Novel Measurement of the Neutron Magnetic Form Factor from A=3 Mirror Nuclei

The electromagnetic form factors of the proton and neutron encode information on the spatial structure of their charge and magnetization distributions. While measurements of the proton are relatively straightforward, the lack of a free neutron target makes measurements of the neutron's electromagnetic structure more challenging and more sensitive to experimental or model-dependent uncertainties. Various experiments have attempted to extract the neutron form factors from scattering from the neutron in deuterium, with different techniques providing different, and sometimes large, systematic uncertainties. We present results from a novel measurement of the neutron magnetic form factor using quasielastic scattering from the mirror nuclei ^{3}H and ^{3}He, where the nuclear effects are larger than for deuterium but expected to largely cancel in the cross-section ratios. We extracted values of the neutron magnetic form factor for low-to-modest momentum transfer, 0.6 Collapse

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IDDSI-compliant recipes containing oral contrast agents for radiological dysphagia diagnostics

Videofluoroscopic swallowing study (VFSS), alongside flexible endoscopic evaluation of swallowing, represents the gold standard for diagnosing swallowing disorders and to determine severity, pathophysiology, and effective interventions, including texture modification. The clinical swallowing examination and assessment supplements these instrumental methods and serves as the basis for the modules of swallowing diagnostics. The adaptation of food and drink consistencies in dysphagia management has become widespread. For valid results of a VFSS with respect to confirming swallowing safety and efficiency of different liquid and food consistencies and textures, the use of uniform recipes containing radio-opaque contrast media is important. Our goal was to identify recipes that would produce consistencies that conform to the liquid and food levels of 0-7, as defined by the International Dysphagia Diet Standardization Initiative (IDDSI), with barium- and iodine-based contrast media, xanthan gum-based thickeners, and other edible components, which also show sufficient contrast on VFSS. In this study, we determined the different recipes using IDDSI testing methods and explored their radiological characteristics using a Philips MultiDiagnost Eleva fluoroscopy system and two different fluid contrast agents: barium- (Micropaque®) and iodine-based (Telebrix®). All recipes showed sufficient contrast on fluoroscopy and could be visualized in the amounts used for swallowing examinations. They were practical and easy to implement in terms of production and availability of the components. The homogeneity of the recipes diminished with higher IDDSI levels, which represent transitional food, but appeared still sufficient for fluoroscopic examination. The opacity did not significantly differ between the barium- and iodine-based contrast media.

Amplitude Analysis of the B^{0}→K^{*0}μ^{+}μ^{-} Decay

An amplitude analysis of the B^{0}→K^{*0}μ^{+}μ^{-} decay is presented using a dataset corresponding to an integrated luminosity of 4.7  fb^{-1} of pp collision data collected with the LHCb experiment. For the first time, the coefficients associated to short-distance physics effects, sensitive to processes beyond the standard model, are extracted directly from the data through a q^{2}-unbinned amplitude analysis, where q^{2} is the μ^{+}μ^{-} invariant mass squared. Long-distance contributions, which originate from nonfactorizable QCD processes, are systematically investigated, and the most accurate assessment to date of their impact on the physical observables is obtained. The pattern of measured corrections to the short-distance couplings is found to be consistent with previous analyses of b- to s-quark transitions, with the largest discrepancy from the standard model predictions found to be at the level of 1.8 standard deviations. The global significance of the observed differences in the decay is 1.4 standard deviations.

Stereoselective Ring Expansion Metathesis Polymerization with Cationic Molybdenum Alkylidyne N-Heterocyclic Carbene Complexes

Molybdenum alkylidyne N-heterocyclic carbene (NHC) complexes of the type [Mo(C-p-C6H4Y)(OC(R)(CF3)2)2 (L)(NHC)][B(ArF)4] (Y = OMe, NO2; R = CH3, CF3; L = none, pivalonitrile, tetrahydrofuran; NHC = 1,3-dimesitylimidazol-2-ylidene (IMes), 1,3-dimesityl-3,4-dihydroimidazol-2-ylidene (IMesH2), 1,3-dimesityl-3,4-dichloroimidazol-2-ylidene (IMesCl2), 1,3-diisopropylimidazol-2-ylidene (IiPr); B(ArF)4- = tetrakis(3,5-bis(trifluoromethyl)phen-1-yl)borate) were used in the ring expansion metathesis polymerization (REMP) of cyclic olefins. With cis-cyclooctene (cCOE) cyclic, low molecular weight oligomers were obtained at low monomer concentrations and the cyclic nature of the polymer was confirmed by MALDI-TOF measurements. High-molecular weight cyclic poly(cCOE) became available at high monomer concentrations. Also, post-REMP allowed for converting low-molecular-weight cyclic poly(cCOE) into high-molecular-weight cyclic poly(cCOE). Tailored catalysts together with suitable additives offered access to the stereoselective REMP of functional norbornenes providing functional cis-isotactic (cis-it), cis-syndiotactic (cis-st) and trans-it poly(norbornene)s with up to 99% stereoselectivity. Mechanistic details supported by density functional theory (DFT) calculations are outlined.

Fraction of χ_{c} Decays in Prompt J/ψ Production Measured in pPb Collisions at sqrt[s_{NN}]=8.16 TeV

The fraction of χ_{c1} and χ_{c2} decays in the prompt J/ψ yield, F_{χ_{c}→J/ψ}=σ_{χ_{c}→J/ψ}/σ_{J/ψ}, is measured by the LHCb detector in pPb collisions at sqrt[s_{NN}]=8.16  TeV. The study covers the forward (1.5 Collapse

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Observation of Cabibbo-Suppressed Two-Body Hadronic Decays and Precision Mass Measurement of the Ω_{c}^{0} Baryon

The first observation of the singly Cabibbo-suppressed Ω_{c}^{0}→Ω^{-}K^{+} and Ω_{c}^{0}→Ξ^{-}π^{+} decays is reported, using proton-proton collision data at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.4  fb^{-1}, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be B(Ω_{c}^{0}→Ω^{-}K^{+})/B(Ω_{c}^{0}→Ω^{-}π^{+})=[6.08±0.51(stat)±0.40(syst)]%,B(Ω_{c}^{0}→Ξ^{-}π^{+})/B(Ω_{c}^{0}→Ω^{-}π^{+})=[15.81±0.87(stat)±0.44(syst)±0.16(ext)]%. In addition, using the Ω_{c}^{0}→Ω^{-}π^{+} decay channel, the Ω_{c}^{0} baryon mass is measured to be M(Ω_{c}^{0})=2695.28±0.07(stat)±0.27(syst)±0.30(ext)  MeV, improving the precision of the previous world average by a factor of 4.

