2,392 research outputs found

### CP asymmetry in B --> phi K_S decays in left-right models and its implications on B_s decays

In left-right models the gluonic penguin contribution to b --> s s-bar s
transition is enhanced by m_t/m_b due to the presence of (V+A) currents and by
the larger values of loop functions than in the Standard Model. Together those
may completely overcome the suppression due to small left-right mixing angle xi
phi K_S decay amplitude
appearing in a large class of left-right models may therefore modify the time
dependent CP asymmetry in this decay mode by O(1) and explain the recent BaBar
and Belle CP asymmetry measurements in this channel. This new physics scenario
implies observable deviations from the Standard Model also in B_s decays which
could be measured at upcoming Tevatron and LHC.Comment: references adde

### Exponentially spread dynamical Yukawa couplings from non-perturbative chiral symmetry breaking in the dark sector

We propose a new paradigm for generating exponentially spread standard model
Yukawa couplings from a new $U(1)_F$ gauge symmetry in the dark sector. Chiral
symmetry is spontaneously broken among dark fermions that obtain non-vanishing
masses from a non-perturbative solution to the mass gap equation. The necessary
ingredient for this mechanism to work is the existence of higher derivative
terms in the dark $U(1)_F$ theory, or equivalently the existence of Lee-Wick
ghosts, that (i) allow for a non-perturbative solution to the mass gap equation
in the weak coupling regime of the Abelian theory; (ii) induce exponential
dependence of the generated masses on dark fermion $U(1)_F$ quantum numbers.
The generated flavor and chiral symmetry breaking in the dark sector is
transferred to the standard model Yukawa couplings at one loop level via Higgs
portal type scalar messenger fields. The latter carry quantum numbers of
squarks and sleptons. A new intriguing phenomenology is predicted that could be
potentially tested at the LHC, provided the characteristic mass scale of the
messenger sector is accessible at the LHC as is suggested by naturalness
arguments.Comment: Text improved, new equations and references added, version to appear
in Phys.Rev.D, 12 pages, 2 figure

### Hints for a non-standard Higgs boson from the LHC

We reconsider Higgs boson invisible decays into Dark Matter in the light of
recent Higgs searches at the LHC. Present hints in the CMS and ATLAS data favor
a non-standard Higgs boson with approximately 50% invisible branching ratio,
and mass around 143 GeV. This situation can be realized within the simplest
thermal scalar singlet Dark Matter model, predicting a Dark Matter mass around
50 GeV and direct detection cross section just below present bound. The present
runs of the Xenon100 and LHC experiments can test this possibility.Comment: 6 pages, 2 figures. Final version to appear on PR

### Neutrino Mass, Muon Anomalous Magnetic Moment, and Lepton Flavor Nonconservation

If the generating mechanism for neutrino mass is to account for both the
newly observed muon anomalous magnetic moment as well as the present
experimental bounds on lepton flavor nonconservation, then the neutrino mass
matrix should be almost degenerate and the underlying physics be observable at
future colliders. We illustrate this assertion in two specific examples, and
show that $\Gamma (\mu \to e \gamma)/m_\mu^5$, $\Gamma (\tau \to e
\gamma)/m_\tau^5$, and $\Gamma (\tau \to \mu \gamma) /m_\tau^5$ are in the
ratio $(\Delta m^2)_{sol}^2/2$, $(\Delta m^2)_{sol}^2 /2$, and $(\Delta
m^2)_{atm}^2$ respectively, where the $\Delta m^2$ parameters are those of
solar and atmospheric neutrino oscillations and bimaximal mixing has been
assumed.Comment: Erratum adde

### Three Active and Two Sterile Neutrinos in an E_6 Model of Diquark Baryogenesis

In the U(1)_N extension of the supersymmetric standard model with E_6
particle content, the heavy singlet superfield N may decay into a quark and a
diquark as well as an antiquark and an antidiquark, thus creating a baryon
asymmetry of the Universe. We show how the three doublet and two singlet
neutrinos in this model acquire mass from physics at the TeV scale without the
benefit of using N as a heavy right-handed neutrino. Specifically, the active
neutrinos get masses via the bilinear term \mu LX^c which conserves R-parity,
and via the nonzero masses of the sterile neutrinos. We predict fixed
properties of the extra Z' boson, as well as the new lepton doublets X and X^c,
and the observation of diquark resonances at hadron colliders in this scenario.Comment: LATEX, 13 page

### Prospects for constrained supersymmetry at $\sqrt{s}=33$ TeV and $\sqrt{s}=100$ TeV proton-proton super-colliders

Discussions are underway for a high-energy proton-proton collider. Two
preliminary ideas are the $\sqrt{s}=33$ TeV HE-LHC and the $\sqrt{s}=100$ TeV
VLHC. With Bayesian statistics, we calculate the probabilities that the LHC,
HE-LHC and VLHC discover SUSY in the future, assuming that nature is described
by the CMSSM and given the experimental data from the LHC, LUX and Planck. We
find that the LHC with $300$/fb at $\sqrt{s}=14$ TeV has a $15$-$75%$
probability of discovering SUSY. Should that run fail to discover SUSY, the
probability of discovering SUSY with $3000$/fb is merely $1$-$10%$. Were SUSY
to remain undetected at the LHC, the HE-LHC would have a $35$-$85%$ probability
of discovering SUSY with $3000$/fb. The VLHC, on the other hand, ought to be
definitive; the probability of it discovering SUSY, assuming that the CMSSM is
the correct model, is $100%$.Comment: 21 pages, 5 figures. Matches version published in Eur.Phys.J. C.
Results and conclusions unchange

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