| 1. |
- Basso, Eduardo, et al.
(författare)
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Nuclear effects in Drell-Yan pair production in high-energy pA collisions
- 2016
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Ingår i: Physical Review D (Particles, Fields, Gravitation and Cosmology). - 1550-7998. ; 93:9
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Tidskriftsartikel (refereegranskat)abstract
- The Drell-Yan (DY) process of dilepton pair production off nuclei is not affected by final state interactions, energy loss, or absorption. A detailed phenomenological study of this process is thus convenient for investigation of the onset of initial-state effects in proton-nucleus (pA) collisions. In this paper, we present a comprehensive analysis of the DY process in pA interactions at RHIC and LHC energies in the color dipole framework. We analyze several effects affecting the nuclear suppression, RpA
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| 2. |
- Goncalves, Victor P., et al.
(författare)
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Drell-Yan process in pA collisions : Path-integral treatment of coherence effects
- 2016
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Ingår i: Physical Review D - Particles, Fields, Gravitation and Cosmology. - 2470-0010. ; 94:11
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Tidskriftsartikel (refereegranskat)abstract
- 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, RA, 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) lc RA. Since the onset of coherence effects is controlled by the coherence length lc, 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 (s 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 lc 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.
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| 3. |
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| 4. |
- Krelina, Michal, et al.
(författare)
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Drell-Yan process in p+Pb collisions at the LHC
- 2016
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Ingår i: Proceedings of Science. - 1824-8039. ; Part F128560
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Tidskriftsartikel (refereegranskat)abstract
- We study the initial-state interactions (non-coherence) and nuclear shadowing (coherence) effects in the Drell-Yan pair production process in p+Pb collisions at the LHC energies. The analysis of the nuclear suppression, RpA < 1, has been performed in the color dipole approach in the large coherence length approximation. The Z0 boson contribution relevant at large dilepton invariant masses has been included. We showed that the initial-state interactions cause a strong suppression at large pT, large dilepton masses and forward rapidities leading to a breakdown of QCD factorisation that can be verified by LHC measurements. The nuclear effects on the correlation function C(Δφ) in azimuthal angle Δφ between dilepton pair and a forward pion have been discussed as well. We predict a characteristic double-peak structure of C(Δφ) for very forward pions and large-mass dilepton pairs.
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