Электронный каталог

Статья

Acharya, S.
Exclusive Photoproduction of Excited *r Mesons Decaying to Four Pions in Ultraperipheral Pb–Pb Collisions at *%s&sub(NN) = 5.02 TeV TeV / S.Acharya, B.Batyunya, C.Ceballos Sanchez, R.A.Diaz, S.Grigoryan, A.Kondratyev, L.Malinina, K.Mikhaylov, P.Nomokonov, V.Pozdniakov, E.Rogochaya, A.Vodopyanov, [ALICE Collab.]. – Text : electronic // Physics Letters B. – 2026. – Vol. 872. – P. 140006. – URL: https://doi.org/10.1016/j.physletb.2025.140006. – Bibliogr.: 44.

The intense photon fluxes from relativistic nuclei provide an opportunity to study photonuclear interactions in ultraperipheral collisions. In particular, it allows for the investigations of excited, light-flavour vector mesons. The measurement of coherently photoproduced *p&sup(+)*p&sup(-)*p&sup(+)*p&sup(-) final states in ultraperipheral Pb–Pb collisions at *% 𝑠&sub(NN) = 5.02 TeV is presented for the first time. The cross section, d*s/d𝑦, times the branching ratio (𝜌 *> *p&sup+)*p&sup(-)*p&sup(+)*p&sup(-)) is found to be 47.8 *{ 2.3 (stat.) *{ 7.7 (syst.) mb in the rapidity interval |𝑦| < 0.5. The invariant mass distribution is not well described with a single Breit-Wigner resonance without an interference term. Including interference with a non-resonant contribution results in the mass and width values being too far from those reported in PDG, while the production of two interfering resonances, *r(1450) and *r(1700), also provides a good description of the data. The values of the masses (𝑚) and widths (Γ) of the resonances extracted from the fit assuming two interfering resonances are 𝑚&sub(1) = 1385 *{ 14 (stat.) *{ 3 (syst.) MeV/𝑐&sup(2) , Γ&sub(1) = 431 *{ 36 (stat.) *{ 82 (syst.) MeV/𝑐&sup(2) , 𝑚&sub(2) = 1663 *{ 13 (stat.) *{ 22 (syst.) MeV/𝑐&sup(2) and Γ&sub(2) = 357 *{ 31 (stat.) *{ 49 (syst.) MeV/𝑐&sup(2) , respectively. The measured cross sections times the branching ratios are compared to recent theoretical predictions.



Спец.(статьи,препринты) = С 346.6а1 - Векторные мезоны
Спец.(статьи,препринты) = С 343 е2 - Взаимодействие релятивистских ядер с ядрами
ОИЯИ = ОИЯИ (JINR)2026