Enhanced Production of Λ_{b}^{0} Baryons in High-Multiplicity pp Collisions at sqrt[s]=13 TeV

The production rate of Λ_{b}^{0} baryons relative to B^{0} mesons in pp collisions at a center-of-mass energy sqrt[s]=13  TeV is measured by the LHCb experiment. The ratio of Λ_{b}^{0} to B^{0} production cross sections shows a significant dependence on both the transverse momentum and the measured charged-particle multiplicity. At low multiplicity, the ratio measured at LHCb is consistent with the value measured in e^{+}e^{-} collisions, and increases by a factor of ∼2 with increasing multiplicity. At relatively low transverse momentum, the ratio of Λ_{b}^{0} to B^{0} cross sections is higher than what is measured in e^{+}e^{-} collisions, but converges with the e^{+}e^{-} ratio as the momentum increases. These results imply that the evolution of heavy b quarks into final-state hadrons is influenced by the density of the hadronic environment produced in the collision. Comparisons with several models and implications for the mechanisms enforcing quark confinement are discussed.

Life cycle assessment for early-stage process optimization of microbial biosurfactant production using kinetic models-a case study on mannosylerythritol lipids (MEL)

Introduction: This study assesses the environmental impacts of mannosylerythritol lipids (MELs) production for process optimization using life cycle assessment (LCA). MELs are glycolipid-type microbial biosurfactants with many possible applications based on their surface-active properties. They are generally produced by fungi from the family of Ustilaginaceae via fermentation in aerated bioreactors. The aim of our work is to accompany the development of biotechnological products at an early stage to enable environmentally sustainable process optimization. Methods: This is done by identifying hotspots and potentials for improvement based on a reliable quantification of the environmental impacts. The production processes of MELs are evaluated in a cradle-to-gate approach using the Environmental Footprint (EF) 3.1 impact assessment method. The LCA model is based on upscaled experimental data for the fermentation and purification, assuming the production at a 10 m³ scale. In the case analyzed, MELs are produced from rapeseed oil and glucose, and purified by separation, solvent extraction, and chromatography. Results: The results of the LCA show that the provision of substrates is a major source of environmental impacts and accounts for 20% of the impacts on Climate Change and more than 70% in the categories Acidification and Eutrophication. Moreover, 33% of the impacts on Climate Change is caused by the energy requirements for aeration of the bioreactor, while purification accounts for 42% of the impacts respectively. For the purification, solvents are identified as the main contributors in most impact categories. Discussion: The results illustrate the potentials for process optimization to reduce the environmental impacts of substrate requirements, enhanced bioreactor aeration, and efficient solvent use in downstream processing. By a scenario analysis, considering both experimental adaptations and prospective variations of the process, the laboratory development can be supported with further findings and hence efficiently optimized towards environmental sustainability. Moreover, the presentation of kinetic LCA results over the fermentation duration shows a novel way of calculating and visualizing results that corresponds to the way of thinking of process engineers using established environmental indicators and a detailed system analysis. Altogether, this LCA study supports and demonstrates the potential for further improvements towards more environmentally friendly produced surfactants.

Improved Measurement of CP Violation Parameters in B_{s}^{0}→J/ψK^{+}K^{-} Decays in the Vicinity of the ϕ(1020) Resonance

The decay-time-dependent CP asymmetry in B_{s}^{0}→J/ψ(→μ^{+}μ^{-})K^{+}K^{-} decays is measured using proton-proton collision data, corresponding to an integrated luminosity of 6  fb^{-1}, collected with the LHCb detector at a center-of-mass energy of 13 TeV. Using a sample of approximately 349 000 B_{s}^{0} signal decays with an invariant K^{+}K^{-} mass in the vicinity of the ϕ(1020) resonance, the CP-violating phase ϕ_{s} is measured, along with the difference in decay widths of the light and heavy mass eigenstates of the B_{s}^{0}-B[over ¯]_{s}^{0} system, ΔΓ_{s}, and the difference of the average B_{s}^{0} and B^{0} meson decay widths, Γ_{s}-Γ_{d}. The values obtained are ϕ_{s}=-0.039±0.022±0.006  rad, ΔΓ_{s}=0.0845±0.0044±0.0024  ps^{-1}, and Γ_{s}-Γ_{d}=-0.0056_{-0.0015}^{+0.0013}±0.0014  ps^{-1}, where the first uncertainty is statistical and the second systematic. These are the most precise single measurements to date and are consistent with expectations based on the Standard Model and with the previous LHCb analyses of this decay. These results are combined with previous independent LHCb measurements. The phase ϕ_{s} is also measured independently for each polarization state of the K^{+}K^{-} system and shows no evidence for polarization dependence.

Measurement of CP Violation in B^{0}→ψ(→ℓ^{+}ℓ^{-})K_{S}^{0}(→π^{+}π^{-}) Decays

A measurement of time-dependent CP violation in the decays of B^{0} and B[over ¯]^{0} mesons to the final states J/ψ(→μ^{+}μ^{-})K_{S}^{0}, ψ(2S)(→μ^{+}μ^{-})K_{S}^{0} and J/ψ(→e^{+}e^{-})K_{S}^{0} with K_{S}^{0}→π^{+}π^{-} is presented. The data correspond to an integrated luminosity of 6  fb^{-1} collected at a center-of-mass energy of sqrt[s]=13  TeV with the LHCb detector. The CP-violation parameters are measured to be S_{ψK_{S}^{0}}=0.717±0.013(stat)±0.008(syst) and C_{ψK_{S}^{0}}=0.008±0.012(stat)±0.003(syst). This measurement of S_{ψK_{S}^{0}} represents the most precise single measurement of the CKM angle β to date and is more precise than the current world average. In addition, measurements of the CP-violation parameters of the individual channels are reported and a combination with the LHCb Run 1 measurements is performed.

Multi-omics for studying and understanding polar life

Polar ecosystems are experiencing amongst the most rapid rates of regional warming on Earth. Here, we discuss 'omics' approaches to investigate polar biodiversity, including the current state of the art, future perspectives and recommendations. We propose a community road map to generate and more fully exploit multi-omics data from polar organisms. These data are needed for the comprehensive evaluation of polar biodiversity and to reveal how life evolved and adapted to permanently cold environments with extreme seasonality. We argue that concerted action is required to mitigate the impact of warming on polar ecosystems via conservation efforts, to sustainably manage these unique habitats and their ecosystem services, and for the sustainable bioprospecting of novel genes and compounds for societal gain.

