Drell-Yan process in pA collisions: Path-integral treatment of coherence effects

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21340%2F16%3A00310006" target="_blank" >RIV/68407700:21340/16:00310006 - isvavai.cz</a>

Výsledek na webu

<a href="http://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.114009" target="_blank" >http://journals.aps.org/prd/abstract/10.1103/PhysRevD.94.114009</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1103/PhysRevD.94.114009" target="_blank" >10.1103/PhysRevD.94.114009</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Drell-Yan process in pA collisions: Path-integral treatment of coherence effects

Popis výsledku v původním jazyce

In this work, we investigate production of Drell-Yan (DY) pairs in proton-nucleus collisions in kinematic regions where the corresponding coherence length does not exceed the nuclear radius, R-A, and the quantum coherence effects should be treated with special care. The results for the nucleus-to-nucleon production ratio available in the literature so far are usually based on the assumption of a very long coherence length (LCL) l(c) >> R-A. Since the onset of coherence effects is controlled by the coherence length l(c), we estimated its magnitude in various kinematic regions of the DY process and found that the LCL approximation should not be used at small and medium c. m. collision energies (root S less than or similar to 200 GeV) as well as at large dilepton invariant masses. In order to obtain realistic predictions, we computed for the first time the DY cross section using the generalized color dipole approach based on the rigorous Green function formalism, which naturally incorporates the color transparency and quantum coherence effects and hence allows us to estimate the nuclear shadowing with no restrictions on the CL. In addition to the shadowing effect, we studied a complementary effect of initial state interactions (ISI) that causes an additional suppression at large values of the Feynman variable. Numerical results for the nuclear modification factor accounting for the ISI effect and the finite l(c) are compared to the data available from the fixed-target Fermi National Laboratory measurements and a good agreement has been found. Besides, we present new predictions for the nuclear suppression as a function of dilepton rapidity and invariant mass in the kinematic regions that can be probed by the RHIC collider as well as by the planned AFTER@LHC and LHCb fixed-target experiments.

Název v anglickém jazyce

Drell-Yan process in pA collisions: Path-integral treatment of coherence effects

Popis výsledku anglicky

In this work, we investigate production of Drell-Yan (DY) pairs in proton-nucleus collisions in kinematic regions where the corresponding coherence length does not exceed the nuclear radius, R-A, and the quantum coherence effects should be treated with special care. The results for the nucleus-to-nucleon production ratio available in the literature so far are usually based on the assumption of a very long coherence length (LCL) l(c) >> R-A. Since the onset of coherence effects is controlled by the coherence length l(c), we estimated its magnitude in various kinematic regions of the DY process and found that the LCL approximation should not be used at small and medium c. m. collision energies (root S less than or similar to 200 GeV) as well as at large dilepton invariant masses. In order to obtain realistic predictions, we computed for the first time the DY cross section using the generalized color dipole approach based on the rigorous Green function formalism, which naturally incorporates the color transparency and quantum coherence effects and hence allows us to estimate the nuclear shadowing with no restrictions on the CL. In addition to the shadowing effect, we studied a complementary effect of initial state interactions (ISI) that causes an additional suppression at large values of the Feynman variable. Numerical results for the nuclear modification factor accounting for the ISI effect and the finite l(c) are compared to the data available from the fixed-target Fermi National Laboratory measurements and a good agreement has been found. Besides, we present new predictions for the nuclear suppression as a function of dilepton rapidity and invariant mass in the kinematic regions that can be probed by the RHIC collider as well as by the planned AFTER@LHC and LHCb fixed-target experiments.

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

BF - Elementární částice a fyzika vysokých energií

OECD FORD obor

—

Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

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

Rok uplatnění

2016

Kód důvěrnosti údajů

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

Název periodika

Physical Review D

ISSN

2470-0010

e-ISSN

—

Svazek periodika

94

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

—

Kód UT WoS článku

000390273000001

EID výsledku v databázi Scopus

—