Probing the messenger of supersymmetry breaking by the muon anomalous magnetic moment

Motivated by the recently measured muon's anomalous magnetic moment $a_{\mu}$, we examine the supersymmetry contribution to $a_{\mu}$ in various mediation models of supersymmetry breaking which lead to predictive flavor conserving soft parameters at high energy scale. The studied models include dilaton/modulus-mediated models in heterotic string/$M$ theory, gauge-mediated model, no-scale or gaugino-mediated model, and also the minimal and deflected anomaly-mediated models. For each model, the range of $a^{SUSY}_{\mu}$ allowed by other experimental constraints, e.g. b --> s\gamma and the collider bounds on superparticle masses, is obtained together with the corresponding parameter region of the model. Gauge-mediated models with low messenger scale can give any $a^{SUSY}_{\mu}$ within the $2\sigma$ bound. In many other models, b --> s\gamma favors $a^{SUSY}_{\mu}$ smaller than either the $-1\sigma$ value ($26\times 10^{-10}$) or the central value ($42\times 10^{-10}$).Comment: RevTeX, 29 pages, 14 eps figures, figure for deflected anomaly mediation is corrected, reference adde

Selective emitter using a screen printed etch barrier in crystalline silicon solar cell

The low level doping of a selective emitter by etch back is an easy and low cost process to obtain a better blue response from a solar cell. This work suggests that the contact resistance of the selective emitter can be controlled by wet etching with the commercial acid barrier paste that is commonly applied in screen printing. Wet etching conditions such as acid barrier curing time, etchant concentration, and etching time have been optimized for the process, which is controllable as well as fast. The acid barrier formed by screen printing was etched with HF and HNO(3) (1:200) solution for 15 s, resulting in high sheet contact resistance of 90 Ω/sq. Doping concentrations of the electrode contact portion were 2 × 10(21) cm(−3) in the low sheet resistance (Rs) region and 7 × 10(19) cm(−3) in the high Rs region. Solar cells of 12.5 × 12.5 cm(2) in dimensions with a wet etch back selective emitter J(sc) of 37 mAcm(−2), open circuit voltage (V(oc)) of 638.3 mV and efficiency of 18.13% were fabricated. The result showed an improvement of about 13 mV on V(oc) compared to those of the reference solar cell fabricated with the reactive-ion etching back selective emitter and with J(sc) of 36.90 mAcm(−2), V(oc) of 625.7 mV, and efficiency of 17.60%

Sneutrino-Antisneutrino Mixing and Neutrino Mass in Anomaly--mediated Supersymmetry Breaking Scenario

In supersymmetric models with nonzero Majorana neutrino mass, the sneutrino and antisneutrino mix, which may lead to same sign dilepton signals in future collider experiments. We point out that the anomaly-mediated supersymmetry breaking scenario has a good potential to provide an observable rate of such signals for the neutrino masses suggested by the atmospheric and solar neutrino oscillations. The sneutrino mixing rate is naturally enhanced by m_{3/2}/m_{\tilde{\nu}}={\cal O}(4\pi/\alpha) while the sneutrino decay rate is small enough on a sizable portion of the parameter space. We point out also that the sneutrino-antisneutrino mixing can provide much stronger information on some combinations of the neutrino masses and mixing angles than neutrino experiments.Comment: Revtex, 13 pages, 2 figure

Exercise training and NR supplementation to improve muscle mass and fitness in adolescent and young adult hematopoietic cell transplant survivors: a randomized controlled trial {1}

Abstract Background Advances in hematopoietic cell transplantation (HCT) have led to marked improvements in survival. However, adolescents and young adults (AYAs) who undergo HCT are at high risk of developing sarcopenia (loss of skeletal muscle mass) due to the impact of HCT-related exposures on the developing musculoskeletal system. HCT survivors who have sarcopenia also have excess lifetime risk of non-relapse mortality. Therefore, interventions that increase skeletal muscle mass, metabolism, strength, and function are needed to improve health in AYA HCT survivors. Skeletal muscle is highly reliant on mitochondrial energy production, as reflected by oxidative phosphorylation (OXPHOS) capacity. Exercise is one approach to target skeletal muscle mitochondrial OXPHOS, and in turn improve muscle function and strength. Another approach is to use “exercise enhancers”, such as nicotinamide riboside (NR), a safe and well-tolerated precursor of nicotinamide adenine dinucleotide (NAD+), a cofactor that in turn impacts muscle energy production. Interventions combining exercise with exercise enhancers like NR hold promise, but have not yet been rigorously tested in AYA HCT survivors. Methods/design We will perform a randomized controlled trial testing 16 weeks of in-home aerobic and resistance exercise and NR in AYA HCT survivors, with a primary outcome of muscle strength via dynamometry and a key secondary outcome of cardiovascular fitness via cardiopulmonary exercise testing. We will also test the effects of these interventions on i) muscle mass via dual energy x-ray absorptiometry; ii) muscle mitochondrial OXPHOS via an innovative non-invasive MRI-based technique, and iii) circulating correlates of NAD+ metabolism via metabolomics. Eighty AYAs (ages 15-30y) will be recruited 6–24 months post-HCT and randomized to 1 of 4 arms: exercise + NR, exercise alone, NR alone, or control. Outcomes will be collected at baseline and after the 16-week intervention. Discussion We expect that exercise with NR will produce larger changes than exercise alone in key outcomes, and that changes will be mediated by increases in muscle OXPHOS. We will apply the insights gained from this trial to develop individualized, evidence-supported precision initiatives that will reduce chronic disease burden in high-risk cancer survivors. Trial registration ClinicalTrials.gov, NCT05194397. Registered January 18, 2022, https://clinicaltrials.gov/ct2/show/NCT05194397 {2a}