An explorative single-arm clinical study to assess craving in patients with alcohol use disorder using Virtual Reality exposure (CRAVE)-study protocol

BACKGROUND

Alcohol use disorder (AUD) belongs to the most burdensome clinical disorders worldwide. Current treatment approaches yield unsatisfactory long-term effects with relapse rates up to 85%. Craving for alcohol is a major predictor for relapse and can be intentionally induced via cue exposure in real life as well as in Virtual Reality (VR). The induction and habituation of craving via conditioned cues as well as extinction learning is used in Cue Exposure Therapy (CET), a long-known but rarely used strategy in Cognitive Behavioral Therapy (CBT) of AUD. VR scenarios with alcohol related cues offer several advantages over real life scenarios and are within the focus of current efforts to develop new treatment options. As a first step, we aim to analyze if the VR scenarios elicit a transient change in craving levels and if this is measurable via subjective and psychophysiological parameters.

METHODS

A single-arm clinical study will be conducted including n = 60 patients with AUD. Data on severity of AUD and craving, comorbidities, demographics, side effects and the feeling of presence in VR will be assessed. Patients will use a head-mounted display (HMD) to immerse themselves into three different scenarios (neutral vs. two target situations: a living room and a bar) while heart rate, heart rate variability, pupillometry and electrodermal activity will be measured continuously. Subjective craving levels will be assessed before, during and after the VR session.

DISCUSSION

Results of this study will yield insight into the induction of alcohol craving in VR cue exposure paradigms and its measurement via subjective and psychophysiological parameters. This might be an important step in the development of innovative therapeutic approaches in the treatment of patients with AUD.

TRIAL REGISTRATION

This study was approved by the Charité-Universitätsmedizin Berlin Institutional Review Board (EA1/190/22, 23.05.2023). It was registered on ClinicalTrials.gov (NCT05861843).

Observation of New Baryons in the Ξ_{b}^{-}π^{+}π^{-} and Ξ_{b}^{0}π^{+}π^{-} Systems

The first observation and study of two new baryonic structures in the final state Ξ_{b}^{0}π^{+}π^{-} and the confirmation of the Ξ_{b}(6100)^{-} state in the Ξ_{b}^{-}π^{+}π^{-} decay mode are reported using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1}. In addition, the properties of the known Ξ_{b}^{*0}, Ξ_{b}^{'-} and Ξ_{b}^{*-} resonances are measured with improved precision. The new decay mode of the Ξ_{b}^{0} baryon to the Ξ_{c}^{+} π^{-} π^{+} π^{-} final state is observed and exploited for the first time in these measurements.

Precision Measurement of CP Violation in the Penguin-Mediated Decay B_{s}^{0}→ϕϕ

A flavor-tagged time-dependent angular analysis of the decay B_{s}^{0}→ϕϕ is performed using pp collision data collected by the LHCb experiment at the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6  fb^{-1}. The CP-violating phase and direct CP-violation parameter are measured to be ϕ_{s}^{ss[over ¯]s}=-0.042±0.075±0.009  rad and |λ|=1.004±0.030±0.009, respectively, assuming the same values for all polarization states of the ϕϕ system. In these results, the first uncertainties are statistical and the second systematic. These parameters are also determined separately for each polarization state, showing no evidence for polarization dependence. The results are combined with previous LHCb measurements using pp collisions at center-of-mass energies of 7 and 8 TeV, yielding ϕ_{s}^{ss[over ¯]s}=-0.074±0.069  rad and |λ|=1.009±0.030. This is the most precise study of time-dependent CP violation in a penguin-dominated B meson decay. The results are consistent with CP symmetry and with the standard model predictions.

Deciphering sources of PET signals in the tumor microenvironment of glioblastoma at cellular resolution

Various cellular sources hamper interpretation of positron emission tomography (PET) biomarkers in the tumor microenvironment (TME). We developed an approach of immunomagnetic cell sorting after in vivo radiotracer injection (scRadiotracing) with three-dimensional (3D) histology to dissect the cellular allocation of PET signals in the TME. In mice with implanted glioblastoma, translocator protein (TSPO) radiotracer uptake per tumor cell was higher compared to tumor-associated microglia/macrophages (TAMs), validated by protein levels. Translation of in vitro scRadiotracing to patients with glioma immediately after tumor resection confirmed higher single-cell TSPO tracer uptake of tumor cells compared to immune cells. Across species, cellular radiotracer uptake explained the heterogeneity of individual TSPO-PET signals. In consideration of cellular tracer uptake and cell type abundance, tumor cells were the main contributor to TSPO enrichment in glioblastoma; however, proteomics identified potential PET targets highly specific for TAMs. Combining cellular tracer uptake measures with 3D histology facilitates precise allocation of PET signals and serves to validate emerging novel TAM-specific radioligands.

Measurement of the Λ_{b}^{0}→Λ(1520)μ^{+}μ^{-} Differential Branching Fraction

The branching fraction of the rare decay Λ_{b}^{0}→Λ(1520)μ^{+}μ^{-} is measured for the first time, in the squared dimuon mass intervals q^{2}, excluding the J/ψ and ψ(2S) regions. The data sample analyzed was collected by the LHCb experiment at center-of-mass energies of 7, 8, and 13 TeV, corresponding to a total integrated luminosity of 9  fb^{-1}. The result in the highest q^{2} interval, q^{2}>15.0  GeV^{2}/c^{4}, where theoretical predictions have the smallest model dependence, agrees with the predictions.

Observation of New Ω_{c}^{0} States Decaying to the Ξ_{c}^{+}K^{-} Final State

Two new excited states, Ω_{c}(3185)^{0} and Ω_{c}(3327)^{0}, are observed in the Ξ_{c}^{+}K^{-} invariant-mass spectrum using proton-proton collision data collected by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1}. Five previously observed excited Ω_{c}^{0} states are confirmed, namely Ω_{c}(3000)^{0}, Ω_{c}(3050)^{0}, Ω_{c}(3065)^{0}, Ω_{c}(3090)^{0}, and Ω_{c}(3119)^{0}. The masses and widths of these seven states are measured with the highest precision to date.

Evidence of a J/ψK_{S}^{0} Structure in B^{0}→J/ψϕK_{S}^{0} Decays

An amplitude analysis of B^{0}→J/ψϕK_{S}^{0} decays is performed using proton-proton collision data, corresponding to an integrated luminosity of 9  fb^{-1}, collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. Evidence with a significance of 4.0 standard deviations of a structure in the J/ψK_{S}^{0} system, named T_{ψs1}^{θ}(4000)^{0}, is seen, with its mass and width measured to be 3991_{-10}^{+12} _{-17}^{+9}  MeV/c^{2} and 105_{-25}^{+29} _{-23}^{+17}  MeV, respectively, where the first uncertainty is statistical and the second systematic. The T_{ψs1}^{θ}(4000)^{0} state is likely to be the isospin partner of the T_{ψs1}^{θ}(4000)^{+} state, previously observed in the J/ψK^{+} system of the B^{+}→J/ψϕK^{+} decay. When isospin symmetry for the charged and neutral T_{ψs1}^{θ}(4000) states is assumed, the signal significance increases to 5.4 standard deviations.

