Search results for "Matrix"
showing 10 items of 3205 documents
Bell inequality, nonlocality and analyticity
2003
The Bell and the Clauser-Horne-Shimony-Holt inequalities are shown to hold for both the cases of complex and real analytic nonlocality in the setting parameters of Einstein-Podolsky-Rosen-Bohm experiments for spin 1/2 particles and photons, in both the deterministic and stochastic cases. Therefore, the theoretical and experimental violation of the inequalities by quantum mechanics excludes all hidden variables theories with that kind of nonlocality. In particular, real analyticity leads to negative definite correlations, in contradiction with quantum mechanics.
Phase diagram of the two-channel kondo lattice model in one dimension.
2004
Employing the density matrix renormalization group method and strong-coupling perturbation theory, we study the phase diagram of the $\mathrm{SU}(2)\ifmmode\times\else\texttimes\fi{}\mathrm{SU}(2)$ Kondo lattice model in one dimension. We show that, at quarter filling, the system can exist in two phases depending on the coupling strength. The weak-coupling phase is dominated by RKKY exchange correlations, while the strong-coupling phase is characterized by strong antiferromagnetic correlations of the channel degree of freedom. These two phases are separated by a quantum critical point. For conduction-band fillings of less than one-quarter, we find a paramagnetic metallic phase at weak coupl…
Features of quark and lepton mixing from differential geometry of curves on surfaces
1998
It is noted that the CKM matrix elements for both quarks and leptons as conceived in the Dualized Standard Model (DSM) can be interpreted as direction cosines obtained by moving the Darboux trihedron (a 3-frame) along a trajectory on a sphere traced out through changing energy scales by a 3-vector factorized from the mass matrix. From the `Darboux' analogues of the well-known Serret--Frenet formulae for space curves, it is seen that the corner elements ($V_{ub}, V_{td}$ for quarks, and $U_{e3}, U_{\tau 1}$ for leptons) are associated with the (geodesic) torsion, while the other off-diagonal elements ($V_{us}, V_{cd}$ and $V_{cb}, V_{ts}$ for quarks, and $U_{e2}, U_{\mu 1}$ and $U_{\mu 3}, U…
Improved measurement ofCPobservables inB±→DCP0K±decays
2008
We present a study of the decay B{sup -} {yields} D{sub (CP)}{sup 0}K{sup -} and its charge conjugate, where D{sub (CP)}{sup 0} is reconstructed in both a non-CP flavor eigenstate and in CP (CP-even and CP-odd) eigenstates, based on a sample of 382 million {Upsilon}(4S) {yields} B{bar B} decays collected with the BABAR detector at the PEP-II e{sup +}e{sup -} storage ring. We measure the direct CP asymmetries A{sub CP{+-}} and the ratios of the branching fractions R{sub CP{+-}}: A{sub CP+} = 0.27 {+-} 0.09(stat) {+-} 0.04(syst), A{sub CP-} = -0.09 {+-} 0.09(stat) {+-} 0.02(syst), R{sub CP+} = 1.06 {+-} 0.10(stat) {+-} 0.05(syst), R{sub CP-} = 1.03 {+-} 0.10(stat) {+-} 0.05(syst). These resul…
Relating quarks and leptons without grand-unification
2011
In combination with supersymmetry, flavor symmetry may relate quarks with leptons, even in the absence of a grand-unification group. We propose an SU(3)xSU(2)xU(1) model where both supersymmetry and the assumed A4 flavor symmetries are softly broken, reproducing well the observed fermion mass hierarchies and predicting: (i) a relation between down-type quarks and charged lepton masses, and (ii) a correlation between the Cabibbo angle in the quark sector, and the reactor angle characterizing CP violation in neutrino oscillations.
Quark–lepton mass relation in a realistic A4 extension of the Standard Model
2013
We propose a realistic A4A4 extension of the Standard Model involving a particular quark–lepton mass relation, namely that the ratio of the third family mass to the geometric mean of the first and second family masses are equal for down-type quarks and charged leptons. This relation, which is approximately renormalization group invariant, is usually regarded as arising from the Georgi–Jarlskog relations, but in the present model there is no unification group or supersymmetry. In the neutrino sector we propose a simple modification of the so-called Zee–Wolfenstein mass matrix pattern which allows an acceptable reactor angle along with a deviation of the atmospheric and solar angles from thei…
Resummed jet rates for $e^+e^-$ annihilation into massive quarks
2003
Expressions for Sudakov form factors for heavy quarks are presented. They are used to construct resummed jet rates for up to four jets in $e^+e^-$ annihilation. The coefficients of leading and next-to-leading logarithmic corrections, mandatory for a combination with higher order matrix elements, are evaluated up to second order in $\alpha_s$.
A new way to search for right-handed currents in semileptonic B→ρℓν‾ decay
2016
AbstractThere exist a long standing tension among determinations of the CKM matrix element |Vub| from various (semi)leptonic B decay channels with varying significance of up to ∼3σ. An interesting possibility to ease this tension is to allow for a right-handed contribution to the standard model left-handed weak current mediating the b→u quark decay. Current bounds on such a contribution are fairly weak. We propose a new way to search for such a right-handed current in semileptonic B→ρ meson decays. We describe a new variable that we propose, and discuss the theoretical uncertainties. Especially we investigate the uncertainties and their correlations among all contributing form factors with …
Spontaneous CP violation in the left-right model and the kaon system
1996
A left-right model with spontaneous $CP$ breakdown, consistent with the particle physics phenomenology, is presented. Constraints on free parameters of the model: mass of the new right handed gauge boson $M_2$ and ratio $r$ of the two vacuum expectation values of the bidoublet, are found from the measurement of $\epsilon$ in the kaon system. For most of the parameter space, $M_2$ is restricted to be below 10 TeV. Higher masses can be achieved only by fine tuning of Kobayashi-Maskawa matrix elements, quark masses, $r$ and the phase $\alpha$ which is the unique source of $CP$-violation in the model. Large number of combinations of signs of quark masses, which are observables of the model, are…
Quark-lepton mass relation and CKM mixing in an A(4) extension of the minimal supersymmetric standard model
2013
An interesting mass relation between down-type quarks and charged leptons has been recently predicted within a supersymmetric SU(3)(c) circle times SU(2)(L) circle times U(1)(Y) model based on the A(4) flavor symmetry. Here we propose a simple extension which provides an adequate full description of the quark sector. By adding a pair of vectorlike up quarks, we show how the CKM entries V-ub, V-cb, V-td and V-ts arise from deviations of the unitarity. We perform an analysis including the most relevant observables in the quark sector, such as oscillations and rare decays of kaons, B-d and B-s mesons. In the lepton sector, the model predicts an inverted hierarchy for the neutrino masses, leadi…