Центральне ексклюзивне продукування на LHCb

• Видавець: Publishing house "Academperiodika"
• Дата: 2019
• Автор: Van Hulse, C.
• Формат: Стаття
• Мова: English
• Опубліковано: Publishing house "Academperiodika" 2019
• Теми: exclusive photoproduction; ultra-peripheral collisions; generalised parton distributions; parton distribution functions; -
• Онлайн доступ: https://ujp.bitp.kiev.ua/index.php/ujp/article/view/2019462

The LHCb collaboration has measured central exclusive production of J/ф, ф(2S), and ϒ mesons as well as J/фJ/ф, J/фф(2S), ф(2S)ф(2S), and xcxc meson pairs in proton-proton collisions. The analyses of ϒ and charmonium pairs are performed at the centre-of-mass energies of 7 TeV and 8 TeV, and those of J/ф and ф(2S) are done at 7 TeV and 13 TeV. The analysis at 13 TeV involves the use of new shower counters. These allow a reduction in the background by vetoing events with activity in an extended region in rapidity. The measurements of central exclusive production at LHCb are sensitive to gluon distributions for Bjorken-x values down to 2×10−6 (at 13 TeV). An overview of the LHCb results is presented and compared to existing measurements of other experiments and theoretical calculations.