arXiv subjects

Yuan-Guo Xu

Publications and source records attributed to Yuan-Guo Xu.

At least 19 recordsLinked to original sources

arXiv2026

Studying the tensor resonance contributions in $B \to PP\ell^+\ell^-$ and $B \to PV\ell^+\ell^-$ decays

We analyze the semileptonic $B \to T\ell^+\ell^-$, $B \to T(\to PP)\ell^+\ell^-$, and $B \to T(\to PV)\ell^+\ell^-$ decays with $\ell=e,μ,τ$ based on flavor SU(3) analysis in the standard model ($T$ denotes the light tensor meson, $P$ denotes the light pseudoscalar meson, and $V$ denotes the light vector meson). The hadronic amplitudes of the $B \to T\ell^+\ell^-$ decays are related by the nonperturbative parameters, and all branching ratios of the $B \to T\ell^+\ell^-$ decays are obtained by the experimental data of the branching ratio of $B^0_s\to f^{\prime}_{2}(1525)μ^+μ^-$ in three cases, and then the branching ratios of the $B \to T(\to PP)\ell^+\ell^-$ and $B \to T(\to PV)\ell^+\ell^-$ decays are predicted by the narrow width approximation and further considering finite width effects of the intermediate resonances. Compared with the narrow width results, the finite width effects slightly reduce the branching fractions for most decays. However, sizeable finite width effects are found in some near threshold modes. For the subthreshold $K_2^*(1430)\to Kη'$ relevant channels, the finite width of the tensor resonance can open a nonzero contribution. Compared with the measured $B \to PP\ell^+\ell^-$ and $B \to PV\ell^+\ell^-$ decays, we find that the branching ratios with the tensor resonance states are small. Therefore, other resonances, for example, the vector mesons, the scalar mesons, the axial-vector mesons or their excited states, might give the dominant contributions to the relevant decays. Our results might be tested in current and future experiments.

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arXiv2026

Study of $χ_{c1,2}$ decays to $PPP$ via light meson resonances

The three-body decays of charmonium states provide a valuable laboratory for probing non-perturbative QCD dynamics and investigating light meson resonances. Three-body decays $χ_{c1,2} \to P_{1}P_{2}P_{3}$ are studied in this work ($P$ denotes the light pseudoscalar meson). Branching ratio analysis is performed for the $χ_{c1,2} \to P_{1}P_{2}P_{3}$ decays incorporating light vector ($V$) meson resonance, light tensor ($T$) meson resonance and light scalar ($S$) meson resonance contributions. Based on the SU(3) flavor symmetry approach, we calculate the branching ratios under both the narrow width approximation and the finite width effect, and provide the predict results in the $χ_{c1,2}\to (V/T)P_{3} \to P_{1}P_{2}P_{3}$ processes. Furthermore, based on the significant $a^{+}_{0}(980)$ resonance signal in $χ_{c1} \to π^{+ }π^{- }η$ decay, the predict results for $χ_{c1}\to SP_{3} \to P_{1}P_{2}P_{3}$ are also obtained. While the resonance signals observed in current experiments are mainly concentrated in the $χ_{c1} \to π^+ π^- η$ decay, our results suggest potential resonance contributions in other channels. Especially in $χ_{c1,2}\to KKπ$ channels, the predicted results show the significant resonance contributions from $V$ mesons and $T$ mesons, which is worth further experimental verification and exploration.

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arXiv2025

Flavor SU(3) analysis of the charmless semileptonic $B \to PV\ell^+ν_\ell$ decays

