The charm fragmentation function has been measured in photoproduction of jets containing D^*+- mesons. The measured function has been used to extract free parameters of different fragmentation models. Measurements of excited charm, D_1(2420)^0 and D_2^*(2460)^0, and charm-strange, D_{s1}(2536)^+-, mesons and a search for the radially excited charm meson, D^{*'}(2640)^+-, were also performed. The results are compared with those measured previously and with theoretical expectation.
Measurement of D^\pm production in deep inelastic ep scattering with the ZEUS detector at HERA
Charm production in deep inelastic ep scattering was measured with the ZEUS detector using an integrated luminosity of 354 pb^{-1}. Charm quarks were identified by reconstructing D^{+} mesons in the D^{+} -> K^{-} pi^{+} pi^{+} decay channel. Lifetime information was used to reduce combinatorial background substantially. Differential cross sections were measured in the kinematic region 5 < Q^{2} < 1000 GeV^{2}, 0.02 < y < 0.7, 1.5 < p_{T} (D^{+}) < 15 GeV and |eta(D^{+})| < 1.6, where Q^{2} is the photon virtuality, y is the inelasticity, and p_{T} (D^{+}) and eta(D^{+}) are the transverse mom…
In the present work, we investigate the production of $P-$wave charmed or charmed-strange mesons in the pion or kaon induced reactions on a proton target. The total cross sections as well as the differential cross sections depending on the scattering angle are evaluated in an effective Lagrangian approach. Our estimations indicate that magnitude of the cross sections strongly depends on the model parameter but such dependence can be almost completely canceled for the cross section ratios. These model independent ratios can be taken as a good criterion of the validity of heavy quark limit in th…
We present a new method for detection of multiply charmed baryons via their decays into strange baryons, using `strangeness tracking'. This method makes use of the state-of-the-art upgraded silicon detectors in ALICE during Runs 3, 4 and beyond will enable the novel possibility of tracking strange hadrons directly before they decay, leading to a very significant improvement in impact-parameter resolution. In this work, we will discuss how this new technique will be crucial to distinguish secondary strange baryons originating from charm decays from primary strange baryons. This is a particularl…
In the present work, we adopt a relativistic constituent quark model to depict the charmed strange meson spectroscopy, in which $D_{s0}(2317)$ and $D_{s1}(2460)$ are considered as the $1^3P_0$ and $1P_1^\prime$ charmed strange mesons, respectively. By using the wave function obtained from the relativistic quark model, we further investigate the electric transitions between charmed strange mesons. We find the long wave length approximation is reasonable for the charmed strange meson radiative decay by comparing the results with different approximations. The estimated partial widths are all safe…
It has been recently suggested that the charged charmoniumlike resonances $Z_c(4100)$ and $Z_c(4200)$ are two states of hadrocharmonium, related by the charm quark spin symmetry in the same way as the lowest charmonium states $η_c$ and $J/ψ$. It is pointed out here that in this picture one might expect existence of their somewhat heavier strange counterparts, $Z_{cs}$, decaying to $η_c K$ and $J/ψK$. Some expected properties of such charmoniumlike strange resonances are discussed that set benchmarks for their search in the decays of the strange $B_s$ mesons.
We investigate the production of the hidden-charm pentaquark $P_{cs}^0(4459)$ with strangeness in the $K^- p \to J/ψΛ$ reaction, employing two different theoretical frameworks, i.e., the effective Lagrangian method and the Regge approach. Having determined all relevant coupling constants, we are able to compute the total and differential cross sections for the $K^- p \to J/ψΛ$ reaction. We examine the contributions of $P_{cs}$ with different sets of spin-parity quantum number assigned. The present results may give a guide for possible future experiments.
Production of strange and charmed baryons in pion induced reactions
我们基于两种不同的理论框架：有效拉格朗日方法和Regge方法，研究了π介子束诱导的奇异和粲产生，即$π^-$ p $\rightarrow$ $K^{*0}Λ$和$π^-$ p $\rightarrow$ $D^{*-}Λ_c^+$反应.为了估计粲子产生相对于奇异度产生的大小，我们假设粲子和重子顶点的耦合常数与奇异度通道的耦合常数相同。我们发现，魅力生产的总截面约为$10^3 - 10^6$倍小于奇异生产，这取决于理论方法和运动学区域。我们还讨论了每一个贡献，这两个反应的观测。一般来说，Regge方法在整个能量区域内很好地解释了实验数据。
On the search for the electric dipole moment of strange and charm baryons at LHC
基本粒子的永久电偶极矩（EDM）为标准模型之外的物理学提供了强有力的探针。我们建议在大型强子对撞机上寻找奇异和魅力重子的EDM，扩展正在进行的中子，μ子，原子，分子和轻核的实验计划。从大型强子对撞机pp碰撞产生的粲重子的弱衰变中选出的奇异λ重子的EDM，可以通过研究探测器跟踪系统的磁场中的自旋进动来确定。CPT对称性的检验可以通过测量λ重子和反λ重子的磁偶极矩来进行。对于短寿命的Lambsons+和Xic+重子，在固定靶实验中使用7 TeV LHC束产生，并在弯曲晶体中引导，自旋进动是由晶体原子平面之间的强电磁场引起的。基于LHCb探测器的实验布局和预期的灵敏度在未来几年进行了讨论。
We investigate the electromagnetic properties of possible charm-strange pentaquarks in the framework of the light-cone QCD sum rule using the photon distribution amplitudes. In particular, by calculating the corresponding electromagnetic form factors defining the radiative transitions under consideration we estimate the magnetic dipole and electric quadrupole moments of the pentaquark systems of a charm, an anti-strange and three light quarks. We observe that the values of magnetic dipole moments are considerably large, however, the quadrupole moments are very small. Any future measurements of…
