1,280 research outputs found

    ON THE 82-TH SMARANDACHE’S PROBLEM

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    The main purpose of this paper is using the elementary method to study the asymptotic properties of the integer part of the k-th root positive integer, and give two interesting asymptotic formulae

    Masses of Scalar and Axial-Vector B Mesons Revisited

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    The SU(3) quark model encounters a great challenge in describing even-parity mesons. Specifically, the qqˉq\bar q quark model has difficulties in understanding the light scalar mesons below 1 GeV, scalar and axial-vector charmed mesons and 1+1^+ charmonium-like state X(3872)X(3872). A common wisdom for the resolution of these difficulties lies on the coupled channel effects which will distort the quark model calculations. In this work, we focus on the near mass degeneracy of scalar charmed mesons, Ds0D_{s0}^* and D00D_0^{*0}, and its implications. Within the framework of heavy meson chiral perturbation theory, we show that near degeneracy can be qualitatively understood as a consequence of self-energy effects due to strong coupled channels. Quantitatively, the closeness of Ds0D_{s0}^* and D00D_0^{*0} masses can be implemented by adjusting two relevant strong couplings and the renormalization scale appearing in the loop diagram. Then this in turn implies the mass similarity of Bs0B_{s0}^* and B00B_0^{*0} mesons. The P0P1P_0^* P'_1 interaction with the Goldstone boson is crucial for understanding the phenomenon of near degeneracy. Based on heavy quark symmetry in conjunction with corrections from QCD and 1/mQ1/m_Q effects, we obtain the masses of B(s)0B^*_{(s)0} and B(s)1B'_{(s)1} mesons, for example, MBs0=(5715±1)MeV+δΔSM_{B_{s0}^*}= (5715\pm1)\,{\rm MeV}+\delta\Delta_S, MBs1=(5763±1)MeV+δΔSM_{B'_{s1}}=(5763\pm1)\,{\rm MeV}+\delta\Delta_S with δΔS\delta\Delta_S being 1/mQ1/m_Q corrections. We find that the predicted mass difference of 48 MeV between Bs1B'_{s1} and Bs0B_{s0}^* is larger than that of 203020\sim 30 MeV inferred from the relativistic quark models, whereas the difference of 15 MeV between the central values of MBs1M_{B'_{s1}} and MB1M_{B'_1} is much smaller than the quark model expectation of 6010060-100 MeV.Comment: 21 pages, 1 figure, to appear in Eur. Phys. J. (2017). arXiv admin note: text overlap with arXiv:1404.377

    An open problem on Jeśmanowicz\u27 conjecture concerning primitive Pythagorean triples

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    Let (m>31) be an even integer with (gcd(m,31)=1). In this paper, using some elementary methods, we prove that the equation ((m^2-31^2)^x+(62m)^y=(m^2+31^2)^z) has only the positive integer solution ((x,y,z)=(2,2,2)). This result resolves an open problem raised by T. Miyazaki ({em Acta Arith.} 186 (2018), 1--36) about Je\u27smanowicz\u27 conjecture concerning primitive Pythagorean triples

    General Split Variational Inclusion Problem in Hilbert Spaces

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    We consider a general split variational inclusion problem (GSFVIP) and propose an algorithm for finding the solutions of GSFVIP in Hilbert space. We establish the strong convergence of the proposed algorithm to a solution of GSFVIP. Our results extend and improve the related results in the literature

    Top quark decays with flavor violation in the B-LSSM

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    The decays of top quark tcγ,  tcg,  tcZ,  tcht\rightarrow c\gamma,\;t\rightarrow cg,\;t\rightarrow cZ,\;t\rightarrow ch are extremely rare processes in the standard model (SM). The predictions on the corresponding branching ratios in the SM are too small to be detected in the future, hence any measurable signal for the processes at the LHC is a smoking gun for new physics. In the extension of minimal supersymmetric standard model with an additional local U(1)BLU(1)_{B-L} gauge symmetry (B-LSSM), new gauge interaction and new flavor changing interaction affect the theoretical evaluations on corresponding branching ratios of those processes. In this work, we analyze those processes in the B-LSSM, under a minimal flavor violating assumption for the soft breaking terms. Considering the constraints from updated experimental data, the numerical results imply Br(tcγ)5×107Br(t\rightarrow c\gamma)\sim5\times10^{-7}, Br(tcg)2×106Br(t\rightarrow cg)\sim2\times10^{-6}, Br(tcZ)4×107Br(t\rightarrow cZ)\sim4\times10^{-7} and Br(tch)3×109Br(t\rightarrow ch)\sim3\times10^{-9} in our chosen parameter space. Simultaneously, new gauge coupling constants gB,  gYBg_{_B},\;g_{_{YB}} in the B-LSSM can also affect the numerical results of Br(tcγ,  cg,  cZ,  ch)Br(t\rightarrow c\gamma,\;cg,\;cZ,\;ch).Comment: 20 pages, 4 figures, published in EPJC. arXiv admin note: substantial text overlap with arXiv:1803.0990

