1,445 research outputs found

### Sensitivity to new supersymmetric thresholds through flavour and CP violating physics

Treating the MSSM as an effective theory below a threshold scale Lambda, we
study the consequences of having dimension-five operators in the superpotential
for flavour and CP-violating processes. Below the supersymmetric threshold such
terms generate flavour changing and/or CP-odd effective operators of dimension
six composed from the Standard Model fermions, that have the interesting
property of decoupling linearly with the threshold scale, i.e. as 1/(Lambda
m_soft), where m_soft is the scale of soft supersymmetry breaking. The
assumption of weak-scale supersymmetry, together with the stringent limits on
electric dipole moments and lepton flavour-violating processes, then provides
sensitivity to Lambda as high as 10^7-10^9 GeV. We discuss the varying
sensitivity to these scales within several MSSM benchmark scenarios and also
outline the classes of UV physics which could generate these operators.Comment: 28 pages, 9 figure

### Lorentz Violation in Supersymmetric Field Theories

We construct supersymmetric Lorentz violating operators for matter and gauge
fields. We show that in the supersymmetric Standard Model the lowest possible
dimension for such operators is five, and therefore they are suppressed by at
least one power of an ultra--violet energy scale, providing a possible
explanation for the smallness of Lorentz violation and its stability against
radiative corrections. Supersymmetric Lorentz noninvariant operators do not
lead to modifications of dispersion relations at high energies thereby escaping
constraints from astrophysical searches for Lorentz violation.Comment: Minor correction

### Up-Down Unification just above the supersymmetric threshold

Large corrections to the quark mass matrices at the supersymmetric threshold
allow the theory to have identical Yukawa matrices in the superpotential. We
demonstrate that Up-Down unification can take place in a moderate quark-squark
alignment scenario with an average squark mass of the order 1 TeV and with
$\tan\beta>15$Comment: 12 pages, latex, two figure

### A large Muon Electric Dipole Moment from Flavor?

We study the prospects and opportunities of a large muon electric dipole
moment (EDM) of the order (10^{-24} - 10^{-22}) ecm. We investigate how natural
such a value is within the general minimal supersymmetric extension of the
Standard Model with CP violation from lepton flavor violation in view of the
experimental constraints. In models with hybrid gauge-gravity mediated
supersymmetry breaking a large muon EDM is indicative for the structure of
flavor breaking at the Planck scale, and points towards a high messenger scale.Comment: 12 pages, 12 figures. v3: References and Eq 28 fixed; conclusions
unchange

### Electric dipole and magnetic quadrupole moments of the $W$ boson via a CP-violating $HWW$ vertex in effective Lagrangians

The possibility of nonnegligible $W$ electric dipole ($\widetilde{\mu}_W$)
and magnetic quadrupole ($\widetilde{Q}_W$) moments induced by the most general
$HWW$ vertex is examined via the effective Lagrangian technique. It is assumed
that new heavy fermions induce an anomalous CP-odd component of the $HWW$
vertex, which can be parametrized by an $SU_L(2)\times U_Y(1)$-invariant
dimension-six operator. This anomalous contribution, when combined with the
standard model CP-even contribution, lead to CP-odd electromagnetic properties
of the $W$ boson, which are characterized by the form factors $\Delta
\widetilde{\kappa}$ and $\Delta \widetilde{Q}$. It is found that $\Delta
\widetilde{\kappa}$ is divergent, whereas $\Delta \widetilde{Q}$ is finite,
which reflects the fact that the latter cannot be generated at the one-loop
level in any renormalizable theory. Assuming reasonable values for the unknown
parameters, we found that $\widetilde{\mu}_W\sim 3-6\times 10^{-21}$ e-cm,
which is eight orders of magnitude larger than the SM prediction and close to
the upper bound derived from the neutron electric dipole moment. The estimated
size of the somewhat less-studied $\widetilde{Q}_W$ moment is of the order of
$-10^{-36}$ e-cm^2, which is fifteen orders of magnitude above the SM
contribution.Comment: 7 pages, 6 figures, REVTEX styl

### Elastic scattering signals of solar neutrinos with enhanced baryonic currents

The coupling of the baryonic current to new neutrino states \nu_b with
strength in excess of the weak interactions is a viable extension of the
Standard Model. We analyze the signature of \nu_b appearance in the solar
neutrino flux that gives rise to an elastic scattering signal in dark matter
direct detection and in solar neutrino experiments. This paper lays out an
in-depth study of \nu_b detection prospects for current and future underground
rare event searches. We scrutinize the model as a possible explanation for the
reported anomalies from DAMA, CoGeNT, and CRESST-II and confront it with
constraints from other null experiments.Comment: 30 pages, 9 figures; code-correction to Xenon ionization (S2)
analyses; Xenon10 constraint in Fig.6 is weakened and Xenon100 projection in
Fig.7 is revise

### Classification of Dimension 5 Lorentz Violating Interactions in the Standard Model

We give a complete classification of mass dimension five
Lorentz-non-invariant interactions composed from the Standard Model fields,
using the effective field theory approach. We identify different classes of
Lorentz violating operators, some of which are protected against transmutation
to lower dimensions even at the loop level. Within each class of operators we
determine a typical experimental sensitivity to the size of Lorentz violation.Comment: 26 page

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