Dirac Neutrino Masses from Generalized Supersymmetry Breaking

We demonstrate that Dirac neutrino masses in the experimentally preferred range are generated within supersymmetric gauge extensions of the Standard Model with a generalized supersymmetry breaking sector. If the usual superpotential Yukawa couplings are forbidden by the additional gauge symmetry (such as a U(1)'), effective Dirac mass terms involving the "wrong Higgs" field can arise either at tree level due to hard supersymmetry breaking fermion Yukawa couplings, or at one-loop due to nonanalytic or "nonholomorphic" soft supersymmetry breaking trilinear scalar couplings. As both of these operators are naturally suppressed in generic models of supersymmetry breaking, the resulting neutrino masses are naturally in the sub-eV range. The neutrino magnetic and electric dipole moments resulting from the radiative mechanism also vanish at one-loop order.Comment: 5 pages, 1 figure, references added, note added on effective superpotential mass terms generated upon U(1)' breakin

Baha Tevfik Dergiciliğinde Kadın: Temsil Mi, Tasavvur Mu?

Türk basın tarihinin önemli bir ismi olan ve Batıcılaşma akımı temsilcileri arasında yer alan Baha Tevfik, fikir, edebiyat ve mizah dergiciliğine yaptığı katkılarla tanınmaktadır. Toplumsal hayatta yaşanan dönüşüm ve kırılmaların takibi için basın tarihi araştırmalarının sosyal bilimlere açtığı yeni imkânlar ve geniş pencere çerçevesinde Baha Tevfik’in dergicilik anlayışı, 20. yüzyılın ilk yarısında Osmanlı sosyal, siyasal ve kültürel hayatı ile alakalı sunduğu zengin veriyle dikkat çekmektedir. Dönem, kadın kimliğinde yaşanan bir dönüşümün kuvvetli sinyallerini vermesi sebebiyle de mercek altına alınmayı hak etmektedir. Bu bağlamda, özellikle II. Meşrutiyet’in ilanını takip eden ve sosyal dönüşümün hızlandığı yıllarda Baha Tevfik’in yayımına katkıda bulunduğu fikir dergisi olan Yirminci Asırda Zeka izleğinde, kadının görsel materyallerle temsili hakkındaki bu çalışma, dönemin kadın söylemine dair bulguları sunmayı hedeflemektedir. Göstergebilim yaklaşımı çalışmanın yöntemi olarak seçilmiştir. Bu bağlamda çalışmada derginin kapağında kullanılan görsel malzeme, Roland Barthes’ın düz ve yan anlam kavramlarına dayanılarak, kadın bedeni ve kimliğinin sunulma biçimine dair yorum yapma olanağına ulaşılması amaçlanmıştır. Böylece kadını sembolize eden görsellerin, toplum gerçeklerini mi temsil etmekte, yoksa yeni bir kadın tasavvuru mu geliştirmekte olduğuna odaklanılmıştır. Neticede mezkur derginin kapak fotoğrafları aracılığıyla Batılı normlarda sunulan kadında, toplumsal gerçeklikle mütekabiliyetinin bulunmadığı, diğer taraftan teşhire varan bir görsel kullanımının gerçekleştirildiği tespit edilmiştir

Can Measurements of Electric Dipole Moments Determine the Seesaw Parameters?

In the context of the supersymmetrized seesaw mechanism embedded in the Minimal Supersymmetric Standard Model (MSSM), complex neutrino Yukawa couplings can induce Electric Dipole Moments (EDMs) for the charged leptons, providing an additional route to seesaw parameters. However, the complex neutrino Yukawa matrix is not the only possible source of CP violation. Even in the framework of Constrained MSSM (CMSSM), there are additional sources, usually attributed to the phases of the trilinear soft supersymmetry breaking couplings and the mu-term, which contribute not only to the electron EDM but also to the EDMs of neutron and heavy nuclei. In this work, by combining bounds on various EDMs, we analyze how the sources of CP violation can be discriminated by the present and planned EDM experiments.Comment: 26 pages, 9 figures; added reference

