Measurement of antiproton production from antihyperon decays in p He collisions at √sNN = 110 GeV

The interpretation of cosmic antiproton flux measurements from space-borne experiments is currently limited by the knowledge of the antiproton production cross-section in collisions between primary cosmic rays and the interstellar medium. Using collisions of protons with an energy of 6.5TeV incident on helium nuclei at rest in the proximity of the interaction region of the LHCb experiment, the ratio of antiprotons originating from antihyperon decays to prompt production is measured for antiproton momenta between 12 and 110GeV. The dominant antihyperon contribution, namely Λ¯→p¯π+ decays from promptly produced Λ¯ particles, is also exclusively measured. The results complement the measurement of prompt antiproton production obtained from the same data sample. At the energy scale of this measurement, the antihyperon contributions to antiproton production are observed to be significantly larger than predictions of commonly used hadronic production models

Direct CP violation in charmless three-body decays of B± mesons

Measurements of C P asymmetries in charmless three-body decays of B ± mesons are reported using proton-proton collision data collected by the LHCb detector, corresponding to an integrated luminosity of 5.9     fb − 1 . The previously observed C P asymmetry in B ± → π ± K + K − decays is confirmed, and C P asymmetries are observed with a significance of more than five standard deviations in the B ± → π ± π + π − and B ± → K ± K + K − decays, while the C P asymmetry of B ± → K ± π + π − decays is confirmed to be compatible with zero. The distributions of these asymmetries are also studied as a function of the three-body phase space and suggest contributions from rescattering and resonance interference processes. An indication of the presence of the decays B ± → π ± χ c 0 ( 1 P ) in both B ± → π ± π + π − and B ± → π ± K + K − decays is observed, as is C P violation involving these amplitudes

Measurement of J/ψ -pair production in pp collisions at √s = 13 TeV and study of gluon transverse-momentum dependent PDFs

The production cross-section of J/ψ pairs in proton-proton collisions at a centre-of-mass energy of √s = 13 TeV is measured using a data sample corresponding to an integrated luminosity of 4.2 fb−1 collected by the LHCb experiment. The measurement is performed with both J/ψ mesons in the transverse momentum range 0 < pT< 14 GeV/c and rapidity range 2.0 < y < 4.5. The cross-section of this process is measured to be 16.36 ± 0.28 (stat) ± 0.88 (syst) nb. The contributions from single-parton scattering and double-parton scattering are separated based on the dependence of the cross-section on the absolute rapidity difference ∆y between the two J/ψ mesons. The effective cross-section of double-parton scattering is measured to be σeff = 13.1 ± 1.8 (stat) ± 2.3 (syst) mb. The distribution of the azimuthal angle ϕCS of one of the J/ψ mesons in the Collins-Soper frame and the pT-spectrum of the J/ψ pairs are also measured for the study of the gluon transverse-momentum dependent distributions inside protons. The extracted values of ⟨cos 2ϕCS⟩ and ⟨cos 4ϕCS⟩ are consistent with zero, but the presence of azimuthal asymmetry at a few percent level is allowed

Impact of the COVID-19 Pandemic on Births, Vaginal Deliveries, Cesarian Sections, and Maternal Mortality in a Brazilian Metropolitan Area: A Time-Series Cohort Study

