Mass Insertion Research Articles

Study lepton flavor violation $B^0\rightarrow{{l_i}^{\pm}{l_j}^{\mp}}$ within the Mass Insertion Approximation

Abstract We study lepton flavor violating (LFV) decays $B^0\rightarrow{{l_i}^{\pm}{l_j}^{\mp}}$ ($B^0\rightarrow e{\mu}$, $B^0\rightarrow e{\tau}$ and $B^0\rightarrow {\mu}{\tau}$) in the $U(1)_X$SSM (SSM is acronym for the supersymmetric standard model), which is the $U(1)_X$ extension of the minimal supersymmetric standard model (MSSM). The local gauge group of $U(1)_X$SSM is $SU(3)_C\times SU(2)_L \times U(1)_Y \times U(1)_X$. These processes ($B^0\rightarrow e{\mu}$, $B^0\rightarrow e{\tau}$ and $B^0\rightarrow {\mu}{\tau}$) are strictly forbidden in the standard model (SM), but these LFV decays are a signal of new physics (NP).
We use the Mass Insertion Approximation (MIA) to find sensitive parameters that directly influence the result of the branching ratio of LFV decay $B_d\rightarrow{{l_i}^{\pm}{l_j}^{\mp}}$. Combined with the latest experimental results, we analyze the relationship between different sensitive parameters and the branching ratios of the three processes. According to the numerical analysis, these elements are very restricted from the non observation of CLFV.

Long-term degradation study of Polytetrafluoroethylene in a low temperature oxygen plasma

Atomic oxygen (AO) is the most common gas species in the Low-Earth-Orbit (LEO) and responsible for material degradation of the outer shell of spacecrafts within this space region. Due to their similar properties, low temperature oxygen plasmas are suited for material degradation studies taking place on earth instead of quite expensive space studies. Here we focus on the long-term degradation of Polytetrafluoroethylene (PTFE), which is often employed on the outside of spacecrafts. Up to date, there is no complete understanding of the degradation process on molecular level, which is necessary for materials improvement and new materials development.For the degradation studies, a self-constructed capacitively driven 13.56 MHz RF reactor was used to generate an oxygen plasma for the simulation of LEO conditions. PTFE was characterised in the pristine state and after AO treatment at different times by ToF-SIMS, XPS and SEM. During plasma treatment, the samples show a linear mass loss behaviour. ToF-SIMS surface analysis reveal mass fragments which show a clear chemical reaction of oxygen species with PTFE. The presence of these molecular indicators was verified by XPS, where additional carbon species were found after plasma treatment. SEM micrographs showed an inhomogeneous degradation on the surface in the first hours similar to actual LEO exposure. For a complete understanding of the degradation progress, operando mass spectrometric studies of the plasma composition were carried out to detect volatile degradation products.In summary, a steady degradation has been observed that leads to constant mass loss, defluorination, chain shortening and insertion of oxygen into the polymer.

The flavor transition process b → sγ in the U(1)XSSM with the mass insertion approximation

People extend the MSSM with the local gauge group U(1)X to obtain the U(1)XSSM. In the framework of the U(1)XSSM, we study the flavor transition process b→sγ with the mass insertion approximation (MIA). By the MIA method and some reasonable parameter assumptions, we can intuitively find the parameters that have obvious effect on the analytic results of the flavor transition process b→sγ. By means of the influences of different sensitive parameters, we can obtain reasonable results to better fit the experimental data.

Study on muon MDM and lepton EDM in BLMSSM via the mass insertion approximation

In the framework of the MSSM extension with local gauged baryon and lepton numbers (BLMSSM), we calculate the muon anomalous magnetic dipole moment (MDM) and lepton (e, μ, τ) electric dipole moment (EDM), and discuss how the muon MDM and lepton EDM depend on the parameters within the mass insertion approximation. Among many parameters, , g L , m L and μ H are more sensitive parameters for . Considering the experimental limitations, our best numerical result of is around 2.5 × 10−9, which can well compensate the departure between the experiment data and standard model (SM) prediction. The CP violating phases in BLMSSM are more than those in the MSSM, including new parameters and θ L . They can give large contributions, which play an important role in exploring the source of CP violation and probing new physics beyond SM.

