New Renormalization Group Equations and the Naturalness Problem

Looking for an observable manifestation of the so-called unnaturalness of scalar fields we introduce a seemingly new set of differential equations for connected Green functions. These equations describe the momentum dependence of the Green functions and are close relatives to the previously known renormalization group equations. Applying the new equations to the theory of scalar field with $\phi^4$ interaction we identify a relation between the four-point Green function and the propagator which expresses the unnaturalness of the scalar field. Possible manifestations of the unnaturalness at low momenta are briefly discussed.Comment: 12 revtex pages; a coefficient has been corrected in eq. (34), four new references added; final version to appear in Phys. Rev.

Meling Pot U.S.A. : l’anglicisation des Hispano-Américains

Basée sur des données recueillies lors du Sondage sur le Revenu et l’Éducation de 1976 (Survey of Income and Education) par Ie Bureau du Recensement américain, cette recherche démontre qu’il n’y a aucune évidence permettant de supposer une résistance massive des Hispano-Américains à l’anglicisation aux États-Unis. Au contraire lorsque les données sont décomposées adéquatement par lieu de naissance (et période d’immigration pour ceux qui sont nés à l’extérieur), elles montrent que les Hispano-Américains sont en train de s’assimiler rapidement et uniformément au groupe anglophone. Les données indiquent que l’anglicisation est plus répandue chez les groupes d’âge plus jeunes, i.e. que les taux d’anglicisation se sont accentués au cours des dernières décennies. De plus, malgré certaines variations régionales de ces taux danglicisation, les taux actuels de déplacement linguistique de l’espagnol à l’anglais dépassent 50% dans toutes les régions du pays, y compris celles qui sont limitrophes au Mexique

Le sort de la francophonie aux États-Unis

Les données tirées de l’Enquête sur le revenu et la scolarité, effectuée aux États-Unis en 1976, démontrent que les principales concentrations de groupes francophones se composent en majorité de personnes avancées en âge. Les données nous révèlent également des degrés élevés d’anglicisation, que celle-ci s’accompagne du maintien du français comme langue seconde ou d’un abandon du français. Par ailleurs, les ménages bilingues ne parviennent pas à transmettre la langue française aux jeunes. Dans le sud de la Nouvelle-Angleterre, les francophones ont toujours connu un taux élevé d’anglicisation. Dans le nord de la Nouvelle-Angleterre, les taux d’anglicisation sont plus faibles mais ils augmentent régulièrement. Le déclin est plus marqué en Louisiane où l’anglicisation des jeunes est déjà achevée et où il n’existe à peu près pas de bilingues de moins de vingt-cinq ans

Two component theory and electron magnetic moment

The two-component formulation of quantum electrodynamics is studied. The relation with the usual Dirac formulation is exhibited, and the Feynman rules for the two-component form of the theory are presented in terms of familiar objects. The transformation from the Dirac theory to the two-component theory is quite amusing, involving Faddeev-Popov ghost loops of a fermion type with bose statistics. The introduction of an anomalous magnetic moment in the two-component formalism is simple; it is not equivalent to a Pauli term in the Dirac formulation. Such an anomalous magnetic moment appears not to destroy the renormalizability of the theory but violates unitarity

Off-Shell Scattering Amplitudes for WW Scattering and the Role of the Photon Pole

We derive analytic expressions for high energy $2 \to 2$ off-shell scattering amplitudes of weak vector bosons. They are obtained from six fermion final states in processes of the type $e^+ e^- \to \bar\nu_e + (WW) + \nu_e \to \bar\nu_e + (l\nu)(l\nu) + \nu_e$. As an application we reconsider the unitarity bounds on the Higgs mass. Particular attention is given to the role of the photon exchange which has not been considered in earlier investigations; we find that the photon weakens the bound of the Higgs mass.Comment: 16 pages, 8 figure

Dropping rho and A_1 Meson Masses at Chiral Phase Transition in the Generalized Hidden Local Symmetry

We study the chiral symmetry restoration using the generalized hidden local symmetry (GHLS) which incorporates the rho and A_1 mesons as the gauge bosons of the GHLS and the pion as the Nambu-Goldstone boson consistently with the chiral symmetry of QCD. We show that a set of parameter relations, which ensures the first and second Weinberg's sum rules, is invariant under the renormalization group evolution. Then, we found that the Weinberg's sum rules together with the matching of the vector and axial-vector current correlators inevitably leads to {\it the dropping masses of both rho and A_1 mesons} at the symmetry restoration point, and that the mass ratio as well as the mixing angle between the pion and A_1 meson flows into one of three fixed points.Comment: 17 pages, 7 figures; references added and discussions expande

