Nonstandard Interactions And B-Hadron Decays

In this work, we study the decays of heavy hadrons that contain the b quark. We study the decay modes B → D(*) τ-¯ʋ_τ Λb → Λc τ -¯ʋ_τ and B → Xc τ -¯ʋ_τ and analyze the effects of beyond the standard model new physics in various observables of these decay modes. This is important since the measurements of the decay B → D(*)τ -¯ʋ_τ deviate from the standard model predictions and this points to physics beyond the standard model. We also study CP violation in the angular distribution of the decay B → D*(→ Dπ) µ- ¯ʋµ and use it as a way to differentiate various new physics scenarios. Finally we focus on the muon (g - 2) anomaly and study a solution to this anomaly that relates it to all other B-meson anomalies. This leads to a lot of interesting signals that can be probed in the current and future experiments

Phenomenology of Λb→Λcτνˉτ\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau} using lattice QCD calculations

In a recent paper we studied the effect of new-physics operators with different Lorentz structures on the semileptonic $\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}$ decay. This decay is of interest in light of the $R({D^{(*)}})$ puzzle in the semileptonic $\bar{B} \to D^{(*)} \tau {\bar\nu}_\tau$ decays. In this work we add tensor operators to extend our previous results and consider both model-independent new physics (NP) and specific classes of models proposed to address the $R({D^{(*)}})$ puzzle. We show that a measurement of $R(\Lambda_c) = {\cal B}[\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}] / {\cal B}[\Lambda_b \to \Lambda_c \ell \bar{\nu}_{\ell}]$ can strongly constrain the NP parameters of models discussed for the $R({D^{(*)}})$ puzzle. We use form factors from lattice QCD to calculate all $\Lambda_b \to \Lambda_c \tau \bar{\nu}_{\tau}$ observables. The $\Lambda_b \to \Lambda_c$ tensor form factors had not previously been determined in lattice QCD, and we present new lattice results for these form factors here.Comment: 44 pages, 105 figure

Dark sector origin of the KOTO and MiniBooNE anomalies

© 2020 The Author(s) We present a dark sector model that reproduces the KOTO, MiniBooNE and muon anomalous magnetic moment anomalies. The dark sector is comprised of a light scalar singlet S that has a large coupling to a slightly heavier sterile neutrino that mixes with the active neutrinos. The scalar couples to standard model fermions via Yukawa couplings, and to photons via a higher-dimensional coupling. The KOTO signal is a result of the flavor-changing penguin process KL→π0S followed by the decay of S to neutrinos. The sterile neutrino produced in neutrino-nucleus scattering at MiniBooNE decays to an active neutrino and S, which decays electromagnetically and creates an event excess at low energies

Comparison of effects of propofol and ketofol (Ketamine-Propofol mixture) on emergence agitation in children undergoing tonsillectomy

Background: The aim of this study was to compare the effect of propofol and ketofol (ketamine-propofol mixture) on EA in children undergoing tonsillectomy.Method: In this randomized clinical trial, 87 ASA class I and II patients, aged 3-12 years, who underwent tonsillectomy, were divided into two groups to receive  either propofol 100 µg/kg/min (group p, n=44) or ketofol : ketamine 25 µg/kg/min + propofol 75 µg/kg/min (group k, n= 43). Incidence and severity of EA was evaluated using the Pediatric Anesthesia Emergence Delirium (PAED) scales on arrival at the recovery room, and 10 and 30 min after that time.   Results: There was no statistically significant difference in demographic data between the two groups. In the ketofol group, the need for agitation treatment and also mean recovery duration were lower than in the propofol group (30 and 41%, and 29.9 and 32.7 min), without statistically significant difference (P value=0.143 and P value=0.187). Laryngospasm or bronchospasm occurred in 2 patients in each group and bleeding was observed in only one individual in the ketofol group.Conclusion: Infusion of ketofol in children undergoing tonsillectomy provides shorter recovery time and lower incidence of EA despite the non significant difference with propofol.Keywords:  Emergence agitation, ketofol, propofol

Multidimensional Comparison of Lightweight Steel and Reinforced Concrete Structures: A Case Study

Lightweight steel construction has some undeniable advantages over concrete construction; however, reinforced concrete structures are used ubiquitously in Mediterranean countries and therefore most of the scientific studies have been focused on the reinforced concrete structures. One of the main reasons for not using the lightweight steel construction widely is lack on knowhow about this method. This study is aimed at raising the knowledge about the technical features of cold-formed steel members as well as advantages of lightweight steel structure in comparison with reinforced concrete. To fulfil this aim, a case study was conducted to compare lightweight steel structure with reinforced concrete structure in different points of view in detail. From the case study, it is found out that the building total covered area and mass designed by reinforced concrete structure are 2.6% larger and 9 times greater than the lightweight steel structure respectively. It was also concluded that the total cost (indirect and direct) and construction duration for the reinforced concrete structural frame are approximately 17.7% and 70.9% respectively higher than constructing the lightweight steel structural frame

Resolving the (g−2)μ(g-2)_{\mu} and BB anomalies with leptoquarks and a dark Higgs boson

At present, there are outstanding discrepancies between standard model predictions and measurements of the muon's $g-2$ and several $B$-meson properties. We resolve these anomalies by considering a two-Higgs-doublet model extended to include leptoquarks and a dark Higgs boson $S$. The leptoquarks modify $B$-meson decays and also induce an $S \gamma \gamma$ coupling, which contributes to the muon's $g-2$ through a Barr-Zee diagram. We show that, for TeV-scale leptoquarks and dark Higgs boson masses $m_{S} \sim 10-200~\text{MeV}$, a consistent resolution to all of the anomalies exists. The model predicts interesting new decays, such as $B \to K^{(*)} e^+ e^-$, $B \to K^{(*)} \gamma \gamma$, $K \to \pi \gamma \gamma$, and $h \to \gamma \gamma \gamma \gamma$, with branching fractions not far below current bounds.Comment: 25 pages, 7 figures. Matches published versio