Search

Recently, the Belle II collaboration announced the first measurement of $\mathcal B(B^+\to K^+\nu\bar\nu)$, which is found to be about $2.7\sigma$ higher than the SM prediction. We decipher the data with two new physics scenarios: the underlying $b\to s \nu\bar\nu$ transition is, besides the SM contribution, further affected by heavy new mediators that are much heavier than the EW scale, or amended by an additional decay channel with undetected light final states like dark matter or axion-like particles. These two scenarios can be most conveniently analyzed in the SMEFT and the dark SMEFT (DSMEFT) framework, respectively. We consider the flavour structures of the resulting effective operators to be either generic or satisfy the minimal flavour violation (MFV) hypothesis, both for the quark and lepton sectors. In the first scenario, once the MFV is assumed, only one SM-like low-energy effective operator induced by the SMEFT dim-6 operators can account for the Belle II excess, the parameter space of which is, however, excluded by the Belle upper bound on $\mathcal B(B^0\to K^{*0}\nu\bar\nu)$. In the second scenario, it is found that the Belle II excess can be accommodated by 22 of the DSMEFT operators involving one or two scalar, fermionic, or vector dark matters as well as ALPs. These operators also receive dominant constraints from the $B^0\to K^{*0}+$inv and $B_s\to$inv decays. In the MFV hypothesis, the number of viable operators is reduced to 14, and the $B^+\to\pi^+ +$inv and $K^+\to\pi^++$inv decays start to put further constraints. Within the parameter space allowed by all the current experimental data, the $q^2$ distributions (and $F_L$) of the $B\to K^{(*)}+$inv decays are studied for each viable operator. In addition, we, for the first time, calculate systematically the longitudinal polarization fraction $F_L$ of $K^*$ in the $B\to K^*+$inv decays within the DLEFT., Comment: 51 pages, 13 figures, comments welcome; v2: discussions on $F_L$ of the $B \to K^* + \text{inv}$ decay in the DSMEFT added, errors in the $B \to V + \text{inv}$ decays for some operators involving two scalar or vector DM fields fixed, the related discussions and figures 2, 6, 7, 11 and 12 corrected, main conclusion unchanged, a few comments and refs added

Motivated by the latest CDF $W$-mass measurement as well as the muon $g-2$ anomaly and the discrepancies observed in $b \to s \ell^+ \ell^-$ transitions, we propose an extension of the Standard Model (SM) with the $SU(2)_L$-singlet vector-like fermion partners that are featured by additional $U(1)^\prime$ gauge symmetry. The fermion partners have the same SM quantum numbers as of the right-handed SM fermions, and can therefore mix with the latter after the electroweak and the $U(1)^\prime$ symmetry breaking. As a result, desirable loop-level corrections to the $(g-2)_\mu$, the $W$-boson mass $m_W$ and the Wilson coefficient $C_9$ in $b \to s \mu^+ \mu^-$ transitions can be obtained. The final allowed parameter space is also consistent with the constraints from the $Z \to \mu^+ \mu^-$ decay, the neutrino trident production and the LHC direct searches for the vector-like quarks and leptons., Comment: 34 pages, 15 figures, comments welcome

The recently updated measurement of the $W$-boson mass by the CDF collaboration exhibits a $7\sigma$ deviation from the SM expectation, which may imply a sign of new physics beyond the SM. The observed discrepancy could be explained by new fermions that carry the electroweak gauge charges and affect the vacuum polarization of gauge bosons. Notably, if the new fermions also have the same quantum numbers as of the SM quarks, they can mix with the latter and thus modify the penguin diagrams governing the $b \to s \ell^+ \ell^-$ transitions. Therefore, the $W$-boson mass shift could be related to the $b \to s \ell^+ \ell^-$ anomalies observed by the LHCb collaboration during the past few years. To investigate this possibility, we consider in this paper a model containing a vector-like top partner gauged under a new $U(1)^\prime$ symmetry. It is found that the latest CDF $m_W$ measurement and the $b \to s \ell^+ \ell^-$ anomalies can be simultaneously accommodated at $2\sigma$ level., Comment: 7 pages, 3 figures, typos fixed, figures refined, and references added

The recently updated measurement of the $W$-boson mass by the CDF collaboration exhibits a $7\sigma$ deviation from the SM expectation, which may imply a sign of new physics beyond the SM. The observed discrepancy could be explained by new fermions that carry the electroweak gauge charges and affect the vacuum polarization of gauge bosons. Notably, if the new fermions also have the same quantum numbers as of the SM quarks, they can mix with the latter and thus modify the penguin diagrams governing the $b \to s \ell^+ \ell^-$ transitions. Therefore, the $W$-boson mass shift could be related to the $b \to s \ell^+ \ell^-$ anomalies observed by the LHCb collaboration during the past few years. To investigate this possibility, we consider in this paper a model containing a vector-like top partner gauged under a new $U(1)^\prime$ symmetry. It is found that the latest CDF $m_W$ measurement and the $b \to s \ell^+ \ell^-$ anomalies can be simultaneously accommodated at $2\sigma$ level., Comment: 7 pages, 3 figures, typos fixed, figures refined, and references added

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

The recently updated measurement of the $W$-boson mass by the CDF collaboration exhibits a $7\sigma$ deviation from the SM expectation, which may imply a sign of new physics beyond the SM. The observed discrepancy could be explained by new fermions that carry the electroweak gauge charges and affect the vacuum polarization of gauge bosons. Notably, if the new fermions also have the same quantum numbers as of the SM quarks, they can mix with the latter and thus modify the penguin diagrams governing the $b \to s \ell^+ \ell^-$ transitions. Therefore, the $W$-boson mass shift could be related to the $b \to s \ell^+ \ell^-$ anomalies observed by the LHCb collaboration during the past few years. To investigate this possibility, we consider in this paper a model containing a vector-like top partner gauged under a new $U(1)^\prime$ symmetry. It is found that the latest CDF $m_W$ measurement and the $b \to s \ell^+ \ell^-$ anomalies can be simultaneously accommodated at $2\sigma$ level., Comment: 7 pages, 3 figures, typos fixed, figures refined, and references added