Measurement of the Ratios of Branching Fractions R(D^{*}) and R(D^{0})

The ratios of branching fractions R(D^{*})≡B(B[over ¯]→D^{*}τ^{-}ν[over ¯]_{τ})/B(B[over ¯]→D^{*}μ^{-}ν[over ¯]_{μ}) and R(D^{0})≡B(B^{-}→D^{0}τ^{-}ν[over ¯]_{τ})/B(B^{-}→D^{0}μ^{-}ν[over ¯]_{μ}) 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 τ^{-}→μ^{-}ν_{τ}ν[over ¯]_{μ}. The measured values are R(D^{*})=0.281±0.018±0.024 and R(D^{0})=0.441±0.060±0.066, where the first uncertainty is statistical and the second is systematic. The correlation between these measurements is ρ=-0.43. The 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.

Measurement of the Prompt D^{0} Nuclear Modification Factor in p-Pb Collisions at sqrt[s_{NN}]=8.16 TeV

The production of prompt D^{0} mesons in proton-lead collisions in both the forward and backward rapidity regions at a center-of-mass energy per nucleon pair of sqrt[s_{NN}]=8.16  TeV is measured by the LHCb experiment. The nuclear modification factor of prompt D^{0} mesons is determined as a function of the transverse momentum p_{T}, and the rapidity in the nucleon-nucleon center-of-mass frame y^{*}. In the forward rapidity region, significantly suppressed production with respect to pp collisions is measured, which provides significant constraints on models of nuclear parton distributions and hadron production down to the very low Bjorken-x region of ∼10^{-5}. In the backward rapidity region, a suppression with a significance of 2.0-3.8 standard deviations compared to parton distribution functions in a nuclear environment expectations is found in the kinematic region of p_{T}>6  GeV/c and -3.25 Collapse

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Measurement of the Time-Integrated CP Asymmetry in D^{0}→K^{-}K^{+} Decays

The time-integrated CP asymmetry in the Cabibbo-suppressed decay D^{0}→K^{-}K^{+} is measured using proton-proton collision data, corresponding to an integrated luminosity of 5.7  fb^{-1} collected at a center-of-mass energy of 13 TeV with the LHCb detector. The D^{0} mesons are required to originate from promptly produced D^{*+}→D^{0}π^{+} decays, and the charge of the companion pion is used to determine the flavor of the charm meson at production. The time-integrated CP asymmetry is measured to be A_{CP}(K^{-}K^{+})=[6.8±5.4±1.6]×10^{-4} where the first uncertainty is statistical and the second systematic. The direct CP asymmetries in D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays, a_{K^{-}K^{+}}^{d} and a_{π^{-}π^{+}}^{d}, are derived by combining A_{CP}(K^{-}K^{+}) with the time-integrated CP asymmetry difference, ΔA_{CP}=A_{CP}(K^{-}K^{+})-A_{CP}(π^{-}π^{+}), and other inputs, giving a_{K^{-}K^{+}}^{d}=(7.7±5.7)×10^{-4},a_{π^{-}π^{+}}^{d}=(23.2±6.1)×10^{-4},with a correlation coefficient corresponding to ρ=0.88. The compatibility of these results with CP symmetry is 1.4 and 3.8 standard deviations for D^{0}→K^{-}K^{+} and D^{0}→π^{-}π^{+} decays, respectively. This is the first evidence for direct CP violation in a specific D^{0} decay.

Measurement of the Branching Fractions B(B^{0}→pp[over ¯]pp[over ¯]) and B(B_{s}^{0}→pp[over ¯]pp[over ¯])

Searches for the rare hadronic decays B^{0}→pp[over ¯]pp[over ¯] and B_{s}^{0}→pp[over ¯]pp[over ¯] are performed using proton-proton collision data recorded by the LHCb experiment and corresponding to an integrated luminosity of 9  fb^{-1}. Significances of 9.3σ and 4.0σ, including statistical and systematic uncertainties, are obtained for the B^{0}→pp[over ¯]pp[over ¯] and B_{s}^{0}→pp[over ¯]pp[over ¯] signals, respectively. The branching fractions are measured relative to the topologically similar normalization decays B^{0}→J/ψ(→pp[over ¯])K^{*0}(→K^{+}π^{-}) and B_{s}^{0}→J/ψ(→pp[over ¯])⁢ϕ(→K^{+}K^{-}). The branching fractions are measured to be B(B^{0}→pp[over ¯]pp[over ¯])=(2.2±0.4±0.1±0.1)×10^{-8} and B(B_{s}^{0}→pp[over ¯]pp[over ¯])=(2.3±1.0±0.2±0.1)×10^{-8}. In these measurements, the first uncertainty is statistical, the second is systematic, and the third one is due to the external branching fraction of the normalization channel.

Observation of a Resonant Structure near the D_{s}^{+}D_{s}^{-} Threshold in the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} Decay

An amplitude analysis of the B^{+}→D_{s}^{+}D_{s}^{-}K^{+} decay is carried out to study for the first time its intermediate resonant contributions, using proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. A near-threshold peaking structure, referred to as X(3960), is observed in the D_{s}^{+}D_{s}^{-} invariant-mass spectrum with significance greater than 12 standard deviations. The mass, width, and the quantum numbers of the structure are measured to be 3956±5±10  MeV, 43±13±8  MeV, and J^{PC}=0^{++}, respectively, where the first uncertainties are statistical and the second systematic. The properties of the new structure are consistent with recent theoretical predictions for a state composed of cc[over ¯]ss[over ¯] quarks. Evidence for an additional structure is found around 4140 MeV in the D_{s}^{+}D_{s}^{-} invariant mass, which might be caused either by a new resonance with the 0^{++} assignment or by a J/ψϕ↔D_{s}^{+}D_{s}^{-} coupled-channel effect.

Evidence for Modification of b Quark Hadronization in High-Multiplicity pp Collisions at sqrt[s]=13 TeV

The production rate of B_{s}^{0} mesons relative to B^{0} mesons is measured by the LHCb experiment in pp collisions at a center-of-mass energy sqrt[s]=13  TeV over the forward rapidity interval 2 Collapse

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Test of Lepton Universality in b→sℓ^{+}ℓ^{-} Decays

The first simultaneous test of muon-electron universality using B^{+}→K^{+}ℓ^{+}ℓ^{-} and B^{0}→K^{*0}ℓ^{+}ℓ^{-} decays is performed, in two ranges of the dilepton invariant-mass squared, q^{2}. The analysis uses beauty mesons produced in proton-proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9  fb^{-1}. Each of the four lepton universality measurements reported is either the first in the given q^{2} interval or supersedes previous LHCb measurements. The results are compatible with the predictions of the Standard Model.

