ترغب بنشر مسار تعليمي؟ اضغط هنا

Photon-hadron and photon-photon collisions in ALICE

63   0   0.0 ( 0 )
 نشر من قبل Rainer Schicker M
 تاريخ النشر 2015
  مجال البحث
والبحث باللغة English
 تأليف R. Schicker




اسأل ChatGPT حول البحث

A review is given on photon-hadron and photon-photon collisions in the ALICE experiment. The physics motivation for studying such reactions is outlined, and the results obtained in proton-lead and lead-lead collisions in Run 1 of the LHC are discussed. The improvement in detector rapidity coverage due to a newly added detector system is presented. The ALICE perspectives for data taking in LHC Run II are summarised.

قيم البحث

اقرأ أيضاً

81 - T. Jezo , M. Klasen , F. Konig 2016
We present a calculation of direct photon production at next-to-leading order of QCD and a matching of this calculation with parton showers using POWHEG BOX. Based on simulations with POWHEG+PYTHIA, we perform a detailed phenomenological analysis of PHENIX data on prompt photon production and photon-hadron jet correlations in pp collisions at RHIC, considerably improving the description of these data with respect to previous calculations, and we suggest additional interesting analyses.
We investigate the prospect of an alternative laboratory-based search for the coupling of axions and axion-like particles to photons. Here, the collision of two laser beams resonantly produces axions, and a signal photon is detected after magnetic re conversion, as in light-shining-through-walls (LSW) experiments. Conventional searches, such as LSW or anomalous birefrigence measurements, are most sensitive to axion masses for which substantial coherence can be achieved; this is usually well below optical energies. We find that using currently available high-power laser facilities, the bounds that can be achieved by our approach outperform traditional LSW at axion masses between $0.5-6$ eV, set by the optical laser frequencies and collision angle. These bounds can be further improved through coherent scattering off laser substructures, probing axion-photon couplings down to $g_{agammagamma}sim 10^{-8} {text{GeV}^{-1}}$, comparable with existing CAST bounds. Assuming a day long measurement per angular step, the QCD axion band can be reached.
The high-energy behaviour of the total cross section for highly virtual photons, as predicted by the BFKL equation at next-to-leading order (NLO) in QCD, is presented. The NLO BFKL predictions, improved by the BLM optimal scale setting, are in excell ent agreement with recent OPAL and L3 data at CERN LEP2.
We review the charged particle and photon multiplicity, and transverse energy production in heavy-ion collisions starting from few GeV to TeV energies. The experimental results of pseudorapidity distribution of charged particles and photons at differ ent collision energies and centralities are discussed. We also discuss the hypothesis of limiting fragmentation and expansion dynamics using the Landau hydrodynamics and the underlying physics. Meanwhile, we present the estimation of initial energy density multiplied with formation time as a function of different collision energies and centralities. In the end, the transverse energy per charged particle in connection with the chemical freeze-out criteria is discussed. We invoke various models and phenomenological arguments to interpret and characterize the fireball created in heavy-ion collisions. This review overall provides a scope to understand the heavy-ion collision data and a possible formation of a deconfined phase of partons via the global observables like charged particles, photons and the transverse energy measurement.
133 - J. Binnewies , 1996
We study inclusive charged-hadron production in collisions of quasireal photons at NLO in perturbative QCD, using fragmentation functions recently extracted from PEP and LEP1 data. We superimpose the direct (DD), single-resolved (DR), and double-reso lved (RR) gamma-gamma channels. First, we confront existing data taken by TASSO at PETRA and by MARK II at PEP with our NLO calculations. We also make comparisons with the neutral-kaon to charged-hadron ratio measured by MARK II. Then, we present NLO predictions for LEP2, a next-generation e+e- linear collider (NLC) in the TESLA design, and a Compton collider obtained by converting a NLC. We analyze transverse-momentum and rapidity spectra with regard to the scale dependence, the interplay of the DD, DR, and RR components, the sensitivity to the gluon density in the resolved photon, and the influence of gluon fragmentation. It turns out that the inclusive measurement of small-p_T hadrons at a Compton collider would greatly constrain the gluon density of the photon and the gluon fragmentation function.
التعليقات
جاري جلب التعليقات جاري جلب التعليقات
سجل دخول لتتمكن من متابعة معايير البحث التي قمت باختيارها
mircosoft-partner

هل ترغب بارسال اشعارات عن اخر التحديثات في شمرا-اكاديميا