Sneutrino identification in dilepton events at the LHC

Heavy neutral resonances appearing in the clean Drell-Yan channel may be the first new physics to be observed at the proton-proton CERN LHC. If a new resonance is discovered at the LHC as a (narrow) peak in the dilepton invariant mass distribution, the characterization of its spin and couplings will proceed via the measurement of production rates and angular distributions of the decay products. We discuss the discrimination of a spin-0 resonance (sneutrino) predicted by supersymmetric theories with R-parity breaking against the spin-1 of Z^\prime bosons and the Randall-Sundrum graviton resonance (spin-2) with the same mass and producing the same number of events under the observed peak. To assess the region of sneutrino parameters (couplings and masses) where the spin determination can be performed to a given confidence level, we focus on the event rate and the angular distributions of the Drell-Yan leptons, in particular using the center-edge asymmetry, A_{\rm CE}. We find that although the measured event rate permits solving the above problem partially, the center-edge asymmetry, on the contrary allows to differentiate the various spins entirely with a minimal number of events around 200.Comment: 20 pages; version to appear in PR

Single WRW_R Production in e−e−e^-e^- Collisions at the NLC

Single $W_R$ production in $e^-e^-$ collisions at the NLC can be used to probe the Majorana nature of the heavy neutrinos present in the Left-Right Symmetric Model below the kinematic threshold for their direct production. For colliders in the $\sqrt {s}=1-1.5$ TeV range, typical cross sections of order $1-10 fb$ are obtained, depending on the specific choice of model parameters. Backgrounds arising from Standard Model processes are shown to be small. This analysis greatly extends the kinematic range of previous studies wherein the production of an on-shell, like-sign pair of $W_R$'s at the NLC was considered.Comment: 13pp, 3 figures (available on request), LaTex, SLAC-PUB-647

Female Employment and Fertility in Rural China

Data on 2,288 married women from the 2006 China Health and Nutrition Survey are deployed to study how off-farm female employment affects fertility. Such employment reduces a married woman's actual number of children by 0.64, her preferred number by 0.48, and her probability of having more than one child by 54.8 percent. Causality flows in both directions; hence, we use well validated instrumental variables to estimate employment status. China has deep concerns with both female employment and population size. Moreover, female employment is growing quickly. Hence, its implications for fertility must be understood. Ramifications for China's one-child policy are discussed.

Transport properties in correlated systems: An analytical model

Several studies have so far investigated transport properties of strongly correlated systems. Interesting features of these materials are the lack of resistivity saturation well beyond the Mott-Ioffe-Regel limit and the scaling of the resistivity with the hole density in underdoped cuprates. Due to the strongly correlated nature of these materials, mainly numerical techniques have been employed. A key role in this regards is thought to be played by the continuous transfer of spectral weight from coherent to incoherent states. In this paper we employ a simple analytical expression for the electronic Green's function to evaluate both quasi-particle and transport properties in correlated systems. Our analytical approach permits to enlighten the specific role of the spectral transfer due to the correlation on different features. In particular we investigate the dependence of both quasi-particle and transport scattering rate on the correlation degree and the criterion for resistivity saturation. systems.Comment: 11 pages, 8 figures. New version correcting a mistake of the previous version and added figure

Endocrinology in the time of covid-19: A rapid evolution of knowledge and care

American singer-writer and visual artist Bob Dylan produced the song "The Times They Are a-Changin" in the 1960s, which became a rallying cry for the civil rights and anti-war movements in that decade [...]

Low Scale Non-universal, Non-anomalous U(1)'_F in a Minimal Supersymmetric Standard Model

We propose a non-universal U(1)'_F symmetry combined with the Minimal Supersymmetric Standard Model. All anomaly cancellation conditions are satisfied without exotic fields other than three right-handed neutrinos. Because our model allows all three generations of chiral superfields to have different U(1)'_F charges, upon the breaking of the U(1)'_F symmetry at a low scale, realistic masses and mixing angles in both the quark and lepton sectors are obtained. In our model, neutrinos are predicted to be Dirac fermions and their mass ordering is of the inverted hierarchy type. The U(1)'_F charges of the chiral super-fields also naturally suppress the mu term and automatically forbid baryon number and lepton number violating operators. While all flavor-changing neutral current constraints in the down quark and charged lepton sectors can be satisfied, we find that constraint from D0-D0bar turns out to be much more stringent than the constraints from the precision electroweak data.Comment: 21 pages, 2 figures; v2: discussion on sparticle mass spectrum included, 27 pages, 2 figure

Incretin-Based Therapies Role in COVID-19 Era: Evolving Insights

The current coronavirus disease 2019 (COVID-19) pandemic has led the scientific community to breach new frontiers in the understanding of human physiology and disease pathogenesis. It has been hypothesized that the human dipeptidyl peptidase 4 (DPP4) enzyme receptor may be a functional target for the spike proteins of severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). Since DPP4-inhibitors are currently used for the treatment of patients with type-2 diabetes (T2DM), there is currently high interest in the possibility that these agents, or incretin-based therapies (IBTs) in general, may be of benefit against the new coronavirus infection. Diabetes is associated with increased COVID-19 severity and mortality, and accumulating evidence suggests that IBTs may favorably alter the clinical course of SARS-CoV-2 infection due to their inherent mechanisms of action. Further research into prognostic variables associated with various antidiabetic treatment regimens, and in particular the IBT, in patients with T2DM affected by the COVID-19 pandemic is therefore warranted

Higgs pair production in association with a vector boson at e+e- colliders in theories of higher dimensional gravity

The models of large extra compact dimensions, as suggested by Arkani-Hamed, Dimopoulos and Dvali, predict exciting phenomenological consequences with gravitational interactions becoming strong at the TeV scale. Such theories can be tested at the existing and future colliders. In this paper, we study the contribution of virtual Kaluza-Klein excitations (both spin-0 and 2) in the process $e^+e^- \to HHZ$ and $e^+e^- \to HH\gamma$ at future linear collider (NLC). We find that the virtual exchange KK gravitons can modify the cross-section $\sigma(e^+e^- \to HHZ)$ significantly from its Standard Model value and will allow the effective string scale to be probed up to 6.6 TeV. The second process is absent at the tree level in the standard model, and can therefore be used to put limits on the effective string scale of 7.4 TeV.Comment: One new reference is added, some minor corrections, version to appear in Physical Review