16170785
Orbifolded SU(7) and unification of families
Abstract A 5D SU (7) family unification model with two spinor representations of SO (14) is presented. The fifth dimension is compactified on S 1 / Z 2 × Z 2 ′. The orbifolding is used to obtain 4D SO (10) chiral fermions. The 4D grand unification group is the flipped SU (5)× U (1). The doublet–triplet splitting through the missing partner mechanism is achieved. Also, fermion mass matrices are considered.
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.
119316975
GMSB at a stable vacuum and MSSM without exotics from heterotic string
Abstract We show that it is possible to introduce the confining hidden sector gauge group SU ( 5 ) ′ with the chiral matter 10 0 ′ plus 5 ¯ 0 ′ , which are neutral under the standard model gauge group, toward a gauge mediated supersymmetry breaking (GMSB) in a Z 12 − I orbifold compactification of E 8 × E 8 ′ heterotic string. Three families of MSSM result without exotics. We also find a desirable matter parity P (or R-parity) assignment. We note that this model contains the spectrum of the Lee–Weinberg model which has a nice solution of the μ problem.
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.
18138135
Neutrino masses from discrete gauge symmetries
Abstract We investigate a model with an extra Z 2 gauge symmetry in the Standard Model. The symmetry gives a structure to the mass matrix for the neutrinos. With two extra Higgs singlets and two extra singlet right-handed neutrinos we can build a model that fits the requirements of the MSW solution of the Solar neutrino problem. With a third singlet right-handed neutrino it is also possible to have a 10 eV neutrino.
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.
11686379
Direct reconstruction of spherical harmonics from interferometer observations of the CMB polarization
Interferometric observation of the CMB polarization can be expressed as a linear sum of spherical harmonic coefficients a±2,lm of the CMB polarization. The linear weight for a±2,lm depends on the observational configuration such as antenna pointing, baseline orientation, and spherical harmonic number l, m. Since an interferometer is sensitive over a finite range of multipoles, a±2,lm in the range can be determined by fitting a±2,lm for visibilities of various observational configurations. The formalism presented in this paper enables the determination of a±2,lm directly from spherical harmonic spaces without spherical harmonic transformation of pixellized maps. The result of its application to a simulated observation is presented with the formalism.
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.
118997460
Alfv\'en turbulence in the WMAP 5 year data and a forecast for the PLANCK
119300805
Light stop phenomenology
We consider the discovery potential of light stops in the MSSM at the LHC. Here, we assume that the lightest neutralino is the LSP and that the lighter stop i s the NLSP. Direct stop pair production is difficult to probe in scenarios with a small mass splitting between the stop and a neutralino. We discuss two different search channels: the monojet and the two b‐flavoured jets and large missing transverse energy signature. We present the discovery reach in the stop‐neutralino mass plane for both channels. The latter process is sensitive to the stop‐h iggsino‐b quark coupling. This allows us to test a supersymmetry relation involving superpotential couplings. We briefly comment on the possible precision with which the coupling can be measured.
814570
Electroweak contributions to squark pair production at the CERN LHC
In this paper we compute electroweak contributions to the production of squark pairs at hadron colliders. These include the exchange of electroweak gauge bosons in the s-channel as well as electroweak gaugino exchange in the t- and/or u-channel. In many cases these can interfere with the dominant QCD contributions. As a result, we find sizable contributions to the production of two SU(2) doublet squarks. At the LHC, they amount to 10% to 20% for typical mSUGRA (or CMSSM) scenarios, but in more general scenarios they can vary between -40% and +55%, depending on size and sign of the SU(2) gaugino mass. The electroweak contribution to the total squark pair production rate at the LHC is about 3.5 times smaller.