Baarmand, M.M.
WIDTH
Max results
Sort by Reverse order

Showing 3 of 13 results

Date

Neutral Pion Production in Au+Au Collisions at $\sqrt{s_{NN}}$ = 200 GeV

The STAR collaboration Abelev, B.I. ; Aggarwal, M.M. ; Ahammed, Z. ; et al.
Phys.Rev.C 80 (2009) 044905, 2009.
Inspire Record 825863 DOI 10.17182/hepdata.96845

The results of mid-rapidity ($0 < y < 0.8$) neutral pion spectra over an extended transverse momentum range ($1 < p_T < 12$ GeV/$c$) in $\sqrt{s_{NN}}$ = 200 GeV Au+Au collisions, measured by the STAR experiment, are presented. The neutral pions are reconstructed from photons measured either by the STAR Barrel Electro-Magnetic Calorimeter (BEMC) or by the Time Projection Chamber (TPC) via tracking of conversion electron-positron pairs. Our measurements are compared to previously published $\pi^{\pm}$ and $\pi^0$ results. The nuclear modification factors $R_{\mathrm{CP}}$ and $R_{\mathrm{AA}}$ of $\pi^0$ are also presented as a function of $p_T$ . In the most central Au+Au collisions, the binary collision scaled $\pi^0$ yield at high $p_T$ is suppressed by a factor of about 5 compared to the expectation from the yield of p+p collisions. Such a large suppression is in agreement with previous observations for light quark mesons and is consistent with the scenario that partons suffer considerable energy loss in the dense medium formed in central nucleus-nucleus collisions at RHIC.

20 data tables
Figure 1 a, b

The diphoton invariant mass distributions using the EMC-TPC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.

Figure 1 c, d

The diphoton invariant mass distributions using the EMC-TPC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.

Figure 2

The diphoton invariant mass distributions using the EMC-EMC method in 0-20% Au+Au collisions at $\sqrt{s_{NN}}=200$ GeV.

More…

rivet Analysis
Observation of a narrow state decaying into Xi(c)+ pi-

The CLEO collaboration Avery, P. ; Freyberger, A. ; Lingel, K. ; et al.
Phys.Rev.Lett. 75 (1995) 4364-4368, 1995.
Inspire Record 397770 DOI 10.17182/hepdata.47270

Using data recorded by the CLEO-II detector at CESR, we report the first observation of a narrow state decaying into $\Xi_c~+\pi~-$. The state has mass difference $M(\Xi_c~+\pi~-)-M(\Xi_c~+)$ of $178.2\pm0.5\pm1.0$ $\rm{MeV/c~2}$, and a width of $<5.5$ $\rm{MeV/c~2}$ (90\% confidence level limit). The most likely explanation of this new state is that it is the $J=\32$ spin excitation of the $\Xi_c~0$ charmed baryon.

1 data table
Table 1

No description provided.


rivet Analysis
Measurement of two photon production of the chi(c2)

The CLEO collaboration Shelkov, V. ; Dominick, J. ; Sanghera, S. ; et al.
Phys.Rev.D 50 (1994) 4265-4271, 1994.
Inspire Record 359316 DOI 10.17182/hepdata.52343

The CLEO II detector is used to search for the production of χc2 states in two-photon interactions. We use the signature χc2→γJ/ψ→γl+l− with l=e,μ. Using 1.49 fb−1 of data taken with beam energies near 5.29 GeV, the two-photon width of the χc2 is determined to be Γ(χc2→γγ)=1.08±0.30(stat)±0.26(syst) keV, in agreement with predictions from perturbative QCD.

2 data tables
Table 1

Results below were obtained usign J/psi from-factors in the two photon propogators, and assumes that only transversely polarized photons are significant inthe production of the CHI/C2(1P) state.

Table 2

No description provided.