<\/p>\n
Crab Nebula in the Taurus constellation. (NASA \/ ESA \/ JDePasquale(STScI) via SWNS)<\/p>\n
By Stephen Beech<\/p>\n
A \u201cforgotten\u201d particle could answer the mystery of why we exist, say physicists.<\/p>\n
A new theory on the birth of the cosmos has been unveiled, suggesting the early universe<\/a> was shaped by an ancient particle that has been overlooked for decades.<\/p>\n The research, published in the journal Physical Review Letters<\/a>, tackles one of the greatest conundrums in modern physics \u2014 how matter triumphed over antimatter in the aftermath of the \u201cBig Bang<\/a>\u201d.<\/p>\n According to current theories, both should have annihilated each other after a colossal explosion \u2014 leaving nothing but an empty universe of pure energy.<\/p>\n But physicists at the University of Southampton<\/a> and the Indian Institute of Technology Kanpur<\/a> say they found a clue in a neutrino<\/a>, one of the lightest particles in the universe.<\/p>\n The research team discovered that an often-ignored relative of the particles \u2014 known as a \u201cdecoupled\u201d heavy neutrino \u2014 could have helped matter dominate over its counterpart.<\/p>\n Study author and University of Southhampton researcher, Dr. Rishav Roshan. (University of Southampton via SWNS)<\/p>\n By Talker<\/p>\n Study author Rishav Roshan said: \u201cThis decoupled heavy neutrino has long been dismissed as an irrelevant background detail in particle physics.<\/p>\n \u201cHowever, it decays incredibly slowly.<\/p>\n \u201cAs the cosmos cooled after the Big Bang, the particle lived long enough that it temporarily took over the energy density of the universe and triggered a matter-dominated period.\u201d<\/p>\n Roshan, from the University of Southampton<\/a>, says most theories on why matter won over antimatter ignored the decoupled heavy particle because experts deemed it too weak to have any impact on others.<\/p>\n However, the Southampton and Kanpur researchers found that the forgotten particle could affect the particle-antiparticle asymmetry essential for our existence.<\/p>\n Roshan said: \u201cThe fact that we are here at all proves that an asymmetry between matter and antimatter occurred.<\/p>\n (Photo by Talha Resitoglu via Pexels)<\/p>\n By Talker<\/p>\n \u201cThe decoupled neutrino shifted the temperature in the early universe at which fundamental particles \u2014 like electrons and other leptons \u2014 interacted with their antiparticles with the help of Standard Model Higgs boson.<\/p>\n \u201cThis temperature acts like a switch that shapes how the matter-antimatter imbalance was built up.\u201d<\/p>\n Paper co-author Sudipta Show says the findings change our understanding of how the early universe expanded so quickly after the Big Bang<\/a>.<\/p>\n He said: \u201cIt offers us a new explanation for how matter won.<\/p>\n \u201cThe dramatic shift in the early expansion of the cosmos leaves distinct but detectable imprints of changes, for example on primordial gravitational waves.\u201d<\/p>\n<\/p>\n
<\/p>\n