THE LADINIAN AMMONOIDS FROM CALCARE DI ESINO OF VAL PARINA (BERGAMASC ALPS, NORTHERN ITALY). PT. 1

This paper deals with the description of a rich ammonoid assemblage collected in calcareous lenses outcropping within the Ladinian Calcare di Esino of Val Parina (Northern ltaly). The faunas come from lenses outcropping on the northern slope opposite of Val di Lavaggio. The Material was collected by M. Gervasutti and is stored in the Museo Civico di Scienze Naturali "E. Caffi" in Bergamo (Italy). More than 60 species were identified, including about twenty new species and three new genera: Parinaia (fam. Ceratitidae), Rossiceras  (fam. Hungaritidae) and Gervasuttia (fam. Aplococeratidae). The new taxa give a substantial contribution to the knowledge of the poorly studied Tethyan faunas ofthe Ladinian. Whether these faunas are endemic or not is at present difficult to determine. The fossiliferous levels extend from 550 m to 850 m altitude. In this interval 5 assemblages were recognized (from bottom to top): 1) Assemblage with Chieseiceras perticaense, Norites, Gevanites, Iberites, Epigymnites, Aplococeras, Proarcestes, Procladiscites, Eoprotrachyceras, Monophyllites; 2) Assemblage with Eoprotrachyceras recubariense, Norites, Chieseiceras, Gevanites, Sturia, Epigymnites, Aplococeras, Eoprotrachyceras, Monophyllites; 3)Assemblage with Protrachyceras margaritosum, Iberites, Epigymnites, Gervasuttia  Argolites, Monophyllites; 4) Assemblage with Gervasuttia, Arpadites, Protrachyceras, Monophyllites; 5) Assemblage with Protrachyceras longobardicum, Sageceras, Iberites, Rossiceras, Sturia, Epigymnites, Praepinacoceras, Proarcestes, Protrachyceras, Detoniceras, Arpadites, Argolìtes, Monophyllites. The assemblages 1) and 2) can be ascribed to the Curionii Zone; assemblages 3) and 4) to the Gredleri Zone, and assemblage 5) to the lower part of the Archelaus Zone

I CORALLI DEL CALCARE DI ZU (TRIASSICO SUPERIORE) DELLA LOMBARDIA (ITALIA). NUOVE SEGNALAZIONI

This paper deals with the description and illustration of three species of Stylophyllidae from the Calcare di Zu (Zu Limestone) of Late Triassic age. Stylophyllum paradoxum Frech, Stylophyllum polyacanthum Reuss and Stylophyllum pygmaeum Frech are found for the first time in the Bergamo area, associated to the large coral fauna, already described, commonly occurring in the same formation of the Southern Alps

THE MIDDLE TRIASSIC OF THE BREMBANA VALLEY: PRELIMINARY STUDY OF THE ESINO PLATFORM (Bergamasc Alps)

The stratigraphy and paleogeography of the ladinian Esino Limestone outcropping in Valle Brembana-Valle Parina, have been integrated with the biostratigraphic analysis of cephalopod fauna. A complex internal structure of the upper anisian-ladinian Esino carbonate platform has been identified. Six different lithozones have been recognized, they record the stratigraphic-paleogeographic evolution of the Esino Limestone. This carbonate platform developed through three stages: 1) construction of a lower edifice (Late Anisian-? Early Ladinian) representing the first phase of carbonate piatform diffusion on structural highs, which were already the site of carbonate deposition during the Middle Anisian (peritidal dolomites of the Angolo Limestone); 2) buildup of the carbonate complex (main edifice). In this second phase (Early Ladinian-Late Ladinian p.p.) the most important one, the platform growth took place by prevalent aggradation; 3) development of the upper edifice and progradation of the piatform in the Late Ladinian. In this third phase, inner plarform facies with diagenetic caps at the top of peritidal cycles are common. The buildup developed in the second phase yields bioclastic packstones with ammonoids, gastropods, echinoderms, and bivalves clustered within lithozone 4 and in the proximity of the southern margin of the platform in Val Parina. Studies in progress of ammonoids and gastropods allowed for the recognition of different fossil assemblages which date from Early Ladinian to Late Ladinian. A few problematic ammonoid assemblage of probably Early Ladinian age, has been found in a stratigraphic level above the base of the Esino Limestone

