Muon to electron conversion in the Littlest Higgs model with T-parity

Little Higgs models provide a natural explanation of the little hierarchy between the electroweak scale and a few TeV scale, where new physics is expected. Under the same inspiring naturalness arguments, this work completes a previous study on lepton flavor-changing processes in the Littlest Higgs model with T-parity exploring the channel that will eventually turn out to be the most sensitive, \mu-e conversion in nuclei. All one-loop contributions are carefully taken into account, results for the most relevant nuclei are provided and a discussion of the influence of the quark mixing is included. The results for the Ti nucleus are in good agreement with earlier work by Blanke et al., where a degenerate mirror quark sector was assumed. The conclusion is that, although this particular model reduces the tension with electroweak precision tests, if the restrictions on the parameter space derived from lepton flavor violation are taken seriously, the degree of fine tuning necessary to meet these constraints also disfavors this model.Comment: 26 pages, 7 figures, 4 tables; discussion improved, results unchanged, one reference added, version to appear in JHE

Top Partner Discovery in the T→tZT\to tZ channel at the LHC

In this paper we study the discovery potential of the LHC run II for heavy vector-like top quarks in the decay channel to a top and a $Z$ boson. Despite the usually smaller branching ratio compared to charged-current decays, this channel is rather clean and allows for a complete mass reconstruction of the heavy top. The latter is achieved in the leptonic decay channel of the $Z$ boson and in the fully hadronic top channel using boosted jet and jet substructure techniques. To be as model-independent as possible, a simplified model approach with only two free parameters has been applied. The results are presented in terms of parameter space regions for $3\sigma$ evidence or $5\sigma$ discovery for such new states in that channel.Comment: 24 pages, 8 figures, version 2 updated to JHEP 01 (2015) 08

Supersymmetric contributions to Bˉs→ϕπ0\bar{B}_s \to \phi \pi^0 and Bˉs→ϕρ0\bar{B}_s \to \phi \rho^0 decays in SCET

We study the decay modes $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi \rho^0$ using Soft Collinear Effective Theory. Within Standard Model and including the error due to the SU(3) breaking effect in the SCET parameters we find that BR $\bar{B}_s\to \phi \pi^0 =7_{-1-2}^{+1+2}\times 10^{-8}$ and BR $\bar{B}_s\to \phi \pi^0=9_{-1-4}^{+1+3}\times 10^{-8}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively.For the decay mode $\bar{B}_s\to \phi \rho^0$, we find that BR $\bar{B}_s\to \phi \rho^0 = 20.2^{+1+9}_{-1-12}\times 10^{-8}$ and BR $\bar{B}_s\to \phi \rho^0 = 34.0^{+1.5 + 15}_{-1.5-22}\times 10^{-8}$ corresponding to solution 1 and solution 2 of the SCET parameters respectively. We extend our study to include supersymmetric models with non-universal A-terms where the dominant contributions arise from diagrams mediated by gluino and chargino exchanges. We show that gluino contributions can not lead to an enhancement of the branching ratios of $\bar{B}_s\to \phi \pi^0$ and $\bar{B}_s\to \phi \rho^0$. In addition, we show that SUSY contributions mediated by chargino exchange can enhance the branching ratio of $\bar{B}_s\to \phi \pi^0$ by about 14% with respect to the SM prediction. For the branching ratio of $\bar{B}_s\to \phi \rho^0$, we find that SUSY contributions can enhance its value by about 1% with respect to the SM prediction.Comment: 25 pages,5 figures, version accepted for publicatio

Event-related alpha suppression in response to facial motion

This article has been made available through the Brunel Open Access Publishing Fund.While biological motion refers to both face and body movements, little is known about the visual perception of facial motion. We therefore examined alpha wave suppression as a reduction in power is thought to reflect visual activity, in addition to attentional reorienting and memory processes. Nineteen neurologically healthy adults were tested on their ability to discriminate between successive facial motion captures. These animations exhibited both rigid and non-rigid facial motion, as well as speech expressions. The structural and surface appearance of these facial animations did not differ, thus participants decisions were based solely on differences in facial movements. Upright, orientation-inverted and luminance-inverted facial stimuli were compared. At occipital and parieto-occipital regions, upright facial motion evoked a transient increase in alpha which was then followed by a significant reduction. This finding is discussed in terms of neural efficiency, gating mechanisms and neural synchronization. Moreover, there was no difference in the amount of alpha suppression evoked by each facial stimulus at occipital regions, suggesting early visual processing remains unaffected by manipulation paradigms. However, upright facial motion evoked greater suppression at parieto-occipital sites, and did so in the shortest latency. Increased activity within this region may reflect higher attentional reorienting to natural facial motion but also involvement of areas associated with the visual control of body effectors. © 2014 Girges et al

Effective Lagrangian approach to neutrinoless double beta decay and neutrino masses

Neutrinoless double beta ($0\nu\beta\beta$) decay can in general produce electrons of either chirality, in contrast with the minimal Standard Model (SM) extension with only the addition of the Weinberg operator, which predicts two left-handed electrons in the final state. We classify the lepton number violating (LNV) effective operators with two leptons of either chirality but no quarks, ordered according to the magnitude of their contribution to \znbb decay. We point out that, for each of the three chirality assignments, $e_Le_L, e_Le_R$ and $e_Re_R$, there is only one LNV operator of the corresponding type to lowest order, and these have dimensions 5, 7 and 9, respectively. Neutrino masses are always induced by these extra operators but can be delayed to one or two loops, depending on the number of RH leptons entering in the operator. Then, the comparison of the $0\nu\beta\beta$ decay rate and neutrino masses should indicate the effective scenario at work, which confronted with the LHC searches should also eventually decide on the specific model elected by nature. We also list the SM additions generating these operators upon integration of the heavy modes, and discuss simple realistic examples of renormalizable theories for each case.Comment: Accepted for publication. Few misprints corrected and new references adde

Increasing upper limb training intensity in chronic stroke using embodied virtual reality: a pilot study.

