In this article, we calculate the B*→ηc form-factors with the three-point QCD sum rules, then study the semileptonic decays B*→ηclυl. The tiny decay widths may be observed experimentally in the future at the LH...In this article, we calculate the B*→ηc form-factors with the three-point QCD sum rules, then study the semileptonic decays B*→ηclυl. The tiny decay widths may be observed experimentally in the future at the LHCb, while the B*→ηc form-factors can be taken as basic input parameters in other phenomenologieal analysis.展开更多
By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^...By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^0(ω, φ)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B^± → ρ^±η(') (B^0 → ρ^0(ω, φ)η(')decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACP^dir(B^± → ρ^±η(')) are consistent with the data, while the predicted .ACP(B^0 → ρ^0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.展开更多
The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. Th...The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential (OGEP). An overall agreement is obtained with the experimental masses and decay widths.展开更多
Considering the experimental constraints on the free parameters of the 331 model with a leptonic sector consistent of five triplets, we investigate the lepton flavor violation(LFV) tau decays τ→μM with M = P and V,...Considering the experimental constraints on the free parameters of the 331 model with a leptonic sector consistent of five triplets, we investigate the lepton flavor violation(LFV) tau decays τ→μM with M = P and V,where P and V denote a pseudoscalar meson(π, η or η′) and a vector meson(ρ0, ω or φ), respectively. We find that the contributions of the 331 model to the LFV decays τ→μM mainly come from the new neutral gauge boson Z′. The 331 model considered in this paper can not make the values of the branching ratio Br(τ→μM) approach the corresponding experimental upper limits.展开更多
Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majoran...Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majorana zero modescan be revealed as a subgap state whose energy oscillatesaround zero in magnetic field. This oscillation was interpretedas overlapping Majoranas. However, the oscillation amplitudeeither dies away after an overshoot or decays, sharply oppositeto the theoretically predicted enhanced oscillations for Majoranabound states, as the magnetic field increases. Several theoreticalstudies have tried to address this discrepancy, but arepartially successful. This discrepancy has raised the concernson the conclusive identification of Majorana bound states, andhas even endangered the scheme of Majorana qubits basedon the nanowires.展开更多
We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scala...We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scalar a_(0)(980)and a_(0)(1450)[K^(∗)_(0)(800)(orκ)and K^(∗)_(0)(1430)],with the perturbative QCD factorization approach under the assumption of two-quark structure for the a_(0)and K^(∗)_(0)states.The numerical results show that the branching ratios of the B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0)decays are in the order of 10^(−6),while the decay rates of the B^(s)_(0)→a^(+)_(0)a^(−)_(0)modes are in the order of 10−5.In light of the measured modes with the same quark components in the pseudoscalar sector,namely,B^(0)_(d)→K^(+)k_(-)and B^(0)_(s)→π^(+)π_(−),the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-Ⅱexperiments in the(near)future.Meanwhile,it is of great interest to find that the twist-3 distribution amplitudesφ^(S)andφ^(T)with inclusion of the Gegenbauer polynomials for the scalar a_(0)(1450)and K^(∗)_(0)(1430)states in scenario 2 contribute slightly to the branching ratios while significantly to the CP violations in the B^(0)_(d)→K^(∗)_(0)(1430)+K^(∗)_(0)(1430)−and B^(0)_(s)→a_(0)(1450)+a_(0)(1450)−decays,which indicates that,compared to the asymptoticφ^(S)andφ^(T),these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels.These predictions await for the future confirmation experimentally,which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.展开更多
In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 ...In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 (5830) andBs2(5840) states, into the (Ds1(2536), Ds2(2573)) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated.展开更多
