5,318 research outputs found
Generalised CP and Family Symmetry
We perform a comprehensive study of family symmetry models based on
combined with the generalised CP symmetry . We investigate the
lepton mixing parameters which can be obtained from the original symmetry
breaking to different remnant symmetries in the
neutrino and charged lepton sectors. We find that only one case is
phenomenologically viable, namely in the neutrino sector and in the charged lepton sector, leading to the
prediction of no CP violation, namely and the Majorana phases
and are all equal to either zero or . We then
propose an effective supersymmetric model based on the symmetry in which trimaximal lepton mixing is predicted together with
either zero CP violation or with non-trivial
Majorana phases. An ultraviolet completion of the effective model yields a
neutrino mass matrix which depends on only three real parameters. As a result
of this, all three CP phases and the absolute neutrino mass scale are
determined, the atmospheric mixing angle is maximal, and the Dirac CP can
either be preserved with or maximally broken with
and sharp predictions for the Majorana phases and
neutrinoless double beta decay.Comment: 38 pages, 3 figure
Disentangling the timescales behind the non-perturbative heavy quark potential
The static part of the heavy quark potential has been shown to be closely
related to the spectrum of the rectangular Wilson loop. In particular the
lowest lying positive frequency peak encodes the late time evolution of the
two-body system, characterized by a complex potential. While initial studies
assumed a perfect separation of early and late time physics, where a simple
Lorentian (Breit-Wigner) shape suffices to describe the spectral peak, we argue
that scale decoupling in general is not complete. Thus early time, i.e.
non-potential effects, significantly modify the shape of the lowest peak. We
derive on general grounds an improved peak distribution that reflects this
fact. Application of the improved fit to non-perturbative lattice QCD spectra
now yields a potential that is compatible with a transition to a deconfined
screening plasma.Comment: 5 pages, 3 figure
Complex Heavy-Quark Potential at Finite Temperature from Lattice QCD
We calculate for the first time the complex potential between a heavy quark
and antiquark at finite temperature across the deconfinement transition in
lattice QCD. The real and imaginary part of the potential at each separation
distance is obtained from the spectral function of the thermal Wilson loop.
We confirm the existence of an imaginary part above the critical temperature
, which grows as a function of and underscores the importance of
collisions with the gluonic environment for the melting of heavy quarkonia in
the quark-gluon-plasma.Comment: 4 pages, 3 figures, to be published in PR
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