertex corrections and the hard spectator interactions in QCD factorization. We treat the charm quark as light, compared to the large scale provided by the mass of the decaying b quark (m_c ≪m_b and m_c fixed as m_b→∞). Our obtained branching ratio of is (1.36±0.02)×10^-5 using naive factorization, which is smaller than the experimental data: (1.2±0.4)×10^-4. On the other hand, by considering QCD corrections in QCDF and by treating D-meson as a light, we have obtained the value (2.57±0.01)×10^-5, which has been used to decrease the discrepancy between the theoretical and experimental data.

We consider a local action with both the real scalar field and its dual in two Euclidean dimensions. The role of singular line discontinuities is emphasized. Exotic properties of the correlation of the field with its dual, the generation of spin from scalar fields, and quantization of dual charges are pointed out. Wick's theorem and rotation properties of fermions are recovered for half-integer quantization.

We study the 126 GeV Higgs boson pair production through e⁺e^- collision in the noncommutative extension of the standard model using the Seiberg–Witten map of this to the first order of the noncommutative parameter Θ_μν. The process is forbidden in the standard model at the tree level. We study the time-averaged cross-section of the pair production at TeV scale linear collider and investigate the sensitivity of the cross-section on the orientation angle η and the noncommutative scale Λ. We found that Λ lies in the range 0.5 TeV–1.0 TeV, which can be reached by the upcoming linear collider.

We present a global analysis of latest solar and reactor neutrino data in the three-neutrino mixing scheme by using both the simple grid scanning and the Markov Chain Monte Carlo (MCMC) sampling methods. Accuracy and efficiency of the two sampling methods are compared and advantages of the latter are discussed. The fitting results of three oscillation parameters θ₁₂, θ₁₃ and are provided with both old and new evaluations of the reactor antineutrino flux. Possible correlation between the fitting parameters is also discussed.