Search results for "GLASS"

Transmission of ultra-cold neutrons through guides coated with materials of high optical potential

2014

Abstract We have measured the transmission of ultra-cold neutrons (UCN) through tubes coated on the inside with materials of high optical potentials. The best transmission value, T, normalised to 1 m long UCN guides was obtained with a beryllium coated quartz guide, T=(99.0±1.0)%. Furthermore, excellent transmission coefficients were found for (i) a glass tube coated with NiMo(88/12), T=(97.3 ±0.6)%, (ii) a NiMo(85/15) guide made by the replication technique, T=(97.1 ±0.8)% and (iii) a glass guide coated with NiMo(82/18), T=(96.3 ±2.1)%. The results demonstrate that UCN guides made from coated glass tubes have the same excellent transmission properties as those produced with the replication…

Detector response of Cherenkov radiators for calorimetry in the energy range below 14 MeV

2020

Abstract A study of the detector response of PbF 2  crystals and three different types of lead glass blocks to electrons from a 14-MeV beam of the Mainz Microtron MAMI is presented. For the first time, signal height, signal width, and homogeneity of the response of these Cherenkov radiators were determined for energies between 10 and 14 MeV. To complement the beam tests, optical properties of the materials, in particular measured transmittances in the near UV and visible spectrum, were studied. The measured detector responses were also compared to Monte Carlo simulations of energy-loss, light production, transport, and detection. These Cherenkov radiators are considered as active material o…

Corrigendum to “Systematics of azimuthal anisotropy harmonics in proton–nucleus collisions at the LHC from the Color Glass Condensate” [Phys. Lett. B…

2019

On the gluon spectrum in the glasma

2010

We study the gluon distribution in nucleus-nucleus collisions in the framework of the Color-Glass-Condensate. Approximate analytical solutions are compared to numerical solutions of the non-linear Yang-Mills equations. We find that the full numerical solution can be well approximated by taking the full initial condition of the fields in Coulomb gauge and using a linearized solution for the time evolution. We also compare kt-factorized approximations to the full solution.

PREDICTIONS FOR p+PbCOLLISIONS AT $\sqrt{s_{_{\it NN}}} = 5$

2013

Predictions for charged hadron, identified light hadron, quarkonium, photon, jet and gauge bosons in p+Pb collisions at $\sqrt{s_{_{\it NN}}} = 5\, {\rm TeV}$ are compiled and compared. When test run data are available, they are compared to the model predictions.

Centrality dependence of the pseudorapidity density distribution for charged particles in Pb–Pb collisions at sNN=2.76 TeV

2017

We present the charged-particle pseudorapidity density in Pb-Pb collisions at $\sqrt{s_{\mathrm{NN}}}=5.02\,\mathrm{Te\kern-.25exV}$ in centrality classes measured by ALICE. The measurement covers a wide pseudorapidity range from $-3.5$ to $5$, which is sufficient for reliable estimates of the total number of charged particles produced in the collisions. For the most central (0-5%) collisions we find $21\,400\pm 1\,300$ while for the most peripheral (80-90%) we find $230\pm 38$. This corresponds to an increase of $(27\pm4)\%$ over the results at $\sqrt{s_{\mathrm{NN}}}=2.76\,\mathrm{Te\kern-.25exV}$ previously reported by ALICE. The energy dependence of the total number of charged particles…

Nuclear modification of forward J/ψ production in proton-nucleus collisions at the LHC

2016

We re-evaluate the nuclear suppression of forward J/ψ production at high energy in the Color Glass Condensate framework. We use the collinear approximation for the projectile proton probed at large x and an up to date dipole cross section fitted to HERA data to describe the target in proton-proton collisions. We show that using the Glauber approach to generalize the proton dipole cross section to the case of a nucleus target leads to a nuclear modification factor much closer to LHC data than previous estimates using the same framework.

Single inclusive particle production at high energy from HERA data to proton-nucleus collisions

2013

We study single inclusive hadron production in proton-proton and proton-nucleus collisions in the CGC framework. The parameters in the calculation are determined solely by standard nuclear geometry and by electron-proton deep inelastic scattering data, which is fit using the running coupling BK equation. We show that it is possible to obtain a good fit of the HERA inclusive cross section also without an anomalous dimension in the initial condition. We argue that one must consistently use the proton transverse area as measured by a high virtuality probe in DIS also for the single inclusive cross section in proton-proton and proton-nucleus collisions. We show that this leads to a midrapidity …

Centrality dependence of forward J/ψ suppression in high energy proton–nucleus collisions

2015

The production of forward $J/\psi$ mesons in proton-nucleus collisions can provide important information on gluon saturation. In a previous work we studied this process in the Color Glass Condensate framework, describing the target using a dipole cross section fitted to HERA inclusive data and extrapolated to the case of a nuclear target using the optical Glauber model. In this work we study the centrality dependence of the nuclear suppression in this model and compare our results with recent LHC data for this observable.

Small x physics and RHIC data

2010

This is a review of applications of the Color Glass Condensate to the phenomenology of relativistic heavy ion collisions. The initial stages of the collision can be understood in terms of the nonperturbatively strong nonlinear glasma color fields. We discuss how the CGC framework can and has been used to compute properties of the initial conditions of AA collisions. In particular this has led to recent progress in understanding multiparticle correlations, which can provide a directly observable signal of the properties of the initial stage of the collision process.