Lepton flavor violating decays of vector mesons in the MRSSM* *Supported by the Natural Science Foundation of Hebei Province (A2022104001, A2022201017), the Shanxi Scholarship Council of China (2021-31), the youth top-notch talent support program of the Hebei Province, and the Foundation of Baoding University (2018Z01)

In this study, we analyze the rare decays of the neutral vector mesons and in the scenario of the minimal R-symmetric supersymmetric standard model using the effective Lagrangian method. The predicted branching ratios are dominated by the mass insertion parameters , i.e., the off-diagonal inputs, and the contributions of different parts are comparable. Taking into account the experimental constraints on the mass insertion parameters, the predicted branching ratios for the most promising processes are ten orders of magnitude smaller than the present experimental bounds.

Accuracy of atlantoaxial screw placement using computed tomography-based navigation system-assisted surgery: The single-level vertebral registration

ObjectivePosterior screw fixation via a C1 lateral mass screw combined with a C2 pedicle screw is a well-known technique for atlantoaxial instability. However, screw malposition can occur because of the complex anatomical structure of this region. This study aimed to evaluate the accuracy and risk factors of cortical breach following the C1 lateral mass and/or C2 pedicle screw insertion using a preoperative computed tomography (CT)-based navigation system with a single-level vertebral registration method. MethodsThis retrospective cohort study included patients who had undergone a C1 lateral mass and/or a C2 pedicle screw placement using a preoperative CT-based navigation system from January 2013 to March 2020 from the university hospital. The extent of screw deviation was classified as: within the pedicle (grade 0), out of pedicle < 2 mm (grade I), from 2 to 4 mm (grade II), and > 4 mm (grade III). The risk of cortical breach was evaluated using multivariate analysis. ResultsSeventy-eight C1 lateral masses and 71 C2 pedicle screws were inserted into 42 patients. The accuracy of screw placement was as follows: 133 grade 0 (89.3 %), 14 grade I (9.4 %), and two grade II (1.3 %). No screws required repositioning, and no vertebral artery injury or neurological deficit was associated with this technique. Additionally, a diameter of < 5 mm was associated with the cortical breach in the multivariate analysis. ConclusionsC1 lateral mass and C2 pedicle screw placement could be safely and effectively performed by using a preoperative CT-based navigation system with a single-level registration technique. The risk factors for cortical breach are the C1 lateral mass and C2 pedicle diameters.

The discrepancy between FDG uptake and myocardial fibrosis in patients with pulmonary arterial hypertension – PET/MRI study

Abstract Background Inflammatory processes play an important role in pulmonary arterial hypertension (PAH) pathophysiology. We previously confirmed that in case of right ventricle (RV) failure, changes of cytokines' levels are correlated with myocardial metabolic and hemodynamic alterations observed in PET/MRI hybrid imaging. Presence of late gadolinium enhancement (LGE) in RV insertion points (RVIPs) has been found in majority of PAH patients and is often recognized as evidence of myocardial fibrosis due to RV pressure overload. As qualitative and/or quantitative assessments of LGE may vary due to natural PAH progression or specific therapy, we hypothesized that simple presence of LGE at RVIPs is not unequivocal to fibrotic tissue (without metabolic activity). Purpose To check the relationship between LGE mass and 18F-fluorodexyglucose uptake in RV insertion points in PAH patients using PET/MRI hybrid imaging. Methods Twenty-eight clinically stable PAH patients (49.9±15.9 years) had simultaneous PET/MRI scans during baseline and follow up (FU) visits, Figure. 18F-fluorodexyglucose (FDG) was used as a tracer and its cardiac uptake was presented as a maximum standardized uptake value (SUV) for RV insertion points (SUV in RVIPS). Septal delayed enhancement mass was quantified in RVIPs and presented as LGE mass. Occurrences of clinical end-points (CEP, defined as death or clinical deterioration) were assessed during 24 months observation. Results LGE was found in RVIPs of all PAH patients. Mean LGE mass was 6.32±4.41 g and mean SUV in RVIPS was 7.28±5.36. Follow up values were 8.01±7.75g (p=0.4) and 5.80±3.16 (p=0.16), respectively. We observed significant correlation between baseline SUV in RVIPS and mean pulmonary pressure, mPAP (r=0.49, p=0.04) but no correlation was found between LGE mass and SUV in RVIPS (in both baseline and FU scans). Between baseline and follow up visits, 16 patients had CEP and needed PAH therapy escalation. CEP+ group of PAH patients presented higher baseline LGE mass (7.53±4.75 vs 3.92±2.21, p=0.04) and SUV in RVIPS (7.27±5.42 vs 6.01±4.52, p=0.4). In all CEP patients who initiated prostacycline therapy and survived (n=8, 50%), SUV in RVIPS decreased in FU PET scans together with an increase in LGE mass in MRI. At FU visits we also observed significant improvement of MRI-derived RV ejection fraction (45.1±9.6% to 52.4±12.9%, p=0.01), and mPAP (50.5±18.3 to 42.8±18.6 mmHg, p=0.03). Conclusions Effective PAH therapy have an impact on both LGE mass and FDG uptake in cardiac local tissue changes. Since there was no correlation between LGE mass and FDG uptake RV insertion points, the question arises what the cause of these LGE changes is. Increased fibrosis should cause diminished local glucose metabolism. This phenomenon opens new questions concerning pathophysiology processes in RVIPs and requires confirmation on bigger PAH population. Funding Acknowledgement Type of funding sources: Public grant(s) – National budget only. Main funding source(s): National Center for Science in Poland