In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar mes...In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6.展开更多
To explain the anomALously large decay rate of ∑+→p+μ+μ-, it was proposed that a new mechanism where a light CP-odd pseudoscaJar boson of mAo = 214.3 MeV makes a crucial contribution. Later, some authors have s...To explain the anomALously large decay rate of ∑+→p+μ+μ-, it was proposed that a new mechanism where a light CP-odd pseudoscaJar boson of mAo = 214.3 MeV makes a crucial contribution. Later, some authors have studied the transition π0→e+e- and γ→γA10 in terms of the same mechanism and their result indicates that with the suggested mass one cannot fit the data. This discrepancy might be caused by experimental error of ∑+→p+μ+μ- because there were only a few events. Whether the mechanism is a reasonable one motivates us to investigate the transitions π0→e+e-;η(η′)→μ+μ-;ηc→μ+μ-;ηb→τ+τ- within the same framework. It is noted that for π0→ e+ e-, the standard model (SM) prediction is smaller than the data, whereas the experimental central value of η→μ+μ- is also above the SM prediction. It means that there should be extra contributions from other mechanisms and the contribution of A may be a possible one. Theoretically calculating the branching ratios of the concerned modes, we would cheek if we can obtain a univers mass for A10 which reconcile the theoretical predictions and data for all the modes. Unfortunately, we find that it is impossible conclude that the phenomenology does not favor such a to have such a mass with the same coupling|gt|. Therefore we light A10, even though a small window is still open.展开更多
Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searche...Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searches and explaining the g-2 deviation,we consider the contributions of ALPs with mass in the range of 1.5GeV展开更多
Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles ...Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.展开更多
Motivated by the recently updated experimental measurement on Bd→μ^+μ^- and B^-→π^-μ+μ^- decays by CDF and Belle collaborations, we revisit these decays, as well as B^-→ρ^-μ^+μ^- decay, within the Standa...Motivated by the recently updated experimental measurement on Bd→μ^+μ^- and B^-→π^-μ+μ^- decays by CDF and Belle collaborations, we revisit these decays, as well as B^-→ρ^-μ^+μ^- decay, within the Standard Model, and evaluate the effects of a family non-universal Z' boson. Under the constraint from β(B- → π^-μ+μ^-), we find the ranges of the Z' couplings SLRμμ 〈 -5.2 × 10^-2 or Dμμ^LR 〈 -8.1 × 10^-2 are excluded. Within the allowed Z' parameters spaces, comparing with the SM predictions, we find that B(Bd→μ^+μ^-), B(B^-→π^-μ+μ^-), and B(B^-→ρ^-μ+μ^-) could be enhanced by a factor about 226%, 245%, and 254%, respectively, by Z' contributions. However, they are hardly to be reduced. Furthermore, the zero crossing in the normalized forward-backward asymmetry spectrum of B^-→ρ^-μ+μ^- decay at low dimuon mass always exists.展开更多
To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neut...To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neutral-even CP is the combination of Hu, Hd and S. In the NMSSM, the Higgs sector is increased to 7 (compared with 5 hogs in the MSSM), including three Higgs-which are the even-CP hi,2,3 (mh1〈 mh2〈 mh3), two Higgs-which are odd-CP a1,2 (ma1 〈 ma2) and a couple of charged Higgs H^±. The decays Higgs into Higgs is one of the remarkable new points of the NMSSM. In this paper, we study the decays H^± into W^± and at. The decay width is calculated to one loop vertex correction. The numerical results are also described together with evaluations.展开更多
In this article, we assign the higher charm mesons D1^*(2680), D3^*(2760), D2^*(3000) to be the 2S 1^-, 1D3^- and 1F 2^+ states, respectively, and study the two-body strong decays to the ground state charm m...In this article, we assign the higher charm mesons D1^*(2680), D3^*(2760), D2^*(3000) to be the 2S 1^-, 1D3^- and 1F 2^+ states, respectively, and study the two-body strong decays to the ground state charm mesons and light pseudoscalar mesons with the heavy meson effective theory. We obtain the ratios among the strong decays, which can be confronted to the experimental data in the future and shed light on the nature of those higher charm mesons.展开更多
