Events containing a Z boson and a charm jet are studied for the first time in the forward region of proton-proton collisions. The data sample used corresponds to an integrated luminosity of 6 fb(-1) collected at a center-of-mass energy of 13 TeV with the LHCb detector. In events with a Z boson and a jet, the fraction of charm jets is determined in intervals of Z-boson rapidity in the range 2.0 < y(Z) < 4.5. A sizable enhancement is observed in the forwardmost y(Z) interval, which could be indicative of a valencelike intrinsic-charm component in the proton wave function.
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Marie Theres Christin Bachmayer, Serhii Cholak, Ettore Zaffaroni, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Yunxuan Song, Vitalii Lisovskyi, Sonia Amina Bouchiba, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Andrea Merli, Gianluca Zunica, Abdul-Kerim Guseinov, Roberto Ribatti, Spencer Edward Collaviti
Olivier Schneider, Aurelio Bay, Guido Haefeli, Tatsuya Nakada, Frédéric Blanc, Lesya Shchutska, Elena Graverini, Sebastian Schulte, Marie Theres Christin Bachmayer, Ettore Zaffaroni, Aravindhan Venkateswaran, Luis Miguel Garcia Martin, Yunxuan Song, Vitalii Lisovskyi, Sonia Amina Bouchiba, Federico Ronchetti, Radoslav Marchevski, Anni Matilda Kauniskangas, Dimitrios Kaminaris, Raphaël van Laak, Pierre Paul Louis Mayencourt, Andrea Merli, Gianluca Zunica, Abdul-Kerim Guseinov, Roberto Ribatti, Spencer Edward Collaviti