2,842 research outputs found
Revisiting the -physics anomalies in -parity violating MSSM
In recent years, several deviations from the Standard Model predictions in
semileptonic decays of -meson might suggest the existence of new physics
which would break the lepton-flavour universality. In this work, we have
explored the possibility of using muon sneutrinos and right-handed sbottoms to
solve these -physics anomalies simultaneously in -parity violating
minimal supersymmetric standard model. We find that the photonic penguin
induced by exchanging sneutrino can provide sizable lepton flavour universal
contribution due to the existence of logarithmic enhancement for the first
time. This prompts us to use the two-parameter scenario to explain anomaly. Finally, the
numerical analyses show that the muon sneutrinos and right-handed sbottoms can
explain and anomalies simultaneously,
and satisfy the constraints of other related processes, such as decays, mixing, decays, as well as
, , , , , , and decays.Comment: 10 pages, 8 figures, matches to the version published in EPJ
Explaining anomalies of -physics, muon and mass in -parity violating MSSM with seesaw mechanism
The recent experimental results including the ,
, and mass show the deviations from the
standard model (SM) predictions, implying the clues of the new physics (NP). In
this work, we investigate the explanations of these anomalies in the -parity
violating minimal supersymmetric standard model (RPV-MSSM) extended with the
inverse seesaw mechanism. The non-unitarity extent and the loop
corrections involving the interaction are
utilized to raise the prediction through muon decays. We also find that
the interaction including the right-handed
(RH)/singlet (s)neutrinos can explain the and
anomalies simultaneously when considering nonzero . For nonzero
, this model fulfils the whole fit but
cannot be accordant with measurements. Furthermore, the
explanations in both cases are favored by the data, neutrino
oscillation data and the relevant constraints we scrutinised.Comment: 33 pages, 2 figure
The -vertex corrections to W-boson mass in the R-parity violating MSSM
Inspired by the astonishing discrepancy between the recent CDF-II
measurement and the Standard Model prediction on the mass of -boson, we
investigate the unique - corrections to the vertex of decay in the context of the -parity violating minimal
supersymmetric standard model. These corrections can raise the -boson mass
independently. Combined with recent -pole measurements,
GeV can be reached. We find that these vertex corrections cannot explain the
CDF result entirely. However, these corrections, together with the oblique
ones, can increase to around GeV, which is accordant with the
CDF result at the edge of level.Comment: 13 pages, 2 figures; more Refs are added and typos are fixed;
discussions including the oblique corrections are adde
Mixing and 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 , we perform a detailed study of mixing and
decay in the -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 (\textit{i.e.}, while the flavour-conserving
off-diagonal element is kept in both of these two
sectors, only the flavour-violating off-diagonal elements
and () are kept in the
\text{LL} and \text{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 , while complying with the experimental
constraints from the branching ratios of and decays.Comment: 48 pages, 7 figures, and 2 tables; More discussions and references
added, final version to be published in JHE
GL-Segnet: Global-Local representation learning net for medical image segmentation
Medical image segmentation has long been a compelling and fundamental problem in the realm of neuroscience. This is an extremely challenging task due to the intensely interfering irrelevant background information to segment the target. State-of-the-art methods fail to consider simultaneously addressing both long-range and short-range dependencies, and commonly emphasize the semantic information characterization capability while ignoring the geometric detail information implied in the shallow feature maps resulting in the dropping of crucial features. To tackle the above problem, we propose a Global-Local representation learning net for medical image segmentation, namely GL-Segnet. In the Feature encoder, we utilize the Multi-Scale Convolution (MSC) and Multi-Scale Pooling (MSP) modules to encode the global semantic representation information at the shallow level of the network, and multi-scale feature fusion operations are applied to enrich local geometric detail information in a cross-level manner. Beyond that, we adopt a global semantic feature extraction module to perform filtering of irrelevant background information. In Attention-enhancing Decoder, we use the Attention-based feature decoding module to refine the multi-scale fused feature information, which provides effective cues for attention decoding. We exploit the structural similarity between images and the edge gradient information to propose a hybrid loss to improve the segmentation accuracy of the model. Extensive experiments on medical image segmentation from Glas, ISIC, Brain Tumors and SIIM-ACR demonstrated that our GL-Segnet is superior to existing state-of-art methods in subjective visual performance and objective evaluation
Fast radio bursts generated by coherent curvature radiation from compressed bunches for FRB 20190520B
The radiation mechanism of fast radio bursts (FRBs) has been extensively
studied but still remains elusive. Coherent radiation is identified as a
crucial component in the FRB mechanism, with charged bunches also playing a
significant role under specific circumstances. In the present research, we
propose a phenomenological model that draws upon the coherent curvature
radiation framework and the magnetized neutron star, taking into account the
kinetic energy losses of outflow particles due to inverse Compton scattering
(ICS) induced by soft photons within the magnetosphere. By integrating the ICS
deceleration mechanism for particles, we hypothesize a potential compression
effect on the particle number density within a magnetic tube/family, which
could facilitate achieving the necessary size for coherent radiation in the
radial direction. This mechanism might potentially enable the dynamic formation
of bunches capable of emitting coherent curvature radiation along the curved
magnetic field. Moreover, we examine the formation of bunches from an energy
perspective. Our discussion suggests that within the given parameter space the
formation of bunches is feasible. Finally, we apply this model to FRB
20190520B, one of the most active repeating FRBs discovered and monitored by
FAST. Several observed phenomena are explained, including basic
characteristics, frequency downward drifting, and bright spots within certain
dynamic spectral ranges.Comment: 16 pages, 9 figures, and 1 table. Accepted for publication in Ap
Efficacy and safety of mineralocorticoid receptor antagonists for patients with heart failure and diabetes mellitus: a systematic review and meta-analysis
The influence of outflows on the 1/f-like luminosity fluctuations
In accretion systems, outflows may have significant influence on the
luminosity fluctuations. In this paper, following the Lyubarskii's general
scheme, we revisit the power spectral density of luminosity fluctuations by
taking into account the role of outflows. Our analysis is based on the
assumption that the coupling between the local outflow and inflow is weak on
the accretion rate fluctuations. We find that, for the inflow mass accretion
rate , the power spectrum of flicker noise component will
present a power-law distribution for
advection-dominated flows. We also obtain descriptions of for both
standard thin discs and neutrino-cooled discs, which show that the power-law
index of a neutrino-cooled disc is generally larger than that of a
photon-cooled disc. Furthermore, the obtained relationship between and
indicates the possibility of evaluating the strength of outflows by the
power spectrum in X-ray binaries and gamma-ray bursts. In addition, we discuss
the possible influence of the outflow-inflow coupling on our results.Comment: 6 pages, 1 figure, accepted for publication in MNRA
- …