Nuclear geometry at high energy from exclusive vector meson production

Publisher Copyright: © 2022 authors. Published by the American Physical Society. Published by the American Physical Society under the terms of the "https://creativecommons.org/licenses/by/4.0/"Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI. Funded by SCOAP3.We show that when saturation effects are included one obtains a good description of the exclusive J/ψ production spectra in ultraperipheral lead-lead collisions as recently measured by the ALICE Collaboration at the LHC. As exclusive spectra are sensitive to the spatial distribution of nuclear matter at small Bjorken-x, this implies that gluon saturation effects modify the impact parameter profile of the target as we move towards small x. In addition to saturation effects, we find a preference for larger nuclear strong-interaction radii compared to the typical charge radius. We demonstrate the role of finite photon transverse momentum and the interference between the cases for which the role of photon emitter and target are switched between the nuclei. We show that these effects are comparable to the experimental precision for pT-differential cross sections and as such need to be included when comparing to LHC data. Finally, the integrated J/ψ production cross sections from the LHC and preliminary transverse momentum spectra from RHIC are shown to prefer calculations with fluctuating nucleon substructure, although these datasets would require even stronger saturation effects than predicted from our framework.Peer reviewe

Direct quarkonium-plus-gluon production in DIS in the Color Glass Condensate

We compute the differential cross-section for direct quarkonium production accompanied by a gluon in high-energy deep inelastic scattering (DIS) at small-$x$. We employ the Non-Relativistic QCD factorization framework, focusing on the $S$-wave contribution to the formation of the quarkonium, and including both color singlet and octet contributions. Our short distance coefficients for the production of the heavy quark pair are obtained within the Color Glass Condensate effective field theory. Our results pave the way towards the next-to-leading order computation of direct quarkonium in DIS, as well as the study of azimuthal correlations of direct quarkonium and jet.Comment: 52 pages, 7 figures, 1 tabl

Effects of nuclear structure and quantum interference on diffractive vector meson production in ultra-peripheral nuclear collisions

We study diffractive vector meson production in ultra-peripheral collisions (UPCs) of heavy nuclei, utilizing a theoretical framework based on the Color Glass Condensate (CGC) formalism. We focus on Au+Au, U+U, Ru+Ru, Zr+Zr, and Pb+Pb collisions, examining the transverse momentum dependence of vector meson production cross-sections and ${\rm cos(2\Delta\Phi)}$ asymmetries in the decay product distributions to explore the role of nuclear geometry. The angular modulation is due to the linear polarization of the incoming photons and quantum interference effects. We extract nuclear radii and find them to be consistent with experimental data from the STAR collaboration. The amplitudes of the ${\rm cos(2\Delta\Phi)}$ modulation in the cross-section and the extracted radii depend on the nuclear geometry. This dependence is dominated by the geometry-dependent variation of the minimum impact parameter required for ultra-peripheral collisions

Correspondence between Color Glass Condensate and High-Twist Formalism

The Color Glass Condensate (CGC) effective theory and the collinear factorization at high-twist (HT) are two well-known frameworks describing perturbative QCD multiple scatterings in nuclear media. It has long been recognized that these two formalisms have their own domain of validity in different kinematics regions. Taking direct photon production in proton-nucleus collisions as an example, we clarify for the first time the relation between CGC and HT at the level of a physical observable. We show that the CGC formalism beyond shock-wave approximation, and with the Landau-Pomeranchuk-Migdal interference effect is consistent with the HT formalism in the transition region where they overlap. Such a unified picture paves the way for mapping out the phase diagram of parton density in nuclear medium from dilute to dense region.Comment: 7 pages, 3 figures + supplemental materia

Azimuthal correlations in diffractive scattering at the Electron-Ion Collider

Peer reviewe

Reconstrucción de encefalocele frontoetmoidal con injerto de acetábulo

El encefalocele frontoetmoidal es un defecto congénito deltubo neural caracterizado por una herniación parcial delcerebro y las meninges, a través de un defecto craneal anteriorque genera deformidad facial. Se presenta el reporte de unniño de 10 años con un defecto facial en línea media quecorrespondió a un encefalocele frontoetmoidal. Se realizócorrección quirúrgica acompañado de colocación de injertode acetábulo, obteniéndose una mejoría estética y anatómicafavorable. Este parece ser el primer caso en la literatura en elque se utiliza el injerto de acetábulo para la reconstrucción deun encefalocele frontoetmoidal

Transient mutism and cerebellar ischemic stroke: Case report

The ischemic stroke is one of the most common conditions in our hospitals, representing 50% of revenues of neurology services. A variety of processes is cerebral ischemic myocardial cerebellum. Cerebellar infarction is not a rare disease, representing between 2 to 4% of all cerebrovascular events in clinical and autopsy series, and their ratio is 4-5 times higher than cerebellar hemorrhage. Although it is increasingly documented, it rarely Recognized stills like a phenomenon. Mutism occurs primarily in children and occasionally in adults as a well-recognized complication of posterior fossa surgery. Rarely been reported transient mutism associated with cerebellar infarction as isolated episode

Latex and silicon allergy related to cerebrospinal shunt hardware: A review

A less frequent complications of shunt systems ventriculoperitoneal used for the management of hydrocephalus is the allergy materials which usually are built, silicone and latex. Patients undergoing multiple changes device may be at risk of developing high rejection to materials. Differential diagnosis should be done with infections and obstructions, usual causes of dysfunction. We present a review updated literature focused neurosurgeon

Transoral osteosynthesis for C1 fractures: two cases report

The upper cervical spine fractures are rare and often fatal injuries so immediately with the traumatic event. Due to the amplitude of the spinal canal in the upper cervical region, only 16% of the survivors exhibit neurological compromise, so they can go unnoticed for emergency care. CI injuries are rare. We report two cases in relation to our experience in the management of this injury through transoral

Early Holocene ritual complexity in South America: the archaeological record of Lapa do Santo (east-central Brazil)

Early Archaic human skeletal remains found in a burial context in Lapa do Santo in eastcentral Brazil provide a rare glimpse into the lives of hunter-gatherer communities in South America, including their rituals for dealing with the dead. These included the reduction of the body by means of mutilation, defleshing, tooth removal, exposure to fire and possibly cannibalism, followed by the secondary burial of the remains according to strict rules. In a later period, pits were filled with disarticulated bones of a single individual without signs of body manipulation, demonstrating that the region was inhabited by dynamic groups in constant transformation over a period of centuries