Dilson Palhares Ferreira,1,* Cláudia Vicari Bolognani,2,3,* Levy Aniceto Santana,2,* Sérgio Eduardo Soares Fernandes,2,3,* Matheus Serwy Fiuza de Moraes,3,* Luana Argollo Souza Fernandes,3,* Camila de Sousa Pereira,3,* Gabriela Billafan Ferreira,3,* Leila Bernarda Donato Göttems,2,3,* Fábio Ferreira Amorim1– 4,* 1Graduation Program in Health Sciences, University of Brasília (UnB), Brasília, Federal District, Brazil; 2Department of Research and Scientific Communication, Escola Superior de Ciências da Saúde (ESCS), Brasília, Federal District, Brazil; 3Medical School, Escola Superior de Ciências da Saúde (ESCS), Brasília, Federal District, Brazil; 4Graduation Program in Health Sciences of School Health Sciences, Escola Superior de Ciências da Saúde (ESCS), Brasília, Federal District, Brazil*These authors contributed equally to this workCorrespondence: Fábio Ferreira Amorim; Dilson Palhares Ferreira, Coordenação de Pesquisa e Comunicação Científica - Escola Superior de Ciências da Saúde, SMHN Quadra 03, conjunto A, Bloco 1 - Edifício FEPECS, Brasília, Federal District, CEP 70701-907, Brazil, Email [email protected]; [email protected]: The COVID-19 pandemic posed a worldwide challenge, leading to radical changes in healthcare. The primary objective of the study was to assess the impact of the COVID-19 pandemic on birth, vaginal delivery, and cesarian section (c-section) rates. The secondary objective was to compare the maternal mortality before and after the pandemic.Patients and Methods: Time-series cohort study including data of all women admitted for childbirth (vaginal delivery or c-section) at the maternities in the Public Health System of Federal District, Brazil, between March 2018 and February 2022, using data extracted from the Hospital Information System of Brazilian Ministry of Health (SIH/DATASUS) on September 30, 2022. Causal impact analysis was used to evaluate the impact of COVID-19 on birth, vaginal delivery, and c-section using the CausalImpact R package, and a propensity score matching was used to evaluate the effect on maternal mortality rate using the Easy R (EZR) software.Results: There were 150,617 births, and considering total births, the effect of the COVID-19 pandemic was not statistically significant (absolute effect per week: 5.5, 95% CI: − 24.0− 33.4). However, there was an increase in c-sections after COVID-19 (absolute effect per week: 18.1; 95% CI: 11.9− 23.9). After propensity score matching, the COVID-19 period was associated with increased maternal mortality (OR: 3.22, 95% CI: 1.53− 6.81). The e-value of the adjusted OR for the association between the post-COVID-19 period and maternal mortality was 5.89, with a 95% CI: 2.43, suggesting that unmeasured confounders were unlikely to explain the entirety of the effect.Conclusion: Our study revealed a rise in c-sections and maternal mortality during the COVID-19 pandemic, possibly due to disruptions in maternal care. These findings highlight that implementing effective strategies to protect maternal health in times of crisis and improve outcomes for mothers and newborns is crucial.Keywords: COVID-19, cesarean section, maternal health services, maternal mortalit

Measurement of the CKM angle γ in the B0→DK *0 channel using self-conjugate D→ KS0h+ h- decays

A model-independent study of CP violation in B-0 -> DK (*0) decays is presented using data corresponding to an integrated luminosity of 9 fb(-1) collected by the LHCb experiment at centre-of-mass energies of v s = 7, 8 and 13TeV. The CKM angle. is determined by examining the distributions of signal decays in phase-space bins of the self-conjugate D. K(S)(0)h(+) h(-) decays, where h = p, K. Observables related to CP violation are measured and the angle. is determined to be. = (49+22 -19).. Measurements of the amplitude ratio and strong-phase difference between the favoured and suppressed B-0 decays are also presented

Search for D∗(2007)0→μ+μ−D^{*}(2007)^{0} \rightarrow \mu ^{+} \mu ^{-} in B−→π−μ+μ−B^{-}\rightarrow \pi ^{-} \mu ^{+} \mu ^{-} decays

AbstractThe very rare $${{D} ^*} (2007)^0\!\rightarrow {\mu ^+\mu ^-}$$ D ∗ ( 2007 ) 0 → μ + μ - decay is searched for by analysing $${{{B} ^-}} \!\rightarrow {{\pi } ^-} {\mu ^+\mu ^-}$$ B - → π - μ + μ - decays. The analysis uses a sample of beauty mesons produced in proton–proton collisions collected with the LHCb detector between 2011 and 2018, corresponding to an integrated luminosity of 9$$\text {\,fb} ^{-1}$$ \,fb - 1 . The signal signature corresponds to simultaneous peaks in the $${\mu ^+\mu ^-}$$ μ + μ - and $${{\pi } ^-} {\mu ^+\mu ^-}$$ π - μ + μ - invariant masses. No evidence for an excess of events over background is observed and an upper limit is set on the branching fraction of the decay at \mathcal{B}({{D} ^*} (2007)^0\!\rightarrow {\mu ^+\mu ^-} ) < 2.6\times 10^{-8} B ( D ∗ ( 2007 ) 0 → μ + μ - ) &lt; 2.6 × 10 - 8 at $$90\%$$ 90 % confidence level. This is the first limit on the branching fraction of $${{D} ^*} (2007)^0\!\rightarrow {\mu ^+\mu ^-}$$ D ∗ ( 2007 ) 0 → μ + μ - decays and the most stringent limit on $${{D} ^*} (2007)^0$$ D ∗ ( 2007 ) 0 decays to leptonic final states. The analysis is the first search for a rare charm-meson decay exploiting production via beauty decays.</jats:p