Pennsylvanian-Early Triassic stratigraphy in the Alborz Mountains (Iran)

New fieldwork was carried out in the central and eastern Alborz, addressing the sedimentary succession from the Pennsylvanian to the Early Triassic. A regional synthesis is proposed, based on sedimentary analysis and a wide collection of new palaeontological data. The Moscovian Qezelqaleh Formation, deposited in a mixed coastal marine and alluvial setting, is present in a restricted area of the eastern Alborz, transgressing on the Lower Carboniferous Mobarak and Dozdehband formations. The late Gzhelian–early Sakmarian Dorud Group is instead distributed over most of the studied area, being absent only in a narrow belt to the SE. The Dorud Group is typically tripartite, with a terrigenous unit in the lower part (Toyeh Formation), a carbonate intermediate part (Emarat and Ghosnavi formations, the former particularly rich in fusulinids), and a terrigenous upper unit (Shah Zeid Formation), which however seems to be confined to the central Alborz. A major gap in sedimentation occurred before the deposition of the overlying Ruteh Limestone, a thick package of packstone–wackestone interpreted as a carbonate ramp of Middle Permian age (Wordian–Capitanian). The Ruteh Limestone is absent in the eastern part of the range, and everywhere ends with an emersion surface, that may be karstified or covered by a lateritic soil. The Late Permian transgression was directed southwards in the central Alborz, where marine facies (Nesen Formation) are more common. Time-equivalent alluvial fans with marsh intercalations and lateritic soils (Qeshlaq Formation) are present in the east. Towards the end of the Permian most of the Alborz emerged, the marine facies being restricted to a small area on the Caspian side of the central Alborz. There, the Permo-Triassic boundary interval is somewhat similar to the Abadeh–Shahreza belt in central Iran, and contains oolites, flat microbialites and domal stromatolites, forming the base of the Elikah Formation. The P–T boundary is established on the basis of conodonts, small foraminifera and stable isotope data. The development of the lower and middle part of the Elikah Formation, still Early Triassic in age, contains vermicular bioturbated mudstone/wackestone, and anachronostic-facies-like gastropod oolites and flat pebble conglomerates. Three major factors control the sedimentary evolution. The succession is in phase with global sea-level curve in the Moscovian and from the Middle Permian upwards. It is out of phase around the Carboniferous–Permian boundary, when the Dorud Group was deposited during a global lowstand of sealevel. When the global deglaciation started in the Sakmarian, sedimentation stopped in the Alborz and the area emerged. Therefore, there is a consistent geodynamic control. From the Middle Permian upwards, passive margin conditions control the sedimentary evolution of the basin, which had its depocentre(s) to the north. Climate also had a significant role, as the Alborz drifted quickly northwards with other central Iran blocks towards the Turan active margin. It passed from a southern latitude through the aridity belt in the Middle Permian, across the equatorial humid belt in the Late Permian and reached the northern arid tropical belt in the Triassic

THE EARLY-MIDDLE TRIASSIC BOUNDARY AT CHIOS (GREECE)

