120460443
DEGENERACIES IN THE MEASUREMENT OF NEUTRINO OSCILLATION PARAMETERS: PROBLEM AND SOLUTION IN NEUTRINO FACTORIES
44006804
Revising the solution of the neutrino oscillation parameter degeneracies at neutrino factories
In the context of neutrino factories, we review the solution of the degeneracies in the neutrino oscillation parameters. In particular, we have set limits to ${sin﻿}^{2}2{\ensuremath{\theta}}_{13}$ in order to accomplish the unambiguous determination of ${\ensuremath{\theta}}_{23}$ and $\ensuremath{\delta}$. We have performed two different analysis. In the first, at a baseline of 3000 km, we simulate a measurement of the channels ${\ensuremath{\nu}}_{e}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\mu}}$, ${\ensuremath{\nu}}_{e}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\tau}}$, and ${\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}\ensuremath{\rightarrow}{\overline{\ensuremath{\nu}}}_{\ensuremath{\mu}}$, combined with their respective conjugate ones, with a muon energy of 50 GeV and a running time of five years. In the second, we merge the simulated data obtained at $L=3000\text{ }\text{ }\mathrm{km}$ with the measurement of ${\ensuremath{\nu}}_{e}\ensuremath{\rightarrow}{\ensuremath{\nu}}_{\ensuremath{\mu}}$ channel at 7250 km, the so-called ``magic baseline.'' In both cases, we have studied the impact of varying the ${\ensuremath{\nu}}_{\ensuremath{\tau}}$ detector efficiency-mass product, $({ϵ}_{{\ensuremath{\nu}}_{\ensuremath{\tau}}}\ifmmode\times\else\texttimes\fi{}{M}_{\ensuremath{\tau}})$, at 3000 km, keeping unchanged the ${\ensuremath{\nu}}_{\ensuremath{\mu}}$ detector mass and its efficiency. At $L=3000\text{ }\text{ }\mathrm{km}$, we found the existence of degenerate zones, that correspond to values of ${\ensuremath{\theta}}_{13}$, which are equal or almost equal to the true ones. These zones are extremely difficult to discard, even when we increase the number of events. However, in the second scenario, this difficulty is overcome, demonstrating the relevance of the ``magic baseline.'' From this scenario, the best limits of ${sin﻿}^{2}2{\ensuremath{\theta}}_{13}$, reached at $3\ensuremath{\sigma}$, for ${sin﻿}^{2}2{\ensuremath{\theta}}_{23}=0.95$, 0.975, and 0.99 are: 0.008, 0.015, and 0.045, respectively, obtained at $\ensuremath{\delta}=0$, and considering $({ϵ}_{{\ensuremath{\nu}}_{\ensuremath{\tau}}}\ifmmode\times\else\texttimes\fi{}{M}_{\ensuremath{\tau}})\ensuremath{\approx}125$, which is 5 times the initial efficiency-mass combination.
118615915
SUSY renormalization group effects in ultra high energy neutrinos
We have explored the question of whether the renormalization group running of the neutrino mixing parameters in the Minimal Supersymmetric Standard Model is detectable with ultra-high energy neutrinos from active galactic nuclei (AGN). We use as observables the ratios of neutrino fluxes produced at the AGN, focusing on four different neutrino production models: $ \left( {\Phi_{{\nu_e} + {{\bar{\nu }}_e}}^0:\Phi_{{\nu_\mu } + {{\bar{\nu }}_\mu }}^0:\Phi_{{\nu_\tau } + {{\bar{\nu }}_\tau }}^0} \right) = \left( {1:2:0} \right),\left( {0:1:0} \right),\left( {1:0:0} \right) $, and (1 : 1 : 0). The prospects for observing deviations experimentally are taken into consideration, and we find out that it is necessary to impose a cut-off on the transferred momentum of Q2 ≥ 107 GeV2. However, this condition, together with the expected low value of the diffuse AGN neutrino flux, yields a negligible event rate at a km-scale C̆erenkov detector such as IceCube.
211009558
FLAVOUR SYMMETRIES AND SUSY SOFT BREAKING AT THE LHC∗
Supersymmetry is one of the best options among the possible extensions of the SM that can be found at the LHC. However, most of the phenomenological analysis have been done neglecting flavour structures. In this paper, we show that a realistic flavour symmetry can simultaneously explain the flavour structures in the Yukawa matrices and solve the so-called SUSY flavour problem without ad hoc modifications of the SUSY model. Furthermore, departures from the SM expectations in these models can be used to discriminate among different possibilities. We find that large contributions can be expected in lepton flavour violating decays, as μ → eγ and τ → μγ, electric dipole moments, de and dn and kaon CP-violating processes as K . Thus, these flavoured MSSM realizations are phenomenologically sensitive to the experimental searches in the realm of flavour and CP violation physics.
119268104
RGE behaviour of U(2)^3 symmetry in SUSY
From the naturalness point of view, the first LHC results seem to disfavour any constrained MSSM realization with universal conditions at the SUSY-breaking scale. A more motivated scenario is given by split-family SUSY, in which the first two generations of squarks are heavy, compatible with a U(2)^3 flavour symmetry. Here, after reviewing the flavour structures obtained in this framework, we consider the flavour symmetry to be broken at a very high scale, and study the consequences at low energies through its RGE evolution. Initial conditions compatible with a split scenario are found, and the preservation of correlations from minimal U(2)^3 breaking are checked.
53724505
Flavour and collider interplay for SUSY at LHC7
The current 7 TeV run of the LHC experiment shall be able to probe gluino and squark masses up to values larger than 1 TeV. Assuming that hints for SUSY are found in the jets plus missing energy channel by the end of a 5 fb−1 run, we explore the flavour constraints on three models with a CMSSM-like spectrum: the CMSSM itself, a seesaw extension of the CMSSM, and Flavoured CMSSM. In particular, we focus on decays that might have been measured by the time the run is concluded, such as Bs→μμ and μ→eγ. We also analyse constraints imposed by neutral meson bounds and electric dipole moments. The interplay between collider and flavour experiments is explored through the use of three benchmark scenarios, finding the flavour feedback useful in order to determine the model parameters and to test the consistency of the different models.
14406736
Gauge Coupling Unification in MSSM + 5 Flavors
We investigate gauge coupling unification at 2-loops for theories with 5 extra vectorlike SU(5) fundamentals added to the MSSM. This is a borderline case where unification is only predicted in certain regions of parameter space. We establish a lower bound on the scale for the masses of the extra flavors, as a function of the sparticle masses. Models far outside of the bound do not predict unification at all (but may be compatible with unification), and models outside but near the boundary cannot reliably claim to predict it with an accuracy comparable to the MSSM prediction. Models inside the boundary can work just as well as the MSSM.