This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a...This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a strange meson (K<sup>+</sup>) with the emission of either electron-positron (e<sup>+</sup>e<sup>-</sup>) or muon-antimuon (<span style="white-space:nowrap;"><em>μ</em></span><sup>+</sup><em>μ</em><sup>-</sup>). The ratio (<em>R</em><sub>K</sub>) of branching fractions for B<sup>+ </sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>- </sup>and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>-</sup> decays is measured to be <em>R</em><sub>K</sub> = 0.846 instead of 1 in the violation of lepton universality in the Standard Model. This paper proposes that the violation is derived from the binary isotope mixture of two beauty-quarks, b<sub>7</sub> (4979 MeV mass) and b<sub>8</sub> (143,258 MeV mass) whose masses are calculated from the periodic table of elementary particles. b<sub>7</sub> is the observable B, while b<sub>8</sub> is the hidden B to preserve the generation number symmetry between the three lepton family generations and the three quark family generations in the Standard Model. The preservation of the generation number symmetry forbids b<sub>8</sub> to decay into K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>. In the transition state involving the virtual particles (<span style="white-space:nowrap;"><em>γ</em></span>, W± and Z<span style="white-space:nowrap;">°</span>) before the decay, b<sub>7</sub> and b<sub>8</sub> emerge to form the binary isotope mixture from B. The rates of emergence as the rates of diffuse in Graham’s law of diffusion are proportional to inverse square root of mass. The rate ratio between b<sub>8</sub>/b<sub>7</sub> is (4979/143,258)<sup>1/2</sup> = 0.1864. Since b<sub>7</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, while b<sub>8</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and forbidden <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, the calculated ratio (RK) of branching fractions for B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup> and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>- </sup>is 0.5/(0.1864 × 0.5+ 0.5) = 0.843 in excellent agreement with the observed 0.846. The agreement between the calculated RK and the observed RK confirms the validity of the periodic table of elementary particles which provides the answers for the dominance of matter over antimatter, dark-matter, and the mass hierarchy of elementary particles.展开更多
This paper is the extension of our previous work entitled''Searching a systematics for nonfactorizable contributions to B and B^(0)hadronic decays''.Obtaining the factorizable contributions from the sp...This paper is the extension of our previous work entitled''Searching a systematics for nonfactorizable contributions to B and B^(0)hadronic decays''.Obtaining the factorizable contributions from the spectator-quark model for Nc=3,a systematics was identified among the isospin reduced amplitudes for the nonfactorizable terms amongB→Dπ/D^(∗)π/Dρdecay modes.This systematics enables us to derive a generic formula to help predict the branching fractions forB^(0)−decays.Inspired by this observation,we extend our analysis to p-wave meson emitting decays of B−mesonB→PA/PT/PS,particularlyB→a_(1)D/πD_(1)/πD′1/πD_(2)/πD_(0),which have similar isospin structures and make predictions forB^(0)−decays,for which experimental measurements are not yet available.展开更多
In this study,we extend our previous study on the D^(*)D^(*)molecular states with J^(PC)=0^(++),1^(+-),and 2^(++)to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality...In this study,we extend our previous study on the D^(*)D^(*)molecular states with J^(PC)=0^(++),1^(+-),and 2^(++)to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality.We obtain the partial decay widths and,therefore,the total widths of the ground states with J^(PC)=0^(++),1^(+-),and 2^(++),which indicate that it is reasonable to assign X_(2)(4014)as the D^(*)D^(*) tetraquark molecular states with J^(PC)=2^(++).展开更多
A well-known problem in particle physics and cosmology is the observed matter–antimatter asymmetry in the Universe.According to the Big Bang theory,equal amounts of matter and antimatter should have been produced in ...A well-known problem in particle physics and cosmology is the observed matter–antimatter asymmetry in the Universe.According to the Big Bang theory,equal amounts of matter and antimatter should have been produced in the early universe.However,astrophysical observations show that the visible universe today is overwhelmingly dominated by matter.展开更多