Within the Standard Model, we investigate the CP violations and the $K_S^0-K_L^0$ asymmetries in $D^{\pm}\rightarrow K^{\ast}(892)^{0} \pi^{\pm} + \bar{K}^{\ast }(892)^{0}\pi^{\pm}\rightarrow K_{S,L}^{0}\pi^0 \pi^{\pm}$ decays basing on the factorization-assisted topological-amplitude (FAT) approach and the topological amplitude (TA) approach of Cheng and Chiang [Phys. Rev. D 104, 073003 (2021).]. We find that the CP violations in these decays $A_{CP}^{K_{S,L}^0}$ can exceed the order of $10^{-3}$ in the two approaches and consist of three parts: the indirect CP violations in $K^0 -\bar{K}^0$ mixing $A_{CP,K_{S,L}^0}^{mix}$, the direct CP violations in charm decays $A_{CP,K_{S,L}^0}^{dir}$ and the new CP violation effects $A_{CP,K_{S,L}^0}^{int}$, which are induced from the interference between two tree (Cabibbo-favored and doubly Cabibbo-suppressed) amplitudes with the neutral kaon mixing. The indirect CP violations in $K^0 -\bar{K}^0$ mixing play a dominant role in $A_{CP}^{K_{S,L}^0}$, the new CP violation effects have a non-negligible contribution to $A_{CP}^{K_{S,L}^0}$. We estimate the numerical results of the $K_S^0-K_L^0$ asymmetries $R_{K_{S}-K_{L}}^{D^{\pm}}$ and find that there exist a large difference between the numerical results in the FAT approach and that of the TA approach. We also find that if ones adopt the values of the decay time parameters $t_0 = 3.0 \tau_S$ and $t_1 = 10.0 \tau_S$, the new CP violation effect $A_{CP,K_{S}^0}^{int}$ would dominate the CP violation in $D^{\pm} \rightarrow K^{\ast}(892)^{0} \pi^{\pm} + \bar{K}^{\ast }(892)^{0}\pi^{\pm}\rightarrow K_{S}^0\pi^0 \pi^{\pm}$ decays and could be observed with $6.7\times 10^{6}$ and $6.5\times 10^{6}$ $D^{\pm}$ events-times-efficiency in the FAT approach and the TA approach, respectively. Our results could be tested by the LHCb, Belle II and BESIII experiments., Comment: 38 pages

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

The recently updated measurement of the $W$-boson mass by the CDF collaboration exhibits a $7\sigma$ deviation from the SM expectation, which may imply a sign of new physics beyond the SM. The observed discrepancy could be explained by new fermions that carry the electroweak gauge charges and affect the vacuum polarization of gauge bosons. Notably, if the new fermions also have the same quantum numbers as of the SM quarks, they can mix with the latter and thus modify the penguin diagrams governing the $b \to s \ell^+ \ell^-$ transitions. Therefore, the $W$-boson mass shift could be related to the $b \to s \ell^+ \ell^-$ anomalies observed by the LHCb collaboration during the past few years. To investigate this possibility, we consider in this paper a model containing a vector-like top partner gauged under a new $U(1)^\prime$ symmetry. It is found that the latest CDF $m_W$ measurement and the $b \to s \ell^+ \ell^-$ anomalies can be simultaneously accommodated at $2\sigma$ level., Comment: 7 pages, 3 figures, typos fixed, figures refined, and references added

A typical vibration signal of fault bearing is composed of periodic repetitive transient impulses, multiple vibration disturbance and background noise. Variational mode decomposition (VMD) represents a potential tool for analyzing such signals. However, the reasonable selection of VMD algorithm parameters hinders its application in mechanical signal processing to a certain extent. According to the specific characteristics of rolling bearing fault signal, the composite dimensionless index is constructed as the objective function to ensure the optimal decomposition of VMD. To further enhance the fault characteristics, the tunable Q-factor wavelet transform (TQWT) along with sparse code shrinkage is proposed to denoise the modal components containing periodic impulses, which further highlights the impulses and improves the sparseness of fault signal. Simulation and experimental signal analysis verify the effectiveness and reliability of this method. The results show that the use of optimized VMD and TQWT based sparse code shrinkage dramatically sharpens the impulses from the mixed signal with noise interference and increases the sparseness to a level.

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

Human activities both aggravate and alleviate streamflow drought. Here we show that aggravation is dominant in contrasting cases around the world analysed with a consistent methodology. Our 28 cases included different combinations of human-water interactions. We found that water abstraction aggravated all drought characteristics, with increases of 20%-305% in total time in drought found across the case studies, and increases in total deficit of up to almost 3000%. Water transfers reduced drought time and deficit by up to 97%. In cases with both abstraction and water transfers into the catchment or augmenting streamflow from groundwater, the water inputs could not compensate for the aggravation of droughts due to abstraction and only shift the effects in space or time. Reservoir releases for downstream water use alleviated droughts in the dry season, but also led to deficits in the wet season by changing flow seasonality. This led to minor changes in average drought duration (-26 to +38%) and moderate changes in average drought deficit (-86 to +369%). Land use showed a smaller impact on streamflow drought, also with both increases and decreases observed (-48 to +98%). Sewage return flows and pipe leakage possibly counteracted the effects of increased imperviousness in urban areas; however, untangling the effects of land use change on streamflow drought is challenging. This synthesis of diverse global cases highlights the complexity of the human influence on streamflow drought and the added value of empirical comparative studies. Results indicate both intended and unintended consequences of water management and infrastructure on downstream society and ecosystems.

