scholarly journals Gluon saturation: Survival probability for leading neutrons in DIS

2012 ◽  
Vol 892 ◽  
pp. 1-20 ◽  
Author(s):  
Eugene Levin ◽  
Sebastian Tapia
2002 ◽  
Vol 8 (1) ◽  
pp. 21-30 ◽  
Author(s):  
Giacomo Tavecchia ◽  
Roger Pradel ◽  
François Gossmann ◽  
Claudine Bastat ◽  
Yves Ferrand ◽  
...  

2008 ◽  
Vol 73 (6-7) ◽  
pp. 755-770 ◽  
Author(s):  
Andriy Pysanenko ◽  
Ján Žabka ◽  
Zdeněk Herman

The scattering of the hydrocarbon radical cation C2D4•+ from room-temperature carbon (highly oriented pyrolytic graphite, HOPG) surface was investigated at low incident energies of 6-12 eV. Mass spectra, angular and translational energy distributions of product ions were measured. From these data, information on processes at surfaces, absolute ion survival probability, and kinematics of the collision was obtained. The projectile ion showed both inelastic, dissociative and reactive scattering, namely the occurrence of H-atom transfer reaction with hydrocarbons present on the room-temperature carbon surface. The absolute survival probability of the ions for the incident angle of 30° (with respect to the surface) decreased from about 1.0% (16 eV) towards zero at incident energies below 10 eV. Estimation of the effective surface mass involved in the collision process led to m(S)eff of about 57 a.m.u. for inelastic non-dissociative collisions of C2D4•+ and of about 115 a.m.u. for fragment ions (C2D3+, C2D2•+) and ions formed in reactive surface collisions (C2D4H+, C2D2H+, contributions to C2D3+ and C2D2•+). This suggested a rather complex interaction between the projectile ion and the hydrocarbon-covered surface during the collision.


Author(s):  
Claudia Pigini ◽  
Stefano Staffolani

AbstractA recent reform in the Italian labour market has modified the permanent contract by reducing firing costs. Using a discontinuity in the application of the reform, we evaluate its effect on the probability of being still employed about three and a half years later. In contrast with theoretical predictions, we find that the job survival probability is not smaller for the treated and even significantly larger in some cases. We investigate the composition of permanent workers hired after the reform and we find evidence of treated firms changing their recruitment strategy in favour of potentially more productive workers.


2021 ◽  
Vol 2021 (5) ◽  
Author(s):  
Kaustav Chakraborty ◽  
Debajyoti Dutta ◽  
Srubabati Goswami ◽  
Dipyaman Pramanik

Abstract We study the physics potential of the long-baseline experiments T2HK, T2HKK and ESSνSB in the context of invisible neutrino decay. We consider normal mass ordering and assume the state ν3 as unstable, decaying into sterile states during the flight and obtain constraints on the neutrino decay lifetime (τ3). We find that T2HK, T2HKK and ESSνSB are sensitive to the decay-rate of ν3 for τ3/m3 ≤ 2.72 × 10−11s/eV, τ3/m3 ≤ 4.36 × 10−11s/eV and τ3/m3 ≤ 2.43 × 10−11s/eV respectively at 3σ C.L. We compare and contrast the sensitivities of the three experiments and specially investigate the role played by the mixing angle θ23. It is seen that for experiments with flux peak near the second oscillation maxima, the poorer sensitivity to θ23 results in weaker constraints on the decay lifetime. Although, T2HKK has one detector close to the second oscillation maxima, having another detector at the first oscillation maxima results in superior sensitivity to decay. In addition, we find a synergy between the two baselines of the T2HKK experiment which helps in giving a better sensitivity to decay for θ23 in the higher octant. We discuss the octant sensitivity in presence of decay and show that there is an enhancement in sensitivity which occurs due to the contribution from the survival probability Pμμ is more pronounced for the experiments at the second oscillation maxima. We also obtain the combined sensitivity of T2HK+ESSνSB and T2HKK+ESSνSB as τ3/m3 ≤ 4.36 × 10−11s/eV and τ3/m3 ≤ 5.53 × 10−11s/eV respectively at 3σ C.L.


2021 ◽  
Vol 2021 (7) ◽  
Author(s):  
E. Iancu ◽  
A. H. Mueller ◽  
D. N. Triantafyllopoulos ◽  
S. Y. Wei

Abstract Using the dipole picture for electron-nucleus deep inelastic scattering at small Bjorken x, we study the effects of gluon saturation in the nuclear target on the cross-section for SIDIS (single inclusive hadron, or jet, production). We argue that the sensitivity of this process to gluon saturation can be enhanced by tagging on a hadron (or jet) which carries a large fraction z ≃ 1 of the longitudinal momentum of the virtual photon. This opens the possibility to study gluon saturation in relatively hard processes, where the virtuality Q2 is (much) larger than the target saturation momentum $$ {Q}_s^2 $$ Q s 2 , but such that z(1 − z)Q2 ≲ $$ {Q}_s^2 $$ Q s 2 . Working in the limit z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we predict new phenomena which would signal saturation in the SIDIS cross-section. For sufficiently low transverse momenta k⊥ ≪ Qs of the produced particle, the dominant contribution comes from elastic scattering in the black disk limit, which exposes the unintegrated quark distribution in the virtual photon. For larger momenta k⊥ ≳ Qs, inelastic collisions take the leading role. They explore gluon saturation via multiple scattering, leading to a Gaussian distribution in k⊥ centred around Qs. When z(1 − z)Q2 ≪ Q2, this results in a Cronin peak in the nuclear modification factor (the RpA ratio) at moderate values of x. With decreasing x, this peak is washed out by the high-energy evolution and replaced by nuclear suppression (RpA< 1) up to large momenta k⊥ ≫ Qs. Still for z(1 − z)Q2 ≪ $$ {Q}_s^2 $$ Q s 2 , we also compute SIDIS cross-sections integrated over k⊥. We find that both elastic and inelastic scattering are controlled by the black disk limit, so they yield similar contributions, of zeroth order in the QCD coupling.


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