The matter-antimatter asymmetry observed in nature is one of the biggest mysteries in physics,and the resolution of this puzzle could be one of the necessary paths to identifying the ultimate theory of the universe.Th...The matter-antimatter asymmetry observed in nature is one of the biggest mysteries in physics,and the resolution of this puzzle could be one of the necessary paths to identifying the ultimate theory of the universe.The violation of the combined charge-conjugation and parity(CP)symmetry is one of the required ingredients for explaining this asymmetry[1].展开更多
The ends of the velocity vectors of the decay particles of resonance represent material points-velocities in the hyperbolic Lobachevsky velocity space of negative curvature k=−1/C2(C=1 is the speed of light,the rest m...The ends of the velocity vectors of the decay particles of resonance represent material points-velocities in the hyperbolic Lobachevsky velocity space of negative curvature k=−1/C2(C=1 is the speed of light,the rest masses of the decay particles are assigned to the points-velocities).Two points-velocities of the decay particles can be connected by a line segment and an arc of a line of constant curvature 0,called the oricycle.Archimedes’leverage laws define a 3rd point on the arc of the oricycle to which an additive mass(sum of rest masses of particles)is assigned.Connecting 3 points-velocities by line segments,we obtain isosceles triangles of decays of resonances in the Beltrami model of the Lobachevsky velocity space.In the decay triangles of resonances,the golden section is found and the Stewart,Brettschneider theorems on oricyclic arcs are satisfied.Near the decay triangles of scalar,strange mesons andΔ,N baryons,isosceles triangles-satellites with integer values of their characteristics were found.On the satellite triangles,the Lorentz invariant function—the product of the length of the arc of the oricycle subtending the base and the cotangent of half the angle at the vertex opposite the base—takes integer values.The function is called the oricyclic cotangent of a triangle(OCT).In addition to the integer values of OCT,these satellite triangles also have the sum of the hyperbolic cosines of the lengths of the lateral sides and the hyperbolic cosines of the base lengths equal to integers.These satellite triangles are called Heron triangles.On Heron triangles,the generalized cosines of the angles between the tangent to the oricycle at the point-velocity of the additive mass and the tan-gent at the point-velocity of the base of the triangle take multiples of 1/2 values.展开更多
基金Supported by National Natural Science Foundation under Grant Nos.11075053,11375063the Fundamental Research Funds for the Central Universities
文摘In this article, we calculate the B*→ηc form-factors with the three-point QCD sum rules, then study the semileptonic decays B*→ηclυl. The tiny decay widths may be observed experimentally in the future at the LHCb, while the B*→ηc form-factors can be taken as basic input parameters in other phenomenologieal analysis.
基金Supported by the National Natural Science Foundation of China under Grant No.10575052,10605012,and 10735080
文摘By employing the perturbative QCD (pQCD) factorization approach, we calculate some important next- to-leading-order (NLO) contributions to the two-body charmless hadronic decays B^+ →ρ^+η(') and B^0 → ρ^0(ω, φ)η('), induced by the vertex QCD corrections, the quark-loops as well as the chromo-magnetic penguins. From the numerical results and phenomenological analysis we find that (a) for B^± → ρ^±η(') (B^0 → ρ^0(ω, φ)η(')decays, the partial NLO contributions to branching ratios are small (large) in magnitude; and (b) the pQCD predictions for ACP^dir(B^± → ρ^±η(')) are consistent with the data, while the predicted .ACP(B^0 → ρ^0(ω)η(')) are generally large in magnitude and could be tested by the forthcoming LHCb experiments.
文摘The phenomenological non-relativistic quark model (NRQM) has been employed to obtain the masses of bottomonium states. In the frame work of NRQM an exhaustive study of radiative and leptonic decays has been made. The Hamiltonian used in the investigation has kinetic energy, confinement potentiM and one gluon exchange potential (OGEP). An overall agreement is obtained with the experimental masses and decay widths.