The decays $K^{\ast}(892)\rightarrow K_{S,L}^{0}\pi$ can be used to study CP violation and CPT violation. The $K^{\ast}(892)$ (hereinafter referred to as $K^{\ast}$) meson can be produced via $J/\psi$ decays at BESIII. In this paper, we study CP violation and $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays involving the $K^{\ast}$ meson in the final states and obtain the following results \begin{align} {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S}\pi f_{J/\psi}\right)=\left(3.64\pm0.04\right)\times 10^{-3},\nonumber\\ {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{L}\pi f_{J/\psi}\right)=\left(-3.32\pm0.04\right)\times 10^{-3},\nonumber \end{align} and \begin{align} &R\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S,L}\pi f_{J/\psi} \right)=\left(3.51\pm0.03\right)\times 10^{-3},\nonumber\\ &R\left(J/\psi\rightarrow \bar{K}^{\ast} \bar{f}_{J/\psi}\rightarrow K^0_{S,L}\pi \bar{f}_{J/\psi} \right)=\left(-3.45\pm0.03\right)\times 10^{-3}.\nonumber \end{align} Basing on two cases: the samples of $10^{10}$ and $10^{12}$ $J/\psi$ events, we calculate the expected numbers of the observed signal events on the CP violation and the $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays with $K^{\ast}$ meson in the final states, we find that the BESIII experiment may be able to unambiguously observe CP violation and $K_S^0-K_L^0$ asymmetry for each of these two cases. We study the possibility to constraint the CPT violation parameter $z$ and discuss the sensitivity for the measurement of $z$ in $J/\psi$ decays with $K^{\ast}$ meson in the final states at BESIII. The sensitivity of the measurement of $z$ depend on the measured precision of the parameters $m_L-m_S$, $\Gamma_L$, $\Gamma_S$, $p$ and $q$ and the consistence between the values of $t_0$ and $t_1$ and the event selection criteria in experiment., Comment: 23 pages. arXiv admin note: text overlap with arXiv:2107.10683

The large data sample of the $B_c$ meson collected at the LHC experiment and the HL-LHC experiment provides us the opportunity to study the $B_c$ decays and the related physics. In this paper, we investigate the effect of $K^0-\bar{K}^0$ mixing on the the branching ratios, CP violations and CPT violations in the $B_{c}^{\pm}\rightarrow B^{\pm} K_{S,L}^{0}$ decays. We find that some of the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decay chains have large branching ratios, whose maximum value can exceed the order of $10^{-6}$, the minimum number of $B_c^\pm$ events times efficiency for observing the decays at three standard deviations (3$\sigma$) level is about $ 10^6$. We study the CP asymmetries in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0$ decays and find that the CP asymmetries can exceed the order of $10^{-3}$, which are dominated by $K^0-\bar{K}^0$ mixing. We give the most promising processes to observe the CP violations and the ranges of the numbers of $B_c^\pm$ events-times-efficiency needed to observe the CP asymmetries at a significance of 3$\sigma$ in these decays. We investigate the possibility to constraint the CPT violation parameter $z$ in the $B_c^{\pm}\rightarrow B^{\pm} K_{S,L}^0\rightarrow f_{B^{\pm}} f_{K_{S,L}^0}$ decays and give the most promising processes to constraint the parameter $z$., Comment: 32 pages,2 figures

Motivated by the recent anomalies in $b \to s \ell^+ \ell^-$ transitions, we explore a minimal $Z^\prime$ scenario, in which the $Z^\prime$ boson has a flavour-changing coupling to charm and top quarks and a flavour-conserving coupling to muons. It is found that such a $Z^\prime$ boson can explain the current $b \to s \ell^+ \ell^-$ anomalies, while satisfying other flavour and collider constraints simultaneously. The $Z^\prime$ boson can be as light as few hundreds GeV. In this case, the $t \to c \mu^+ \mu^-$ decay and the $tZ^\prime$ associated production at the LHC could provide sensitive probes of such a $Z^\prime$ boson. As a special feature, the $Z^\prime$ contributions to all rare $B$- and $K$-meson processes are controlled by one parameter. This results in interesting correlations among these processes, which could provide further insights into this scenario. In addition, an extended scenario, in which the $Z^\prime$ boson interacts with the $SU(2)_L$ fermion doublets with analogous couplings as in the minimal scenario, is also investigated., Comment: 40 pages, 13 figures, typos fixed, comments and references added

The decays $K^{\ast}(892)\rightarrow K_{S,L}^{0}\pi$ can be used to study CP violation and CPT violation. The $K^{\ast}(892)$ (hereinafter referred to as $K^{\ast}$) meson can be produced via $J/\psi$ decays at BESIII. In this paper, we study CP violation and $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays involving the $K^{\ast}$ meson in the final states and obtain the following results \begin{align} {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S}\pi f_{J/\psi}\right)=\left(3.64\pm0.04\right)\times 10^{-3},\nonumber\\ {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{L}\pi f_{J/\psi}\right)=\left(-3.32\pm0.04\right)\times 10^{-3},\nonumber \end{align} and \begin{align} &R\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S,L}\pi f_{J/\psi} \right)=\left(3.51\pm0.03\right)\times 10^{-3},\nonumber\\ &R\left(J/\psi\rightarrow \bar{K}^{\ast} \bar{f}_{J/\psi}\rightarrow K^0_{S,L}\pi \bar{f}_{J/\psi} \right)=\left(-3.45\pm0.03\right)\times 10^{-3}.\nonumber \end{align} Basing on two cases: the samples of $10^{10}$ and $10^{12}$ $J/\psi$ events, we calculate the expected numbers of the observed signal events on the CP violation and the $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays with $K^{\ast}$ meson in the final states, we find that the BESIII experiment may be able to unambiguously observe CP violation and $K_S^0-K_L^0$ asymmetry for each of these two cases. We study the possibility to constraint the CPT violation parameter $z$ and discuss the sensitivity for the measurement of $z$ in $J/\psi$ decays with $K^{\ast}$ meson in the final states at BESIII. The sensitivity of the measurement of $z$ depend on the measured precision of the parameters $m_L-m_S$, $\Gamma_L$, $\Gamma_S$, $p$ and $q$ and the consistence between the values of $t_0$ and $t_1$ and the event selection criteria in experiment., Comment: 23 pages. arXiv admin note: text overlap with arXiv:2107.10683

Motivated by the recent anomalies in $b \to s \ell^+ \ell^-$ transitions, we explore a minimal $Z^\prime$ scenario, in which the $Z^\prime$ boson has a flavour-changing coupling to charm and top quarks and a flavour-conserving coupling to muons. It is found that such a $Z^\prime$ boson can explain the current $b \to s \ell^+ \ell^-$ anomalies, while satisfying other flavour and collider constraints simultaneously. The $Z^\prime$ boson can be as light as few hundreds GeV. In this case, the $t \to c \mu^+ \mu^-$ decay and the $tZ^\prime$ associated production at the LHC could provide sensitive probes of such a $Z^\prime$ boson. As a special feature, the $Z^\prime$ contributions to all rare $B$- and $K$-meson processes are controlled by one parameter. This results in interesting correlations among these processes, which could provide further insights into this scenario. In addition, an extended scenario, in which the $Z^\prime$ boson interacts with the $SU(2)_L$ fermion doublets with analogous couplings as in the minimal scenario, is also investigated., Comment: 40 pages, 13 figures, typos fixed, comments and references added

