Shi-Yuan Li

Gluon Shadowing and Hadron Production at RHIC

Nuclear Science Division, Mailstop 70-319, Lawrence Berkeley Laboratory, Berkeley, California 94720.(October 3,2001)Hadron multiplicity in the central rapidity region of high-energy heavy-ion collisions is investi-gated within a two-component mini-jet model which consists of soft and semi-hard particle produc-tion. The hard contribution from mini-jets is reevaluated using the latest parameterization of partondistributions and nuclear shadowing. The energy dependence of the experimental data from RHICrequires a strong nuclear shadowing of the gluon distribution in this model. The centrality depen-dence of the hadron multiplicity at√s = 130 GeV is reproduced well with the impact-parameterdependent parton shadowing. However, energy variation of the centrality dependence is needed todistinguish different particle production mechanisms such as the parton saturation model.25.75.-q,12.38.Bx,12.38.Mh,24.85.+p

New Bs0π± and Ds±π± states in high energy multiproduction process

The production rate of the X(5568) measured by D0 collaboration is quite large and difficult to be understood by various general hadronization mechanism. We propose the inclusive production formulation for the cross section, and predict the distributions and production rates of X(5568) at LHC energies, which are crucial information for the relevant measurements. We also suspect D s π ± state can be copiously produced and observed.

Probing color separate states ine+e−annihilation at theZ0pole

Hadronic events in

Identify Charged Higgs Boson in

e^+ e^- \to Z^0

W^\pm H^\mp

are generated by a Monte-Carlo model including the production of colour separate states. These events are compared with those produced by the JETSET with default set of parameters where the colour connections are colour singlet chains. By selecting two-jet-like events and a sensitive observable, we find that these two kinds of colour connections lead to significant differences in the hadronic states.

Associated Production at LHC

We investigate the possibility to discover the charged Higgs via

Doubly heavy baryon production at γγ collider

pp\to W^{\pm}H^{\mp}\to l+\met+b\bar{b}jj

Colour connection and diquark fragmentation in e+e−→cc¯qq¯→h′s process

process at LHC, which suffers from large QCD backgrounds. We optimize the kinematic cuts to suppress the backgrounds, so that the reconstruction of the charged Higgs through hadronic decay is possible. The angular distribution of the b-jet from

Search for a doubly charmed hadron at B factories

H^{\pm}

Colour connections of four quark

decay is investigated as a way to identify the charged scalar from vector bosons.