基金Supported by the National Natural Science Foundation of China under Grant No.11275088the Natural Science Foundation of the Liaoning Scientific Committee under Grant No.201102114Foundation of Liaoning Educational Committee under Grant No.LT2011015
文摘Considering the experimental constraints on the free parameters of the 331 model with a leptonic sector consistent of five triplets, we investigate the lepton flavor violation(LFV) tau decays τ→μM with M = P and V,where P and V denote a pseudoscalar meson(π, η or η′) and a vector meson(ρ0, ω or φ), respectively. We find that the contributions of the 331 model to the LFV decays τ→μM mainly come from the new neutral gauge boson Z′. The 331 model considered in this paper can not make the values of the branching ratio Br(τ→μM) approach the corresponding experimental upper limits.
文摘Majorana zero modes in the hybrid semiconductor-superconductornanowire is one of the promising candidates for topologicalquantum computing. Recently, in nanowires with a superconductingisland, the signature of Majorana zero modescan be revealed as a subgap state whose energy oscillatesaround zero in magnetic field. This oscillation was interpretedas overlapping Majoranas. However, the oscillation amplitudeeither dies away after an overshoot or decays, sharply oppositeto the theoretically predicted enhanced oscillations for Majoranabound states, as the magnetic field increases. Several theoreticalstudies have tried to address this discrepancy, but arepartially successful. This discrepancy has raised the concernson the conclusive identification of Majorana bound states, andhas even endangered the scheme of Majorana qubits basedon the nanowires.
基金supported in part by the National Natural Science Foundation of China under Grant Nos.11765012 and 11205072by the Research Fund of Jiangsu Normal University(No.HB2016004)supported by the Undergraduate Research&Practice Innovation Program of Jiangsu Province(No.201810320103Z)。
文摘We study the CP-averaged branching fractions and the CP-violating asymmetries in the pure annihilation decays of B^(s)_(0)→a^(+)_(0)a^(−)_(0)and B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0),where a_(0)[K^(∗)_(0)]denotes the scalar a_(0)(980)and a_(0)(1450)[K^(∗)_(0)(800)(orκ)and K^(∗)_(0)(1430)],with the perturbative QCD factorization approach under the assumption of two-quark structure for the a_(0)and K^(∗)_(0)states.The numerical results show that the branching ratios of the B^(0)_(d)→K^(∗+)_(0)K^(∗−)_(0)decays are in the order of 10^(−6),while the decay rates of the B^(s)_(0)→a^(+)_(0)a^(−)_(0)modes are in the order of 10−5.In light of the measured modes with the same quark components in the pseudoscalar sector,namely,B^(0)_(d)→K^(+)k_(-)and B^(0)_(s)→π^(+)π_(−),the predictions for the considered decay modes in this work are expected to be measured at the Large Hadron Collider beauty and/or Belle-Ⅱexperiments in the(near)future.Meanwhile,it is of great interest to find that the twist-3 distribution amplitudesφ^(S)andφ^(T)with inclusion of the Gegenbauer polynomials for the scalar a_(0)(1450)and K^(∗)_(0)(1430)states in scenario 2 contribute slightly to the branching ratios while significantly to the CP violations in the B^(0)_(d)→K^(∗)_(0)(1430)+K^(∗)_(0)(1430)−and B^(0)_(s)→a_(0)(1450)+a_(0)(1450)−decays,which indicates that,compared to the asymptoticφ^(S)andφ^(T),these Gegenbauer polynomials could change the strong phases evidently in these pure annihilation decay channels.These predictions await for the future confirmation experimentally,which could further provide useful information to help explore the inner structure of the scalars and shed light on the annihilation decay mechanism.
基金Supported by the National Natural Science Foundation of China under Grant No. 10975184
文摘In the framework of the heavy quark effective theory, the leading order Isgur-Wise functions relevant to semileptonie decays of the orbitally P-wave excited Bs meson states Bs*, including the newly found narrow Bs1 (5830) andBs2(5840) states, into the (Ds1(2536), Ds2(2573)) doublet are calculated from QCD sum rules. With these universal form factors, the decay rates and branching ratios are also estimated.