The decays $K^{\ast}(892)\rightarrow K_{S,L}^{0}\pi$ can be used to study CP violation and CPT violation. The $K^{\ast}(892)$ (hereinafter referred to as $K^{\ast}$) meson can be produced via $J/\psi$ decays at BESIII. In this paper, we study CP violation and $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays involving the $K^{\ast}$ meson in the final states and obtain the following results \begin{align} {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S}\pi f_{J/\psi}\right)=\left(3.64\pm0.04\right)\times 10^{-3},\nonumber\\ {\mathcal A}_{CP}\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{L}\pi f_{J/\psi}\right)=\left(-3.32\pm0.04\right)\times 10^{-3},\nonumber \end{align} and \begin{align} &R\left(J/\psi\rightarrow K^{\ast}f_{J/\psi}\rightarrow K^0_{S,L}\pi f_{J/\psi} \right)=\left(3.51\pm0.03\right)\times 10^{-3},\nonumber\\ &R\left(J/\psi\rightarrow \bar{K}^{\ast} \bar{f}_{J/\psi}\rightarrow K^0_{S,L}\pi \bar{f}_{J/\psi} \right)=\left(-3.45\pm0.03\right)\times 10^{-3}.\nonumber \end{align} Basing on two cases: the samples of $10^{10}$ and $10^{12}$ $J/\psi$ events, we calculate the expected numbers of the observed signal events on the CP violation and the $K_S^0-K_L^0$ asymmetry in the $J/\psi$ decays with $K^{\ast}$ meson in the final states, we find that the BESIII experiment may be able to unambiguously observe CP violation and $K_S^0-K_L^0$ asymmetry for each of these two cases. We study the possibility to constraint the CPT violation parameter $z$ and discuss the sensitivity for the measurement of $z$ in $J/\psi$ decays with $K^{\ast}$ meson in the final states at BESIII. The sensitivity of the measurement of $z$ depend on the measured precision of the parameters $m_L-m_S$, $\Gamma_L$, $\Gamma_S$, $p$ and $q$ and the consistence between the values of $t_0$ and $t_1$ and the event selection criteria in experiment., Comment: 23 pages. arXiv admin note: text overlap with arXiv:2107.10683

Daneng Wei,1,* Yafei Zhao,2,* Mengmeng Zhang,1 Lei Zhu,1 Li Wang,1 Xing Yuan,3 Chunjie Wu1 1Pharmacy College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, People’s Republic of China; 2Acupuncture and Moxibustion College, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 610075, People’s Republic of China; 3School of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, Chengdu, Sichuan 611137, People’s Republic of China*These authors contributed equally to this workCorrespondence: Xing YuanSchool of Medical and Life Sciences, Chengdu University of Traditional Chinese Medicine, No. 1166 Liutai Avenue, Wenjiang District, Chengdu, Sichuan 611137, People’s Republic of ChinaEmail yuanxing19891222@163.comChunjie WuPharmacy College, Chengdu University of Traditional Chinese Medicine, No. 1166 Liutai Avenue, Wenjiang District, Chengdu, Sichuan 611137, People’s Republic of ChinaEmail wucjcdtcm@163.comBackground: Anxiety disorders (ADs) are the most prevalent mental disorders worldwide. Stress-induced activation of the hypothalamic-pituitary-adrenal (HPA) axis and dysbiosis of gut microbiota seem to contribute to the onset of ADs. This study was designed to investigate the ameliorative effect of volatile oil of Zanthoxylum bungeanum (VOZB) on chronic unpredictable stress (CUS) induced anxiety behavior, as well as the altered HPA axis and gut microbiota.Methods: Experimental rats were exposed to the CUS for 14 consecutive days. Meanwhile, VOZB was administered at doses of 50, 100 and 200 mg/kg/day for 14 days. The anxiety behavior was evaluated by elevated plus-maze (EPM) and open field (OF). The protein expressions and mRNA levels of corticotropin-releasing hormone (CRH) and glucocorticoid receptor (GR) in hypothalamus was determined, as well the hormone levels of HPA axis in serum. Furthermore, gut microbiota was detected by16S rRNA gene sequencing. T

During the past few years, hints of Lepton Flavour Universality (LFU) violation have been observed in $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ transitions. Recently, the $D^*$ and $\tau$ polarization fractions $P_L^{D^*}$ and $P_L^\tau$ in $B \to D^* \tau \bar\nu$ decay have also been measured by the Belle collaboration. Motivated by these intriguing results, we revisit the $R_{D^{(*)}}$ and $R_{K^{(*)}}$ anomalies in a scalar leptoquark (LQ) model, in which two scalar LQs, one being $SU(2)_L$ singlet and the other $SU(2)_L$ triplet, are introduced simultaneously. We consider five $b \to c \tau \bar\nu$ mediated decays, $B \to D^{(*)}\tau \bar\nu$, $B_c \to \eta_c \tau \bar\nu$, $B_c \to J/\psi \tau \bar\nu$, and $\Lambda_b \to \Lambda_c \tau \bar\nu$, and focus on the LQ effects on the $q^2$ distributions of the branching fractions, the LFU ratios, and the various angular observables in these decays. Under the combined constraints by the available data on $R_{D^{(*)}}$, $R_{J/\psi}$, $P_L^\tau(D^*)$, and $P_L^{D^*}$, we perform scans for the LQ couplings and make predictions for a number of observables. It is found numerically that both the differential branching fractions and the LFU ratios are largely enhanced by the LQ effects, with the latter being expected to provide testable signatures at the SuperKEKB and High-Luminosity LHC experiments., Comment: 35 pages, 5figures

