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We study cold and hot nuclear matter effects on charmonium production in p+Pb collisions at √ sNN = 5.02 TeV in a transport approach. At the forward rapidity, the cold medium effect on all the cc states and the hot medium effect on the excited cc states only can explain well the J/ψ and ψ ′ yield and transverse momentum distribution measured by the ALICE collaboration, and we predict a significantly larger ψ ′ pT broadening in comparison with J/ψ. However, we can not reproduce the J/ψ and ψ ′ data at the backward rapidity with reasonable cold and hot medium effects.There are two kinds of nuclear matter effects on charmonium production in heavy ion collisions [1]. One is the hot nuclear matter effect during the evolution of the fireball, and the other is the cold nuclear matter effect before the formation of the fireball. The former includes color screening [2] and regeneration [3][4][5][6] which work in an opposite way and lead respectively to charmonium suppression and enhancement. The later contains mainly the shadowing effect [7-10], Cronin effect [11,12] and nuclear absorption [13]. To be sure that the charmonium production is a sensitive probe of the hot Quark-Gluon Plasma (QGP) [1], one needs to clearly understand the cold medium in nucleus-nucleus (A+B) collisions. Proton-nucleus (p+A) collisions where the hot medium is expected to be small and the effect is weak are widely considered as a good laboratory to measure the cold medium.Recently, the ALICE collaboration measured the nuclear modification factor R pA and averaged transverse momentum square p 2 T pA for J/ψ and ψ ′ in p+Pb collisions at √ s N N = 5.02 TeV [14-17]. The charmonium production in small systems is also widely investigated in energy loss model [18], transport model [19] and comover model [20]. In this paper, we focus on the charmonium evolution in p+A collisions in the frame of a transport approach [6,21]. By comparing with the data, we hope to understand the cold and hot nuclear matter effects on the ground and excited charmonium states.There are different charmonium production mechanisms, initial production via hard processes [22], recombination of charm quarks inside QGP [3][4][5][6], and decay from excited states and B hadrons [23][24][25]. Since the charm quark number created in p+A collisions is small, the recombination can be reasonably ignored. At LHC energy, the collision time is much shorter than the charmonium formation time and the QGP formation time. Therefore, one can safely neglect the nuclear absorption and the difference in the shadowing and Cronin effects between the ground and excited charmonium states.Generally, the initially produced charmonium distribution f Ψ for Ψ = J/ψ, ψ ′ , χ c in transverse plane in an A+B collision at fixed impact parameter b can be obtained through a superposition of effective nucleon-nucleon (p+p) collisions [26],

Phase-based fringe projection metrology systems have been widely used to obtain the shape of 3D objects. One vital step is calibration, which defines the relationship between the phase and depth data. Existing calibration methods are complicated because of the dependence of the relationship on the pixel position. In this Letter, a simple calibration procedure is introduced based on an uneven fringe projection technique, in which the relationship between phase and depth becomes independent of the pixel position and can be represented by a single polynomial function for all pixels. Therefore, given a set of discrete points with a known phase and depth in the measuring volume, the coefficient set of the polynomial function can be determined. A white plate having discrete markers with known separation is used to calibrate the 3D imaging system. Experimental results demonstrate that the proposed calibration method is simple to apply and can build up an accurate relationship between phase and depth data.

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One important step of phase-based three-dimensional imaging system is calibration, which defines the relationship between phase and depth data. Existing calibration methods are complicated and hard to carry out because of using a translation stage or gauge block in a laboratory environment. This Letter introduces a new simple, flexible calibration method by using a checkerboard and a white plate having discrete markers with known separation. The checkerboard determines the internal parameters of a CCD camera. The plate gives phase and depth data of each pixel to establish their relationship. Experimental results and performance evaluation show that the proposed calibration method can reliably build up the accurate relationship between phase map and depth data in a simple, flexible way.

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