Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userProbing Hadronization with Strangeness
169
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
The Omega-bar/Omega ratio originating from string decays is predicted to be larger than unity in proton-proton interaction at SPS energies. The anti-omega dominance increases with decreasing beam energy. This surprising behavior is caused by the combinatorics of quark-antiquark production in small and low-mass strings. Since this behavior is not found in a statistical description of hadron production in proton-proton collisions, it may serve as a key observable to probe the hadronization mechanism in such collisions.
rate research
Read More
If the deconfinement phase transformation of strongly interacting matter is of first-order and the expanding chromodynamic matter created in a high-energy nuclear collision enters the corresponding region of phase coexistence, a spinodal phase separation might occur. The matter would then condense into a number of separate blobs, each having a particular net strangeness that would remain approximately conserved during the further evolution. We investigate the effect that such `strangeness trapping may have on strangeness-related hadronic observables. The kaon multiplicity fluctuations are significantly enhanced and thus provide a possible tool for probing the nature of the phase transition experimentally.
The extraction of the nucleons strangeness axial charge, Delta_s, from inclusive, quasielastic neutral current neutrino cross sections is studied within the framework of the plane-wave impulse approximation. We find that the value of Delta_s can depend significantly on the choice of nuclear model used in analyzing the quasielastic cross section. This model-dependence may be reduced by one order of magnitude when Delta_s is extracted from the ratio of total proton to neutron yields. We apply this analysis to the interpretation of low-energy neutrino cross sections and arrive at a nuclear theory uncertainty of plus/minus 0.03 on the value of Delta_s expected to be determined from the ratio of proton and neutron yields measured by the LSND collaboration. This error compares favorably with estimates of the SU(3)-breaking uncertainty in the value of Delta_s extracted from inclusive, polarized deep-inelastic structure function measurements. We also point out several general features of the quasielastic neutral current neutrino cross section and compare them with the analogous features in inclusive, quasielastic electron scattering.
We review the status as regards the existence of three- and four-body bound states made of neutrons and $Lambda$ hyperons. For interesting cases, the coupling to neutral baryonic systems made of charged particles of different strangeness has been addressed. There are strong arguments showing that the $Lambda nn$ system has no bound states. $LambdaLambda nn$ strong stable states are not favored by our current knowledge of the strangeness $-1$ and $-2$ baryon-baryon interactions. However, a possible $Xi^- t$ quasibound state decaying to $LambdaLambda nn$ might exist in nature. Similarly, there is a broad agreement about the nonexistence of $LambdaLambda n$ bound states. However, the coupling to $Xi NN$ states opens the door to a resonance above the $LambdaLambda n$ threshold.
Recently, many efforts are being put in studying three-hadron systems made of mesons and baryons and interesting results are being found. In this talk, I summarize the main features of the formalism used to study such three hadron systems with strangeness $S=-1,0$ within a framework built on the basis of unitary chiral theories and solution of the Faddeev equations. In particular, I present the results obtained for the $pibar{K}N$, $Kbar{K}N$ and $KKbar{K}$ systems and their respective coupled channels. In the first case, we find four $Sigma$s and two $Lambda$s with spin-parity $J^P=1/2^+$, in the 1500-1800 MeV region, as two meson-one baryon s-wave resonances. In the second case, a $1/2^+$ $N^*$ around 1900 MeV is found. For the last one a kaon close to 1420 MeV is formed, which can be identified with K(1460).
We study the properties of strange mesons in vacuum and in the hot nuclear medium within unitarized coupled-channel effective theories. We determine transition probabilities, cross sections and scattering lengths for strange mesons. These scattering observables are of fundamental importance for understanding the dynamics of strangeness production and propagation in heavy-ion collisions.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