General Tensor Lagrangians from Gravitational Higgs Mechanism

The gravitational Higgs mechanism proposed by 't Hooft in arXiv:0708.3184 involves the spacetime metric g_{mu nu} as well as the induced metric \bar{g}_{mu nu} proportional to \eta_{a b} \partial_{mu} \phi^a \partial_{nu} \phi^b where \phi^{a} (a=0,...,3), as we call it, break all four diffeomorphisms spontaneously via the vacuum expectation values proportional to x^a. In this framework, we construct and analyze the most general action density in terms of various invariants involving the curvature tensors, connexion coefficients, and the contractions and the determinants of the two metric fields. We show that this action admits a consistent expansion about the flat background such that the resulting Lagrangian possesses several novel features not found in the linearized Einstein-Hilbert Lagrangian with Fierz-Pauli mass term (LELHL-FP): (i) its kinetic part generalizes that of LELHL-FP by weighing the corresponding structures with certain coefficients generated by invariants, (ii) the entire Lagrangian is ghost-- and tachyon--free for mass terms not necessarily in the Fierz-Pauli form, and, (iii) a consistent mass term is generated with no apparent need to higher derivative couplings.Comment: 20 pp; added a referenc

Effects of annealing on device parameters of organic field effect transistors using liquid-crystalline tetrasubstituted zinc phthalocyanine

The device performance of organic thin-film transistors (OTFTs) employing the solution processed films of room temperature liquid-crystalline tetrasubstituted zinc phthalocyanine derivative was found to depend upon the film morphology. Atomic force microscopic and X-Ray diffraction studies show that the annealing at 70° produced a preferentially unidirectional void-free film with improved surface smoothness. The OTFTs with the annealed films exhibited enhanced conductivity, threefold reduction in threshold voltage, a nearly one order of magnitude increase in the on/off ratio and more than one-third reduction of hysteresis in the transfer characteristics.This work is sponsored by the Air Force Office of Scientific Research, Air Force Material Command, USAF, under grant No. FA8655-13-1-3018. TB acknowledges the financial support from the Ministry of Education and Science of the Russian Federation

Doubly Charged Higgsinos at Tevatron

Several supersymmetric models with extended gauge structures, motivated by either grand unification or by neutrino mass generation, predict light doubly-charged Higgsinos. In this work we study the signals of doubly-charged Higgsinos at the Tevatron in both pair-- and single--production modes, and show that it is possible, especially from the events containing same-sign same-flavor isolated leptons, to disentangle the effects of doubly-charged Higgsinos in the Tevatron data.Comment: 21 pages, 6 figures, 2 table

Hadronic EDMs, the Weinberg Operator, and Light Gluinos

We re-examine questions concerning the contribution of the three-gluon Weinberg operator to the electric dipole moment of the neutron, and provide several QCD sum rule-based arguments that the result is smaller than - but nevertheless consistent with - estimates which invoke naive dimensional analysis. We also point out a regime of the MSSM parameter space with light gluinos for which this operator provides the dominant contribution to the neutron electric dipole moment due to enhancement via the dimension five color electric dipole moment of the gluino.Comment: 6 pages, RevTeX, 3 figures; v2: references added; v3: typos corrected, to appear in Phys. Rev.

Preserving the Lepton Asymmetry in the Brane World

In models where the Standard Model spectrum is localized on a brane embedded in a higher dimensional spacetime, we discuss the lepton number violation induced by the emission of right-handed neutrinos from the brane. We show that quite generically the presence of the right-handed neutrinos in the bulk leads to rapid lepton number violating processes which above the electroweak scale would wash away any prior lepton or baryon asymmetry. In order to preserve the lepton asymmetry, the brane-bulk couplings for at least one lepton flavor must be extremely suppressed. We show that this has a natural interpretation in the brane world.Comment: 13 pages, latex, 2 eps figure clarifications and reference adde

CP Violation in Supersymmetric U(1)' Models

The supersymmetric CP problem is studied within superstring-motivated extensions of the MSSM with an additional U(1)' gauge symmetry broken at the TeV scale. This class of models offers an attractive solution to the mu problem of the MSSM, in which U(1)' gauge invariance forbids the bare mu term, but an effective mu parameter is generated by the vacuum expectation value of a Standard Model singlet S which has superpotential coupling of the form SH_uH_d to the electroweak Higgs doublets. The effective mu parameter is thus dynamically determined as a function of the soft supersymmetry breaking parameters, and can be complex if the soft parameters have nontrivial CP-violating phases. We examine the phenomenological constraints on the reparameterization invariant phase combinations within this framework, and find that the supersymmetric CP problem can be greatly alleviated in models in which the phase of the SU(2) gaugino mass parameter is aligned with the soft trilinear scalar mass parameter associated with the SH_uH_d coupling. We also study how the phases filter into the Higgs sector, and find that while the Higgs sector conserves CP at the renormalizable level to all orders of perturbation theory, CP violation can enter at the nonrenormalizable level at one-loop order. In the majority of the parameter space, the lightest Higgs boson remains essentially CP even but the heavier Higgs bosons can exhibit large CP-violating mixings, similar to the CP-violating MSSM with large mu parameter.Comment: 29 pp, 3 figs, 2 table