In the past few years, several hints of lepton flavour universality (LFU) violation have emerged in the $b \to c \tau \bar\nu$ and $b \to s \ell^+ \ell^-$ data. Quite recently, the Belle Collaboration has reported the first measurement of the $D^*$ longitudinal polarization fraction in the $B \to D^* \tau \bar\nu$ decay. Motivated by this intriguing result, together with the recent measurements of $R_{J/\psi}$ and $\tau$ polarization, we study $b \to c \tau \bar\nu$ decays in the Supersymmetry (SUSY) with $R$-parity violation (RPV). We consider $B \to D^{(*)} \tau \bar\nu$, $B_c \to \eta_c \tau \bar\nu$, $B_c \to J/\psi \tau \bar\nu$ and $\Lambda_b \to \Lambda_c \tau \bar\nu$ modes and focus on the branching ratios, the LFU ratios, the forward-backward asymmetries, polarizations of daughter hadrons and $\tau$ lepton. It is found that the RPV SUSY can explain the $R_{D^{(*)}}$ anomalies at $2\sigma$ level, after taking into account various flavour constraints. In the allowed parameter space, the differential branching fractions and LFU ratios are largely enhanced by the SUSY effects, especially in the large dilepton invariant mass region. In addition, a lower bound $\mathcal B(B^+ \to K^+ \nu \bar\nu) > 7.37 \times 10^{-6}$ is obtained. These observables could provide testable signatures at the High-Luminosity LHC and SuperKEKB, and correlate with direct searches for SUSY., Comment: 32 pages, 5 figures, to be published in Chinese Physics C. arXiv admin note: text overlap with arXiv:1905.01795

We study the scalar perturbation on the background of a Kerr black hole in the dynamical Chern-Simons modified gravity with a quadratic coupling between the scalar field and Chern-Simons term. In particular, the late-time tails of scalar perturbations are investigated numerically in time domain by using the hyperboloidal foliation method. It is found that the Kerr black hole becomes unstable under linear perturbations in a certain region of the parameter space, which depends on the harmonic azimuthal index $m$ of the perturbation's mode. This may indicate that some Kerr black holes in this theory will get spontaneously scalarized into a non-Kerr black hole., Comment: 26 pages, 10 figures, v2: references added, submitted to PRD; v3: discussions on EFT included; v4: matched with the published version

Motivated by the rencent LHC data on the lepton-flavor violating (LFV) decays $h\to \ell_1 \ell_2$ and $B_{s,d}\to \ell_1 \ell_2$, we study the Higgs-mediated flavor-changing neutral current (FCNC) interactions in the effective field theory (EFT) approach without and with the minimal flavor violation (MFV) hypothesis, and concentrate on the later. After considering the $B$ and $K$ physics data, the various LFV processes, and the LHC Higgs data, severe constraints on the Higgs FCNC couplings are derived, which are dominated by the LHC Higgs data, the $B_s - \bar B_s$ mixing, and the $\mu \to e \gamma$ decay. In the general case and the MFV framework, allowed ranges of various observables are obtained, such as $\mathcal B (B_s\to \ell_1 \ell_2)$, $\mathcal B (h\to \ell_1 \ell_2)$, $\mathcal B (h\to q_1 q_2)$, and the branching ratio of $\mu \to e$ conversion in Al. Future prospects of searching for the Higgs FCNC interactions at the low-energy experiments and the LHC are discussed., Comment: 26 pages, 5 figures, minor errors corrected, figures slightly changed, comments and references added

We study the possibility to observe sterile neutrinos with masses in the range between 5 GeV and 20 GeV at the LHC, using the exclusive semileptonic modes involving pions, namely W to lepton + N to n pions + lepton+lepton (n = 1, 2, 3). The two pion and three pion modes require extrapolations of form factors to large time-like $q^2$, which we do using vector dominance models as well as light front holographic QCD, with remarkable agreement. This mass region is difficult to explore with inclusive dilepton+dijet modes or trilepton modes and impossible to explore in rare meson decays. While particle identification is a real challenge in these modes, vertex displacement due to the long living neutrino in the above mass range can greatly help reduce backgrounds. Assuming a sample of $10^9$ W bosons at the end of the LHC Run 2, these modes could discover a sterile neutrino in the above mass range or improve the current bounds on the heavy-to-light lepton mixings by an order of magnitude, $U_{l N}^2 \sim 2 \times 10^{-6}$. Moreover, by studying the equal sign and opposite sign dileptons, the Majorana or Dirac character of the sterile neutrino may be revealed., Comment: 18 pages, 4 double figures

Fan Gao,1 Chen Chen,2 Jun Lyu,1 Jie Zheng,1 Xian-Cang Ma,1,3 Xing-Yun Yuan,2 Kang Huo,2 Jian-Feng Han2 1Clinical Research Center, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China; 2Department of Neurology, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China; 3Department of Psychiatry, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, People’s Republic of China Purpose: The platelet distribution width (PDW) reflects the status of platelet activity and may be useful for early predictions of the clinical outcome of stroke patients. The purpose of the study was to determine the associations between PDW and clinical outcomes after intravenous thrombolysis in stroke patients. Patients and methods: Acute ischemic stroke patients who received intravenous treatment with recombinant tissue-type plasminogen activator were selected for inclusion in the retrospective cohort of this study. The relations between PDW at admission and clinical outcomes were analyzed, including a poor outcome as assessed using the modified Rankin Scale at 3 months, early neurological improvement, and any hemorrhage. The effect of PDW at admission on a poor outcome at 3 months was analyzed using a multivariable logistic regression model with adjustment for potential confounders. The optimal PDW cutoff for predicting poor outcome at 3 months was determined by analyzing the receiver operating characteristics curve. Results: PDW was significantly higher for a good outcome than a poor outcome (p=0.005), with median (interquartile range) values of 16.2 (13.2–17.2) and 13.6 (12.5–15.9), respectively. PDW was also higher in patients with early neurological improvement than in patients without improvement (p=0.020) and did not differ between hemorrhage and nonhemorrhage pa

An investigation of free convection in a horizontal concentric annuli with different inner shapes where the inner and outer surfaces are kept at a constant temperature is presented. The simulation is categorized into four groups based on the shape of the inner entity which can be either cylindrical, elliptical, square or triangular. Flow and thermal fields are exhibited by means of streamlines and isotherms. Overall heat transfer correlations incorporating thermal radiation are established and presented in terms of the Nusselt numbers. It is observed that the surface radiation and existence of the corners and larger top space can enhance the heat transfer rate. As the reference temperature and Rayleigh number increases, surface radiation plays a more prominent role in the overall heat transfer performance.