Lepton flavor violating decays l_jrightarrow {l_igamma } in the U(1)_XSSM model within the mass insertion approximation

Three singlet new Higgs superfields and right-handed neutrinos are added to MSSM to obtain U(1)_XSSM model. Its local gauge group is SU(3)_Ctimes SU(2)_L times U(1)_Y times U(1)_X. In the framework of U(1)_XSSM, we study muon anomalous magnetic moment and lepton flavor violating decays l_jrightarrow {l_igamma }(j=2,3;i=1,2) within the mass insertion approximation (MIA). Through the MIA method, we can find the parameters that directly affect the analytical result of the lepton flavor violating decays l_jrightarrow {l_igamma }, which make our work more convenient. We want to provide a set of simple analytic formulas for the form factors and the associated effective vertices, that may be very useful for future phenomenological studies of the lepton flavor violating decays. According to the accuracy of the numerical results which the influence of different sensitive parameters, we come to the conclusion that the non-diagonal elements which correspond to the generations of the initial lepton and final lepton are main sensitive parameters and lepton flavor violation (LFV) sources. This work can provide a clear signal of new physics (NP).

Nonunion fracture of the sublime tubercle in a collegiate baseball pitcher: A case report

Introduction: Elbow pathology including fractures to the coronoid process are common in overhead throwing athletes such as baseball pitchers. Only four cases have been reported of sublime tubercle avulsion fractures in the literature. This case study investigates a novel treatment for such injuries.Case Presentation: A 21-year-old collegiate baseball pitcher presented with medial elbow pain. Radiographic evaluation showed a nonunion fracture of the sublime tubercle of the coronoid process as well as medial epicondylitis and a partial ulnar collateral ligament (UCL) tear. The senior author performed platelet rich plasma injections into the origin of the flexor-pronator mass and UCL insertion. After an 8-week rehabilitation program, he was able to return to sport with no complications or drop in performance. Conclusion: Platelet-rich plasma injection may be a viable treatment option for management of patients with delayed union fractures to the sublime tubercle, medial epicondylitis and partial UCL tear.

Posterior First and Second Cervical Vertebrae Fusion by Screw Fixation Technique using the Modern Pre-fabricated Template Method on Cadaver Samples

Introduction:C1 lateral mass and C2 pedicular screws insertion are used for C1-C2 posterior fusion. Fluoroscopy Guided technique is routinely used for screw placement but it is associated with risk of injury to spinal cord and vertebral artery. 3D printing has developed rapidly in the fields of medicine. It is helpful in improving precise treatment and used for instrumentation in spine. We want to evaluate the accuracy of C1 lateral mass screws and C2 pedicle screws insertion by Pre-Fabricated Template made by three-dimensional (3D) printing.Materials and methods:Five cervical samples were obtained from cadavers. Based on fine-cut CT scan 3D-images reconstructed and the path of the screws designed by special software. A template produced by 3D-printer from 3D images. After printing the templates, they were fixed on the relevant vertebra in the operation room and based on the template path, C1 lateral mass screw and C2 pedicular screws were inserted. Placement of the screws was evaluated using CT scans post-operatively.Results:A total of 14 screws were inserted by above-mentioned method. After evaluation with CT scans none of the screws were entered in the spinal canal. Two screws had vertebral artery canal perforation with less than 50% breach. Violation was judged as noncritical and would probably not have resulted in injury to vertebral artery.Conclusions:The accuracy of C1 lateral mass screw and C2 pedicle screw insertion is acceptable with pre-fabricated template and can provide a useful aid for screw placement.