基金Supported by the National Natural Science Foundation of China under Grant Nos. 10575052, 10605012, and 10735080
文摘In this article, we calculate the branching ratios of B→K0^* (1430)K decays by employing the pertur-bative QCD (pQCD) approach at leading order. We perform the evaluations in the two scenarios for the scalar meson spectrum. We find that (i) The leading order pQCD predictions for the branching ratio Br(B^+→K^+K0^*(1430)^0)are in good agreement with the experimental upper limit in both scenarios, while the pQCD predictions for other considered B→K0^*(1430)K decay modes are also presented and will be tested by the LHC experiments; (ii) The annihilation contributions play an important role in these considered decays, for B^0→K0^*(1430)^±K^± decays,for example,which are found to be (1-4)×10^-6.
基金Supported by the National Natural Science Foundation of China under Grant Nos.11075079and11005079the Special Grant for the Ph.D.Program of Ministry of Eduction of China No.20100032120065
文摘To explain the anomALously large decay rate of ∑+→p+μ+μ-, it was proposed that a new mechanism where a light CP-odd pseudoscaJar boson of mAo = 214.3 MeV makes a crucial contribution. Later, some authors have studied the transition π0→e+e- and γ→γA10 in terms of the same mechanism and their result indicates that with the suggested mass one cannot fit the data. This discrepancy might be caused by experimental error of ∑+→p+μ+μ- because there were only a few events. Whether the mechanism is a reasonable one motivates us to investigate the transitions π0→e+e-;η(η′)→μ+μ-;ηc→μ+μ-;ηb→τ+τ- within the same framework. It is noted that for π0→ e+ e-, the standard model (SM) prediction is smaller than the data, whereas the experimental central value of η→μ+μ- is also above the SM prediction. It means that there should be extra contributions from other mechanisms and the contribution of A may be a possible one. Theoretically calculating the branching ratios of the concerned modes, we would cheek if we can obtain a univers mass for A10 which reconcile the theoretical predictions and data for all the modes. Unfortunately, we find that it is impossible conclude that the phenomenology does not favor such a to have such a mass with the same coupling|gt|. Therefore we light A10, even though a small window is still open.
基金Supported by the National Natural Science Foundation of China under Grant Nos 11275088 and 11747318
文摘Axion-like particles(ALPs)are often defined as relatively light pseudoscalar particles and appear in many extensions of the Standard Model.Taking into account constraints on the free parameters from existing searches and explaining the g-2 deviation,we consider the contributions of ALPs with mass in the range of 1.5GeV
基金the National Natural Science Foundation of China under
文摘Amplitudes for φ(2S) sequential decays into 2(π^+π^-)pp^-γ via XCJ are constructed in effective coupling scheme. A Mote-Carlo simulation is carried out to study angular distributions of the decayed particles in laboratory system. The results can be taken as a reference for measuring the decay of XCJ into at BESⅡ/BEPC in the near future.
基金Supported by the National Natural Science Foundation under Grant Nos. 11105043 and 11075059Research Fund for the Doctoral Program of Higher Education of China under Grant No. 20114104120002Startup Foundation for Doctor of Henan Normal University under Grant No. 1006
文摘Motivated by the recently updated experimental measurement on Bd→μ^+μ^- and B^-→π^-μ+μ^- decays by CDF and Belle collaborations, we revisit these decays, as well as B^-→ρ^-μ^+μ^- decay, within the Standard Model, and evaluate the effects of a family non-universal Z' boson. Under the constraint from β(B- → π^-μ+μ^-), we find the ranges of the Z' couplings SLRμμ 〈 -5.2 × 10^-2 or Dμμ^LR 〈 -8.1 × 10^-2 are excluded. Within the allowed Z' parameters spaces, comparing with the SM predictions, we find that B(Bd→μ^+μ^-), B(B^-→π^-μ+μ^-), and B(B^-→ρ^-μ+μ^-) could be enhanced by a factor about 226%, 245%, and 254%, respectively, by Z' contributions. However, they are hardly to be reduced. Furthermore, the zero crossing in the normalized forward-backward asymmetry spectrum of B^-→ρ^-μ+μ^- decay at low dimuon mass always exists.
