Parity violation in pre-inflationary bounce

The power suppression on large scale in the CMB TT-mode power spectrum might imply the occurrence of a pre-inflationary bounce. We calculate the circularly polarized gravitational wave, leaded by the gravitational Chern–Simons term universally appearing in particle physics and string theory, in the inflation model with the pre-inflationary bounce. The circularly polarized gravitational wave will induce TB- and EB-mode correlations at CMB last scatting surface. We find that if the pre-inflationary bounce actually occurs, the TB- and EB-mode correlations on large scale will be enhanced, while the BB-mode correlation on corresponding scales is suppressed

Estimating the mass of the hidden charm 1+(1+) tetraquark state via QCD sum rules

By using QCD sum rules, the mass of the hidden charm tetraquark [cu][c¯d¯] state with IG(JP)=1+(1+) (HCTV) is estimated, which presumably will turn out to be the newly observed charmonium-like resonance Zc+(3900) . In the calculation, contributions up to dimension eight in the operator product expansion (OPE) are taken into account. We find m1+c=(3912-153+306)MeV , which is consistent, within the errors, with the experimental observation of Zc+(3900) . Extending to the b-quark sector, m1+b=(10561-163+395)MeV is obtained. The calculational result strongly supports the tetraquark picture for the “exotic” states of Zc+(3900) and Zb+(10610)

CMB anomalies from an inflationary model in string theory

Recent Planck measurements show some CMB anomalies on large angular scales, which confirms the early observations by WMAP. We show that an inflationary model, in which before the slow-roll inflation the Universe is in a superinflationary phase, can generate a large-scale cutoff in the primordial power spectrum, which may account for not only the power suppression on large angular scales, but also a large dipole power asymmetry in the CMB. We discuss an implementation of our model in string theory

Deformation relaxation in heavy-ion collisions

In deeply inelastic heavy-ion collisions, the quadrupole deformations of both fragments are taken as stochastic independent dynamical variables governed by the Fokker–Planck equation (FPE) under the corresponding driving potential. The mean values, variances and covariance of the fragments are analytically expressed by solving the FPE in head on collisions. The characteristics and mechanism of the deformation are discussed. It is found that both the internal structures and interactions of the colliding partners are critical for the deformation relaxation in deeply inelastic collisions

Leptonic CP violation and Wolfenstein parametrization for lepton mixing

We investigate a general structure of lepton mixing matrix resulting from the <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi mathvariant="normal">SU</mi></mrow><mrow><mi>F</mi></mrow></msub><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></math> gauge family model with an appropriate vacuum structure of <math altimg="si1.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi mathvariant="normal">SU</mi></mrow><mrow><mi>F</mi></mrow></msub><mo stretchy="false">(</mo><mn>3</mn><mo stretchy="false">)</mo></math> symmetry breaking. It is shown that the lepton mixing matrix can be parametrized by using the Wolfenstein parametrization method to characterize its deviation from the tri-bimaximal mixing. A general analysis for the allowed leptonic CP-violating phase <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>δ</mi></mrow><mrow><mi>e</mi></mrow></msub></math> and the leptonic Wolfenstein parameters <math altimg="si3.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>λ</mi></mrow><mrow><mi>e</mi></mrow></msub></math> , <math altimg="si4.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>A</mi></mrow><mrow><mi>e</mi></mrow></msub></math> , <math altimg="si5.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>ρ</mi></mrow><mrow><mi>e</mi></mrow></msub></math> is carried out based on the observed lepton mixing angles. We demonstrate how the leptonic CP violation correlates to the leptonic Wolfenstein parameters. It is found that the phase <math altimg="si2.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>δ</mi></mrow><mrow><mi>e</mi></mrow></msub></math> is strongly constrained and only a large or nearly maximal leptonic CP-violating phase <math altimg="si6.gif" xmlns="http://www.w3.org/1998/Math/MathML"><mo stretchy="false">|</mo><msub><mrow><mi>δ</mi></mrow><mrow><mi>e</mi></mrow></msub><mo stretchy="false">|</mo><mo>≃</mo><mn>3</mn><mi>π</mi><mo stretchy="false">/</mo><mn>4</mn><mo>∼</mo><mi>π</mi><mo stretchy="false">/</mo><mn>2</mn></math> is favorable when <math altimg="si7.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>λ</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>&gt;</mo><mn>0.15</mn></math> . In particular, when taking <math altimg="si3.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>λ</mi></mrow><mrow><mi>e</mi></mrow></msub></math> to be the Cabibbo angle <math altimg="si8.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>λ</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>≃</mo><mi>λ</mi><mo>≃</mo><mn>0.225</mn></math> , a sensible result for leptonic Wolfenstein parameters and CP violation is obtained with <math altimg="si9.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>A</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>=</mo><mn>1.40</mn></math> , <math altimg="si10.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>ρ</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>=</mo><mn>0.20</mn></math> , <math altimg="si11.gif" xmlns="http://www.w3.org/1998/Math/MathML"><msub><mrow><mi>δ</mi></mrow><mrow><mi>e</mi></mrow></msub><mo>∼</mo><mn>101.76</mn><mi mathvariant="normal">°</mi></math> , which is compatible with the one in quark sector. An interesting correlation between leptons and quarks is observed, which indicates a possible common origin of masses and mixing for the charged leptons and quarks