Observation of the Bs0 {\textrm{B}}_{\textrm{s}}^0 → χc1_{c1}(3872)π+^{+}π−^{−} decay

International audienceThe first observation of the ${B}_s^0$→ (χ$_{c1}$(3872) → J/ψπ$^{+}$π$^{−}$)π$^{+}$π$^{−}$ decay is reported using proton-proton collision data, corresponding to integrated luminosities of 1, 2 and 6 fb$^{−1}$, collected by the LHCb experiment at centre-of-mass energies of 7, 8 and 13 TeV, respectively. The ratio of branching fractions relative to the ${B}_s^0$→ (ψ(2S) → J/ψπ$^{+}$π$^{−}$)π$^{+}$π$^{−}$ decay is measured to be$\frac{\mathcal{B}\left({B}_s^0\to {\chi}_{c1}(3872){\pi}^{+}{\pi}^{-}\right)\times \mathcal{B}\left({\chi}_{c1}(3872)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}{\mathcal{B}\left({B}_s^0\to \psi (2S){\pi}^{+}{\pi}^{-}\right)\times \mathcal{B}\left(\psi (2S)\to J/\psi {\pi}^{+}{\pi}^{-}\right)}=\left(6.8\pm 1.1\pm 0.2\right)\times {10}^{-2},$where the first uncertainty is statistical and the second systematic. The mass spectrum of the π$^{+}$π$^{−}$ system recoiling against the χ$_{c1}$(3872) meson exhibits a large contribution from ${B}_s^0$→ χ$_{c1}$(3872) (f$_{0}$(980) → π$^{+}$π$^{−}$) decays.[graphic not available: see fulltext

Evidence for the decays B0 → (D)over-bar(*)0φ and updated measurements of the branching fractions of the Bs0 → (D)over-bar(*)0φ decays

Evidence for the decays B-0 -&gt; (D) over bar (0)phi and B-0 -&gt; (D) over bar (*0) phi is reported with a significance of 3.6 sigma and 4.3 sigma, respectively. The analysis employs pp collision data at centre-of-mass energies root s = 7, 8 and 13TeV collected by the LHCb detector and corresponding to an integrated luminosity of 9 fb(-1). The branching fractions are measured to beB(B-0 -&gt; (D) over bar (0)phi) = (7.7 +/- 2.1 +/- 0.7 +/- 0.7) x 10(-7),B(B-0 -&gt; (D) over bar (*0)phi) = (2.2 +/- 05 +/- 0.2 +/- 0.2) x 10(-6).In these results, the first uncertainty is statistical, the second systematic, and the third is related to the branching fraction of the B-0 -&gt; (D) over bar K-0(+) K- decay, used for normalisation. By combining the branching fractions of the decays B-0 -&gt; (D) over bar ((*)0)phi and B-0 -&gt; (D) over bar ((*)0)omega, the omega-phi mixing angle delta is constrained to be tan(2)delta = (3.6 +/- 0.7 +/- 0.4) x 10(-3), where the first uncertainty is statistical and the second systematic. An updated measurement of the branching fractions of the B-s(0) -&gt; (D) over bar ((*)0).phi decays, which can be used to determine the CKM angle gamma, leads toB(B-s(0) -&gt; (D) over bar (0)phi) = (2.30 +/- 0.10 +/- 0.11 +/- 0.20) x 10(-5),B(B-s(0) -&gt; (D) over bar (*0)phi) = (3.17 +/- 0.16 +/- 0.17 +/- 0.27) x 10(-5)