An investigation of free convection in a horizontal concentric annuli with different inner shapes where the inner and outer surfaces are kept at a constant temperature is presented. The simulation is categorized into four groups based on the shape of the inner entity which can be either cylindrical, elliptical, square or triangular. Flow and thermal fields are exhibited by means of streamlines and isotherms. Overall heat transfer correlations incorporating thermal radiation are established and presented in terms of the Nusselt numbers. It is observed that the surface radiation and existence of the corners and larger top space can enhance the heat transfer rate. As the reference temperature and Rayleigh number increases, surface radiation plays a more prominent role in the overall heat transfer performance.

I integrate temporal self-regulatory theory with literature on personal value of time and social information processing theory to consider an individual's adoption of feedback avoiding behavior as a temporal self-regulatory strategy motivated by both internal factors (i.e., an individual employee's monochronicity) and external factors (i.e., the interaction partner's monochronicity and their relationship quality). In a two-wave time-lagged, two-source field study with 92 Chinese mentor-protégé dyads, I found that protégés' monochronicity was positively associated with their feedback avoiding behavior and this relationship was mitigated by mentors' monochronicity. Results also showed that this two-way interaction was further moderated by mentor-protégé mentorship quality. Specifically, when mentor-protégé mentorship quality was high, the moderation effect of mentor monochronicity became stronger such that protégés’ monochronicity was not only less positively related but also became negatively related to their feedback avoiding behavior. I discuss important theoretical and practical implications. Keywords: Individual time value orientation; monochronicity; temporal self-regulation; feedback avoiding behavior

Recent research in large-scale hydroclimatic variability is surveyed, focusing on five topics: (i) variability in general, (ii) droughts, (iii) floods, (iv) land-atmosphere coupling, and (v) hydroclimatic prediction. Each surveyed topic is supplemented by illustrative examples of recent research, as presented at a 2016 symposium honoring the career of Professor Eric Wood. Taken together, the recent literature and the illustrative examples clearly show that current research into hydroclimatic variability is strong, vibrant, and multifaceted., Water Resources

A recent LHCb measurement of the ratio $R_{K^*}$ of $B\to K^*\mu\bar\mu$ to $B\to K^*e\bar e$ branching fractions has produced results in mild tension with the standard model (SM). This adds to the known anomalies also induced by the $b\to s\ell\bar\ell$ transitions, resulting in a confidence level now as high as 4$\sigma$. We analyze whether the parameter space preferred by all the $b\to s\ell\bar\ell$ anomalies is compatible with a heavy $Z'$ boson assumed to have nonuniversal couplings to SM fermions dictated by the principle of minimal flavor violation (MFV). We deal with the MFV couplings of the $Z'$ to leptons in the context of the type-I seesaw scenario for generating neutrino masses. The flavor-violating $Z'$ interactions are subject to stringent constraints from other processes, especially $B$-$\bar B$ mixing, charged lepton decays $\ell_i\to\ell_j\ell_k\bar\ell_l$ occurring at tree level, and the loop induced $\mu\to e\gamma$. We perform scans for parameter regions allowed by various data and predict the ranges for a number of observables. Some of the predictions, such as the branching fractions of lepton-flavor violating $\tau\to3\mu$, $B\to K e\mu$, $K_L\to e\mu$, and $Z\to\ell\ell'$, are not far below their experimental bounds and therefore could be probed by searches in the near future. The viable parameter space depends strongly on the neutrino mass hierarchy, with a preference for the inverted one., Comment: 25 pages, 5 figures, slightly enlarged, comments & references added, matches journal version

Recent LHCb data for time-dependent CP violation in $B_d^0 \to \pi^+\pi^-$ and $B^0_s\to K^+K^-$ show deviations from theoretical predictions. Besides their central values for $\mathcal C_{K^+K^-}$, $\mathcal S_{K^+K^-}$ and $\mathcal A^{\Delta \Gamma}_{K^+K^-}$ violate quantum mechanic CPT invariant sum rule (CPT sum rule) prediction of $|\mathcal C_{K^+K^-}|^2 + |\mathcal S_{K^+K^-}| ^2 + |\mathcal A^{\Delta \Gamma}_{K^+K^-}|^2 = 1$ (LHCb data imply the sum to be $0.67\pm 0.20$.), their values for $\mathcal C_{K^+ K^-}= 0.24\pm 0.06\pm {0.02}$ and $\mathcal C_{\pi^+ \pi^-} = - 0.24\pm 0.07\pm 0.01$ also show large violation of SU(3) or its U-spin sub-group symmetry (SU(3)/U) relation $\mathcal C_{K^+ K^-} /\mathcal C_{\pi^- \pi^+} = - \mathcal B(B_d^0 \to \pi^- \pi^+)\tau_{B^0_s}/\mathcal B(B^0_s \to K^+ K^-)\tau_{B_d^0}$ (LHCb data imply the ratio of left-side to right-side to be $4.67\pm 1.88$.) . The LHCb results need to be further confirmed to be taken seriously. We suggest to use time-dependent CP violation in $B_s\to K^0\bar K^0, \pi^+\pi^-, \pi^0\pi^0$ to further test the CPT sum rule. Assuming that the sum rule holds, we propose that violation of the SU(3)/U relation may indicate a large FSI phase difference in the $\pi^+\pi^-$ and $K^+K^-$ re-scattering. We suggest several other U-spin pairs of $B\to PP$ decays to further test SU(3)/U relations., Comment: 12 pages, 1 figure; ACP of $B^0_d \to \pi^+ \pi^-$ updated to the latest HFAG average, figures slightly changed, a few comments and refs added

Loop-induced $Hgg$ and $H\gamma\gamma$ coupling play an important role in the Higgs production and decay at the LHC. These vertices can be affected by various New Physics contributions, including new particles, anomalous Yukawa couplings, and so on. We point out some ratios of the Higgs signal strengths could help disentangle the contributions of new particles from other sources of New Physics., Comment: 13 pages, 2 figures

We study constraints and implications of the recent LHCb measurement of ${\cal B}(B_s \to \mu^+\mu^-)$ for tree-level Higgs-mediated flavor-changing neutral current (FCNC) interactions. Combined with experimental data on $B_s$ mass difference $\Delta m_s$, the $h \to \mu \tau$, and the $h \to \tau^+\tau^-$ decay branching ratios from the LHC, we find that the Higgs FCNC couplings are severely constrained. The allowed regions for $B_s \to \mu \tau$, $\tau\tau$ and $h \to sb$ decays are obtained. Current data allow large CP violation in the $h \to \tau^+ \tau^-$ decay. Consequences of the Cheng-Sher ansatz for the Higgs Yukawa couplings are discussed in some detail., Comment: 21 pages, 5 figures. Updated the paper with new results from LHC on h to mu tau