Technology-mediated neurorehabilitation is suggested to enhance training intensity and therefore functional gains. Here, we used a novel virtual reality (VR) system for task-specific upper extremity training after stroke. The system offers interactive exercises integrating motor priming techniques and embodied visuomotor feedback. In this pilot study, we examined (i) rehabilitation dose and training intensity, (ii) functional improvements, and (iii) safety and tolerance when exposed to intensive VR rehabilitation. Ten outpatient stroke survivors with chronic (>6 months) upper extremity paresis participated in a ten-session VR-based upper limb rehabilitation program (2 sessions/week). All participants completed all sessions of the treatment. In total, they received a median of 403 min of upper limb therapy, with 290 min of effective training. Within that time, participants performed a median of 4713 goal-directed movements. Importantly, training intensity increased progressively across sessions from 13.2 to 17.3 movements per minute. Clinical measures show that despite being in the chronic phase, where recovery potential is thought to be limited, participants showed a median improvement rate of 5.3% in motor function (Fugl-Meyer Assessment for Upper Extremity; FMA-UE) post intervention compared to baseline, and of 15.4% at one-month follow-up. For three of them, this improvement was clinically significant. A significant improvement in shoulder active range of motion (AROM) was also observed at follow-up. Participants reported very low levels of pain, stress and fatigue following each session of training, indicating that the intensive VR intervention was well tolerated. No severe adverse events were reported. All participants expressed their interest in continuing the intervention at the hospital or even at home, suggesting high levels of adherence and motivation for the provided intervention. This pilot study showed how a dedicated VR system could deliver high rehabilitation doses and, importantly, intensive training in chronic stroke survivors. FMA-UE and AROM results suggest that task-specific VR training may be beneficial for further functional recovery both in the chronic stage of stroke. Longitudinal studies with higher doses and sample sizes are required to confirm the therapy effectiveness. This trial was retrospectively registered at ClinicalTrials.gov database (registration number NCT03094650 ) on 14 March 2017

The tuberculosis necrotizing toxin kills macrophages by hydrolyzing NAD.

Mycobacterium tuberculosis (Mtb) induces necrosis of infected cells to evade immune responses. Recently, we found that Mtb uses the protein CpnT to kill human macrophages by secreting its C-terminal domain, named tuberculosis necrotizing toxin (TNT), which induces necrosis by an unknown mechanism. Here we show that TNT gains access to the cytosol of Mtb-infected macrophages, where it hydrolyzes the essential coenzyme NAD(+). Expression or injection of a noncatalytic TNT mutant showed no cytotoxicity in macrophages or in zebrafish zygotes, respectively, thus demonstrating that the NAD(+) glycohydrolase activity is required for TNT-induced cell death. To prevent self-poisoning, Mtb produces an immunity factor for TNT (IFT) that binds TNT and inhibits its activity. The crystal structure of the TNT-IFT complex revealed a new NAD(+) glycohydrolase fold of TNT, the founding member of a toxin family widespread in pathogenic microorganisms

Response to imatinib rechallenge in a patient with a recurrent gastrointestinal stromal tumor after adjuvant therapy: a case report

<p>Abstract</p> <p>Introduction</p> <p>Adjuvant imatinib improves recurrence-free survival of patients following resection of primary KIT-positive gastrointestinal stromal tumors. However, it is unknown whether patients who previously received adjuvant imatinib therapy will respond to imatinib rechallenge as treatment for recurrent disease. Here we present the first report documenting the benefits of imatinib rechallenge in a patient previously exposed to imatinib during adjuvant treatment.</p> <p>Case presentation</p> <p>A 51-year-old Asian woman with a wedge-resected primary gastric gastrointestinal stromal tumor at high risk of relapse underwent two years of adjuvant treatment with imatinib. Only 10 months after the completion of adjuvant imatinib treatment, a computed tomography scan revealed gastrointestinal stromal tumor recurrence in this patient, with multiple peritoneal nodules in the upper abdomen being detected. Our patient was rechallenged with imatinib 400 mg/day and had a partial response after one month of treatment. Imatinib rechallenge was well tolerated by our patient; the only adverse events she experienced were grade 1 edema, anemia and fatigue. Our patient maintained a partial response two years and six months after the imatinib rechallenge. However, computed tomography scans three months later showed that our patient had disease progression.</p> <p>Conclusions</p> <p>This case report demonstrates that a patient with a gastrointestinal stromal tumor who had previously received adjuvant imatinib therapy responded to imatinib rechallenge as treatment for her recurrent disease. These results indicate that imatinib sensitivity can be maintained in a patient with previous exposure to adjuvant imatinib therapy.</p

Neutrinos

229 pages229 pages229 pagesThe Proceedings of the 2011 workshop on Fundamental Physics at the Intensity Frontier. Science opportunities at the intensity frontier are identified and described in the areas of heavy quarks, charged leptons, neutrinos, proton decay, new light weakly-coupled particles, and nucleons, nuclei, and atoms