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

Probing nuclear structure at the Electron-Ion Collider and in ultra-peripheral nuclear collisions

Within the Color Glass Condensate framework, we demonstrate that exclusive vector meson production at high energy is sensitive to the geometric deformation of the target nucleus and subnucleon scale fluctuations. Deformation of the nucleus enhances the incoherent cross section in the small $|t|$ region. Subnucleon scale fluctuations increase the incoherent cross section in the large $|t|$ region. In ultra-peripheral collisions (UPCs), larger deformation leads to a wider distribution of the minimal impact parameter $B_{min}$ required to produce a UPC. This, together with larger incoherent cross sections for larger deformation, results in smaller extracted radii. Our results demonstrate great potential for future studies of nuclear structure in UPCs and electron-ion collisions.Comment: 4 pages, proceedings of Quark Matter 202

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

Back-to-back inclusive dijets in DIS at small xx: Complete NLO results and predictions

We compute the back-to-back dijet cross-section in deep inelastic scattering (DIS) at small $x$ to next-to-leading order (NLO) in the Color Glass Condensate effective field theory. Our result can be factorized into a convolution of the Weizs\"{a}cker-Williams gluon transverse momentum dependent distribution function (WW gluon TMD) with a universal soft factor and an NLO coefficient function. The soft factor includes both double and single logarithms in the ratio of the relative transverse momentum $P_\perp$ of the dijet pair to the dijet momentum imbalance $q_\perp$; its renormalization group (RG) evolution is resummed into the Sudakov factor. Likewise, the WW TMD obeys a nonlinear RG equation in $x$ that is kinematically constrained to satisfy both lifetime and rapidity ordering of the projectile. Exact analytical expressions are obtained for the NLO coefficient function of transversely and longitudinally polarized photons. Our results allow for the first quantitative separation of the dynamics of Sudakov suppression from that of gluon saturation. They can be extended to other final states and provide a framework for precision tests of novel QCD many-body dynamics at the Electron-Ion Collider.Comment: 41 pages, 9 figures, 5 supplemental materials, to be published in Physical Review Letter

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