Pinning of stripes by local structural distortions in cuprate high-Tc superconductors

We study the spin-density wave (stripe) instability in lattices with mixed low-temperature orthorhombic (LTO) and low-temperature tetragonal (LTT) crystal symmetry. Within an explicit mean-field model it is shown how local LTT regions act as pinning centers for static stripe formation. We calculate the modulations in the local density of states near these local stripe regions and find that mainly the coherence peaks and the van Hove singularity (VHS) are spatially modulated. Lastly, we use the real-space approach to simulate recent tunneling data in the overdoped regime where the VHS has been detected by utilizing local normal state regions.Comment: Conference proceedings for Stripes1

Direct Emission of multiple strange baryons in ultrarelativistic heavy-ion collisions from the phase boundary

We discuss a model for the space-time evolution of ultrarelativistic heavy-ion collisions which employs relativistic hydrodynamics within one region of the forward light-cone, and microscopic transport theory (i.e. UrQMD) in the complement. Our initial condition consists of a quark-gluon plasma which expands hydrodynamically and hadronizes. After hadronization the solution eventually changes from expansion in local equilibrium to free streaming, as determined selfconsistently by the interaction rates between the hadrons and the local expansion rate. We show that in such a scenario the inverse slopes of the $m_T$-spectra of multiple strange baryons ($\Xi$, $\Omega$) are practically unaffected by the purely hadronic stage of the reaction, while the flow of $p$'s and $\Lambda$'s increases. Moreover, we find that the rather ``soft'' transverse expansion at RHIC energies (due to a first-order phase transition) is not washed out by strong rescattering in the hadronic stage. The earlier kinetic freeze-out as compared to SPS-energies results in similar inverse slopes (of the $m_T$-spectra of the hadrons in the final state) at RHIC and SPS energies.Comment: 4 pages, 3 figures, statistics for Omegas improved, slight revision of the manuscript (expansion of hadronization volume more emphasized, pi-Omega scattering is discussed very briefly

Circulating Tumor DNA Monitoring Reveals Molecular Progression before Radiologic Progression in a Real-life Cohort of Patients with Advanced Non-small Cell Lung Cancer

Purpose: The clinical potential of liquid biopsy in patients with advancedcancer is real-time monitoring for early detection of treatment failure.Our study aimed to investigate the clinical validity of circulating tumorDNA (ctDNA) treatment monitoring in a real-life cohort of patients withadvanced non–small cell lung cancer (NSCLC).Experimental Design: Patients with advanced or noncurative locallyadvanced NSCLC were prospectively included in an exploratory study(NCT03512847). Selected cancer-specific mutations were measured inplasma by standard or uniquely designed droplet digital PCR assays beforeevery treatment cycle during first-line treatment until progressive disease(PD). Correlation between an increase in ctDNA (= molecular progres-sion) and radiologic PD was investigated, defined as lead time, and thecorresponding numbers of likely futile treatment cycles were determined.Utility of ctDNA measurements in clarifying the results of nonconclusiveradiologic evaluation scans was evaluated.Results: Cancer-specific mutations and longitudinal plasma sampling werepresent in 132 of 150 patients. ctDNA was detectable in 88 (67%) of132 patients treated by respectively chemotherapy (n = 41), immunotherapy(n = 43), or combination treatment (n = 4). In 66 (90%) of 73 patients ex-periencing PD, a ctDNA increase was observed with a median lead time of1.5 months before radiologic PD. Overall, 119 (33%) of 365 treatment cy-cles were administered after molecular progression. In addition, ctDNAmeasurements could clarify the results in 38 (79%) of 48 nonconclusiveradiologic evaluations.Conclusions: ctDNA monitoring leads to earlier detection of treatmentfailure, and clarifies the majority of nonconclusive radiologic evaluations,giving the potential of sparing patients from likely futile treatments andneedless adverse events.Significance: Treatment monitoring by ctDNA has the clinical potentialto reveal PD before radiologic evaluation and consequently spare patientswith advanced cancer from likely ineffective, costly cancer treatments andadverse events

Strangeness Enhancement in Heavy Ion Collisions - Evidence for Quark-Gluon-Matter ?

The centrality dependence of (multi-)strange hadron abundances is studied for Pb(158 AGeV)Pb reactions and compared to p(158 GeV)Pb collisions. The microscopic transport model UrQMD is used for this analysis. The predicted Lambda/pi-, Xi-/pi- and Omega-/pi- ratios are enhanced due to rescattering in central Pb-Pb collisions as compared to peripheral Pb-Pb or p-Pb collisions. A reduction of the constituent quark masses to the current quark masses m_s \sim 230 MeV, m_q \sim 10 MeV, as motivated by chiral symmetry restoration, enhances the hyperon yields to the experimentally observed high values. Similar results are obtained by an ad hoc overall increase of the color electric field strength (effective string tension of kappa=3 GeV/fm). The enhancement depends strongly on the kinematical cuts. The maximum enhancement is predicted around midrapidity. For Lambda's, strangeness suppression is predicted at projectile/target rapidity. For Omega's, the predicted enhancement can be as large as one order of magnitude. Comparisons of Pb-Pb data to proton induced asymmetric (p-A) collisions are hampered due to the predicted strong asymmetry in the various rapidity distributions of the different (strange) particle species. In p-Pb collisions, strangeness is locally (in rapidity) not conserved. The present comparison to the data of the WA97 and NA49 collaborations clearly supports the suggestion that conventional (free) hadronic scenarios are unable to describe the observed high (anti-)hyperon yields in central collisions. The doubling of the strangeness to nonstrange suppression factor, gamma_s \approx 0.65, might be interpreted as a signal of a phase of nearly massless particles.Comment: published version, discussion on strange mesons and new table added, extended discussion on strange baryon yields. Latex, 20 pages, including 5 eps-figure

Beyond the binary collision approximation for the large-qq response of liquid 4^4He

We discuss corrections to the linear response of a many-body system beyond the binary collision approximation. We first derive for smooth pair interactions an exact expression of the response $\propto 1/q^2$, considerably simplifying existing forms and present also the generalization for interactions with a strong, short-range repulsion. We then apply the latter to the case of liquid $^4$He. We display the numerical influence of the $1/q^2$ correction around the quasi-elastic peak and in the low-intensity wings of the response, far from that peak. Finally we resolve an apparent contradiction in previous discussions around the fourth order cumulant expansion coefficient. Our results prove that the large-$q$ response of liquid $^4$He can be accurately understood on the basis of a dynamical theory.Comment: 19 p. Figs. available on reques

Quark-Gluon Plasma Fireball

Lattice-QCD results provide an opportunity to model, and extrapolate to finite baryon density, the properties of the quark-gluon plasma (QGP). Upon fixing the scale of the thermal coupling constant and vacuum energy to the lattice data, the properties of resulting QGP equations of state (EoS) are developed. We show that the physical properties of the dense matter fireball formed in heavy ion collision experiments at CERN-SPS are well described by the QGP-EoS we presented. We also estimate the properties of the fireball formed in early stages of nuclear collision, and argue that QGP formation must be expected down to 40A GeV in central Pb--Pb interactions.Comment: 10 pages, 9 postscript figures, 1 table, uses revtex, V3: introduced difference between n_f and n_s; fireball restframe energy corrected, references added. Publisched version in press Phys. Rev.