    VcbV_{cb} from the semileptonic decay BDνˉB\to D \ell \bar{\nu}_{\ell} and the properties of the DD meson distribution amplitude

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    The improved QCD light-cone sum rule (LCSR) provides an effective way to deal with the heavy-to-light transition form factors (TFFs). Firstly, we adopt the improved LCSR approach to deal with the BDB\to D TFF f+(q2)f^{+}(q^2) up to twist-4 accuracy. Due to the elimination of the most uncertain twist-3 contribution and the large suppression of the twist-4 contribution, the obtained LCSR shall provide us a good platform for testing the DD-meson leading-twist DA. For the purpose, we suggest a new model for the DD-meson leading-twist DA (ϕ3D\phi_{3D}), whose longitudinal behavior is dominantly determined by a parameter BB. Moreover, we find its second Gegenbauer moment a2DBa^D_2\sim B. Varying BB within certain region, one can conveniently mimic the DD-meson DA behavior suggested in the literature. Inversely, by comparing the estimations with the experimental data on the DD-meson involved processes, one can get a possible range for the parameter BB and a determined behavior for the DD-meson DA. Secondly, we discuss the BDB\to D TFF at the maximum recoil region and present a detailed comparison of it with the pQCD estimation and the experimental measurements. Thirdly, by applying the LCSR on f+(q2)f^{+}(q^2), we study the CKM matrix element \Vcb together with its uncertainties by adopting two types of processes, i.e. the B0/Bˉ0B^0/\bar{B}^0-type and the B±B^{\pm}-type. It is noted that a smaller B0.20B \precsim 0.20 shows a better agreement with the experimental value on \Vcb. For example, for the case of B=0.00B=0.00, we obtain Vcb(B0/Bˉ0type)=(41.284.82+5.681.16+1.13)×103|V_{cb}|(B^0/\bar{B}^0-{\rm type})=(41.28 {^{+5.68}_{-4.82}} {^{+1.13}_{-1.16}}) \times 10^{-3} and Vcb(B±type)=(40.444.72+5.561.00+0.98)×103|V_{cb}|(B^{\pm}-{\rm type})=(40.44 {^{+5.56}_{-4.72}} {^{+0.98}_{-1.00}}) \times 10^{-3}, whose first (second) uncertainty comes from the squared average of the mentioned theoretical (experimental) uncertainties.Comment: 13 pages, 10 figures. Reference updated and discussion improved. To be published in Nucl.Phys.

    The ρ\rho-meson longitudinal leading-twist distribution amplitude

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    In the present paper, we suggest a convenient model for the vector ρ\rho-meson longitudinal leading-twist distribution amplitude ϕ2;ρ\phi_{2;\rho}^\|, whose distribution is controlled by a single parameter B2;ρB^\|_{2;\rho}. By choosing proper chiral current in the correlator, we obtain new light-cone sum rules (LCSR) for the BρB\to\rho TFFs A1A_1, A2A_2 and VV, in which the δ1\delta^1-order ϕ2;ρ\phi_{2;\rho}^\| provides dominant contributions. Then we make a detailed discussion on the ϕ2;ρ\phi_{2;\rho}^\| properties via those BρB\to\rho TFFs. A proper choice of B2;ρB^\|_{2;\rho} can make all the TFFs agree with the lattice QCD predictions. A prediction of Vub|V_{\rm ub}| has also been presented by using the extrapolated TFFs, which indicates that a larger B2;ρB^{\|}_{2;\rho} leads to a larger Vub|V_{\rm ub}|. To compare with the BABAR data on Vub|V_{\rm ub}|, the longitudinal leading-twist DA ϕ2;ρ\phi_{2;\rho}^\| prefers a doubly-humped behavior.Comment: 7 pages, 3 figures. Discussions improved and references updated. To be published in Phys.Lett.
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