56138229
Gauge CP symmetry, wormhole effects, and strong CP problem
The recent observation of four dimensional CP as a discrete gauge symmetry in 8k + 1, 8k + 2 and 8k + 3 Minkowski dimensions calls for a serious reconsid­ eration of various solutions of the strong CP problem. In these possible higher dimensions, the relevant one is a ten dimensional string theory in which a possi­ bility of light fermions exists. We point out that the model independent axion in the heterotic string theory solves the strong CP problem. We also point out that the wormhole effects to low energy global and discrete symmetries are negligible. .. " JIf',!\f':-,',f,' ,. aJ , I <\ " ; \ ,k fL .::LJ.i2" ('If"T 11 . J' ., __ ".1: 1992 11!llllnrB1i1111111 -SAlUT? -·9/ --..5~ o 11bO 0011852 5 .................. • The recent observation of four dimensional CP as a discrete gauge symmetry in 8k +1, 8k +2 and 8k +3 Minkowski dimensions [1] calls for a new understand­ ing on the weak CP violation and the strong CP invariance. Among the possible higher dimensions, the relevant one is 10 because there exists a phenomenologi­ cally viable heterotic string theory [2]. The other extra dimensions not utilized by nature are only of academic interest. In the heterotic string theory, it has been known that the four dimensional CP must be a gauge symmetry since the theory does not have any discrete symmetry except Es +-+ E~ [3]. The discrete symmetry Es +-+ E~ cannot contain the four dimensional CP of light fermions and anti-fermions since they are singlets of E~. In string theories, therefore, the required weak CP violation must arise through spontaneous breaking [4]. The Kobayashi-Maskawa weak CP phase which looks like a hard CP violation at low energy may in fact have descended down from string scale physics through spon­ taneous breaking mechanism [5]. Inflation after the spontaneous CP violation might have removed the dangerous domain walls from our observable universe. The 'calculability' solutions of the Nelson-Barr type [6] to the strong CP problem have a rationale (8QCD = 0) in higher dimensions due to CP as a discrete gauge symmetry of Lagrangian. However, there are two questions to be cleared regarding the strong CP prob­ lem. Firstly, should we consider extra dimensions? Second, what is the effect of gravity on the four dimensional low energy symmetries? In this Letter, we consider both of these questions from Planck scale physics. Regarding the first question, an extension of spatial dimensions should not be in contradiction with low energy physics. Phenomenologically, there is no reason to extend the spatial dimensions. However, one may try to include more spatial dimensions to solve theoretical problems of the standard model. So in consideration of dis'crete and global symmetries in higher dimensions, at present the ten dimensional heterotic string is the only one to be considered. Thus, let us consider the (} parameter in the heterotic string theory in ten dimension. The heterotic string has a model-independent axion aMI [7] whose decay constant is
16580747
String Compactification and Unification of Forces
I review our recent attempts toward obtaining the MSSM from string orbifold compactification. The required constraints are the existence of three families and R parity, vectorlike exotics, one pair of Higgs doublets, and the SU(5)′ hidden sector for dynamical breaking of SUSY toward a GMSB scenario. We also comment on the threshold correction which are influenced by a power law evolution of gauge couplings through the KK radius in non‐prime orbifolds and can be used to fit the couplings.
15739165
SO(10)-like Superstring Standard Model with R-parity from the Heterotic String
We construct a supersymmetric standard model in the context of the Z_{12-I} orbifold compactification of the E_8 x E_8' heterotic string theory. The gauge group is SU(3)_c x SU(2)_L x U(1)_Y x U(1)^4 x [SO(10) x U(1)^3]' with sin^2\theta_W = 3/8. We obtain three families of SO(10) spinor-like chiral matter states, and Higgs doublets. All other extra states are exactly vector-like under the standard model gauge symmetry. There are numerous standard model singlets, many of which get VEVs such that only the standard model gauge symmetry survives and desired Yukawa couplings can be generated at lower energies. In particular, all vector-like exotic states achieve superheavy masses and the R-parity can be preserved.
14574575
Effective Gauss-Bonnet interaction in Randall-Sundrum compactification
The effective gravitational interaction below the Planck scale in the Randall-Sundrum world is shown to be the Gauss-Bonnet term. In this theory we find that there exists another static solution with a positive bulk cosmological constant. Also, there exist solutions for a positive visible sector cosmological constant, which is needed for a later Friedmann-Robertson-Walker universe.
13291931
Hidden sector gaugino condensation and the model independent axion
Abstract In the effective field theory framework, we consider the effect of supersymmetry breaking via gaugino condensation and supergravity in the hidden sector gauge group on the hidden sector vacuum angle θ h . The θ h parameter dependence of the potential yields phenomenologically acceptable invisible axion solutions if the U (1) R symmetry is broken down to a discrete subgroup Z N with N ≥3 ( N =4 is marginal). Anomalous U(1) superstring models are good candidates for this invisible axion resolution of the strong CP puzzle.