All charmless $B \to PV\ell^+ν_\ell$ ($P$ denotes the light pseudoscalar meson and $V$ denotes the vector meson) decays have not been experimentally observed to date, but some of them might be measured in the near future. The charmless $B \to PV\ell^+ν_\ell$ decays with the axial-vector ($A$) resonance states, the tensor ($T$) resonance states and the excited vector ($V_{E,D}$) resonance states are studied based on flavor SU(3) analysis in this work, where $V_E$ contains $\{ρ(1450), K^*(1410), ω(1420), ϕ(1680)\}$ with quantum numbers $n^{2S+1}L_J=2^3S_1$ and $V_D$ contains $\{ρ(1700), K^*(1680), ω(1650), ϕ(2170)\}$ with quantum numbers $n^{2S+1}L_J=1^3D_1$. The hadronic amplitudes of the $B \to A/T \ell^+ν_{\ell}$ decays are related by the nonperturbative parameters, and the branching ratio predictions of $B \to A/T/V_{E,D} \ell^+ν_{\ell}$ are obtained, and then the branching ratios of the $B\to A(A\to PV)\ell^+ν_\ell$, $B\to T(T\to PV)\ell^+ν_\ell$, $B\to V_E(V_E\to PV)\ell^+ν_\ell$ and $B\to V_D(V_D\to PV)\ell^+ν_\ell$ are obtained by the narrow width approximation or further considering the width effects. We find that most branching ratios of the $B \to A \ell^+ν_{\ell}$ decays and many branching ratios of the $B\to A(A\to PV)\ell^+ν_\ell$ decays are on the order of $\mathcal{O}(10^{-4}-10^{-3})$, and all branching ratios with the tensor resonance states and the excited vector resonance states are small. Our results could be tested in the future BelleII and LHCb experiments.

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arXiv2024

Study of semileptonic $B\to DP\ell^+ν_\ell$ decays based on the SU(3) flavor symmetry

Decays $B\to DP\ell^+ν_\ell~(\ell=e,μ,τ)$ with the non-resonance, the charmed vector resonances, the charmed scalar resonances and the charmed tensor resonances are calculated by using the SU(3) flavor symmetry. Firstly, the decay amplitudes of different modes are related by the SU(3) flavor symmetry. Then, relevant experiential data are used to constrain nonperturbative coefficients in the non-resonant and various resonant $B\to DP\ell^+ν_\ell$ decays. Finally, using the constrained nonperturbative coefficients, the branching ratios of not-yet-measured $B\to D^*P\ell^+ν_\ell$ decays with the non-resonant and various charmed resonant contributions are predicted. Many branching ratios are predicted for the first time. We find that $B\to Dη'\ell^+ν_\ell, B_s\to D_sη'\ell^+ν_\ell$ decays only receive the non-resonant contributions, $B\to D_sK\ell^+ν_\ell$, $B_s\to DK\ell^+ν_\ell$, $B\to Dη\ell^+ν_\ell$ and $B_s\to D_sη\ell^+ν_\ell$ decays receive both non-resonant and charmed tensor resonant contributions, $B^+\to D^-π^+\ell^+ν_\ell$ decays receive the non-resonant, the charmed scalar resonant and the charmed tensor resonant contributions, and other $B\to Dπ\ell^+ν_\ell$ decays receive all four kinds of contributions. These results can be used to test the SU(3) flavor symmetry approach in the four-body semileptonic decays by the future LHCb and Belle-II experiments.

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arXiv2024

Study of the axial-vector and tensor resonant contributions to the $D \to VP\ell^+ν_\ell$ decays based on SU(3) flavor analysis

Semileptonic three-body $D \to M\ell^+ν_\ell$ decays, non-leptonic $M \to VP$ decays, and semileptonic four-body $D \to M(M \to VP)\ell^+ν_\ell$ decays are analyzed using the SU(3) flavor symmetry/breaking approach, where $\ell=e/μ$, $M=A/T$, and $A/T/V/P$ denote the axial-vector/tensor/vector/pseudoscalar mesons, respectively. In terms of SU(3) flavor symmetry/breaking, the decay amplitudes of the $D \to M \ell^+ ν_\ell$ decays and the vertex coefficients of the $M \to VP$ decays are related. The relevant non-perturbative parameters of the $D \to A\ell^+ν_\ell$, $A \to VP$ and $T \to VP$ decays are constrained by the present experimental data, and the non-perturbative parameters of $D \to T\ell^+ν_\ell$ decays are taken from the results in the light-front quark model since no experimental data are available at present. The branching ratios of the $D \to M \ell^+ ν_\ell $, $M \to VP$, and $D\to M(M\to VP)\ell^+ν_\ell$ decays are then predicted. We find that some processes receive both tensor and axial-vector resonant contributions, while other processes receive only axial-vector resonant contributions. In cases where both kinds of resonant contributions exist, the axial-vector contributions are dominant. Some branching ratios with axial-vector resonance states are large, and they may be measured experimentally in the near future. In addition, the sensitivities of the branching ratios of $D \to A \ell^+ ν_\ell $ and $A \to VP$ decays to the parameters are also investigated, and some decay branching ratios are found to be sensitive to the non-perturbative parameters.