I integrate temporal self-regulatory theory with literature on personal value of time and social information processing theory to consider an individual's adoption of feedback avoiding behavior as a temporal self-regulatory strategy motivated by both internal factors (i.e., an individual employee's monochronicity) and external factors (i.e., the interaction partner's monochronicity and their relationship quality). In a two-wave time-lagged, two-source field study with 92 Chinese mentor-protégé dyads, I found that protégés' monochronicity was positively associated with their feedback avoiding behavior and this relationship was mitigated by mentors' monochronicity. Results also showed that this two-way interaction was further moderated by mentor-protégé mentorship quality. Specifically, when mentor-protégé mentorship quality was high, the moderation effect of mentor monochronicity became stronger such that protégés’ monochronicity was not only less positively related but also became negatively related to their feedback avoiding behavior. I discuss important theoretical and practical implications. Keywords: Individual time value orientation; monochronicity; temporal self-regulation; feedback avoiding behavior

Recent research in large-scale hydroclimatic variability is surveyed, focusing on five topics: (i) variability in general, (ii) droughts, (iii) floods, (iv) land-atmosphere coupling, and (v) hydroclimatic prediction. Each surveyed topic is supplemented by illustrative examples of recent research, as presented at a 2016 symposium honoring the career of Professor Eric Wood. Taken together, the recent literature and the illustrative examples clearly show that current research into hydroclimatic variability is strong, vibrant, and multifaceted., Water Resources

Recent LHCb data for time-dependent CP violation in $B_d^0 \to \pi^+\pi^-$ and $B^0_s\to K^+K^-$ show deviations from theoretical predictions. Besides their central values for $\mathcal C_{K^+K^-}$, $\mathcal S_{K^+K^-}$ and $\mathcal A^{\Delta \Gamma}_{K^+K^-}$ violate quantum mechanic CPT invariant sum rule (CPT sum rule) prediction of $|\mathcal C_{K^+K^-}|^2 + |\mathcal S_{K^+K^-}| ^2 + |\mathcal A^{\Delta \Gamma}_{K^+K^-}|^2 = 1$ (LHCb data imply the sum to be $0.67\pm 0.20$.), their values for $\mathcal C_{K^+ K^-}= 0.24\pm 0.06\pm {0.02}$ and $\mathcal C_{\pi^+ \pi^-} = - 0.24\pm 0.07\pm 0.01$ also show large violation of SU(3) or its U-spin sub-group symmetry (SU(3)/U) relation $\mathcal C_{K^+ K^-} /\mathcal C_{\pi^- \pi^+} = - \mathcal B(B_d^0 \to \pi^- \pi^+)\tau_{B^0_s}/\mathcal B(B^0_s \to K^+ K^-)\tau_{B_d^0}$ (LHCb data imply the ratio of left-side to right-side to be $4.67\pm 1.88$.) . The LHCb results need to be further confirmed to be taken seriously. We suggest to use time-dependent CP violation in $B_s\to K^0\bar K^0, \pi^+\pi^-, \pi^0\pi^0$ to further test the CPT sum rule. Assuming that the sum rule holds, we propose that violation of the SU(3)/U relation may indicate a large FSI phase difference in the $\pi^+\pi^-$ and $K^+K^-$ re-scattering. We suggest several other U-spin pairs of $B\to PP$ decays to further test SU(3)/U relations., Comment: 12 pages, 1 figure; ACP of $B^0_d \to \pi^+ \pi^-$ updated to the latest HFAG average, figures slightly changed, a few comments and refs added

Loop-induced $Hgg$ and $H\gamma\gamma$ coupling play an important role in the Higgs production and decay at the LHC. These vertices can be affected by various New Physics contributions, including new particles, anomalous Yukawa couplings, and so on. We point out some ratios of the Higgs signal strengths could help disentangle the contributions of new particles from other sources of New Physics., Comment: 13 pages, 2 figures

A recent LHCb measurement of the ratio $R_{K^*}$ of $B\to K^*\mu\bar\mu$ to $B\to K^*e\bar e$ branching fractions has produced results in mild tension with the standard model (SM). This adds to the known anomalies also induced by the $b\to s\ell\bar\ell$ transitions, resulting in a confidence level now as high as 4$\sigma$. We analyze whether the parameter space preferred by all the $b\to s\ell\bar\ell$ anomalies is compatible with a heavy $Z'$ boson assumed to have nonuniversal couplings to SM fermions dictated by the principle of minimal flavor violation (MFV). We deal with the MFV couplings of the $Z'$ to leptons in the context of the type-I seesaw scenario for generating neutrino masses. The flavor-violating $Z'$ interactions are subject to stringent constraints from other processes, especially $B$-$\bar B$ mixing, charged lepton decays $\ell_i\to\ell_j\ell_k\bar\ell_l$ occurring at tree level, and the loop induced $\mu\to e\gamma$. We perform scans for parameter regions allowed by various data and predict the ranges for a number of observables. Some of the predictions, such as the branching fractions of lepton-flavor violating $\tau\to3\mu$, $B\to K e\mu$, $K_L\to e\mu$, and $Z\to\ell\ell'$, are not far below their experimental bounds and therefore could be probed by searches in the near future. The viable parameter space depends strongly on the neutrino mass hierarchy, with a preference for the inverted one., Comment: 25 pages, 5 figures, slightly enlarged, comments & references added, matches journal version

