3,120 research outputs found
Eviction of a 125 GeV "heavy"-Higgs from the MSSM
We prove that the present experimental constraints are already enough to rule
out the possibility of the ~125 GeV Higgs found at LHC being the second
lightest Higgs in a general MSSM context, even with explicit CP violation in
the Higgs potential. Contrary to previous studies, we are able to eliminate
this possibility analytically, using simple expressions for a relatively small
number of observables. We show that the present LHC constraints on the diphoton
signal strength, tau-tau production through Higgs and BR(B -> X_s gamma) are
enough to preclude the possibility of H_2 being the observed Higgs with m_H~125
GeV within an MSSM context, without leaving room for finely tuned
cancellations. As a by-product, we also comment on the difficulties of an MSSM
interpretation of the excess in the gamma-gamma production cross section
recently found at CMS that could correspond to a second Higgs resonance at
m_H~136 GeV.Comment: 38 pages, 9 figures. Final version accepted at JHEP. Sections 2, 3
and appendices simplified. Experimental results updated, several references
added. Small typos corrected and a new comparison of approximate formulas
with full expressions include
Controlled flavor violation in the MSSM from a unified flavor symmetry
We study the phenomenology of a unified supersymmetric theory with a flavor
symmetry . The model accommodates quark and lepton masses, mixing
angles and CP phases. In this model, the Dirac and Majorana mass matrices have
a unified texture zero structure in the entry that leads to the
Gatto-Sartori-Tonin relation between the Cabibbo angle and ratios of the masses
in the quark sectors, and to a natural departure from zero of the
angle in the lepton sector. We derive the flavor structures
of the trilinears and soft mass matrices, and show their general
non-universality. This causes large flavor violating effects. As a consequence,
the parameter space for this model is constrained, allowing it to be
(dis)proven by flavor violation searches in the next decade. Although the
results are model specific, we compare them to previous studies to show similar
flavour effects (and associated constraints) are expected in general in
supersymmetric flavor models, and may be used to distinguish them.Comment: 21 pages, 6 figure
Conceptual and numerical modeling approach of the Guarani Aquifer System
In large aquifers, relevant for their considerable size, regional groundwater modeling remains challenging given geologic complexity and data scarcity in space and time. Yet, it may be conjectured that regional scale groundwater flow models can help in understanding the flow system functioning and the relative magnitude of water budget components, which are important for aquifer management. The Guaranà Aquifer System is the largest transboundary aquifer in South America. It contains an enormous volume of water; however, it is not well known, being difficult to assess the impact of exploitation currently used to supply over 25 million inhabitants. This is a sensitive issue because the aquifer is shared by four countries. Moreover, an integrated groundwater model, and therefore a global water balance, were not available. In this work, a transient regional scale model for the entire aquifer based upon five simplified, equally plausible conceptual models represented by different hydraulic conductivity parametrizations is used to analyze the flow system and water balance components. Combining an increasing number of hydraulic conductivity zones and an appropriate set of boundary conditions, the hypothesis of a continuous sedimentary unit yielded errors within the calibration target in a regional sense. The magnitude of the water budget terms resulted very similar for all parametrizations. Recharge and stream/aquifer fluxes were the dominant components representing, on average, 84.2% of total inflows and 61.4% of total outflows, respectively. However, leakage was small compared to stream discharges of main rivers. For instance, the simulated average leakage for the Uruguay River was 8 m<sup>3</sup> s<sup>−1</sup> while the observed absolute minimum discharge was 382 m<sup>3</sup> s<sup>−1</sup>. Streams located in heavily pumped regions switched from a gaining condition in early years to a losing condition over time. Water is discharged through the aquifer boundaries, except at the eastern boundary. On average, pumping represented 16.2% of inflows while aquifer storage experienced a small overall increment. The model water balance indicates that the current rate of groundwater withdrawals does not exceed the rate of recharge in a regional sense
FCNC and CP Violation Observables in a SU(3)-flavoured MSSM
A non-Abelian flavour symmetry in a minimal supersymmetric standard model can
explain the flavour structures in the Yukawa couplings and simultaneously solve
the SUSY flavour problem. Similarly the SUSY CP problem can be solved if CP is
spontaneously broken in the flavour sector. In this work, we present an
explicit example of these statements with a SU(3) flavour symmetry and
spontaneous CP violation. In addition, we show that it is still possible to
find some significant deviation from the SM expectations as far as FCNC and CP
violation are concerned. We find that large contributions can be expected in
lepton flavour violating decays, as and , electric dipole moments, and and kaon CP violating
processes as . Thus, these flavoured MSSM realizations are
phenomenologically sensitive to the experimental searches in the realm of
flavor and CP vioation physics.Comment: 56 pages, 12 figures; included new NLO contributions to nEDM from
charged Higgs, relevant figures updated, and analysis of O(1) coefficients;
added appendices and reference
Leptogenesis in with a Universal Texture Zero
We investigate the possibility of viable leptogenesis in an appealing
model with a universal texture zero in the (1,1) entry. The model
accommodates the mass spectrum, mixing and CP phases for both quarks and
leptons and allows for grand unification. Flavoured Boltzmann equations for the
lepton asymmetries are solved numerically, taking into account both and
right-handed neutrino decays. The -dominated scenario is successful
and the most natural option for the model, with GeV,
and , which constrains the parameter space of the
underlying model and yields lower bounds on the respective Yukawa couplings.
Viable leptogenesis is also possible in the -dominated scenario, with the
asymmetry in the electron flavour protected from washout by the texture
zero. However, this occurs in a region of parameter space which has a stronger
mass hierarchy , and relatively close to , which
is not a natural expectation of the model.Comment: v2: 20 pages, 2 figures. Version accepted in JHE
Sur certaines relations entre les intégrales trajectorielles et l'opérateur de translation et son dual dans l'espace de Poisson canonique
We study the relationship between the translation operator, its dual and the pathwise integral on the Poisson space with weak conditions on the processes
Rayleigh loops in the random-field Ising model on the Bethe lattice
We analyze the demagnetization properties of the random-field Ising model on
the Bethe lattice focusing on the beahvior near the disorder induced phase
transition. We derive an exact recursion relation for the magnetization and
integrate it numerically. Our analysis shows that demagnetization is possible
only in the continous high disorder phase, where at low field the loops are
described by the Rayleigh law. In the low disorder phase, the saturation loop
displays a discontinuity which is reflected by a non vanishing magnetization
m_\infty after a series of nested loops. In this case, at low fields the loops
are not symmetric and the Rayleigh law does not hold.Comment: 8pages, 6 figure
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