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arXiv2024

Four-body Semileptonic Decays $B\to D^*P\ell^+ν_\ell$ with the SU(3) Flavor Symmetry

We present a complete study of the $B\to D^*P\ell^+ν_\ell~(\ell=e,μ,τ)$ decays with the non-resonant, the charmed axial vector resonant and the charmed tensor resonant contributions by using the SU(3) flavor symmetry. Relevant amplitude relations between different decay modes are obtained by the SU(3) flavor symmetry. We then predict non-measured branching ratios of the $B\to D^*P\ell^+ν_\ell$ decays with the non-resonant and the charmed resonant contributions by using present experimental data of the $B\to D^*P\ell'^+ν_{\ell'}~(\ell'=e,μ)$ decays within $2σ$ errors. We have found that $B^{0,+}\to D^*η\ell^+ν_\ell$, $B^{0,+}\to D^*η'\ell^+ν_\ell$, $B^{0}_s\to D^*_s η\ell^+ν_\ell$, $B^{0}_s\to D^*_sη'\ell^+ν_\ell$ and $B^{0,+}\to D^{*}_sK\ell^+ν_\ell$ decays only receive non-resonant contributions. Decays $B^0_s\to D_s^{*-}π^0\ell^+ν_\ell$ only receive the $D'_{s1}$ resonant contributions. Other decays receive all three kinds of contributions, and three kinds of contributions are important in most of decays.

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arXiv2024

The single parton fragmentation functions of heavy quarkonium in soft gluon factorization

We study the single parton fragmentation functions (FFs) at the input factorization scale $μ_0\gtrsim 2m_Q$, with heavy quark mass $m_Q$, in the soft gluon factorization (SGF) approach. We express the FFs in terms of perturbatively calculable short distance hard parts for producing a heavy quark-antiquark pair in all possible states, convoluted with corresponding soft gluon distribution for the hadronization of the pair to a heavy quarkonium. We compute the perturbative short distance hard parts for producing a heavy quark pair in all possible $S$-wave and $P$-wave states up to $O(α_s^2)$. With our results, the SGF can be further used to study the heavy quarkonium production at the hadron colliders and heavy quarkonium production within a jet.

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arXiv2023

Four-body Semileptonic Charm Decays $D\to P_1P_2\ell^+ν_\ell $ Based on SU(3) Flavor Analysis

Motivated by the significant experimental progress in probing semileptonic decays $D\to P_1P_2\ell^+ν_\ell~(\ell=μ,e)$, we analyze the branching ratios of the $D\to P_1P_2\ell^+ν_\ell $ decays with the non-resonant, the light scalar meson resonant and the vector meson resonant contributions in this work. We obtain the hadronic amplitude relations between different decay modes by the SU(3) flavor analysis, and then predict relevant branching ratios of the $D\to P_1P_2\ell^+ν_\ell$ decays by the present experimental data with $2 σ$ errors. Most of our predicted branching ratios are consistent with present experimental data within $2σ$ error bars, and others are consistent with the data within $3σ$ error bars. We find that some branching ratios of the non-resonant decays are on the order of $\mathcal{O}(10^{-3}-10^{-4})$, the vector meson resonant contributions are dominant in many decays, the non-resonant, the vector meson resonant and the scalar resonant contributions are all important in the $D^0\toηπ^-\ell^+ν_\ell$ decays, and both the non-resonant and the scalar resonant contributions are important in the $D^0\to K^-K^0\ell^+ν_\ell,η'π^-\ell^+ν_\ell$ and $D^+\to \overline{K}^0K^0\ell^+ν_\ell,π^0π^0\ell^+ν_\ell,ηπ^0\ell^+ν_\ell,η'π^0\ell^+ν_\ell$ decays. According to our predictions, many decay modes could be observed in the experiments like BESIII, LHCb and BelleII, and some decay modes might be measured in these experiments in near future.

