UPC 2023: International workshop on the physics of Ultra Peripheral Collisions

Session

Inclusive photonuclear interactions

14 Dec 2023, 09:00

Playa del Carmen

Conveners

Inclusive photonuclear interactions

• Ilkka Helenius (University of Jyväskylä)
• Jamal Jalilian-Marian

Inclusive photonuclear interactions

• Mariola Klusek-Gawenda (Institute of Nuclear Physics Polish Academy of Sciences)
• David Tlusty (Creighton University)

32. Resummation at small x and implications for virtual photon scattering

Anna Maria Stasto (Pennsylvania State University (US))

14/12/2023, 09:00

Session 3: UPC and saturation

20. 'Rapidity gaps in UPC: status and perspectives’’

Mark Strikman (Pennsylvania State University (US))

14/12/2023, 09:30

Session 4: Inclusive photonuclear interactions

We consider processes with production of a leading heavy vector meson, dijet followed by rapidity gap in UPC. We argue that the knock out mechanism of the elastic scattering of hard Pomeron off constituents of nucleon/nucleus dominates in a wide range of momentum transfer due to the structure of the resummed Pomeron. The suit of rapidity gap processes in which neutrons are detected in the...

5. Inclusive and diffractive dijet photoproduction in ultraperipheral Pb-Pb collisions at the LHC

Vadim Guzey (University of Jyvaskyla)

14/12/2023, 10:00

Session 4: Inclusive photonuclear interactions

Photoproduction of dijets is an important complementary probe of the partonic structure of protons, nuclei and real photons in QCD. We will review applications of the next-to-leading order (NLO) perturbative QCD in the framework of collinear factorization to inclusive and diffractive dijet photoproduction in heavy-ion ultraperipheral collisions (UPCs) in the kinematics of the Large Hadron...

12. Collision geometry in UPC dijet production

Petja Paakkinen

14/12/2023, 11:00

Session 4: Inclusive photonuclear interactions

Inclusive dijet photoproduction in ultraperipheral nucleus-nucleus collisions (UPCs) has been promoted as a probe of nuclear parton distribution functions (nPDFs). However, due to the requirement of no nuclear overlap in such events, the impact parameter space is restricted. This becomes important in dijet production, where the requirement of having high-$p_{\mathrm{T}}$ jets means that one has to...

24. Measurement of dijet production in UPC with the ATLAS detector

Blair Daniel Seidlitz (Columbia University (US))

14/12/2023, 11:30

Session 4: Inclusive photonuclear interactions

In relativistic heavy ion collisions, the charged ions produce an intense flux of equivalent photons. Thus, photon-induced processes are the dominant interaction mechanism when the colliding nuclei have a transverse separation larger than the nuclear diameter. In these ultra-peripheral collisions (UPCs), the photon provides a clean, energetic probe of the partonic structure of the nucleus,...

46. Axion Physics in UPC and LbyL Scattering

Mr César Omar Ramírez Álvarez (Benemérita Universidad Autónoma de Puebla)

14/12/2023, 12:00

Session 2: Two-photon physics

The light-by-light scattering (LbyL), $\gamma \gamma \to \gamma \gamma$, is a rare process in the Standard Model (SM) in which two photons interact and produce another pair of photons in the final state. The first direct evidence of this process at the LHC was established by the ATLAS experiment in 2017 [1] and subsequently confirmed by the CMS experiment in 2019 [2], both using data collected in...

42. Open charm/beauty photoproduction in ultraperipheral heavy-ion collisions

Sohyun Park (Boston University)

Session 4: Inclusive photonuclear interactions

In ultraperipheral heavy-ion collisions, a photon emitted by one nucleus can interact with the other nucleus via photon-gluon fusion and lead to heavy quark production. The resulting yields of open charm or beauty depend on the photon flux and the gluon distribution within nuclei, enabling this process to probe the nuclear gluon distribution function. We extend the previous calculations for...