Challenges of direct photon production at forward rapidities and large p(T)

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F17%3A00311855" target="_blank" >RIV/68407700:21340/17:00311855 - isvavai.cz</a>

Result on the web

<a href="http://iopscience.iop.org/article/10.1088/1742-6596/805/1/012003/pdf" target="_blank" >http://iopscience.iop.org/article/10.1088/1742-6596/805/1/012003/pdf</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1088/1742-6596/805/1/012003" target="_blank" >10.1088/1742-6596/805/1/012003</a>

Result language

angličtina

Original language name

Challenges of direct photon production at forward rapidities and large p(T)

Original language description

Direct photons produced in interactions with nuclear targets represent a cleaner probe for investigation of nuclear effects than hadrons, since photons have no final state interaction and no energy loss or absorption is expected in the produced hot medium. Therefore, besides the Cronin enhancement at medium-high transverse momenta p(T) and isospin effects at larger p(T), one should not expect any nuclear effects. However, this fact is in contrast to the PHENIX data providing an evidence for a significant large-p(T) suppression at mid rapidities in central d + Au and Au + Au collisions that cannot be induced by coherent phenomena (gluon shadowing, Color Glass Condensate). We demonstrate that such an unexpected results is subject to deficit of energy induced universally by multiple initial state interactions (ISI) towards the kinematic limits (large Feynman x(F) and/or large x(T) = 2p(T) / root s). For this reason, in order to enhance the effects of coherence, one should be cautious going to forward rapidities and higher energies. In the LHC kinematic region ISI corrections are irrelevant at mid rapidities but cause rather strong suppression at forward rapidities and large p(T). Numerical calculations of invariant p(T) spectra and the nuclear modification factor were performed within two different models, the color dipole formalism and the model based on k(T)-factorization, which are successfully confronted with available data from the RHIC and LHC collider experiments. Finally, we perform also predictions for a strong onset of ISI corrections at forward rapidities and corresponding expected suppression can be verified by the future measurements at LHC.

Czech name

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Czech description

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Type

D - Article in proceedings

CEP classification

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OECD FORD branch

10303 - Particles and field physics

Project

Result was created during the realization of more than one project. More information in the Projects tab.

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2017

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Article name in the collection

Journal of Physics Conference Series

ISBN

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ISSN

1742-6588

e-ISSN

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Number of pages

9

Pages from-to

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Publisher name

IOP Publishing Ltd.

Place of publication

Bristol

Event location

SUBATECH, Nantes

Event date

Sep 9, 2014

Type of event by nationality

WRD - Celosvětová akce

UT code for WoS article

000400394800003