A different perspective on the vev insertion approximation for electroweak baryogenesis

In the vev insertion approximation (VIA) the spacetime dependent part of the mass matrix is treated as a perturbation. We calculate the source terms for baryogenesis expanding both the self-energy and propagator to first order in mass insertions, which gives the same results as the usual approach of calculating the self-energy at second order and using zeroth order propagators. This procedure shows explicitly the equivalence between including the mass in the free or in the interaction Lagrangian. The VIA source then originates from the same term in the kinetic equation as the semi-classical source, but at leading order in the derivative expansion (the expansion in diamond operators). On top, another type of derivative expansion is done, which we estimate to be valid for a bubble width larger than the inverse thermal width. This cuts off the divergence in the VIA source in the limit that the thermal width vanishes.

The effect of systemic and local risk factors on triggering peripherally inserted central catheter–related thrombosis in cancer patients: A prospective cohort study based on ultrasound examination and structural equation modeling

BackgroundThe negative synergistic effect of cancer and a peripherally inserted central catheter could significantly increase the incidence of thrombosis. Rather than identifying risk factors for peripherally inserted central catheter–related thrombosis, exploring the effect of these risk factors might be a promising method to improve the outcomes of thrombosis. ObjectivesTo analyze the effect of systemic and local risk factors on triggering peripherally inserted central catheter–related thrombosis in the first two weeks post–insertion in cancer patients. DesignA prospective cohort study. SettingThe study was conducted at a 4500-bed university-affiliated medical center in China. ParticipantsOne hundred seventy-three cancer patients with peripherally inserted central catheters were included. MethodsPeripherally inserted central catheter–related thrombosis was assessed using ultrasound at a series of timepoints, once every two days post–insertion. Data on age, body mass index, blood hypercoagulation, insertion attempts, catheter-to-vein ratio, and blood flow velocity were collected as risk factors. Descriptive statistics and structural equation modeling were used to describe the study samples and analyze the effects of systemic and local risk factors. ResultsAmong the 173 cancer patients included, 126 (72.8%) patients were diagnosed with peripherally inserted central catheter–related thrombosis. Most thromboses (n = 118, 93.7%) were detected within five days, and 100% were detected within nine days post–insertion. Structural equation modeling analysis showed that local risk factors [catheter-to-vein ratio (standardized path coefficient = 0.32, p < 0.05) and blood flow velocity (standardized path coefficient = −0.35, p < 0.05)] had a greater effect than systemic factors [age (standardized path coefficient = 0.13, p < 0.05) and blood hypercoagulation (standardized path coefficient = 0.17, p < 0.05)] on triggering peripherally inserted central catheter–related thrombosis. ConclusionPeripherally inserted central catheter–related thrombosis is quite common and can occur very early post–insertion in cancer patients. Among the common risk factors, local risk factors reflecting peripherally inserted central catheter technology itself had a greater effect than systemic risk factors reflecting predisposition to thrombosis.Clinical Registration: Clinical Trials ChiCTR1900024890.

Postoperative complications of Goel-Harms C1-C2 screw-rod fixation technique for C1-C2 instability after C2 nerve sacrifice, a prospective study over two years follow up

BackgroundAtlantoaxial instability is mainly caused by trauma. C2 nerve is usually needed to be sacrificed for adequate exposure of the lateral mass and screw insertion. ObjectivesThis study aimed to investigate the clinical outcome of postoperative complications of C1 and C2 screw-rod fixation using the Goel-Harms technique for C1-C2 instability after sacrificing the C2 nerve root. MethodsAmongst forty patients with C1-C2 pathology, twenty-seven cases were enrolled into the study, then variables, including age, sex, primary pathology, operation duration, postoperative pain, paresthesia, anesthesia, and other specific conditions, were documented. Data analyzed by an expert biostatistician. p-value < 0.05 was considered significant. ResultsRegardless of gender, the most postoperative adverse effect was occipital anesthesia (81.5%). Most of the patients (63%) had both occipital pain and anesthesia one-month post-surgery. At 3- and 6-months post-surgery, occipital pain and anesthesia were seen in 40.7% and 14.8%, respectively. ConclusionThe most common postoperative adverse effect of C2 nerve root scarification after C1-C2 fixation is occipital anesthesia followed by occipital paresthesia and pain, which are reduced in severity over time.

