Study of the B−→Λc+Λˉc−K−B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-} decay

The decay $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ is studied in proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV using data corresponding to an integrated luminosity of 5 $\mathrm{fb}^{-1}$ collected by the LHCb experiment. In the $\Lambda_{c}^+ K^{-}$ system, the $\Xi_{c}(2930)^{0}$ state observed at the BaBar and Belle experiments is resolved into two narrower states, $\Xi_{c}(2923)^{0}$ and $\Xi_{c}(2939)^{0}$, whose masses and widths are measured to be $$m(\Xi_{c}(2923)^{0}) = 2924.5 \pm 0.4 \pm 1.1 \,\mathrm{MeV}, \\ m(\Xi_{c}(2939)^{0}) = 2938.5 \pm 0.9 \pm 2.3 \,\mathrm{MeV}, \\ \Gamma(\Xi_{c}(2923)^{0}) = \phantom{000}4.8 \pm 0.9 \pm 1.5 \,\mathrm{MeV},\\ \Gamma(\Xi_{c}(2939)^{0}) = \phantom{00}11.0 \pm 1.9 \pm 7.5 \,\mathrm{MeV},$$ where the first uncertainties are statistical and the second systematic. The results are consistent with a previous LHCb measurement using a prompt $\Lambda_{c}^{+} K^{-}$ sample. Evidence of a new $\Xi_{c}(2880)^{0}$ state is found with a local significance of $3.8\,\sigma$, whose mass and width are measured to be $2881.8 \pm 3.1 \pm 8.5\,\mathrm{MeV}$ and $12.4 \pm 5.3 \pm 5.8 \,\mathrm{MeV}$, respectively. In addition, evidence of a new decay mode $\Xi_{c}(2790)^{0} \to \Lambda_{c}^{+} K^{-}$ is found with a significance of $3.7\,\sigma$. The relative branching fraction of $B^{-} \to \Lambda_{c}^{+} \bar{\Lambda}_{c}^{-} K^{-}$ with respect to the $B^{-} \to D^{+} D^{-} K^{-}$ decay is measured to be $2.36 \pm 0.11 \pm 0.22 \pm 0.25$, where the first uncertainty is statistical, the second systematic and the third originates from the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb public pages

Multidifferential study of identified charged hadron distributions in ZZ-tagged jets in proton-proton collisions at s=\sqrt{s}=13 TeV

Jet fragmentation functions are measured for the first time in proton-proton collisions for charged pions, kaons, and protons within jets recoiling against a $Z$ boson. The charged-hadron distributions are studied longitudinally and transversely to the jet direction for jets with transverse momentum 20 $< p_{\textrm{T}} < 100$ GeV and in the pseudorapidity range $2.5 < \eta < 4$. The data sample was collected with the LHCb experiment at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 1.64 fb$^{-1}$. Triple differential distributions as a function of the hadron longitudinal momentum fraction, hadron transverse momentum, and jet transverse momentum are also measured for the first time. This helps constrain transverse-momentum-dependent fragmentation functions. Differences in the shapes and magnitudes of the measured distributions for the different hadron species provide insights into the hadronization process for jets predominantly initiated by light quarks.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-2022-013.html (LHCb public pages

Measurement of the ratios of branching fractions R(D∗)\mathcal{R}(D^{*}) and R(D0)\mathcal{R}(D^{0})

The ratios of branching fractions $\mathcal{R}(D^{*})\equiv\mathcal{B}(\bar{B}\to D^{*}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(\bar{B}\to D^{*}\mu^{-}\bar{\nu}_{\mu})$ and $\mathcal{R}(D^{0})\equiv\mathcal{B}(B^{-}\to D^{0}\tau^{-}\bar{\nu}_{\tau})/\mathcal{B}(B^{-}\to D^{0}\mu^{-}\bar{\nu}_{\mu})$ are measured, assuming isospin symmetry, using a sample of proton-proton collision data corresponding to 3.0 fb${ }^{-1}$ of integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The tau lepton is identified in the decay mode $\tau^{-}\to\mu^{-}\nu_{\tau}\bar{\nu}_{\mu}$. The measured values are $\mathcal{R}(D^{*})=0.281\pm0.018\pm0.024$ and $\mathcal{R}(D^{0})=0.441\pm0.060\pm0.066$, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is $\rho=-0.43$. Results are consistent with the current average of these quantities and are at a combined 1.9 standard deviations from the predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb public pages

Home-to-work commuting, urban form and potential energy savings: A local scale approach to regional statistics