Hadronic b ′ search at the LHC with top and W taggers

We study the sensitivity of a down type quark b ′ via process pp → b ′ b ¯ ′ $$b^{\prime}\overline{b}^{\prime }$$ → t W − t ¯ W + $$t{W}^{-\overline{t}W+}$$ using jet substructure methods at the LHC with the collision energy s $$\sqrt{s}$$ = 14 TeV. We consider the case that the b ′ is heavy (say from 800 GeV to 1500 GeV) and concentrate on the feasibility of the full hadronic mode. Both top tagger (the HEP top tagger) and W tagger (the CMS W-tagging) are used to reconstruct all objects in the final states. In order to suppress huge SM background events and take into account various cases with different number of boosted objects, we propose a comprehensive reconstruction procedure so as to extract the most crucial observables of the signal events. When b ′ mass is 1 TeV, it is found that with a 200 fb −1 dataset, the LHC may be able to detect the b ′ with a significance up to 10 or better. With a 3000 f b −1 dataset, the LHC may be able to probe the b ′ with a mass around up to 2 TeV, only by using the hadronic mode

Curvaton with nonminimal derivative coupling to gravity

We show a curvaton model, in which the curvaton has a nonminimal derivative coupling to gravity. Thanks to such a coupling, we find that the scale-invariance of the perturbations can be achieved for arbitrary values of the equation-of-state of background, provided that it is nearly a constant. We also discussed about tensor perturbations, the local non-Gaussianities generated by the nonminimal derivative coupling curvaton model, as well as the adiabatic perturbations which are transferred from the field perturbations during the curvaton decay

Holographic fermionic system with dipole coupling on Q-lattice

We construct a holographic model for a fermionic system on Q-lattice and compute the spectral function in the presence of a dipole coupling. Both key features of doped Mott insulators, the dynamical generation of a gap and spectral weight transfer, are observed when adjusting the value of the coupling parameter p . Of particular interest is that when the background is in a deep insulating phase, the Mott gap opens much easier with a smaller coupling parameter in comparison with a metallic background. The effects of lattice parameters on the width of the gap Δ /μ are studied and a turning point is observed near the critical regime of metal-insulator transitions of the background. Furthermore, the temperature dependence of the spectral function is studied. Finally, we also observe that the anisotropic Q-lattice generates anisotropic peaks with different magnitudes, indicating that insulating and metallic phases arise in different directions

A unified description for dipoles of the fine-structure constant and SnIa Hubble diagram in Finslerian universe

We propose a Finsler spacetime scenario of the anisotropic universe. The Finslerian universe requires both the fine-structure constant and the accelerating cosmic expansion to have a dipole structure and the directions of these two dipoles to be the same. Our numerical results show that the dipole direction of the SnIa Hubble diagram locates at (l,b)=(314.6∘±20.3∘,-11.5∘±12.1∘) with magnitude B=(-3.60±1.66)×10-2 . The dipole direction of the fine-structure constant locates at (l,b)=(333.2∘±8.8∘,-12.7∘±6.3∘) with magnitude B=(0.97±0.21)×10-5 . The angular separation between the two dipole directions is about 18.2∘

Cosmology of the spinor emergent universe and scale-invariant perturbations

A nonsingular emergent universe cosmology can be realized by a nonconventional spinor field as first developed in [1] . We study the mechanisms of generating scale-invariant primordial power spectrum of curvature perturbation in the frame of spinor emergent universe cosmology. Particularly, we introduce a light scalar field of which the kinetic term couples to the bilinear of the spinor field. This kinetic coupling can give rise to an effective “Hubble radius” for primordial fluctuations which allows the scalar field to become squeezed at large length scales and to form a nearly scale-invariant power spectrum. We study the stability of the backreaction and constrain the forms of the coupling terms. Through a generalized curvaton mechanism, these almost scale-independent fluctuations are able to be transferred into curvature perturbation after the epoch of emergence and can thus explain cosmological observations