y-ray consists of:

Gamma rays (̳-rays) are a form of high-energy electromagnetic radiation [1]. Unlike alpha and beta radiation, which consist of particles with mass (protons and electrons respectively), gamma rays are weightless packets of energy known as photons [3]. They are characterized as short-wave electromagnetic waves that originate from the disintegration or settling process of an excited atomic nucleus [3]. As part of the electromagnetic spectrum, they possess the highest energy and shortest wavelengths, often less than one-tenth of a nanometer [1]. Because they are pure energy and lack mass or electrical charge, they have high penetrating power, capable of passing through human tissue and requiring dense materials like lead for shielding [3]. Other options like mesons, neutrinos, and Higgs bosons are distinct subatomic particles or force carriers that do not constitute the fundamental nature of gamma radiation.

Sources

1. [1] https://www.sciencedirect.com/topics/biochemistry-genetics-and-molecular-biology/gamma-radiation
2. [2] https://www.epa.gov/radiation/radiation-basics
3. [3] https://www.arpansa.gov.au/understanding-radiation/what-is-radiation/ionising-radiation/gamma-radiation
4. [4] Environment, Shankar IAS Acedemy .(ed 10th) > Chapter 5: Environmental Pollution > 5.9.r. Radioactive Pollution > p. 82