First Observation of a Doubly Charged Tetraquark and Its Neutral Partner

A combined amplitude analysis is performed for the decays B^{0}→D[over ¯]^{0}D_{s}^{+}π^{-} and B^{+}→D^{-}D_{s}^{+}π^{+}, which are related by isospin symmetry. The analysis is based on data collected by the LHCb detector in proton-proton collisions at center-of-mass energies of 7, 8, and 13 TeV. The full data sample corresponds to an integrated luminosity of 9  fb^{-1}. Two new resonant states with masses of 2.908±0.011±0.020  GeV and widths of 0.136±0.023±0.013  GeV are observed, which decay to D_{s}^{+}π^{+} and D_{s}^{+}π^{-} respectively. The former state indicates the first observation of a doubly charged open-charm tetraquark state with minimal quark content [cs[over ¯]ud[over ¯]], and the latter state is a neutral tetraquark composed of [cs[over ¯]u[over ¯]d] quarks. Both states are found to have spin-parity of 0^{+}, and their resonant parameters are consistent with each other, which suggests that they belong to an isospin triplet.

Search for Rare Decays of D^{0} Mesons into Two Muons

A search for the very rare D^{0}→μ^{+}μ^{-} decay is performed using data collected by the LHCb experiment in proton-proton collisions at sqrt[s]=7, 8, and 13 TeV, corresponding to an integrated luminosity of 9  fb^{-1}. The search is optimized for D^{0} mesons from D^{*+}→D^{0}π^{+} decays but is also sensitive to D^{0} mesons from other sources. No evidence for an excess of events over the expected background is observed. An upper limit on the branching fraction of this decay is set at B(D^{0}→μ^{+}μ^{-})<3.1×10^{-9} at a 90% C.L. This represents the world's most stringent limit, constraining models of physics beyond the standard model.

Nuclear Modification Factor of Neutral Pions in the Forward and Backward Regions in p-Pb Collisions

The nuclear modification factor of neutral pions is measured in proton-lead collisions collected at a center-of-mass energy per nucleon of 8.16 TeV with the LHCb detector. The π^{0} production cross section is measured differentially in transverse momentum (p_{T}) for 1.5 Collapse

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Observation of a J/ψΛ Resonance Consistent with a Strange Pentaquark Candidate in B^{-}→J/ψΛp[over ¯] Decays

An amplitude analysis of B^{-}→J/ψΛp[over ¯] decays is performed using 4400 signal candidates selected on a data sample of pp collisions recorded at center-of-mass energies of 7, 8, and 13 TeV with the LHCb detector, corresponding to an integrated luminosity of 9  fb^{-1}. A narrow resonance in the J/ψΛ system, consistent with a pentaquark candidate with strangeness, is observed with high significance. The mass and the width of this new state are measured to be 4338.2±0.7±0.4  MeV and 7.0±1.2±1.3  MeV, where the first uncertainty is statistical and the second systematic. The spin is determined to be 1/2 and negative parity is preferred. Because of the small Q-value of the reaction, the most precise single measurement of the B^{-} mass to date, 5279.44±0.05±0.07  MeV, is obtained.

Prognostic and predictive impact of metastatic organ involvement on maintenance therapy in advanced metastatic CRC: Analysis of patients treated within the PanaMa trial (AIO KRK 0212)

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Background: Despite molecular selection, patients with RAS wildtype mCRC represent a heterogeneous population, including different metastatic patterns and number of organs involved. We investigated metastatic patterns for their prognostic and predictive impact on maintenance therapy with (FU/FA plus Pmab or FU/FA alone) in patients treated within the PanaMa trial. Methods: The study population was stratified according to number of organs involved and also to different patterns including liver metastases alone or in combination with additional organs. Kaplan-Meier method and Cox regressions were used to correlate efficacy endpoints (i.e. progression-free survival (PFS) and overall survival (OS) of maintenance therapy) in the aforementioned populations. Results: Of 248 patients (pts) receiving maintenance therapy, 133 pts had a one-metastatic site disease (53.6%). Of those, 102 pts had liver-only metastases. Furthermore, liver metastases plus one additional involved organ was observed in 61/248 patients (24.6%), and liver metastases plus two or more organs in 40/248 patients (16.1%). In general, one organ disease was associated with favourable PFS of maintenance therapy compared to patients with ≥2 organs involved (HR 0.68, 95% CI 0.52–0.88; P = 0.004). A predictive impact of disease spread in terms of pmab-containing maintenance therapy was present for the PFS of maintenance therapy in patients with ≥ 2 organ disease (HR 0.58, 95% CI 0.39–0.86; P = 0.006) unlike in patients with only one-organ disease (HR 0.83, 95% CI, 0.57-1.21; P = 0.332) and also specifically in patients with a 2-organ disease including the liver (HR 0.57, 95% CI 0.33–0.99; P = 0.046). Conclusions: Consistent with previous reports, organ spread has prognostic impact in mCRC. The efficacy of more intensive maintenance therapy (including pmab and 5-FU/FA) is predominantly seen in patients with more than one organ involved in the metastatic spread, while less striking effects were seen in patients with only one organ disease. These data may support clinical decisions when EGFR-based maintenance therapy is considered. Clinical trial information: NCT01991873 .

Spinal Tuberculosis within the Vertebral Arch Mimicking a Malignant Tumor: Case Report

BACKGROUND

 Spinal tuberculosis is a manifestation of extrapulmonary tuberculosis. The incidence of tuberculosis is low in high-income countries; however, globally, it still remains one of the most frequent fatal infectious diseases. Because of its rarity in developed countries, spinal tuberculosis can be mistaken for malignant tumors of the spine, especially in case of an atypical radiologic manifestation and without pulmonary affection.

METHODS

 We present the case of a 39-year-old man from South India with quickly progressing gait disturbance and hypesthesia below the Th10 level. Magnetic resonance imaging revealed an osteolytic lesion of the vertebral arch Th2 with central necrosis and compression of the spinal cord altogether highly suspicious for spinal metastasis.

RESULTS

 After surgical removal of the mass by laminectomy, the patient regained normal neurologic function. Histology revealed a severe granulomatous inflammation and DNAhybridization of polymerase chain reaction (PCR) products detected Mycobacterium tuberculosis-specific DNA in the sample. Biopsy of an enlarged hilar lymphnode allowed us to obtain material to successfully perform a drug resistance test to start specific antimicrobial therapy.

CONCLUSION

 Spinal tuberculosis, even with atypical radiologic appearance, has to be considered a differential diagnosis in patients with provenance from endemic countries. A multidisciplinary diagnostic approach helps perform antimicrobial susceptibility testing to avoid delaying the start of antibiotic therapy.