119883211
Conflicts between B-violating phenomena in supergravity models
Abstract We show that there is an incompatibility between matter stability and cosmological baryon production in standard N = 1 supergravity models. This discrepancy emerges from the bound on the reheating temperature T rh ⩽ 10 10 GeV which comes from the restriction on the gravitino decay after inflation. Some weird possibilities to bypass the controversy are also analyzed.
119259465
‘Stop’ that ambulance! New physics at the LHC?
A bstractA number of LHC searches now display intriguing excesses. Most prominently, the measurement of the W+W− cross-section has been consistently ∼ 20% higher than the theoretical prediction across both ATLAS and CMS for both 7 and 8 TeV runs. More recently, supersymmetric searches for final states containing two or three leptons have also seen more events than predicted in certain signal regions. We show that a supersymmetric model containing a light stop, winos and binos can consistently match the data. We perform a fit to all measurements and searches that may be sensitive to our model and find a reduction in the log-likelihood of 15.4 compared to the Standard Model which corresponds to 3.5-σ once the extra degrees of freedom in the fit are considered.
118613110
How to make a clean separation between CMB E and B modes with proper foreground masking
We investigate the E/B decomposition of CMB polarization on a masked sky. In real space, operators of E and B mode decomposition involve only differentials of CMB polarization. We may, therefore in principle, perform a clean E/B decomposition from incomplete sky data. Since it is impractical to apply second derivatives to observation data, we usually rely on spherical harmonic transformation and inverse transformation, instead of using real-space operators. In spherical harmonic representation, jump discontinuities in a cut sky produces Gibbs phenomenon, unless a spherical harmonic expansion is made up to an infinitely high multipole. By smoothing a foreground mask, we may suppress the Gibbs phenomenon effectively in a similar manner to apodization of a foreground mask discussed in other works. However, we incur foreground contamination by smoothing a foreground mask, because zero-value pixels in the original mask may be rendered non-zero by the smoothing process. In this work, we investigate an optimal foreground mask, which ensures proper foreground masking and suppresses Gibbs phenomenon. We apply our method to a simulated map of the pixel resolution comparable to the Planck satellite. The simulation shows that the leakage power is lower than unlensed CMB B mode power spectrum of tensor-to-scalar ratio r ∼ 1 × 10 −7 . We compare the result with that of the original mask. We find that the leakage power is reduced by a factor of 10 6 ∼ 10 9 at the cost of a sky fraction 0.07, and that that the enhancement is highest at lowest multipoles. We confirm that all the zero-value pixels in the original mask remain zero in our mask. The application of this method to the Planck data will improve the detectability of primordial tensor perturbation.
118343398
Probing Minimal Flavor Violation with Long-Lived Stops and Light Gravitinos at Hadron Colliders
In the framework of minimal flavor violation (MFV), we discuss the decay properties of a supersymmetric scalar top (stop) in the presence of a light gravitino. Given a small mass difference between the lighter stop and lightest neutralino and an otherwise sufficiently decoupled spectrum, the stop may be long-lived and thus can provide support to MFV at hadron colliders. For a bino-like lightest neutralino, we apply bounds from searches in the gamma gamma plus missing transverse energy channel (ATLAS with 1 fb^-1 and D0 with 6.3 fb^-1) and give a 5 fb^-1 projection for the ATLAS search.
118753210
CP asymmetries in the supersymmetric trilepton signal at the LHC
In the CP-violating Minimal Supersymmetric Standard Model, we study the production of a neutralino–chargino pair at the LHC. For their decays into three leptons, we analyze CP asymmetries which are sensitive to the CP phases of the neutralino and chargino sector. We present analytical formulas for the entire production and decay process, and identify the CP-violating contributions in the spin correlation terms. This allows us to define the optimal CP asymmetries. We present a detailed numerical analysis of the cross sections, branching ratios, and the CP observables. For light neutralinos, charginos, and squarks, the asymmetries can reach several 10%. We estimate the discovery potential for the LHC to observe CP violation in the trilepton channel.
14387976
Fast simulation of the whole-sky CMB map in the presence of primordial magnetic field
We present a novel method for generation of sets of the Cosmic Microwave Background (CMB) anisotropy maps, which reproduces the $\Delta \l=2$ correlations associated with Alfv\'en turbulence. The method is based on the non-linear transformation of the CMB maps, which is obtained from the Monte Carlo simulation of the statistically isotropic Gaussian signal. Our method is computationally fast and efficient. 
We have applied two estimators (the cross-correlation estimator in multipole domain for $\l+1,m$ and $\l-1,m$ modes and circular phase moments) to test the statistical properties of derived maps. Both of these statistics confirm the effectiveness of our generation method. We believe that our method can be useful for fast generation of the non-Gaussian maps in the presence of the primordial magnetic field, and be a valuable tool for the non-Gaussianity investigation of the CMB in the framework of the future PLANCK data analysis.