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arXiv2022

Semileptonic $D$ Meson Decays $D\to P/V/S\ell^+ν_\ell$ with the SU(3) Flavor Symmetry/Breaking

Many exclusive $c\to d/s\ell^+ν_\ell~(\ell=e,μ,τ)$ transitions have been well measured, and they can be used to test the theoretical calculations. Motivated by this, we study the $D\to P/V/S\ell^+ν_\ell$ decays induced by the $c\to d/s\ell^+ν_\ell$ transitions with the SU(3) flavor symmetry approach, where $P$ denotes the pseudoscalar meson, $V$ denotes the vector meson, and $S$ denotes the scalar meson with a mass below $1$ $GeV$. The different decay amplitudes of the $D\to P\ell^+ν_\ell$, $D\to V\ell^+ν_\ell$ or $D\to S\ell^+ν_\ell$ decays can be related by using the SU(3) flavor symmetry and by considering the SU(3) flavor breaking. Using the present data of $D\to P/V/S\ell^+ν_\ell$, we predict the not yet measured or not yet well measured processes in the $D\to P/V/S\ell^+ν_\ell$ decays. We find that the SU(3) flavor symmetry approach works well in the semileptonic $D \to P/V\ell^+ν_\ell$ decays. For the $D \to S\ell^+ν_\ell$ decays, only the decay $D^+_s\to f_0(980)e^+ν_e$ has been measured, the branching ratios of the $D^+_s\to f_0(980)e^+ν_e$ and $D\to S(S\to P_1P_2)\ell^+ν_\ell$ decays are used to constrain the nonperturbative parameters and then predict not yet measured $D \to S\ell^+ν_\ell$ decays, in addition, the two quark and the four quark scenarios for the light scalar mesons are analyzed. The SU(3) flavor symmetry predictions of the $D \to S\ell^+ν_\ell$ decays need to be further tested, and our predictions of the $D \to S\ell^+ν_\ell$ decays are useful for probing the structure of light scalar mesons. Our results in this work could be used to test the SU(3) flavor symmetry approach in the semileptonic $D$ decays by the future experiments at BESIII, LHCb and BelleII.

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arXiv2021

Studying $\mathcal{B}_1(\frac{1}{2}^+)\to \mathcal{B}_2(\frac{1}{2}^+)\ell^+\ell^-$ Semi-leptonic Weak Baryon Decays with the SU(3) Flavor Symmetry

Motivated by recent anomalies in FCNC $b\to s\ell^+\ell^-$, we study $B_1\to B_2\ell^+\ell^-(\ell=e,μ,τ)$ semi-leptonic weak decays with the SU(3) flavor symmetry, where $B_{1,2}$ are the spin-1/2 baryons of single bottomed anti-triplet $T_{b3}$, single charmed anti-triplet $T_{c3}$ or light baryon octet $T_{8}$. Using the SU(3) irreducible representation approach, we first obtain the amplitude relations among different decays, and then predict the relevant not-yet measured observables of these decays. (a) We calculate the branching ratios of the $T_{b3}\to T_8 μ^+μ^-$ and $T_{b3}\to T_8 τ^+τ^-$ in the whole $q^2$ region and in the different $q^2$ bins by the measurement of $Λ^0_b\to Λ^0 μ^+μ^-$. Many of them are obtained for the first time. In addition, the longitudinal polarization fractions and the leptonic forward-backward asymmetries of all $T_{b3}\to T_{8}\ell^+\ell^-$ decays are very similar to each other in certain $q^2$ bin due to the SU(3) flavor symmetry. (b) We analyze the upper limits of $B(T_{c3}\to T_{8}\ell^+\ell^-)$ by using the experimental upper limits of $B(Λ^+_c\to pμ^+μ^-)$ and $B(Λ^+_c\to pe^+e^-)$, and find the experimental upper limit of $B(Λ^+_c\to pμ^+μ^-)$ giving effective bounds on the relevant SU(3) flavor symmetry parameters. The predictions of $B(Ξ^0_c \to Ξ^0e^+e^-)$ and $B(Ξ^0_c \to Ξ^0μ^+μ^-)$ will be different between the single-quark transition dominant contributions and the W-exchange dominant ones. (c) As for $T_{8}\to T'_8 \ell^+\ell^-$ decays, we analyze the single-quark transition contributions and the W-exchange contributions by using two measurements of $ B(Ξ^0\to Λ^0 e^+e^-)$ and $ B(Σ^+\to pμ^+μ^-)$, and give the branching ratio predictions by assuming either single-quark transition dominant contributions or the W-exchange dominant ones.

