Distorted quarkonia and spin alignment

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Yan, Guowei, Lin, Shu
Format: Preprint
Veröffentlicht: 2025
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866911521382072320
author Yan, Guowei
Lin, Shu
author_facet Yan, Guowei
Lin, Shu
contents It is well-known that atoms can change their shape when subject to external electromagnetic fields. Analogous phenomenon is expected for particles, which are much smaller in size with the corresponding shape change much harder to observe. We point out that shape change of particles can be accessed by measurements of their spin alignment. Motivated by recent measurements of spin alignment in relativistic heavy ion collisions, we consider quarkonia in electromagnetic fields as an example. We show that the quarkonia spin alignment receives both spin contribution from spin states mixing and orbital contribution from shape change. By a proper choice of quantization axis, it is possible to switch off the spin contribution, leaving only the orbital contribution. This makes spin alignment measurement a valuable probe of quarkonium structure.
format Preprint
id arxiv_https___arxiv_org_abs_2507_22684
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Distorted quarkonia and spin alignment
Yan, Guowei
Lin, Shu
High Energy Physics - Phenomenology
Nuclear Experiment
Nuclear Theory
It is well-known that atoms can change their shape when subject to external electromagnetic fields. Analogous phenomenon is expected for particles, which are much smaller in size with the corresponding shape change much harder to observe. We point out that shape change of particles can be accessed by measurements of their spin alignment. Motivated by recent measurements of spin alignment in relativistic heavy ion collisions, we consider quarkonia in electromagnetic fields as an example. We show that the quarkonia spin alignment receives both spin contribution from spin states mixing and orbital contribution from shape change. By a proper choice of quantization axis, it is possible to switch off the spin contribution, leaving only the orbital contribution. This makes spin alignment measurement a valuable probe of quarkonium structure.
title Distorted quarkonia and spin alignment
topic High Energy Physics - Phenomenology
Nuclear Experiment
Nuclear Theory
url https://arxiv.org/abs/2507.22684