文摘To solve the/a problem of the Minimal Supersymmetric Standard Model (MSSM), a single field S is added to build the Next Minimal Supersymmetric Standard Model (NMSSM). Vacuum enlarged with non-zero vevs of the neutral-even CP is the combination of Hu, Hd and S. In the NMSSM, the Higgs sector is increased to 7 (compared with 5 hogs in the MSSM), including three Higgs-which are the even-CP hi,2,3 (mh1〈 mh2〈 mh3), two Higgs-which are odd-CP a1,2 (ma1 〈 ma2) and a couple of charged Higgs H^±. The decays Higgs into Higgs is one of the remarkable new points of the NMSSM. In this paper, we study the decays H^± into W^± and at. The decay width is calculated to one loop vertex correction. The numerical results are also described together with evaluations.
基金Supported by National Natural Science Foundation of China under Grant No.11375063Natural Science Foundation of Hebei Province under Grant No.A2014502017
文摘In this article, we assign the higher charm mesons D1^*(2680), D3^*(2760), D2^*(3000) to be the 2S 1^-, 1D3^- and 1F 2^+ states, respectively, and study the two-body strong decays to the ground state charm mesons and light pseudoscalar mesons with the heavy meson effective theory. We obtain the ratios among the strong decays, which can be confronted to the experimental data in the future and shed light on the nature of those higher charm mesons.
文摘This paper purposes an explanation for the recent evidence for the violation of lepton universality in beauty-quark decays at CERN’s Large Hadron Collider. A beauty meson (B<sup>+</sup>) transforms into a strange meson (K<sup>+</sup>) with the emission of either electron-positron (e<sup>+</sup>e<sup>-</sup>) or muon-antimuon (<span style="white-space:nowrap;"><em>μ</em></span><sup>+</sup><em>μ</em><sup>-</sup>). The ratio (<em>R</em><sub>K</sub>) of branching fractions for B<sup>+ </sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>- </sup>and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>-</sup> decays is measured to be <em>R</em><sub>K</sub> = 0.846 instead of 1 in the violation of lepton universality in the Standard Model. This paper proposes that the violation is derived from the binary isotope mixture of two beauty-quarks, b<sub>7</sub> (4979 MeV mass) and b<sub>8</sub> (143,258 MeV mass) whose masses are calculated from the periodic table of elementary particles. b<sub>7</sub> is the observable B, while b<sub>8</sub> is the hidden B to preserve the generation number symmetry between the three lepton family generations and the three quark family generations in the Standard Model. The preservation of the generation number symmetry forbids b<sub>8</sub> to decay into K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>. In the transition state involving the virtual particles (<span style="white-space:nowrap;"><em>γ</em></span>, W± and Z<span style="white-space:nowrap;">°</span>) before the decay, b<sub>7</sub> and b<sub>8</sub> emerge to form the binary isotope mixture from B. The rates of emergence as the rates of diffuse in Graham’s law of diffusion are proportional to inverse square root of mass. The rate ratio between b<sub>8</sub>/b<sub>7</sub> is (4979/143,258)<sup>1/2</sup> = 0.1864. Since b<sub>7</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, while b<sub>8</sub> decays into K<sup>+</sup>, e<sup>+</sup>e<sup>-</sup>, and forbidden <em>μ</em><sup>+</sup><em>μ</em><sup>-</sup>, the calculated ratio (RK) of branching fractions for B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup><em>μ</em><sup>+</sup><em>μ</em><sup>-</sup> and B<sup>+</sup><span style="white-space:nowrap;">→</span> K<sup>+</sup>e<sup>+</sup>e<sup>- </sup>is 0.5/(0.1864 × 0.5+ 0.5) = 0.843 in excellent agreement with the observed 0.846. The agreement between the calculated RK and the observed RK confirms the validity of the periodic table of elementary particles which provides the answers for the dominance of matter over antimatter, dark-matter, and the mass hierarchy of elementary particles.