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arXiv2020

Studying Radiative Baryon Decays with the SU(3) Flavor Symmetry

The weak and electromagnetic radiative baryon decays of octet $T_{8}$, decuplet $T_{10}$, single charmed anti-triplet $T_{c3}$ and sextet $T_{c6}$, single heavy bottomed anti-triplet $T_{b3}$ and sextet $T_{b6}$ are investigated by using SU(3) flavor symmetry irreducible representation approach. We analyze the contributions from a single quark transition $q_1\to q_2γ$ and $W$ exchange transitions, and find that the amplitudes could be easily related by SU(3) flavor symmetry in the $T_{b3,b6}$ weak radiative decays, $T_{c3,c6}$ weak radiative decays, $T_{10}\to T_{8}γ$ weak decays, $T_{10}\to T'_{10}γ$ weak decays and $T_{10}\to T_{8}γ$ electromagnetic decays. Nevertheless, the amplitude relations are a little complex in the $T_{8}\to T'_{8}γ$ and $T_{8}\to T_{10}γ$ weak decays due to quark antisymmetry in $T_{8}$ and $W$ exchange contributions. Predictions for branching ratios of $Λ^{0}_b\to nγ$, $Ξ^{-}_b\to Ξ^-γ$, $Ξ^{-}_b\to Σ^-γ$, $Ξ^{0}_b\to Σ^0γ$, $Ξ^{0}_b\to Λ^0γ$, $Ξ^{0}_b\to Ξ^0γ$, $Ξ^{*}\to Ξγ$, $Σ^{*0}\to Σ^{0}γ$, $Δ^0\to nγ$ and $Δ^+\to pγ$ are given. The results in this work can be used to test SU(3) flavor symmetry approach in the radiative baryon decays by the future experiments at BESIII, LHCb and Belle-II.

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arXiv2020

Studying Two-body Nonleptonic Weak Decays of Hyperons with Topological Diagram Approach

Many decays of light baryons consisting of light $u,d,s$ quarks have been measured, and these measurements will help us to understand the decay properties of light baryons. In this work, we study two-body nonleptonic weak decays of light baryon octet $(T_8)$ and baryon decuplet $(T_{10})$ by the topological diagram approach (TDA) under the SU(3) flavor symmetry for the first time. We find that (1) the TDA and the SU(3) irreducible representation approach (IRA) match consistently in $T_{10}\to T^{(')}_{8,10}P_8$ ($P_8$ is the light pseudoscalar meson octet); (2) almost all relevant not-yet-measured $\mathcal{B}(T_{10}\to T_8 P_8)$ may be predicted by using three experimental data of $\mathcal{B}(Ω^-\to Ξ^0π^-,Ξ^-π^0,Λ^0K^-)$, and the upper limits of $\mathcal{B}(T_{10}\to T{'}_{10}π^-)$ may be obtained from the experimental upper limit of $\mathcal{B}(Ω^-\to Ξ^{*0}π^-)$ by both the TDA and the IRA together, nevertheless, all new predicted branching ratios are too small to br reached in current experiments; (3) $T_8\to T'_8 P_8$ decays are quite complex in terms of the TDA, and we find that W-exchange diagrams give large and even dominant contributions by using relevant experimental data and the isospin relations.

