1,720,965 research outputs found
Parity from SO(7, 1) and SO(7, 7) gauge symmetries
No full textLeft-Right parity symmetry P can arise from a unified gauge symmetry, involving gravitational interactions. Parity can survive to the symmetry breaking of the gauge group at Planck scale and can be spontaneously broken at lower energies, as in Left-Right symmetric models with P
Present and future K and B meson mixing constraints on TeV scale left-right symmetry
No full textWe revisit the ΔF 1⁄4 2 transitions in the K and Bd;s neutral meson systems in the context of the minimal left-right symmetric model. We take into account, in addition to up-to-date phenomenological data, the contributions related to the renormalization of the flavor-changing neutral Higgs tree-level amplitude. These contributions were neglected in recent discussions, albeit formally needed in order to obtain a gauge- independent result. Their impact on the minimal LR model is crucial and twofold. First, the effects are relevant in B meson oscillations, for both CP conserving and CP violating observables, so that for the first time these imply constraints on the LR scenario which compete with those of the K sector (plagued by long- distance uncertainties). Second, they sizably contribute to the indirect kaon CP violation parameter ε. We discuss the bounds from B and K mesons in both cases of LR symmetry: generalized parity (P) and charge conjugation (C). In the case of P, the interplay between the CP-violation parameters ε and ε0 leads us to rule out the regime of very hierarchical bidoublet vacuum expectation values v2=v1 < mb=mt ≃ 0.02. In general, by minimizing the scalar field contribution up to the limit of the perturbative regime and by definite values of the relevant CP phases in the charged right-handed currents, we find that a right-handed gauge boson WR as light as 3 TeV is allowed at the 95% C. L. This is well within the reach of direct detection at the next LHC run. If not discovered, within a decade the upgraded LHCb and Super B factories may reach an indirect sensitivity to a left-right scale of 8 TeV
K→ππ hadronic matrix elements of left-right current-current operators
No full textEffective S 1⁄4 1 four-fermion operators involving left- and right-handed currents are relevant in left-right gauge extensions of the Standard Model and scalar extension of the Yukawa sector. They induce K ! %% decays which are strictly constrained by experimental data, typically resulting in strong bounds on the new physics scales or parameters. We evaluate the K ! %% hadronic matrix elements of such operators within the phenomenological framework of the chiral quark model. The results are consistent with the estimates used in a previous work on TeV scale left-right symmetry, thus confirming the conclusions obtained there
Perturbativity and mass scales in the minimal left-right symmetric model
No full textThe scalar sector of the minimal Left-Right model at TeV scale is revisited in light of the large quartic coupling needed for a heavy flavor-changing scalar. The stability and perturbativity of the effective potential is discussed and merged with constraints from low-energy processes. Thus the perturbative level of the Left-Right scale is sharpened. Lower limits on the triplet scalars are also derived: the left-handed triplet is bounded by oblique parameters, while the doubly-charged right- handed component is limited by the h → γγ, Zγ decays. Current constraints disfavor their detection as long as WR is within the reach of the LHC
Parity from gauge symmetry
Full text linkWe argue that Left-Right parity symmetry can arise as a
discrete remnant of a unified gauge symmetry. The high-energy unification
necessarily includes the gauging of the Lorentz symmetry, bringing into the
game gravitational interactions, and leading to a gravi-GUT scheme. Parity
emerges unbroken below the Planck scale, and can be broken spontaneously at
lower energies making contact with the Standard Model. This framework motivates
the spontaneous origin of parity violation as in Left-Right symmetric theories
with . The possible unifying gauge groups are identified as
SO(1,7) for gravitational and weak interactions, or SO(7,7) for a complete
unification.Comment: 7 pages, version to appear in EPJ
Lepton Number Violation in Higgs Decay at LHC
No full textWe show that within the left-right symmetric model, lepton number violating decays of the Higgs boson can be discovered at the LHC. The process is due to the mixing of the Higgs boson with the triplet that breaks parity. As a result, the Higgs boson can act as a gateway to the origin of the heavy Majorana neutrino mass. To assess the LHC reach, a detailed collider study of the same-sign dileptons plus jets channel is provided. This process is complementary to the existing nuclear and collider searches for lepton number violation and can probe the scale of parity restoration even beyond other direct searches
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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