Related papers: Update on Counting Valence Quarks at RHIC
New physics can be searched for in deep inelastic scattering experiments. New phenomena, like additional production mechanisms for heavy quarks, manifest themselves through production and decays of short-lived hadrons, which give additional…
We compute the hadronic matrix elements of the four-quark operators relevant for $K^0-{\bar K^0}$ mixing beyond the Standard Model. Our results are from lattice QCD simulations with $n_f=2+1$ flavours of domain-wall fermion, which exhibit…
Nucleon properties are modified in the nuclear medium. To understand these modifications and their origin is a central issue in nuclear physics. For example, a wide variety of QCD-based models, including quark-meson coupling and…
We study the suppression of high-pT hadron spectra in nuclear collisions, supplementing the perturbative QCD factorized formalism with radiative parton energy loss. We find that the nuclear modification factor which quantifies the degree of…
We present the results of a reweighting calculation to compute the contribution of the charged quark sea to the neutron electric polarizability. The chief difficulty is the stochastic estimation of weight factors, and we present a hopping…
In relativistic heavy ion collisions, the cross section of heavy hadron production via the combination of a heavy quark with a light one from the quark-gluon matter can be factorized. It is the convolution of twist-4 combination matrix…
Multiple scattering, induced radiative energy loss and modified fragmentation functions of a heavy quark in nuclear matter are studied within the framework of generalized factorization in perturbative QCD. Modified heavy quark fragmentation…
We present a new set of parton distributions obtained at NNLO. These differ from the previous sets available at NNLO due to improvements in the theoretical treatment. In particular we include a full treatment of heavy flavours in the region…
We give an update on our ongoing efforts to compute the nucleon's form factors and moments of structure functions using Nf=2 flavours of non-perturbatively improved Clover fermions. We focus on new results obtained on gauge configurations…
Light nuclei production as a result of nuclear coalescence effect can give some signals on final state of Quark Gluon Plasma formation. We are studying the behavior of nuclear modification factor as a function of different variables using…
Heavy quarks are a unique probe to study the medium produced in ultra-relativistic heavy ion collisions. Within the partonic transport model Boltzmann approach to multi-parton scatterings (BAMPS) the production, energy loss and elliptic…
Chiral symmetry is one of the most fundamental symmetries in QCD. It is closely connected to hadron properties in the nuclear medium via the reduction of the quark condensate <bar{q}q>, manifesting the partial restoration of chiral…
Nuclear modification factors (NMFs) applied to A-B collision systems consist of $p_t$ spectrum ratios rescaled by an estimated number of nucleon-nucleon binary collisions. Interest in NMFs is motivated by possible modification…
We argue that measurements of identified-particle elliptic flow in a wide energy range could shed light on the possible phase change in high-energy heavy ion collisions at the BNL Relativistic Heavy Ion Collider (RHIC). When the…
Constituent quark number scaling of elliptic flow has been proposed as one key observable to identify the phase transition or the absence of the Quark-Gluon Plasma (QGP) in heavy-ion collisions. At the fixed target program at RHIC the STAR…
The modified number of constituent quark (NCQ) scaling $v_{n}/n_{q}^{n/2} \sim KE_{T}/n_{q}$ for mesons and baryons and the scaling relation $v_{n} \sim v_{2}^{n/2}$ for higher-order anisotropic flows, which were observed experimentally,…
We propose a novel method for extracting non-singlet (NS) fragmentation functions (FFs) of light charged hadrons from charge asymmetries measured in hadron fragmentation, using data from both single-inclusive electron-positron annihilation…
Fluctuations of conserved quantities in heavy-ion collisions are used to probe the phase transition and the QCD critical point for the strongly interacting hot and dense nuclear matter. The STAR experiment has carried out moment analysis of…
We report on an analysis of the average quark momentum fraction of the nucleon and related quantities using $N_\mathrm{f}=2+1$ Wilson fermions. Computations are performed on four CLS ensembles covering three values of the lattice spacing at…
The STAR experiment at the Relativistic Heavy Ion Collider (RHIC) studies properties and phase transitions of nuclear matter in various nucleus-nucleus collisions at center-of-mass energies per nucleon collision $\sqrt{s_{NN}}=7.7$-200 GeV.…