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arXiv2020

Study of $a_0^0(980)$-$f_0(980)$ mixing from $a_0(1450) \to a_0^0(980) f_0(500) \to π^+ π^- f_0(500)$

The $a_0^0(980)-f_0(980)$ mixing is one of the most potential tools to learn about the nature of $a_0^0(980)$ and $f_0(980)$. Using the $f_0(980)$-$a_0^0(980)$ mixing intensity $ξ_{af}$ measured recently at BESIII, we calculate the the branching ratio of the the isospin violation decay $J/ψ\rightarrowγη_c \rightarrow γπ^0 a_0^0(1450)\rightarrow γπ^0 a_0^0(980)f_0(500)\rightarrow γπ^0 f_0(980) f_0(500) \rightarrow γπ^0 π^+π^- π^+π^-$. The value of the branching ratio is found to be $O(10^{-6})$, which can be observed with $10^{10}$ $J/ψ$ events collected at BESIII. The narrow peak from the $f_0(980)$-$a_0^0(980)$ mixing in the $π^+π^-$ mass square spectrum can also be observed. In addition, we study the non-resonant decay $a_0^0(1450)\rightarrow f_0(980) π^+π^-(\text{non-resonant})$, which is dominated by the $a_0^0(980)$-$f_{0}(980)$ mixing. We find that the non-resonant decay $a_0^0(1450)\rightarrow f_0(980) π^+π^-$ and the decay $a_0^0(1450)\rightarrow f_0(980) f_0(500)$ can be combined to measure the mixing intensity $ξ_{af}$ in experiment. These decays are the perfect complement to the decay $χ_{c1}\rightarrow f_{0}(980)π^{0}\toπ^{+}π^{-}π^{0}$ which had been observed at BESIII, the observations of them will make the measurement of the mixing intensity $ξ_{af}$ more precisely.

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arXiv2016

Probing the R-parity violating supersymmetric effects in the exclusive b\to c\ell^-\barν_\ell decays

Motivated by recent results from the LHCb, BABAR and Belle collaborations on B\to D^{(*)}\ell^-\barν_\ell decays, which significantly deviate from the Standard Model and hint the possible new physics beyond the Standard Model, we probe the R-parity violating supersymmetric effects in B^-_c\to \ell^-\barν_\ell and B\to D^{(*)}\ell^-\barν_\ell decays. We find that (i) \mathcal{B}(B^-_c\to e^- \barν_e) and \mathcal{B}(B^-_c\toμ^-\barν_μ) are sensitive to the constrained slepton exchange couplings; (ii) the normalized forward-backward asymmetries of B\to De^-\barν_{e} decays have been greatly affected by the constrained slepton exchange couplings, and their signs could be changed; (iii) all relevant observables in the exclusive b\to cτ^-\barν_τdecays and the ratios \mathcal{R}(D^{(*)}) are sensitive to the slepton exchange coupling, \mathcal{R}(D^*) could be enhanced by the constrained slepton exchange coupling to reach each 95\% confidence level experimental range from BABAR, Belle and LHCb, but it could not reach the lower limit of the 95\% confidence level experimental average. Our results in this work could be used to probe R-parity violating effects, and will correlate with searches for direct supersymmetric signals at the running LHCb and the forthcoming Belle-II.

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arXiv2014

Probing the R-parity violating supersymmetric effects in the exclusive $c\to d/s\ellν_\ell$ decays

A lot of branching ratios of the exclusive $c \to d/s\ellν_\ell$ ($\ell=e,μ$) decays have been quite accurately measured by CLEO-c, BELLE, BABAR, BES(I,II,III), ALEPH and MARKIII collaborations. We probe the R-parity violating supersymmetric effects in the exclusive $c \to d/s\ellν_\ell$ decays. From the latest experimental measurements, we obtain new upper limits on the relevant R-parity violating coupling parameters within the decays, and many upper limits are obtained for the first time. Using the constrained new parameter spaces, we predict the R-parity violating effects on the observables, which have not been measured or have not been well measured yet. We find that the R-parity violating effects due to slepton exchange could be large on the branching ratios of $D_{d/s}\to eν_e$ decays and the normalized forward-backward asymmetries of $D_{u/d}\to π/K \ellν_\ell$ as well as $D_s\to K \ellν_\ell$ decays, and all branching ratios of the relevant semileptonic $D$ decays are sensitive to squark exchange couplings. Our results in this work could be used to probe new physics effects in the leptonic decays as well as the semileptonic decays, and will correlate with searches for direct supersymmetric signals at LHC and BESIII.