Performance of the double-cross tomato hybrids from a partial diallel

ABSTRACT Knowledge of the combining ability of genotypes, genetic diversity, and heterosis play the paramount role in obtaining double-cross hybrids with high productivity. This study was aimed at evaluating these parameters in tomato genotypes using partial diallel crosses among the commercial single-cross hybrids, which verified the possibility of using double-cross hybrids for commercial purposes. Tomato genotypes included 15 double-cross hybrids, their genitors, and two commercial genotypes as checks. Of the fifteen double-cross hybrids of tomato, two crosses exhibited superiority, such as Aguamiel × Compack and Dominador × Compack, mainly for the total and commercial fruit yields. The phenotypic expression of the trait is controlled by the genes with non-additive effects, whereas the genes with additive effects account for the genotypes of fruit mass, horizontal diameter, vertical diameter, and bunch insertion height. Regarding the genetic diversity, molecular analyses pointed out polymorphism for 79 percent of the evaluated loci evidencing a high genetic variability among the genitors. The heterosis values were low for most of the crosses, except for Forty × Plutão that represented 107 percent of heterosis for the total fruit yield. As compared with the commercial checks, the diallel cross generated superior quality hybrids, which inferred the possibility of obtaining double-cross hybrids of tomato with significant heterosis.

Searching for lepton flavor violating decays tau rightarrow Pl in the minimal R-symmetric supersymmetric standard model

We analyze the lepton flavor violating decays tau rightarrow Pl (P=pi ,eta ,eta ';;l=e,mu ) in the scenario of the minimal R-symmetric supersymmetric standard model. The prediction on the branching ratios BR(tau rightarrow P e) and BR(tau rightarrow P mu ) is affected by the mass insertion parameters delta ^{13} and delta ^{23}, respectively. These parameters are constrained by the experimental bounds on the branching ratios BR(tau rightarrow e (mu ) gamma ) and BR(tau rightarrow 3e(mu )). The result shows Z penguin dominates the prediction on BR(tau rightarrow Pl) in a large region of the parameter space. The branching ratios for BR(tau rightarrow Pl) are predicted to be, at least, five orders of magnitude smaller than present experimental bounds and three orders of magnitude smaller than future experimental sensitivities.

Preliminary Study of Launch and Orbit of a CubeSat Using a Modified VSB-30 Launcher Vehicle

During the last decade, the world faced the mass insertion of small satellites in the space technology scenario. Every year, the number of micro and nanosatellites launched increases and gets more attention from players in the space market. Despite the lack of a national launcher, the Brazilian Space Program is known for some successful development in the last century, including its space assets, such as a privileged launch site near the equator, a family of flight proven and reliable sounding rockets for suborbital flights and microgravity experiments and universities with established small satellites programs. Thereby, the present work proposes a modification of the Brazilian VSB-30 sounding rocket in order to allow the launch and insertion in low Earth orbit (LEO) of small satellites fulfilling the gap of a national launcher. It also presents a CubeSat orbital decay simulation and orbital insertion simulation with the modified rocket launched from the Alcântara Launch Center as a matter of verifying the potential of national missions using this modified launcher.

