Challenges in QCD matter physics - The Compressed Baryonic Matter experiment at FAIR

Substantial experimental and theoretical efforts worldwide are devoted to explore the phase diagram of strongly interacting matter. At LHC and top RHIC energies, QCD matter is studied at very high temperatures and nearly vanishing net-baryon densities. There is evidence that a Quark-Gluon-Plasma (QGP) was created at experiments at RHIC and LHC. The transition from the QGP back to the hadron gas is found to be a smooth cross over. For larger net-baryon densities and lower temperatures, it is expected that the QCD phase diagram exhibits a rich structure, such as a first-order phase transition between hadronic and partonic matter which terminates in a critical point, or exotic phases like quarkyonic matter. The discovery of these landmarks would be a breakthrough in our understanding of the strong interaction and is therefore in the focus of various high-energy heavy-ion research programs. The Compressed Baryonic Matter (CBM) experiment at FAIR will play a unique role in the exploration of the QCD phase diagram in the region of high net-baryon densities, because it is designed to run at unprecedented interaction rates. High-rate operation is the key prerequisite for high-precision measurements of multi-differential observables and of rare diagnostic probes which are sensitive to the dense phase of the nuclear fireball. The goal of the CBM experiment at SIS100 (sqrt(s_NN) = 2.7 - 4.9 GeV) is to discover fundamental properties of QCD matter: the phase structure at large baryon-chemical potentials (mu_B > 500 MeV), effects of chiral symmetry, and the equation-of-state at high density as it is expected to occur in the core of neutron stars. In this article, we review the motivation for and the physics programme of CBM, including activities before the start of data taking in 2022, in the context of the worldwide efforts to explore high-density QCD matter.Comment: 15 pages, 11 figures. Published in European Physical Journal

Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

The $p_{\rm T}$-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D$^0$, D$^+$, and D$^{*+}$ in the rapidity range $|y|<0.5$, and for transverse momentum $1< p_{\rm T} <12$ GeV/$c$, were measured in proton-proton collisions at $\sqrt{s} = 2.76$ TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D$^0 \rightarrow$K$\pi$, D$^+ \rightarrow$K$\pi\pi$, D$^{*+} \rightarrow$D$^0\pi$, and their charge conjugates, and was performed on a $L_{\rm int} = 1.1$ nb$^{-1}$ event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at $\sqrt{s} = 2.76$ TeV and at 7 TeV was evaluated by extrapolating to the full phase space the $p_{\rm T}$-differential production cross sections at $\sqrt{s} = 2.76$ TeV and our previous measurements at $\sqrt{s} = 7$ TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

Rhinosinusitis derived Staphylococcal enterotoxin B possibly associates with pathogenesis of ulcerative colitis

BACKGROUND: During clinical practice, we noticed that some patients with both ulcerative colitis (UC) and chronic rhinosinusitis (CRS) showed amelioration of UC after treatment of CRS. This study was designed to identify a possible association between CRS and UC. METHODS: Thirty-two patients with both CRS and UC received treatment with functional endoscopic sinus surgery (FESS) for CRS. Clinical symptom scores for CRS and UC, as well as serum levels of anti-Staphylococcal enterotoxin B (SEB) were evaluated at week 0 and week 12. Sinus wash fluid SEB content was measured with enzyme-linked immunosorbent assay (ELISA). The surgically removed tissues were cultured to identify growth of Staphylococcus. aureus (S. aureus). Immunohistochemistry was employed to identify anti-SEB positive cells in the colonic mucosa. Colonic biopsies were obtained and incubated with SEB. Mast cell activation in the colonic mucosa in response to incubation with SEB was observed with electron microscopy and immunoassay. RESULTS: The clinical symptom scores of CRS and UC severe scores (UCSS) were significantly reduced in the UC-CRS patients after FESS. The number of cultured S. aureus colonies from the surgically removed sinus mucosa significantly correlated with the decrease in UCSS. High levels of SEB were detected in the sinus wash fluids of the patients with UC-CRS. Histamine and tryptase release was significantly higher in the culture supernate in the patients with UC-CRS than the patients with UC-only and normal controls. Anti-SEB positive cells were located in the colonic mucosa. CONCLUSION: The pathogenesis of UC in some patients may be associated with their pre-existing CRS by a mechanism of swallowing sinusitis-derived SEB. We speculate that SEB initiates inappropriate immune reactions and inflammation in the colonic mucosa that further progresses to UC

Distribution and number of Cajal-like cells in testis tissue with azoospermia

We investigated the number and distribution of Cajal-like cells in patients with azoospermia. A total of 99 patients with non-obstructive azoospermia were divided into subgroups [19 patientsin hypospermatogenesis group (S1), 40 patients in maturation arrest group (S2), 20 patients in a Sertoli cell-only syndrome (S3), and 20 patients in a testicular atrophy and fibrosis group (S4)], and 20 patients with obstructive azoospermia group (SO). Sections stained with a c-kit antibody were studied by light microscopy to determine the number and distribution of Cajal-like cells in peritubular and perivascular areas of testis. The number of Cajal-like cells were higher in all the non-obstructive groups than in the obstructive group (S0: 2.43 cells/mm(2), S1: 3.14 cells/mm(2), S2: 4.00 cells/mm(2), S3: 4.57 cells/mm(2), S4: 3.86 cells/mm(2)) but statistically significantly different (p < 0.05) in the S2 and S3 subgroups only. Distribution of Cajal-like cells were similar in all groups. The number and distribution of Cajal-like cells in non obstructive groups suggest that these cells may affect spermatogenesis. This cellular type can be responsible for the regulation of cellular motility or spermatogenesis. Electrophysiological and electron microscopic studies are needed to better define morphology and function of Cajal-like cells in the testis, especially totally the normal testis tissue. Copyright (C) 2017, Kaohsiung Medical University. Published by Elsevier Taiwan LLC

The calculation of Columba's arrival in Britain in Bede's <i>Ecclesiastical History</i> and the Pictish king-lists

Bede in his 'Ecclesiastical History' dated the arrival of St Columba in Britain and the foundation of the monastery of Iona to 565, two years after the 563 date derived from sources associated with Iona. This article analyses the different possibilities for how Bede obtained his date, arguing that he used a Pictish source, and places the claim in the 'Ecclesiastical History' that Iona was given to Columba by the Picts in the context of other evidence that Pictish over-kings in the decades before 730 were beginning to attempt to dominate Dal Riata. It also proposes that notes added to the Series longior Pictish king-list at Abernethy in the mid-ninth century display a strong Gaelic influence ultimately derived from a similar chronological source to that used by Bede. As a result Bede's calculation and the king-list notes provide evidence for Pictish scholarship and its cultural connections