Thermodynamics of Dipolar Chain Systems

The thermodynamics of a quantum system of layers containing perpendicularly oriented dipolar molecules is studied within an oscillator approximation for both bosonic and fermionic species. The system is assumed to be built from chains with one molecule in each layer. We consider the effects of the intralayer repulsion and quantum statistical requirements in systems with more than one chain. Specifically, we consider the case of two chains and solve the problem analytically within the harmonic Hamiltonian approach which is accurate for large dipole moments. The case of three chains is calculated numerically. Our findings indicate that thermodynamic observables, such as the heat capacity, can be used to probe the signatures of the intralayer interaction between chains. This should be relevant for near future experiments on polar molecules with strong dipole moments.Comment: 15 pages, 5 figures, final versio

Measurement of the ratio of the ppˉ→Wp\bar{p}\to W+cc-jet cross section to the inclusive ppˉ→Wp\bar{p}\to W+jets cross section

We present a measurement of the fraction of inclusive $W$+jets events produced with net charm quantum number $\pm1$, denoted $W$+$c$-jet, in $p\bar{p}$ collisions at $\sqrt{s}=1.96$ TeV using approximately 1~fb$^{-1}$ of data collected by the D0 detector at the Fermilab Tevatron Collider. We identify the $W$+jets events via the leptonic $W$ boson decays. Candidate $W$+$c$-jet events are selected by requiring a jet containing a muon in association with a reconstructed $W$ boson and exploiting the charge correlation between this muon and $W$ boson decay lepton to perform a nearly model-independent background subtraction. We measure the fraction of $W$+$c$-jet events in the inclusive $W$+jets sample for jet $p_{T}>20$ GeV and pseudorapidity $|\eta|<2.5$ to be 0.074$\pm0.019$(stat.)$\pm^{0.012}_{0.014}$(syst.), in agreement with theoretical predictions. The probability that background fluctuations could produce the observed fraction of $W$+$c$-jet events is estimated to be $2.5\times 10^{-4}$, which corresponds to a 3.5 $\sigma$ statistical significance.Comment: submitted to Physics Letters

Search for the doubly heavy baryon Ξbc+\it{\Xi}_{bc}^{+} decaying to J/ψΞc+J/\it{\psi} \it{\Xi}_{c}^{+}

A first search for the $\it{\Xi}_{bc}^{+}\to J/\it{\psi}\it{\Xi}_{c}^{+}$ decay is performed by the LHCb experiment with a data sample of proton-proton collisions, corresponding to an integrated luminosity of $9\,\mathrm{fb}^{-1}$ recorded at centre-of-mass energies of 7, 8, and $13\mathrm{\,Te\kern -0.1em V}$. Two peaking structures are seen with a local (global) significance of $4.3\,(2.8)$ and $4.1\,(2.4)$ standard deviations at masses of $6571\,\mathrm{Me\kern -0.1em V\!/}c^2$ and $6694\,\mathrm{Me\kern -0.1em V\!/}c^2$, respectively. Upper limits are set on the $\it{\Xi}_{bc}^{+}$ baryon production cross-section times the branching fraction relative to that of the $B_{c}^{+}\to J/\it{\psi} D_{s}^{+}$ decay at centre-of-mass energies of 8 and $13\mathrm{\,Te\kern -0.1em V}$, in the $\it{\Xi}_{bc}^{+}$ and in the $B_{c}^{+}$ rapidity and transverse-momentum ranges from 2.0 to 4.5 and 0 to $20\,\mathrm{Ge\kern -0.1em V\!/}c$, respectively. Upper limits are presented as a function of the $\it{\Xi}_{bc}^{+}$ mass and lifetime.Comment: All figures and tables, along with machine-readable versions and any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-005.html (LHCb public pages

Transcatheter Aortic Valve Replacement in Pure Native Aortic Valve Regurgitation

Cardiolog

Treatment strategies in recurrent esophageal or junctional cancer

Little evidence is available about survival rates in patients with recurrent disease after potentially curative surgery for esophageal or junctional cancer. Only in limited occasions, potentially curative salvage strategies are available. The aim of this study is to analyze survival rates and patterns of dissemination, and to identify independent prognostic factors in a consecutive series of patients who develop recurrent esophageal or junctional cancer. Between 1994 and 2015, patients who developed disease recurrence after neoadjuvant chemo(radio)therapy followed by radical esophagectomy for esophageal or junctional cancer were retrospectively analyzed. The Kaplan- Meier estimates were performed to calculate and compare overall survival between patients with different patterns of dissemination and to compare between different treatment strategies. Furthermore, univariate and multivariate Cox-regression analyses were performed to identify independent prognostic factors for post recurrence survival. In this study, we included 219 patients. The median overall survival of all included patients was 3.2 months (range: 0.0- 101.1 months). The median overall survival in patients with exclusively locoregional recurrence (n = 23, 10.8%) was 4.9 months (range: 0.1- 55.6) and 2.9 months (range: 0.0-101.1) in patients who had distant metastases (n = 189, 89.2%), P = 0.003. Patients who received treatment aimed at complete tumor eradication (n = 28, 13.7%) had a median overall survival of 13.6 months (range: 1.1-101.1) and palliative treated patients (n = 94, 46.1%) of 4.7 months (range: 0.3-25.6), P < 0.001. In a selected group of patients survival of more than 20 months was achieved. Univariate and multivariate Cox-regression analysis showed that a higher age at the diagnosis of recurrent disease (hazard ratio: 1.087, P ≤ 0.001), an irradical resection of the primary tumor (hazard ratio: 3.355, P = < 0.001), the number of positive lymph nodes after neoadjuvant therapy (hazard ratios: ypN2 = 1.724 (P = 0.024) and ypN3 = 2.082 (P = 0.028) and the presence of a single hematogenous distant metastases (hazard ratio: 2.281, P = 0.003) or more than one hematogenous distant metastasis (hazard ratio: 2.385, P = 0.005) were associated with a shorter postrecurrence survival. The prognosis of patients who develop recurrent esophageal or junctional cancer is poor. In a selected group of patients however relatively long survival can be achieved. This offers new perspectives to improve treatment strategies and survival rates