[The application of virtual reality in the treatment of mental disorders]

BACKGROUND

Virtual reality (VR) enables immersion in an interactive digital world with realistic experiences, that can be applied for controlled and personalized interventions. This review summarizes the current research on VR in the treatment of mental disorders.

METHODS

Selective literature search in PubMed and Google Scholar.

RESULTS

An increasing number of publications report the therapeutic application of VR for the treatment of mental disorders. Most VR applications are based on established therapy approaches, such as exposure therapy. According to meta-analytic data, virtual exposure therapy (VRET) for specific phobia and agoraphobia with panic disorder is as effective as traditional in vivo exposure therapy. VRET for the treatment of social phobia is significantly more effective than waitlist and placebo control groups with, however, currently inconsistent metanalytic results when compared to in vivo exposure therapy. VRET for the treatment of posttraumatic stress disorder (PTSD) is similar in effectiveness compared to active psychotherapy. For psychosis, positive results have been reported for the VR-based treatment of auditory verbal hallucinations. For patients with a substance use disorder, VR can induce craving, with still unverified diagnostic and therapeutic relevance.

CONCLUSIONS

VRET can broaden the psychotherapy options for anxiety disorders. Encouraging results of VR-based treatments for psychosis and PTSD indicate the need for further research concerning its effectiveness and safety. In the field of substance use disorders, evaluation of clinical-orientated VR applications is needed.

BAF Complex Maintains Glioma Stem Cells in Pediatric H3K27M Glioma

Diffuse midline gliomas are uniformly fatal pediatric central nervous system cancers that are refractory to standard-of-care therapeutic modalities. The primary genetic drivers are a set of recurrent amino acid substitutions in genes encoding histone H3 (H3K27M), which are currently undruggable. These H3K27M oncohistones perturb normal chromatin architecture, resulting in an aberrant epigenetic landscape. To interrogate for epigenetic dependencies, we performed a CRISPR screen and show that patient-derived H3K27M-glioma neurospheres are dependent on core components of the mammalian BAF (SWI/SNF) chromatin remodeling complex. The BAF complex maintains glioma stem cells in a cycling, oligodendrocyte precursor cell-like state, in which genetic perturbation of the BAF catalytic subunit SMARCA4 (BRG1), as well as pharmacologic suppression, opposes proliferation, promotes progression of differentiation along the astrocytic lineage, and improves overall survival of patient-derived xenograft models. In summary, we demonstrate that therapeutic inhibition of the BAF complex has translational potential for children with H3K27M gliomas.

SIGNIFICANCE

Epigenetic dysregulation is at the core of H3K27M-glioma tumorigenesis. Here, we identify the BRG1-BAF complex as a critical regulator of enhancer and transcription factor landscapes, which maintain H3K27M glioma in their progenitor state, precluding glial differentiation, and establish pharmacologic targeting of the BAF complex as a novel treatment strategy for pediatric H3K27M glioma. See related commentary by Beytagh and Weiss, p. 2730. See related article by Mo et al., p. 2906.

The landscape of tumor cell states and spatial organization in H3-K27M mutant diffuse midline glioma across age and location

Histone 3 lysine27-to-methionine (H3-K27M) mutations most frequently occur in diffuse midline gliomas (DMGs) of the childhood pons but are also increasingly recognized in adults. Their potential heterogeneity at different ages and midline locations is vastly understudied. Here, through dissecting the single-cell transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs, we delineate how age and anatomical location shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation. We show that stem-like oligodendroglial precursor-like cells, present across all clinico-anatomical groups, display varying levels of maturation dependent on location. We reveal a previously underappreciated relationship between mesenchymal cancer cell states and age, linked to age-dependent differences in the immune microenvironment. Further, we resolve the spatial organization of H3-K27M DMG cell populations and identify a mitotic oligodendroglial-lineage niche. Collectively, our study provides a powerful framework for rational modeling and therapeutic interventions.

EPCO-21. THE SPATIAL ORGANIZATION OF H3-K27M MUTANT DIFFUSE MIDLINE GLIOMA

Histone 3 lysine27-to-methionine mutant diffuse midline gliomas (H3-K27M DMGs) are among the most lethal brain tumors. Their putative cellular hierarchy has been shown to be driven by self-renewing stem-like cells arrested in an oligodendrocyte precursor-like (OPC-like) state, of which few cells are able to differentiate towards more mature astrocyte (AC)-like and oligodendrocyte (OC)-like cells. However, the spatial organization underlying this tumor cell architecture and its microenvironmental interactions in intact H3-K27M DMG tissues remain unknown. Here, we profiled the single cell transcriptomes of 45 patient H3-K27M DMGs and derived cell population-specific marker gene combinations to characterize the single cell spatial organization of 16 tumors using targeted in situ sequencing. We thereby resolved different malignant and non-malignant cell populations including cycling, OPC-like, AC-like, OC-like, mesenchymal tumor cells, and non-malignant oligodendrocytes, astrocytes, neurons, myeloid cells, T cells, and vascular cells directly in situ. Global neighborhood analyses indicate a higher tendency of cycling OPC-like cells, vascular cells, and neurons to localize within a more restricted homogeneous compartment, whereas AC-like cells, non-malignant astrocytes and myeloid cells tend to intermingle with different cell populations in a more diffuse manner. Among malignant cells, we observed cycling OPC-like and OC-like cells to co-localize within a niche-like structure that is surrounded by more differentiated AC-like cells. We further validated this stem-like niche at the protein level using multiplexed immunofluorescence via the CODEX system. Finally, we characterized relationships between malignant and non-malignant cells, consistently identifying preferred neighborhoods of mesenchymal tumor cells with vascular and myeloid cells. Together, this study resolves the spatial architecture of H3-K27M DMG malignant and non-malignant cells at single cell resolution and identifies a local niche of the oligodendroglial lineage containing the OPC-like cancer stem-like cells, thus providing novel insights into the cancer stem-like compartment in H3-K27M DMGs and suggesting potential avenues for its perturbation.

JS04.6.A The landscape of tumor cell states and spatial organization in H3-K27M mutant diffuse midline glioma across age and location

Background

Histone 3 lysine27-to-methionine mutations (H3-K27M) frequently occur in childhood diffuse midline gliomas (DMGs) of the pons, thalamus and spinal cord, presumed to be driven by the specific spatiotemporal context of these midline locations during postnatal development. While most common in the pons and at mid-childhood ages, the same oncohistone mutation is recurrently detected in adult DMGs and throughout different midline regions. The potential heterogeneity of tumors at different ages and in different anatomical locations of the midline are vastly understudied.

Material and Methods

Through dissecting the transcriptomic, epigenomic and spatial architectures of a comprehensive cohort of patient H3-K27M DMGs - spanning the age range from 2-68 years and locations from spinal cord to thalamus - at single cell resolution, we delineate how age- and location-dependent contexts shape glioma cell-intrinsic and -extrinsic features in light of the shared driver mutation.

