International Journal of Modern Physics A

An updated technical and methodological comparison of liquid noble gas experiments is presented with particular attention to the low energy physics application of double-phase noble gas detectors in direct Dark Matter investigations.

In many high energy experiments, the physics quantities are obtained by measuring the cross-sections at a few energy points over an energy region. This was referred to as scan experiment. The optimal design of the scan experiment (how many energy points, what the energies are, and what is the luminosity at each energy point) is of great significance both for scientific research and from economical viewpoint. Two approaches, one has recourse to the sampling technique and the other resorts to the analytical proof, are adopted to figure out the optimized scan scheme for the relevant parameters. The final results indicate that for $n$ parameters scan experiment, $n$ energy points are necessary and sufficient for optimal determination of these $n$ parameters; each optimal position can be acquired by single parameter scan (sampling method), or by analysis of auxiliary function (analytic method); the luminosity allocation among the points can be determined analytically with respect to the relative importance between parameters. By virtue of the second optimization theory established in this paper, it is feasible to accommodate the perfectly optimal scheme for any scan experiment.

A thick de Sitter brane constructed by a canonical or phantom scalar field and localization mass spectra of the bulk scalar and vector fields on the de Sitter brane is investigated. It is found that the scalar and vector zero modes are always localized on the de Sitter brane. For the de Sitter brane generated by a canonical scalar field, the spectrum of the scalar (vector) KK modes consists of one or two bound modes (one bound mode) and a set of continuous modes. However, for the de Sitter brane generated by a phantom scalar field, the spectrum of the scalar (vector) KK modes consists of two (one) or more bound KK modes as well as a set of continuous modes. The continuous spectrum on both branes starts with a same value for the scalar (vector) KK modes.

In two-Higgs-doublet models with exact $Z_2$ symmetry, putting $m_h\simeq 125\mathrm{\text{GeV}}$ at the alignment limit, the following limits on the heavy scalar masses are obtained from the conditions of unitarity and stability of the scalar potential: $m_H$, $m_A$, $m_{H^{+}}<1\mathrm{\text{TeV}}$ and $1/8<tan\beta <8$. The constraints from $b\to s\gamma$ and neutral meson mass differences, when superimposed on the unitarity constraints, put a tighter lower limit on $tan\beta$ depending on $m_{H^{+}}$. It has also been shown that larger values of $tan\beta$ can be allowed by introducing soft breaking term in the potential at the expense of a correlation between $m_H$ and the soft breaking parameter.

We study the associated Higgs production with $Z$ boson at future linear colliders in the framework of the minimal noncommutative standard model. Using the Seiberg–Witten map, we calculate the production cross-section considering all orders of the noncommutative parameter ${\Theta }_{\mu \nu }$. We consider the effect of earth’s rotation on the orientation of ${\Theta }_{\mu \nu }$ with respect to the laboratory frame and thus on the total cross-section, its azimuthal distribution and rapidity distribution for the machine energy ranging from 0.5 TeV to 3 TeV corresponding to the noncommutative scale $\Lambda \ge 0.5\mathrm{\text{TeV}}$.

In this paper, we expose some surprising connections between string theory and statistical inference. We consider a large collective of agents sweeping out a family of nearby statistical models for an $M$-dimensional manifold of statistical fitting parameters. When the agents making nearby inferences align along a $d$-dimensional grid, we find that the pooled probability that the collective reaches a correct inference is the partition function of a nonlinear sigma model in $d$ dimensions. Stability under perturbations to the original inference scheme requires the agents of the collective to distribute along two dimensions. Conformal invariance of the sigma model corresponds to the condition of a stable inference scheme, directly leading to the Einstein field equations for classical gravity. By summing over all possible arrangements of the agents in the collective, we reach a string theory. We also use this perspective to quantify how much an observer can hope to learn about the internal geometry of a superstring compactification. Finally, we present some brief speculative remarks on applications to the AdS/CFT correspondence and Lorentzian signature space–times.

In the extended Nambu–Jona-Lasinio model the decay widths $\tau \to \rho (770)({\rho }^{\prime }(1450)){\nu }_{\tau }$ and $\tau \to K^{\ast }(892)(K^{\ast \prime }(1410)){\nu }_{\tau }$ are studied in the quark one-loop approximation. Our estimations of the decay widths $\tau \to K^{\ast }(892)(K^{\ast \prime }(1410)){\nu }_{\tau }$ are in satisfactory agreement with experimental data. In the paper, the decay widths $\tau \to \rho (770)({\rho }^{\prime }(1450)){\nu }_{\tau }$ are also calculated.

IceCube collaboration has published two papers on ultrahigh energy neutrinos observation, recently. They have used the data collected in two years in their first publication, which reveals observation of 2 PeV energy neutrino events. The second publication of the collaboration including more data has also confirmed main features of the former paper. In literature, various interpretations of the IceCube data have been proposed. In this study, it is shown that PeV energy neutrino events observed by the IceCube collaboration can be interpreted as resonance production of color octet neutrinos with masses in 500–800 GeV range.

This paper starts a systematic description of colored knot polynomials, beginning from the first non-(anti)symmetric representation $R=[2,1]$. The project involves several steps:

• ⁽ⁱ⁾parametrization of big families of knots á la [A. Mironov and A. Morozov, arXiv:1506.00339],
• ⁽ⁱⁱ⁾evaluating Racah/mixing matrices for various numbers of strands in various representations á la [A. Mironov, A. Morozov and An. Morozov, J. High Energy Phys. 03, 034 (2012), arXiv:1112.2654],
• ⁽ⁱⁱⁱ⁾tabulating and collecting the results at http://www.knotebook.org.

In this paper, we discuss only the representation $R=[2,1]$ and construct all necessary ingredients that allow one to evaluate knot/links represented by three-strand closed parallel braids with inserted double-fat fingers. In particular, it is used to evaluate knots from a 7-parametric family. This family contains over 80% of knots with up to 10 intersections, but does not include mutants.

In this paper, we examine the behavior of correlation functions for a massless scalar field in de Sitter space with a quartic interaction. We find that two-loop corrections are relevant, and the resummation of these corrections generates a complicated structure whereby high momentum modes stay massless while low momentum modes develop a dynamical mass.