The first measurement of the cross section for incoherent photonuclear production of 𝐽/𝜓 vector mesons as a function of the Mandelstam |𝑡| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |𝑦|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of √𝑠NN=5.02  TeV. This rapidity interval corresponds to a Bjorken-𝑥 range (0.3–1.4)×10−3. Cross sections are given in five |𝑡| intervals in the range 0.04<|𝑡|<1  GeV2 and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |𝑡| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.

First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production / Acharya, S., Adamová, D., Adler, A., Aglieri Rinella, G., Agnello, M., Agrawal, N., Ahammed, Z., Ahmad, S., Ahn, S. U., Ahuja, I., Akindinov, A., Al-Turany, M., Aleksandrov, D., Alessandro, B., Alfanda, H. M., Alfaro Molina, R., Ali, B., Alici, A., Alizadehvandchali, N., Alkin, A., et al.. - In: PHYSICAL REVIEW LETTERS. - ISSN 0031-9007. - STAMPA. - 132:16(2024), pp. 1-14. [10.1103/physrevlett.132.162302]

First Measurement of the |t| Dependence of Incoherent J/ψ Photonuclear Production

Agnello, M.;Bufalino, S.;Catalano, F.;Ciacco, M.;Ferrero, C.;
2024

Abstract

The first measurement of the cross section for incoherent photonuclear production of 𝐽/𝜓 vector mesons as a function of the Mandelstam |𝑡| variable is presented. The measurement was carried out with the ALICE detector at midrapidity, |𝑦|<0.8, using ultraperipheral collisions of Pb nuclei at a center-of-mass energy per nucleon pair of √𝑠NN=5.02  TeV. This rapidity interval corresponds to a Bjorken-𝑥 range (0.3–1.4)×10−3. Cross sections are given in five |𝑡| intervals in the range 0.04<|𝑡|<1  GeV2 and compared to the predictions by different models. Models that ignore quantum fluctuations of the gluon density in the colliding hadron predict a |𝑡| dependence of the cross section much steeper than in data. The inclusion of such fluctuations in the same models provides a better description of the data.
File in questo prodotto:
File Dimensione Formato  
PhysRevLett.132.162302.pdf

accesso aperto

Tipologia: 2a Post-print versione editoriale / Version of Record
Licenza: Creative commons
Dimensione 16.54 MB
Formato Adobe PDF
16.54 MB Adobe PDF Visualizza/Apri
Pubblicazioni consigliate

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11583/2990276