Results

We identify that oligodendrocyte precursor (OPC)-like cells constitute the stem-like compartment in H3-K27M DMGs across all clinico-anatomical groups, however, depending on location, display varying levels of maturity resembling less differentiated pre-OPCs or more mature OPCs further differentiated along the oligodendroglial lineage. We further demonstrate increased mesenchymal cell states in adult tumors, which we link to age-related differences in glioma-associated immune cell compartments. We for the first time resolve the spatial organization of H3-K27M DMG cell types in intact patient tissues, identifying a local niche of the oligodendroglial lineage.

Conclusion

Our study provides a powerful resource for rational modeling and therapeutic frameworks taking into account determinants of age and location in this lethal glioma group.

First Measurement of the Z→μ^{+}μ^{-} Angular Coefficients in the Forward Region of pp Collisions at sqrt[s]=13 TeV

The first study of the angular distribution of μ^{+}μ^{-} pairs produced in the forward rapidity region via the Drell-Yan reaction pp→γ^{*}/Z+X→ℓ^{+}ℓ^{-}+X is presented, using data collected with the LHCb detector at a center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 5.1  fb^{-1}. The coefficients of the five leading terms in the angular distribution are determined as a function of the dimuon transverse momentum and rapidity. The results are compared to various theoretical predictions of the Z-boson production mechanism and can also be used to probe transverse-momentum-dependent parton distributions within the proton.

Study of the doubly charmed tetraquark [Formula: see text]

Quantum chromodynamics, the theory of the strong force, describes interactions of coloured quarks and gluons and the formation of hadronic matter. Conventional hadronic matter consists of baryons and mesons made of three quarks and quark-antiquark pairs, respectively. Particles with an alternative quark content are known as exotic states. Here a study is reported of an exotic narrow state in the D0D0π+ mass spectrum just below the D*+D0 mass threshold produced in proton-proton collisions collected with the LHCb detector at the Large Hadron Collider. The state is consistent with the ground isoscalar [Formula: see text] tetraquark with a quark content of [Formula: see text] and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D*+ mesons is consistent with the observed D0π+ mass distribution. To analyse the mass of the resonance and its coupling to the D*D system, a dedicated model is developed under the assumption of an isoscalar axial-vector [Formula: see text] state decaying to the D*D channel. Using this model, resonance parameters including the pole position, scattering length, effective range and compositeness are determined to reveal important information about the nature of the [Formula: see text] state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.

DIPG-49. International preclinical drug discovery and biomarker program informing an adoptive combinatorial trial for DMG

INTRODUCTION: DMG-ACT (DMG- multi-arm Adaptive and Combinatorial Trial) will implement an innovative clinical trial design of combinatorial arms for patients with DMG at all disease stages, that is adaptive to pre-clinical and correlate data generated in eight collaborating institutions. The goal of the team is to rapidly identify and validate i) promising drugs and drug combinations for clinical use, and ii) predictive biomarkers of promising drugs. METHODS: In vitro (n=30) and in vivo (n=8) models of DMG across fourteen institutions were used to assess single and combination treatment of over 80 drugs and drug combinations. Predictive biomarkers of response for top candidate drugs were identified using extensive molecular assays including proteomics, CRISPR, RNAseq, ELISA, FACS, and IHC. RESULTS: Inhibitory concentration (IC50) of all drugs were established and validated across all participating sites. In vivo validation of single and combination drug assays confirmed drug efficacy as increased survival for: ONC201 (p=0.01), ONC206 (p=0.01), ONC201+ONC206 (p=0.02), ONC201+panobinostat (p=0.01). Marizomib was highly toxic in murine PDX and zebrafish larvae assays. Murine pharmacokinetic analysis showed peak brain levels of ONC201, and ONC206 above pre-clinical IC50 concentrations. Molecular testing and analyses of existing drug screen across 578 cancer cells validated mitochondrial stress and additional proteins, as the main targets induces by ONC201/6. CONCLUSION: Thorough preclinical testing in a multi-site laboratory setting identified promising therapeutics for DMGs, resulting in launch of two clinical trials (PNOC022, ONOC023). Validation of identified biomarkers are ongoing using clinical specimen as well as in vivo PDX models.

Angular Analysis of D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} Decays and Search for CP Violation

The first full angular analysis and an updated measurement of the decay-rate CP asymmetry of the D^{0}→π^{+}π^{-}μ^{+}μ^{-} and D^{0}→K^{+}K^{-}μ^{+}μ^{-} decays are reported. The analysis uses proton-proton collision data collected with the LHCb detector at center-of-mass energies of 7, 8, and 13 TeV. The dataset corresponds to an integrated luminosity of 9  fb^{-1}. The full set of CP -averaged angular observables and their CP asymmetries are measured as a function of the dimuon invariant mass. The results are consistent with expectations from the standard model and with CP symmetry.

DIPG-39. New preclinical models for Diffuse Midline Glioma

Malignant brain tumors are the leading cause of childhood death in Germany, with Diffuse Midline Glioma (DMG) being the most lethal of all paediatric brain tumors. Current treatment strategies are limited to irradiation which prolongs survival only by a few months. Preclinical studies have identified effective drug candidates, but translation into the clinic remains a major obstacle. It is known that interactions between tumor cells and components of the TME (tumor microenvironment), such as cell to cell contacts between malignant and non-malignant cells or secreted factors, can increase therapy resistance and progression of brain tumors. However, these important factors are not present in most conventional cell culture models for drug testing. Consequently, there is a need for more realistic DMG models to improve the relevance and translational potential of current drug screening. Therefore, the goal of this study was to develop a new DMG model for drug testing, consisting of induced pluripotent stem cell (iPSC) derived human brain cells and patient derived DMG cells to better mimic the complex tumor microenvironment. We co-cultured three-dimensional cerebral organoids with DMG tumor spheres resulting in the formation of DMG-Brain-Organoids (DBO). Preliminary results show that co-culture induces distinct tumor cell subpopulations corresponding to those detected in DMG tumors by single cell RNA sequencing (Filbin et al., 2018). These subpopulations mainly differ in their proliferative capacity and their differential response to clinical interventions may be critical for therapeutic success. DBOs subjected to drug treatments (single or combination) were sectioned and individual therapy effects on tumor cell subpopulations and proliferative capacity were monitored using multiplexed immunofluorescence imaging. By observing drug effects in a realistic setup, we hope to improve the predictive power of our preclinical drug screens and to find new combination therapies for DMG.