Low-Energy Effective Theory, Unitarity, and Non-Decoupling Behavior in a Model with Heavy Higgs-Triplet Fields

We discuss the properties of a model incorporating both a scalar electroweak Higgs doublet and an electroweak Higgs triplet. We construct the low-energy effective theory for the light Higgs-doublet in the limit of small (but nonzero) deviations in the rho parameter from one, a limit in which the triplet states become heavy. For small deviations in the rho parameter from one, perturbative unitarity of WW scattering breaks down at a scale inversely proportional to the renormalized vacuum expectation value of the triplet field (or, equivalently, inversely proportional to the square-root of the deviation of the rho parameter from one). This result imposes an upper limit on the mass-scale of the heavy triplet bosons in a perturbative theory; we show that this upper bound is consistent with dimensional analysis in the low-energy effective theory. Recent articles have shown that the triplet bosons do not decouple, in the sense that deviations in the rho parameter from one do not necessarily vanish at one-loop in the limit of large triplet mass. We clarify that, despite the non-decoupling behavior of the Higgs-triplet, this model does not violate the decoupling theorem since it incorporates a large dimensionful coupling. Nonetheless, we show that if the triplet-Higgs boson masses are of order the GUT scale, perturbative consistency of the theory requires the (properly renormalized) Higgs-triplet vacuum expectation value to be so small as to be irrelevant for electroweak phenomenology.Comment: Revtex, 11 pages, 7 eps figures included; references updated and three footnotes adde

Boosting Higgs discovery - the forgotten channel

Searches for a heavy Standard Model Higgs boson focus on the 'gold plated mode' where the Higgs decays to two leptonic Z bosons. This channel provides a clean signature, in spite of the small leptonic branching ratios. We show that using fat jets the semi-leptonic ZZ mode significantly increases the number of signal events with a similar statistical significance as the leptonic mode.Comment: 12 pages, 3 figure

The unit of electric charge and the mass hierarchy of heavy particles

We propose some empirical formulae relating the masses of the heaviest particles in the standard model (the W,Z,H bosons and the t quark) to the charge of the positron $e$ and the Higgs condensate v. The relations for the masses of gauge bosons m_W = (1+e)v/4 and m_Z=sqrt{(1+e^2)/2}*(v/2) are in excellent agreement with experimental values. By requiring the electroweak standard model to be free from quadratic divergencies at the one-loop level, we find: m_t=v/sqrt{2} and m_H=v/sqrt{2e}, or the very simple ratio (m_t/m_H)^2=e.Comment: 6 page

Social Mindfulness and Psychosis: Neural response to socially mindful behavior in first-episode psychosis and patients at clinical high-risk

Background: Psychosis is characterized by problems in social functioning and trust, the assumed glue to positive social relations. But what helps building trust? A prime candidate could be social mindfulness: The ability and willingness to see and consider another person’s needs and wishes during social decision making. We investigated whether first-episode psychosis patients (FEP) and patients at clinical high-risk (CHR) show reduced social mindfulness, and examined the underlying neural mechanisms. Methods: Twenty FEP, 17 CHR and 46 healthy controls, aged 16-31, performed the social mindfulness task (SoMi) during fMRI scanning, spontaneously and after the instruction “to keep the other’s best interest in mind”. As first of two people, participants had to choose one out of four products, of which three were identical and one was unique, differing in a single aspect (e.g., color). Results: FEP tended to choose the unique item (unmindful choice) more often than controls. After instruction, all groups significantly increased the number of mindful choices compared to the spontaneous condition. FEP showed reduced activation of the caudate and medial prefrontal cortex (mPFC) during mindful, and of the anterior cingulate cortex (ACC), mPFC, and left dorso-lateral prefrontal cortex (dlPFC) during unmindful decisions. CHR showed reduced activation of the ACC compared to controls. Discussion: FEP showed a trend towards more unmindful choices. A similar increase of mindful choices after instruction indicated the ability for social mindfulness when prompted. Results suggested reduced sensitivity to the rewarding aspects of social mindfulness in FEP, and reduced consideration for the other player. FEP (and CHR to a lesser extent) might perceive unmindful choices as less incongruent with the automatic mindful responses than controls. Reduced socially mindful behavior in FEP may hinder the building of trust and cooperative interactions