The link between transport energy consumption and land use patterns has been the focus of a considerable amount of academic works over the past decades. While many empirical researches are backed up with solid statistical techniques, most of them do not fully consider the influence of scale underlying empirical quantitative investigations. Using fine-scale home-to-work commuting data for Wallonia (Belgium), this paper re-evaluates Breheny’s (1995) assertion that urban structure should hold the characteristics of major cities if substantial energy savings are to be achieved. A local scale approach highlights efficient settlements in terms of transport energy consumption not only within major towns, butalso within remote rural areas. Furthermore, results suggest that influencing the urban form following local energy efficient examples rather than regional ones could also yield significant gains, without an extreme policy stance of re-urbanisation in major cities.Impact de la Structuration du territoire sur les émissions de GE

What Invariant One-Particle Multiplicity Distributions And Two-Particle Correlations Are Telling Us About Relativistic Heavy-Ion Collisions

INTRODUCTION Many of you are vigorously searching for the quark-gluon plasma---a predicted new phase of nuclear matter where quarks roam almost freely throughout the medium instead of being confined to individual nucleons. 1,2 Such a plasma is believed to have existed in the first 10 ¯s of the universe during the big bang and could be produced in the laboratory during the little bang of a relativistic heavy-ion collision. When nuclei collide head-on at relativistic speeds, the nuclear matter is initially compressed and excited from normal nuclear density and zero temperature to some maximum values---during which pions, kaons, and other particles are produced---and then expands, with a decrease in density and temperature. The early stages of the process are often treated in terms of nuclear fluid dynamics, but at some late stage the expanding matter freezes out into a collection of noninteracting hadrons. To sample the density, temperature, co

QCD Thermodynamics with an almost realistic quark mass spectrum

Schmidt-Sonntag C. QCD Thermodynamics with an almost realistic quark mass spectrum. In: Barnes PD, Cooper MD, Eisenstein RA, van Hecke H, Stephenson GJ, eds. AIP Conference Proceedings. Vol 842. AIP; 2006: 101-103.We will report on the status of a new large scale calculation of thermodynamic quantities in QCD with light up and down quarks corresponding to an almost physical light quark mass value and a heavier strange quark mass. These calculations are currently being performed on the QCDOC Teraflops computers at BNL. We will present new lattice calculations of the transition temperature and various susceptibilities reflecting properties of the chiral transition. All these quantities are of immediate interest for heavy ion phenomenology

Continuous flow synthesis of nitrofuran pharmaceuticals using acetyl nitrate

Nitrofurfural is a key building block for the synthesis of antimicrobial nitrofurans as active pharmaceutical ingredients. Its synthesis involves the nitration of furfural, a substrate derived from biobased resources. However, furfural has a delicate heteroaromatic backbone. Typical nitrations involve harsh reaction conditions, which often compromise this structure, resulting in poor reproducibility and low yields. Although acetyl nitrate, a mild nitrating agent, is suitable for this task, major deterrents remain. First, its conventional preparation method involves conditions that are not compatible with furfural. Second, significant safety concerns are associated with the unstable and explosive nature of acetyl nitrate. These critical issues are addressed herein. A safe and robust continuous flow platform featuring in situ generation of acetyl nitrate for the nitration of furfural to nitrofurfural is reported. The high level of integration and automation enables remote process operation by a single operator. Key furfural-based pharmaceutical intermediates were synthesized with favorable metrics and high reproducibility. The efficiency of this flow platform is demonstrated using a selection of best-selling nitrofuran pharmaceuticals (nifuroxazide, nifurtimox, nitrofurantoin, and nitrofural), which were obtained with excellent isolated yields in under five minutes.Nitrofurfural is a key building block for the synthesis of antimicrobial nitrofurans as active pharmaceutical ingredients. Its synthesis involves the nitration of furfural, a substrate derived from biobased resources. However, furfural has a delicate heteroaromatic backbone. Typical nitrations involve harsh reaction conditions, which often compromise this structure, resulting in poor reproducibility and low yields. Although acetyl nitrate, a mild nitrating agent, is suitable for this task, major deterrents remain. First, its conventional preparation method involves conditions that are not compatible with furfural. Second, significant safety concerns are associated with the unstable and explosive nature of acetyl nitrate. These critical issues are addressed herein. A safe and robust continuous flow platform featuring in situ generation of acetyl nitrate for the nitration of furfural to nitrofurfural is reported. The high level of integration and automation enables remote process operation by a single operator. Key furfural-based pharmaceutical intermediates were synthesized with favorable metrics and high reproducibility. The efficiency of this flow platform is demonstrated using a selection of best-selling nitrofuran pharmaceuticals (nifuroxazide, nifurtimox, nitrofurantoin, and nitrofural), which were obtained with excellent isolated yields in under five minutes.A