12,133 research outputs found
Partial Hasse invariants on splitting models of Hilbert modular varieties
Let be a totally real field of degree , and let be a prime number.
We construct partial Hasse invariants on the characteristic fiber of
the Pappas-Rapoport splitting model of the Hilbert modular variety for with
level prime to , extending the usual partial Hasse invariants defined over
the Rapoport locus. In particular, when ramifies in , we solve the
problem of lack of partial Hasse invariants. Using the stratification induced
by these generalized partial Hasse invariants on the splitting model, we prove
in complete generality the existence of Galois pseudo-representations attached
to Hecke eigenclasses of paritious weight occurring in the coherent cohomology
of Hilbert modular varieties , extending a previous result
of M. Emerton and the authors which required to be unramified in .Comment: 24 pages, refereed version, index changed from the previous versio
Quantum discord for general two--qubit states: Analytical progress
We present a reliable algorithm to evaluate quantum discord for general
two--qubit states, amending and extending an approach recently put forward for
the subclass of X--states. A closed expression for the discord of arbitrary
states of two qubits cannot be obtained, as the optimization problem for the
conditional entropy requires the solution to a pair of transcendental equations
in the state parameters. We apply our algorithm to run a numerical comparison
between quantum discord and an alternative, computable measure of non-classical
correlations, namely the geometric discord. We identify the extremally
non-classically correlated two--qubit states according to the (normalized)
geometric discord, at fixed value of the conventional quantum discord. The
latter cannot exceed the square root of the former for systems of two qubits.Comment: 8 pages, 2 figure
Hybridized tetraquarks
We propose a new interpretation of the neutral and charged X,Z
exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h -tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the View the MathML source
channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X,Z
particles. Considerations on a state with the same quantum numbers as the X(5568)
are also made
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