文摘This paper is the extension of our previous work entitled''Searching a systematics for nonfactorizable contributions to B and B^(0)hadronic decays''.Obtaining the factorizable contributions from the spectator-quark model for Nc=3,a systematics was identified among the isospin reduced amplitudes for the nonfactorizable terms amongB→Dπ/D^(∗)π/Dρdecay modes.This systematics enables us to derive a generic formula to help predict the branching fractions forB^(0)−decays.Inspired by this observation,we extend our analysis to p-wave meson emitting decays of B−mesonB→PA/PT/PS,particularlyB→a_(1)D/πD_(1)/πD′1/πD_(2)/πD_(0),which have similar isospin structures and make predictions forB^(0)−decays,for which experimental measurements are not yet available.
基金Supported by the National Natural Science Foundation(12175068)。
文摘In this study,we extend our previous study on the D^(*)D^(*)molecular states with J^(PC)=0^(++),1^(+-),and 2^(++)to investigate their two-body strong decays via the QCD sum rules based on rigorous quark-hadron duality.We obtain the partial decay widths and,therefore,the total widths of the ground states with J^(PC)=0^(++),1^(+-),and 2^(++),which indicate that it is reasonable to assign X_(2)(4014)as the D^(*)D^(*) tetraquark molecular states with J^(PC)=2^(++).
基金supported in part by the National Key Research and Development Program of China(2023YFA1606000)the National Natural Science Foundation of China(12275277,12335003,and 12435004)the Fundamental Research Funds for the Central Universities(lzujbky-2023-stlt01 and lzujbky-2024-oy02).
文摘A well-known problem in particle physics and cosmology is the observed matter–antimatter asymmetry in the Universe.According to the Big Bang theory,equal amounts of matter and antimatter should have been produced in the early universe.However,astrophysical observations show that the visible universe today is overwhelmingly dominated by matter.
基金supported by the National Key R&D Program of China(2023YFA1609400,2020YFA0406400,and 2023YFA1606000)the National Natural Science Foundation of China(11935018,12221005,12422504,12105127,and 124B2097)the Fundamental Research Funds for the Central Universities,Lanzhou University(lzujbky-2021-ey09 and lzujbky-2023-it32).
文摘The matter-antimatter asymmetry observed in nature is one of the biggest mysteries in physics,and the resolution of this puzzle could be one of the necessary paths to identifying the ultimate theory of the universe.The violation of the combined charge-conjugation and parity(CP)symmetry is one of the required ingredients for explaining this asymmetry[1].
基金financed by the LLP“Industry 4.0”,Almaty,Kazakhstan.
文摘The ends of the velocity vectors of the decay particles of resonance represent material points-velocities in the hyperbolic Lobachevsky velocity space of negative curvature k=−1/C2(C=1 is the speed of light,the rest masses of the decay particles are assigned to the points-velocities).Two points-velocities of the decay particles can be connected by a line segment and an arc of a line of constant curvature 0,called the oricycle.Archimedes’leverage laws define a 3rd point on the arc of the oricycle to which an additive mass(sum of rest masses of particles)is assigned.Connecting 3 points-velocities by line segments,we obtain isosceles triangles of decays of resonances in the Beltrami model of the Lobachevsky velocity space.In the decay triangles of resonances,the golden section is found and the Stewart,Brettschneider theorems on oricyclic arcs are satisfied.Near the decay triangles of scalar,strange mesons andΔ,N baryons,isosceles triangles-satellites with integer values of their characteristics were found.On the satellite triangles,the Lorentz invariant function—the product of the length of the arc of the oricycle subtending the base and the cotangent of half the angle at the vertex opposite the base—takes integer values.The function is called the oricyclic cotangent of a triangle(OCT).In addition to the integer values of OCT,these satellite triangles also have the sum of the hyperbolic cosines of the lengths of the lateral sides and the hyperbolic cosines of the base lengths equal to integers.These satellite triangles are called Heron triangles.On Heron triangles,the generalized cosines of the angles between the tangent to the oricycle at the point-velocity of the additive mass and the tan-gent at the point-velocity of the base of the triangle take multiples of 1/2 values.