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arXiv2013

Analysis of $B_s\to ϕμ^+μ^-$ decay within supersymmetry

Motivated by the first measurement on $\mathcal{B}(B_s\toϕμ^+μ^-)$ by the CDF Collaboration, we study the supersymmetric effects in semi-leptonic $B_s\toϕμ^+μ^-$ decay. In our evaluations, we analyze the dependences of the dimuon invariant mass spectrum and the forward-backward asymmetry on relevant supersymmetric couplings in the MSSM with and without R-parity. The analyses show the new experimental upper limits of $\mathcal{B}(B_s\toμ^+μ^-)$ from the LHCb Collaboration could further improve the bounds on sneutrino exchange couplings and $(δ^u_{LL})_{23}$ as well as $(δ^d_{LL,RR})_{23}$ mass insertion couplings. In addition, within the allowed ranges of relevant couplings under the constraints from $\mathcal{B}(B_s\toϕμ^+μ^-)$, $\mathcal{B}(B\to K^{(*)}μ^+μ^-)$ and $\mathcal{B}(B_s\to μ^+μ^-)$, the dimuon forward-backward asymmetry and the differential dimuon forward-backward asymmetry of $B_s\toϕμ^+μ^-$ are highly sensitive to the squark exchange contribution and the $(δ^u_{LL})_{23}$ mass insertion contribution. The results obtained in this work will be very useful in searching supersymmetric signal at the LHC.

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arXiv2012

Revisiting B_s\toμ^+μ^- and B\to K^{(*)}μ^+μ^- decays in the MSSM with and without R-parity

The rare decays B_s -> μ^+μ^- and B -> K^{(*)}μ^+μ^- are sensitive to new particles and couplings via their interferences with the standard model contributions. Recently, the upper bound on B(B_s -> μ^+μ^-) has been improved significantly by the CMS, LHCb, CDF, and DØ experiments. Combining with the measurements of B(B-> K^{(*)}μ^+μ^-), we derive constraints on the relevant parameters of minimal supersymmetic standard model with and without R-parity, and examine their contributions to the dimuon forward-backward asymmetry in B-> K^{*}μ^+μ^- decay. We find that (i) the contribution of R-parity violating coupling products λ^{\prime}_{2i2}λ^{\prime*}_{2i3} due to squark exchange is comparable with the theoretical uncertainties in B-> K μ^+μ^- decay, but still could be significant in B-> K^{*}μ^+μ^- decay and could account for the forward-backward asymmetry in all dimuon invariant mass regions; (ii) the constrained mass insertion (δ^{u}_{LL})_{23} could have significant contribution to dA_{FB}(B-> K^{*}μ^+μ^-)/ds, and such effects are favored by thr recent results of the Belle, CDF, and LHCb experiments.

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arXiv2011

Studying of B_s^0-\bar{B}_s^0 mixing and B_{s}\to K^{()-}K^{()+} decays within supersymmetry

Recent results from CDF and DØ collaborations favor a large CP asymmetry in B_s^0-\bar{B}_s^0 mixing, while the standard model prediction is very small. Such a large phase may imply sizable new physics effects in B_s^0-\bar{B}_s^0 mixing. We compute the gluino-mediated supersymmetry contributions to B_s^0-\bar{B}_s^0 mixing, B_s->K^{(*)-}K^{(*)+} and B->X_sγdecays in the frame of the mass insertion approximation. Combining the constraints of \DeltaM_s, ΔΓ_s, ϕ^{J/ψϕ}_s, B(B_s->K^{-}K^{+}) and B(B->X_s γ), we find that the effects of the constrained LL and RR insertions in B_s->K^{(*)-}K^{(*)+} decays are small because of the absence of gluino mass enhancement. For m^2_{\tilde{g}}/m^2_{\tilde{q}}=9, the constrained LR insertion can provide sizable contributions to all observables of B_s->K^{(*)-}K^{(*)+} decays except A^{dir}_{CP}(B_s->K^{-}K^{+}), and many observables are sensitive to the modulus and the phase of the LR insertion parameter. Near future experiments at Fermilab Tevatron and CERN LHC-b can test these predictions and shrink/reveal the mass insertion parameter spaces.

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