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.
46649104
Axino cold dark matter revisited
A bstractAxino arises in supersymmetric versions of axion models and is a natural candidate for cold or warm dark matter. Here we revisit axino dark matter produced thermally and non-thermally in light of recent developments. First we discuss the definition of axino relative to low energy axion one for several KSVZ and DFSZ models of the axion. Then we review and refine the computation of the dominant QCD production in order to avoid unphysical cross-sections and, depending on the model, to include production via SU(2) and U(1) interactions and Yukawa couplings.
121882543
Conditions for Natural Suppression of CP Violation
16956302
Cosmological light element bound on R-parity violating parameters
In R parity violating theories, there does not exist the {\it stable} lightest supersymmetric particle (LSP). The LSP, $\chi$, of MSSM decays to lighter ordinary particles with dimension 6 effective R violating interaction terms. Since the lifetime of $\chi$ can be sufficiently long for small R-violating couplings, it can affect the standard nucleosynthesis scenario. This constraint gives an upper limit for the lifetime of $\chi$ in the small $\tau_\chi$ region; $\sim\tau_\chi>10^6$ s. This translates to the sum of squared R-violating couplings, for $m_\chi=$ 60 GeV in the photino (bino) limit, $(0.12 (0.05)|\lambda_{i,j,k}|^2+0.31(0.07) |\lambda^\prime_{i,j\ne 3,k}|^2 +0.04(0.04)|\lambda^{\prime}_{i,3,k}|^2 +0.23(0.12)|\lambda_{i,j,k}^{\prime\prime}(i 7.7\times 10^{-24}$.
118562999
Amplification of endpoint structure for new particle mass measurement at the LHC
We introduce a new collider variable, M{sub CT2}, named as constransverse mass. It is a mixture of 'stransverse mass (M{sub T2})' and 'contransverse mass (M{sub CT})' variables, where the usual endpoint structure of M{sub T2} distribution can be amplified in the M{sub CT2} basis by a large Jacobian factor which is controlled by a trial missing particle mass. Thus, the M{sub CT2} projection of events increases our observability to measure several important endpoints from new particle decays, which are usually expected to be buried by irreducible backgrounds with various systematic uncertainties at the LHC. In this paper we explain the phenomenology of endpoint amplification in M{sub CT2} projection, and describe how one may employ this variable to measure several meaningful mass constraints of new particles.
121954208
SupersymmetricSU (11), the invisible axion, and proton decay
We supersymmetrize the very attractive flavour unification modelSU (11). As with other supersymmetric GUTs the gauge hierarchy problem is simplified, but we may also have observable (τp≈1033 yrs) proton decay. The required split multiplets are obtained by making the adjoint take a particular direction. Supersymmetry is broken softly at the TeV scale. There is a uniqueU(1)A symmetry, and hence there are no true Nambu-Goldstone bosons. TheU(1)A is broken at the GUT scale and there result an invisible axion and neutrino masses.
119291744
Neutrino masses and mixings in the baryon triality constrained minimal supersymmetric standard model
We discuss how the experimental neutrino oscillation data can be realized in the framework of the baryon triality ($B_3$) constrained supersymmetric Standard Model (cSSM). We show how to obtain phenomenologically viable solutions, which are compatible with the recent WMAP observations. We present results for the hierarchical, inverted and degenerate cases which illustrate the possible size and structure of the lepton number violating couplings. We work with a new, as yet unpublished version of SOFTSUSY, where we implemented full one--loop neutrino masses. Finally, we shortly discuss some phenomenological implications at the LHC.
16726847
Testing neutrino masses in the R-parity violating minimal supersymmetric standard model with LHC results
Within the R–parity violating minimal supersymmetric standard model (MSSM), we use a hierarchical ansatz for the lepton–number violating trilinear Yukawa couplings by relating them to the corresponding Higgs–Yukawa couplings. This ansatz reduces the number of free parameters in the lepton–number violating sector from 36 to 6. Baryon–number violating terms are forbidden by imposing the discrete gauge symmetry Baryon Triality. We fit the lepton–number violating parameters to the most recent neutrino oscillation data, including the mixing angle θ13 found by Daya Bay. We find that we obtain phenomenologically viable neutrino masses and mixings only in the case of normal ordered neutrino masses and that the lepton–number violating sector is unambiguously determined by neutrino oscillation data. We discuss the resulting collider signals for the case of a neutralino as well as a scalar tau lightest supersymmetric particle. We use the ATLAS searches for multi–jet events and large transverse missing momentum in the 0, 1 and 2 lepton channel with 7 TeV center–of–mass energy in order to derive exclusion limits on the parameter space of this R–parity violating supersymmetric model.
53580211
The higgsino–singlino world at the large hadron collider
We consider light higgsinos and singlinos in the next-to-minimal supersymmetric standard model at the large hadron collider. We assume that the singlino is the lightest supersymmetric particle and that the higgsino is the next-to-lightest supersymmetric particle with the remaining supersymmetric particles in the multi-TeV range. This scenario, which is motivated by the flavor and CP issues, provides a phenomenologically viable dark matter candidate and improved electroweak fit consistent with the measured Higgs mass. Here, the higgsinos decay into on (off)-shell gauge boson and the singlino. We consider the leptonic decay modes and the resulting signature is three isolated leptons and missing transverse energy which is known as the trilepton signal. We simulate the signal and the Standard Model backgrounds and present the exclusion region in the higgsino–singlino mass plane at the large hadron collider at $$\sqrt{s}=14$$s=14 TeV for an integrated luminosity of 300 fb$$^{-1}$$-1.
6862555
Subfemtosecond synchronization of microwave oscillators with mode-locked Er-fiber lasers.
We synchronize an 8.06 GHz microwave signal from a voltage-controlled oscillator with an optical pulse train from a 77.5 MHz mode-locked Er-fiber laser using a fiber-based optical-microwave phase detector. The residual phase noise between the optical pulse train and the synchronized microwave signal is -133 dBc/Hz (-154 dBc/Hz) at 1 Hz (5 kHz) offset frequency, which results in 838 as integrated rms timing jitter [1 Hz-1 MHz]. The long-term residual phase drift is 847 as (rms) measured over 2 h, which reaches 4×10(-19) fractional frequency instability at 1800 s averaging time. This method has a potential to provide both subfemtosecond-level short-term phase noise and long-term phase stability in microwave extraction from mode-locked fiber lasers.
51693431
Supersymmetric Jarlskog invariants: The neutrino sector
We generalize the notion of the Jarlskog invariant to supersymmetric models with right-handed neutrinos. This allows us to formulate basis-independent necessary and sufficient conditions for $CP$ conservation in such models.