Photoproduction of PP-wave doubly charmed baryon at future e+e−e^+e^- collider

The photoproduction of $P$-wave doubly charmed baryon ($\Xi_{cc}$) is investigated in the context of future high-energy and high-luminosity $e^+e^-$ colliders. The direct photoproduction via the sub-process $\gamma+\gamma \rightarrow \Xi_{cc} +\bar{c}+\bar{c}$ and the resolved channel $\gamma+g \rightarrow \Xi_{cc} +\bar{c}+\bar{c}$ are considered. Within the framework of non-relativistic QCD, the calculation encompasses four $P$-wave $(cc)$-diquark configurations: $(cc)_{\bar{\textbf{3}}}[{}^1P_1]$, $(cc)_{\textbf{6}}[{}^3P_0]$, $(cc)_{\textbf{6}}[{}^3P_1]$ and $(cc)_{\textbf{6}}[{}^3P_2]$. The two $S$-wave states, $(cc)_{\bar{\textbf{3}}}[{}^3S_1]$ and $(cc)_{\textbf{6}}[{}^1S_0]$, are also included for comparison. The cross sections, as well as the differential distributions involving transverse momentum, rapidity, and angular variables, have been computed. Numerical results reveal that the resolved photoproduction process plays a significant role and can provide dominant contributions. The photoproduction rate of the $P$-wave $\Xi_{cc}$ is approximately one order of magnitude lower than that of the $S$-wave

Photoproduction of doubly heavy baryons at future e+e−e^+e^- colliders

The photoprodution of doubly heavy baryon ($\Xi_{cc},\Xi_{bb},\Xi_{bc}$) is investigated in the context of future high-energy and high-luminosity $e^+e^-$ colliders. The study incorporates two sources of initial photons, namely the LBS photon and the WWA photon. Alongside the direct photoproduction via the sub-process $\gamma+\gamma \rightarrow \Xi_{QQ^{'}} +\bar{Q}+\bar{Q^{'}}$ ($Q^{(')}=c,b$), the resolved photoproduction channels are specifically considered, encompassing the sub-processes $\gamma + g \rightarrow \Xi_{QQ^{'}} +\bar{Q}+\bar{Q^{'}}$, $g + g \rightarrow \Xi_{QQ^{'}} +\bar{Q}+\bar{Q^{'}}$, and $q + \bar{q} \rightarrow \Xi_{QQ^{'}} +\bar{Q}+\bar{Q^{'}}$ with $q=u,d,s$. Within the framework of non-relativistic QCD, two $(cc(bb))$-diquark configurations, ${}_{\bar{\textbf{3}}}[{}^3S_1]$ and ${}_{\textbf{6}}[{}^1S_0]$, and four $(bc)$-diquark configurations, $(bc)_{\bar{\textbf{3}}}[{}^3S_1]$, $(bc)_{\textbf{6}}[{}^1S_0]$, $(bc)_{\textbf{6}}[{}^3S_1]$ and $(bc)_{\bar{\textbf{3}}}[{}^1S_0]$, are considered in the calculations. Numerical results show that the single resolved photoproduction processes provide dominant contributions under certain collision configuration. At the future $e^+e^-$ colliders, the doubly heavy baryon generated via the photoproduction mechanism is promisingly observable and can be well studied

The study of lepton EDM in CP violating BLMSSM

In the supersymmetric model with local gauged baryon and lepton numbers(BLMSSM), the CP violating effects are considered to study the lepton electric dipole moment(EDM). The CP violating phases in BLMSSM are more than those in the standard model(SM) and can give large contributions. The analysis of the EDMs for the leptons $e,\mu, \tau$ is shown in this work. It is in favour of exploring the source of CP violation and probing the physics beyond SM.Comment: 20 pages, 10figure

Higgs boson decays to BcB_c meson in the fragmentation-function approach

In the paper, we present a calculation of the decay widths for the Higgs boson decays to the $B_c$, $B_c^*$, $B_c(2^1S_0)$ and $B_c^*(2^3S_1)$ mesons using the fragmentation-function approach. In the calculation, the fragmentation functions up to order $\alpha_s^3$ based on the nonrelativistic QCD factorization theory are used, and the decay widths for $H\to Q+X$ and $H \to g+X$ at the partonic level are calculated up to order $\alpha_s$. The large logarithms of $m_H^2/m_{Bc}^2$ are resummed up to next-to-leading logarithmic accuracy by solving the evolution equations for the running quark masses and the fragmentation functions. Compared to the leading-order decay widths based on the nonrelativistic QCD approach, the decay widths based on the fragmentation-function approach that include the higher-order QCD corrections are reduced significantly. Our numerical results show that there are about $1.2\times 10^5$ $B_c$ events via the Higgs decays to be produced at the HL-LHC with $3ab^{-1}$, and about $1.6\times 10^6$ $B_c$ events via the Higgs decays to be produced at the HE-LHC with $15ab^{-1}$.Comment: 12 pages, 9 figure