The sections of Marathovouno hillock in Chios (Greece), proposed by Assereto (1974) as stratotype for the base of the Anisian, have been revisited. An additional new section, Parthenis, near the town of Chios, was also considered. The ammonoid fauna of the Late Spathian, fairly rich in the Parthenis secion, fully belongs to the Prohungarites/Subcolumbites zone, sensu Kummel (1973). Additional ammonoid collections have been made from the stratotype section of Assereto, as well from section G, where the Aegean Paradanubites has been found above the condensed horizon. In the Parthenis section the earliest Anisian is missing because of a sedimentation gap. Several post- Aegean ammonoids have been found in red limestones olistoliths within the Variegated Series (Bunte Serie). The conodonts gave a more continuous record troughout all the sections. The most significant species to be considered are; Neospathodus homeri, Gondolella timorensis and Gondolella regale. The first occurrence of G. timorensis overlaps the N. homeri range for more than 1 m in thickness, below the bed with the ammonoid Aegeiceras. G. regale seems to be never associated with N. homeri and, appears later than the typical Aegean ammonoid fauna. Microfacies analysis revealed the presence of long ranging foraminifers. As far as the base of the Anisian is concerned, we may advance the following statements. 1) The base of the stage may be traced with the FAD ol Aegeiceras, Paracrochordiceras, Paradanubites and Japonites. 2) The FAD of G. timorensis slightly preceeds the Aegean ammonoid FAD. Thus, if the boundary is drawn on the base of ammonoids, G. timorensis FAD is latest Spathian in age. 3) G. regale FAD occurs later than the Aegean ammonoid fauna FAD. By correlation to the Nevada Star Peak Canyon section, the Aegean fauna of Chios seems correlative to the Japonites welteri beds of Bucher (1989)

Precision measurement of CP\it{CP} violation in the penguin-mediated decay Bs0→ϕϕB_s^{0}\rightarrow\phi\phi

A flavor-tagged time-dependent angular analysis of the decay $B_s^{0}\rightarrow\phi\phi$ is performed using $pp$ collision data collected by the LHCb experiment at % at $\sqrt{s}=13$ TeV, the center-of-mass energy of 13 TeV, corresponding to an integrated luminosity of 6 fb^{-1}. The $\it{CP}$-violating phase and direct $\it{CP}$-violation parameter are measured to be $\phi_{s\bar{s}s} = -0.042 \pm 0.075 \pm 0.009$ rad and $|\lambda|=1.004\pm 0.030 \pm 0.009$, respectively, assuming the same values for all polarization states of the $\phi\phi$ 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 $\phi_{s\bar{s}s} = -0.074 \pm 0.069$ rad and $|lambda|=1.009 \pm 0.030$. This is the most precise study of time-dependent $\it{CP}$ violation in a penguin-dominated $B$ meson decay. The results are consistent with $\it{CP}$ symmetry and with the Standard Model predictions.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-001.html (LHCb public pages

Observation of Cabibbo-suppressed two-body hadronic decays and precision mass measurement of the Ωc0\Omega_{c}^{0} baryon

The first observation of the singly Cabibbo-suppressed $\Omega_{c}^{0}\to\Omega^{-}K^{+}$ and $\Omega_{c}^{0}\to\Xi^{-}\pi^{+}$ decays is reported, using proton-proton collision data at a centre-of-mass energy of $13\,{\rm TeV}$, corresponding to an integrated luminosity of $5.4\,{\rm fb}^{-1}$, collected with the LHCb detector between 2016 and 2018. The branching fraction ratios are measured to be $\frac{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}K^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.0608\pm0.0051({\rm stat})\pm 0.0040({\rm syst})$, $\frac{\mathcal{B}(\Omega_{c}^{0}\to\Xi^{-}\pi^{+})}{\mathcal{B}(\Omega_{c}^{0}\to\Omega^{-}\pi^{+})}=0.1581\pm0.0087({\rm stat})\pm0.0043({\rm syst})\pm0.0016({\rm ext})$. In addition, using the $\Omega_{c}^{0}\to\Omega^{-}\pi^{+}$ decay channel, the $\Omega_{c}^{0}$ baryon mass is measured to be $M(\Omega_{c}^{0})=2695.28\pm0.07({\rm stat})\pm0.27({\rm syst})\pm0.30({\rm ext})\,{\rm MeV}/c^{2}$, improving the precision of the previous world average by a factor of four.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2023-011.html (LHCb public pages

Test of lepton universality in b→sℓ+ℓ−b \rightarrow s \ell^+ \ell^- decays

The first simultaneous test of muon-electron universality using $B^{+}\rightarrow K^{+}\ell^{+}\ell^{-}$ and $B^{0}\rightarrow K^{*0}\ell^{+}\ell^{-}$ 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 $\mathrm{fb}^{-1}$. 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.Comment: All figures and tables, along with any supplementary material and additional information, are available at https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-046.html (LHCb public pages