Fan Gao,1 Chen Chen,2 Jun Lu,1 Jie Zheng,1 Xian-Cang Ma,1,3 Xing-Yun Yuan,2 Kang Huo,2 Jian-Feng Han2 1Clinical Research Center, 2Department of Neurology, 3Department of Psychiatry, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China Purpose: The aspartate transaminase/alanine transaminase ratio (De Ritis ratio, AAR) was reported to be associated with patients’ prognosis in certain diseases recently. The objective of the current study was to determine the association between the AAR at admission and poor outcome at 3 months in acute ischemic stroke (AIS) patients.Patients and methods: This retrospective cohort study included patients who experienced their first-ever AIS between June 2015 and March 2016. The primary outcome measure was a poor outcome at 3 months (modified Rankin Scale score >2). Multivariate logistic regression models were used to assess the relationship between AAR quartiles and clinical outcomes among the AIS patients. Receiver operating characteristic curve analysis was applied to identify the optimal cutoff for AAR in predicting the prognosis of AIS.Results: In terms of the relationship between poor outcome and AAR, the adjusted odds ratio comparing the highest and lowest AAR quartiles was 2.15 (95% confidence interval =1.14–4.05). An AAR of 1.53 was identified as the optimal cutoff. In a prespecified subgroup analysis according to the time from symptom onset to treatment (>24 vs ≤24 hours), there was no significant difference in the effect of AAR >1.53 between the two groups.Conclusion: An increased AAR at admission is significantly associated with a poor outcome at 3 months in AIS patients. Keywords: De Ritis ratio, stroke, prognosis, aspartate transaminase, alanine transaminase, modified Rankin scale, poor outcome

We explore a $Z^\prime$ boson coupled only with the Standard Model (SM) fermions ($Z^\prime f\bar{f}$) in the framework of Minimal Flavor Violation. We study its effects on the processes with lepton flavor violation $\ell_j\to \ell_i\ell_k\bar{\ell}_l$, $\ell_j\to\ell_i\gamma$, $\mu^{-}N\to e^- N$, quark flavor changing neutral currents $b\to s \ell^+\ell^-$, neutral $B$ and $K$ meson mixing, and $e^+e^-\to f\bar{f}$ at the LEP experiment to constrain the parameter space of $Z^\prime$ mass and couplings. We find that among those relevant processes, $\mu\to e\gamma$, $\mu\to 3e$, $\mu$-$e$ conversion and $e^+e^-\to f\bar{f}$ can put more stringent bounds on $Z^\prime f\bar{f}$ couplings normalized by $Z^\prime$ mass. Its implications on various processes are obtained, such as $B$ and $K$ mixing and $B/K\to M \ell_1 \bar\ell_2$ decays. In addition, we also make analysis on $Z^\prime$ signatures at the LHC with $\sqrt{s}=8$ and 13 TeV., Comment: 30 pages, 2 tables, 5 figures. v2: references and minor corrections for Fig.4 included

We revisit the rare leptonic decay $B_s \to \mu^+ \mu^-$ in the two-Higgs doublet models with a softly broken $Z_2$ symmetry, namely type-I, type-II, type-X and type-Y 2HDMs. We have derived the relevant full one-loop Wilson coefficients of the four 2HDMs from the recent calculation in the aligned two-Higgs doublet model by Li, Lu and Pich, which could be mapped to all the four 2HDMs for both large and small $\tan\beta$. It is found that, a new term associated with the soft $Z_2$ symmetry breaking parameter $M$ can be enhanced by $\tan^2\beta$ in the type-II 2HDM, which has not been considered in the literature. Imposing both theoretical and experimental constraints, we have renewed the bounds on the parameter spaces of the four 2HDMs. Different from our previous paper, however, we find that all the four 2HDMs give sizable and similar contributions to $\overline{\mathcal B}(B_s \to \mu^+ \mu^-)$ within the stringently restricted parameter spaces, but very tiny as regards the mass-eigenstate rate asymmetry $\mathcal A_{\Delta\Gamma}$; this makes it unfeasible to discriminate the four types of 2HDM with the correlations between the observables in $B_s \to \mu^+ \mu^-$ decay., Comment: 27 pages, 2 tables, 4 figures; v2: a brief introduction to 2HDM added, matches published version

The top quark flavor changing neutral current (FCNC) process is an excellent probe to search for new physics in top sector since the Standard Model expectation is extremely suppressed. We explore Higgs-mediated top quark FCNC, focusing on $H$-$t$-$c$ Yukawa coupling $\lambda_{ct}$ within the general two Higgs doublet model. After electroweak symmetry breaking the top quark FCNC couplings are included in the charged Higgs Yukawa sector so that they contribute to various processes in flavor physics. To probe $\lambda_{ct}$, we study anomalous single top production and the same sign top pair production at the LHC in association with flavor physics from the tree-level processes $B\to D^{(*)}\tau\nu$, $B\to \tau \nu$ as well as from the loop-level processes $B_d \to X_s \gamma$, $B_{d,s}-{\overline B}_{d,s}$ mixing. We perform combined analysis of all the constraints regarding the fine-tuning argument to fit the data and discuss future prospect. The recently updated measurements on $B\to D^{(*)}\tau\nu$ still prefer large $\lambda_{ct}$, but we show that the current bound on the same sign top pair production at the LHC gives the most significant upper bound on $\lambda_{ct}$ to be less than $10\sim30$ depending on neutral heavy Higgs masses. We also find that for the given upper bound on $\lambda_{ct}$, $B\to D^{(*)}\tau\nu$ put significant lower bound on $H$-$\tau$-$\tau$ Yukawa coupling, and the bound is proportional to the charged Higgs mass., Comment: 29 pages, 9 figures; modified version published in JHEP

There are four types of two-Higgs doublet models under a discrete $Z_2$ symmetry imposed to avoid tree-level flavour-changing neutral current, i.e. type-I, type-II, type-X and type-Y models. We investigate the possibility to discriminate the four models in the light of the flavour physics data, including $B_s-\bar B_s$ mixing, $B_{s,d} \to \mu^+ \mu^-$, $B\to \tau\nu$ and $\bar B \to X_s \gamma$ decays, the recent LHC Higgs data, the direct search for charged Higgs at LEP, and the constraints from perturbative unitarity and vacuum stability. After deriving the combined constraints on the Yukawa interaction parameters, we have shown that the correlation between the mass eigenstate rate asymmetry $A_{\Delta\Gamma}$ of $B_{s} \to \mu^+ \mu^-$ and the ratio $R={\cal B}(B_{s} \to \mu^+ \mu^-)_{exp}/ {\cal B}(B_{s} \to \mu^+ \mu^-)_{SM}$ could be sensitive probe to discriminate the four models with future precise measurements of the observables in the $B_{s} \to \mu^+ \mu^-$ decay at LHCb., Comment: 29 pages, 4 tables, 11 figures. v3: minor corrections included, matches published version in EPJC