Resolving Hubble tension by self-interacting neutrinos with Dirac seesaw

Self-interacting neutrinos that begin to free-stream at close to matter-radiation equality can reduce the physical size of photon sound horizon at last scattering surface. This mechanism can be the reason why standard ΛCDM cosmology sees a lower value of the Hubble constant than local measurements from distance ladder. We propose a new realization of self-interacting Dirac neutrinos (SIDν) with light-dark-photon mediator for a viable interaction mechanism. Our model is UV completed by a Dirac seesaw with anomaly-free dark U(1)X gauge group which charges the right-handed neutrinos. This model naturally generates small masses for Dirac neutrinos and induces self-scattering of right-handed neutrinos. The scattering with left-handed neutrinos is suppressed by a chirality-flip mass insertion when the neutrino energy is much larger than its mass. The resultant neutrino self-scattering is not operative for Eν≳ O(keV), which avoids the cosmological and laboratory constraints. By evolving Boltzmann equations for left- and right-handed neutrino number densities, we show that about 2/3 of the left-handed neutrinos are converted into right-handed neutrinos in a short epoch between the Big-Bang Nucleosynthesis and the recombination, and interact with each other efficiently afterwards. The resultant neutrino non-free-streaming is the crucial ingredient to shrink down the comoving sound horizon at drag epoch, which can reconcile the Hubble tension between early and late time measurements.

Source terms for electroweak baryogenesis in the vev-insertion approximation beyond leading order

In electroweak baryogenesis the baryon asymmetry of the universe is created during the electroweak phase transition. The quantum transport equations governing the dynamics of the plasma particles can be derived in the vev-insertion approximation, which treats the vev-dependent part of the particle masses as a perturbation. We calculate the next-to-leading order (NLO) contribution to the CP-violating source term and CP-conserving relaxation rate, corresponding to Feynman diagrams for the self-energies with four mass insertions. We consider both a pair of Weyl fermions and a pair of complex scalars, that scatter off the bubble wall. We find: (i) The NLO correction becomes large for mathcal{O} (1) couplings. If only the Standard Model (SM) Higgs obtains a vev during the phase transition, this implies the vev-insertion approximation breaks down for top quarks. (ii) The resonant enhancement of the source term and relaxation rate, that exists at leading order in the limit of degenerate thermal masses for the fermions/scalars, persists at NLO.

Flavor Techniques for LFV Processes: Higgs Decays in a General Seesaw Model

Lepton flavor violating processes are optimal observables to test new physics, since they are forbidden in the Standard Model while they may be generated in new theories. The usual approach to these processes is to perform the computations in the physical basis; nevertheless this may lose track of the dependence on some of the fundamental parameters, in particular on those at the origin of the flavor violation. Consequently, in order to obtain analytical expressions directly in terms of these parameters, flavor techniques are often preferred. In this work, we focus on the mass insertion approximation technique, which works with the interaction states instead of the physical ones, and provides diagrammatic expansions of the observables. After reviewing the basics of this technique with two simple examples, we apply it to the lepton flavor violating Higgs decays in the framework of a general type-I seesaw model with an arbitrary number of right-handed neutrinos. We derive an effective vertex valid to compute these observables when the right-handed neutrino masses are above the electroweak scale and show that we recover previous results obtained for low scale seesaws. Finally, we apply current constraints on the model to conclude on maximum Higgs decay rates, which unfortunately are far from current experimental sensitivities.

Bs(d) \u2212 overline{B} s(d) mixing and Bs \u2192 \u03bc+\u03bc\u2212 decay in the NMSSM with the Flavour Expansion Theorem

In this paper, motivated by the observation that the Standard Model predictions are now above the experimental data for the mass difference ΔMs(d), we perform a detailed study of Bs(d) − overline{B} s(d) mixing and Bs → μ+μ− decay in the ℤ3-invariant NMSSM with non-minimal flavour violation, using the recently developed procedure based on the Flavour Expansion Theorem, with which one can perform a purely algebraic mass-insertion expansion of an amplitude written in the mass eigenstate basis without performing any diagrammatic calculations in the interaction/flavour basis. Specifically, we consider the finite orders of mass insertions for neutralinos but the general orders for squarks and charginos, under two sets of assumptions for the squark flavour structures (i.e., while the flavour-conserving off-diagonal element δ33LR is kept in both of these two sectors, only the flavour-violating off-diagonal elements δ23LL and δi3RR (i = 1, 2) are kept in the LL and RR sectors, respectively). Our analytic results are then expressed directly in terms of the initial Lagrangian parameters in the interaction/flavour basis, making it easy to impose the experimental bounds on them. It is found numerically that the NMSSM effects with the above two assumptions for the squark flavour structures can accommodate the observed deviation for ΔMs(d), while complying with the experimental constraints from the branching ratios of Bs → μ+μ− and B → Xsγ decays.