ELFT HÍRADÓ

[Kormányos Andor <andor.kormanyos AT ttk.elte.hu>]

ELTE TTK Fizikai Intézet / ELTE Institute of Physics


ORTVAY KOLLOKVIUM / ORTVAY COLLOQUIUM
(https://physics.elte.hu/ortvayseminar)



Thursday, 10th October  2024, 15:00h.

Pócza Jenő Classroom,  Physics Building 1.71.

Pázmány Péter sétány 1/A, 1117 Budapest



Sándor Varró

ELI, ERIC, ALPS, Szeged


The Massive Photons of Louis de Broglie and the X17 Particle

According to recent experiments, the angular correlations of 
electron-positron pairs, stemming from excited products of certain nuclear 
reactions, show an anomaly at large relative angles. The kinematics of this 
so-called ATOMKI anomaly has been explained by assuming the existence of a 
neutral boson, the “X17 particle” with an invariant mass around 17 MeV/c^2. 
So, besides the zero-mass gamma radiation, such particles would cover the 
energy and momentum of the created pairs. The observation of the ATOMKI 
anomaly has initiated various theoretical studies on the possible nature of 
this hypothetical particle, which we shall briefly review. Then we outline 
our approach, on the basis of which we have recently derived a simple 
analytic formula, yielding the value 17.0087 MeV/c^2 for the invariant mass 
of the dressed radiation generated due to the interaction with a proton. 
Besides the Sommerfeld fine structure constant and the proton mass, the 
derived formula contains merely an elementaty statistical factor. This result 
suggests that the X17 particle may perhaps be a sort of massive photon. By 
broadening the scope of the subject, in the third part of the talk we shall 
highlight the work of Louis de Broglie, who invented the concept of matter 
waves just hundred years ago, as is well-known in the history of quantum 
mechanics. On the other hand, it is lesser known that Louis de Broglie also 
discussed the question of a possible photon mass in several publications 
throughout decades. After summarizing the various concepts on the finite mass 
of the photon, we show the subtleties of emission and propagation of massive 
photons.


Andor Kormányos
coordinator