Dynamic interplay between metal nanoparticles and oxide support under redox conditions

The dynamic interactions between noble metal particles and reducible metal-oxide supports can depend on redox reactions with ambient gases. Transmission electron microscopy revealed that the strong metal-support interaction (SMSI)-induced encapsulation of platinum particles on titania observed under reducing conditions is lost once the system is exposed to a redox-reactive environment containing oxygen and hydrogen at a total pressure of ~1 bar. Destabilization of the metal-oxide interface and redox-mediated reconstructions of titania lead to particle dynamics and directed particle migration that depend on nanoparticle orientation. A static encapsulated SMSI state was reestablished when switching back to purely oxidizing conditions. This work highlights the difference between reactive and nonreactive states and demonstrates that manifestations of the metal-support interaction strongly depend on the chemical environment.

Optimization and Kinetic Modeling of a Fed-Batch Fermentation for Mannosylerythritol Lipids (MEL) Production With Moesziomyces aphidis

Mannosylerythritol lipids are glycolipid biosurfactants with many interesting properties. Despite the general interest in those molecules and the need for a robust process, studies on their production in bioreactors are still scarce. In the current study, the fermentative production of MEL in a bioreactor with Moesziomyces aphidis was performed using a defined mineral salt medium. Several kinetic process parameters like substrate consumption rates and product formation rates were evaluated and subsequently enhanced by increasing the biomass concentration through an exponential fed-batch strategy. The fed-batch approaches resulted in two to three fold increased dry biomass concentrations of 10.9–15.5 g/L at the end of the growth phase, compared with 4.2 g/L in the batch process. Consequently, MEL formation rates were increased from 0.1 g/Lh up to around 0.4 g/Lh during the MEL production phase. Thus, a maximum concentration of up to 50.5 g/L MEL was obtained when oil was added in excess, but high concentrations of residual fatty acids were also present in the broth. By adjusting the oil feeding to biomass-specific hydrolysis and MEL production rates, a slightly lower MEL concentration of 34.3 g/L was obtained after 170 h, but at the same time a very pure crude lipid extract with more than 90% MEL and a much lower concentration of remaining fatty acids. With rapeseed oil as substrate, the ideal oil-to-biomass ratio for full substrate conversion was found to be around 10 g_oil/g_biomass. In addition, off-gas analysis and pH trends could be used to assess biomass growth and MEL production. Finally, kinetic models were developed and compared to the experimental data, allowing for a detailed prediction of the process behavior in future experiments.

Tests of Lepton Universality Using B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} Decays

Tests of lepton universality in B^{0}→K_{S}^{0}ℓ^{+}ℓ^{-} and B^{+}→K^{*+}ℓ^{+}ℓ^{-} decays where ℓ is either an electron or a muon are presented. The differential branching fractions of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays are measured in intervals of the dilepton invariant mass squared. The measurements are performed using proton-proton collision data recorded by the LHCb experiment, corresponding to an integrated luminosity of 9  fb^{-1} . The results are consistent with the standard model and previous tests of lepton universality in related decay modes. The first observation of B^{0}→K_{S}^{0}e^{+}e^{-} and B^{+}→K^{*+}e^{+}e^{-} decays is reported.

Observation of the Decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}

The first observation of the semileptonic b-baryon decay Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ}, with a significance of 6.1σ, is reported using a data sample corresponding to 3  fb^{-1} of integrated luminosity, collected by the LHCb experiment at center-of-mass energies of 7 and 8 TeV at the LHC. The τ^{-} lepton is reconstructed in the hadronic decay to three charged pions. The ratio K=B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}) is measured to be 2.46±0.27±0.40, where the first uncertainty is statistical and the second systematic. The branching fraction B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})=(1.50±0.16±0.25±0.23)% is obtained, where the third uncertainty is from the external branching fraction of the normalization channel Λ_{b}^{0}→Λ_{c}^{+}π^{-}π^{+}π^{-}. The ratio of semileptonic branching fractions R(Λ_{c}^{+})≡B(Λ_{b}^{0}→Λ_{c}^{+}τ^{-}ν[over ¯]_{τ})/B(Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ}) is derived to be 0.242±0.026±0.040±0.059, where the external branching fraction uncertainty from the channel Λ_{b}^{0}→Λ_{c}^{+}μ^{-}ν[over ¯]_{μ} contributes to the last term. This result is in agreement with the standard model prediction.

Observation of Two New Excited Ξ_{b}^{0} States Decaying to Λ_{b}^{0}K^{-}π^{+}

Two narrow resonant states are observed in the Λ_{b}^{0}K^{-}π^{+} mass spectrum using a data sample of proton-proton collisions at a center-of-mass energy of 13 TeV, collected by the LHCb experiment and corresponding to an integrated luminosity of 6  fb^{-1}. The minimal quark content of the Λ_{b}^{0}K^{-}π^{+} system indicates that these are excited Ξ_{b}^{0} baryons. The masses of the Ξ_{b}(6327)^{0} and Ξ_{b}(6333)^{0} states are m[Ξ_{b}(6327)^{0}]=6327.28_{-0.21}^{+0.23}±0.12±0.24 and m[Ξ_{b}(6333)^{0}]=6332.69_{-0.18}^{+0.17}±0.03±0.22  MeV, respectively, with a mass splitting of Δm=5.41_{-0.27}^{+0.26}±0.12  MeV, where the uncertainties are statistical, systematic, and due to the Λ_{b}^{0} mass measurement. The measured natural widths of these states are consistent with zero, with upper limits of Γ[Ξ_{b}(6327)^{0}]<2.20(2.56) and Γ[Ξ_{b}(6333)^{0}]<1.60(1.92)  MeV at a 90% (95%) credibility level. The significance of the two-peak hypothesis is larger than nine (five) Gaussian standard deviations compared to the no-peak (one-peak) hypothesis. The masses, widths, and resonant structure of the new states are in good agreement with the expectations for a doublet of 1D Ξ_{b}^{0} resonances.

Measurement of the Nucleon F_{2}^{n}/F_{2}^{p} Structure Function Ratio by the Jefferson Lab MARATHON Tritium/Helium-3 Deep Inelastic Scattering Experiment

The ratio of the nucleon F_{2} structure functions, F_{2}^{n}/F_{2}^{p}, is determined by the MARATHON experiment from measurements of deep inelastic scattering of electrons from ^{3}H and ^{3}He nuclei. The experiment was performed in the Hall A Facility of Jefferson Lab using two high-resolution spectrometers for electron detection, and a cryogenic target system which included a low-activity tritium cell. The data analysis used a novel technique exploiting the mirror symmetry of the two nuclei, which essentially eliminates many theoretical uncertainties in the extraction of the ratio. The results, which cover the Bjorken scaling variable range 0.19<x<0.83, represent a significant improvement compared to previous SLAC and Jefferson Lab measurements for the ratio. They are compared to recent theoretical calculations and empirical determinations of the F_{2}^{n}/F_{2}^{p} ratio.