I distinctly remember the news of a weird particle which seems to have gone backwards in time .Probably a Higgs singlet It was probably a high energy collision between proton and proton . A particle which was supposed to be the result of collision was found to exist right before the collision itself.
I am not able to find any links to that article or experiment. Can someone throw light on the same?
An important subject in physics is the difference between matter and antimatter. The mathematical transformation which turns a model of a matter particle into a model of an antimatter particle is called "CP." Differences between matter and antimatter are therefore "violations of CP symmetry."
An important theorem says that the combined transformation CPT, where T is the time-reversal transformation, should leave unchanged any system where special relativity works. We have strong evidence that our universe is a place where special relativity works. So one way to hunt for CP violation is to look for T violation. Sometimes people who are totally doing a CP-violation experiment will describe it instead as a search for a violation of time-reversal symmetry, because that's a little easier to explain.
When there is a significant new result on T-violation, the explanatory literature will often say that "we have shown this process would behave differently if time flowed backwards." There is a nonzero chance that an intelligent person would read that sentence and misunderstand "we made time flow backwards to see what would happen." There is also a nonzero chance that this hypothetical, intelligent, misguided person is a science journalist at a major publication who is reading the paper in order to write a news article about it. The wrong articles are delicious clickbait and spread like wildfire.
So nearly every significant new result on CP violation is accompanied by at least one low-quality news story about how "physicists have reversed the flow of time." Over the last twenty years I have read about time flowing backwards at NIST, at Brookhaven, at CERN, and in Antarctica. In those cases I was able to reconstruct (at the time) the actual result from the bogus news story. The bogus stories get harder to find as they age, because their authors realize how badly they've screwed up and correct or unpublish them.
This must refer to "Causality-Violating Higgs Singlets at the LHC", a paper from early 2011. The paper received a reply, and there was a reply to the reply...
The idea of a space-time with time loops (closed timelike curves) in it, has been around for a long time; at least since the logician Kurt Gödel set out to show his friend Einstein what could happen in his theory... The authors were trying to refine one such construction so that the time loops would definitely have small observable effects.
I see no sign that anyone has ever claimed to observe this paper's predicted effects; the media attention they received, was simply about the possibility. A large part of theoretical particle physics now consists of defining hypothetical scenarios and deducing what effects they would produce, but usually these scenarios are more like "what if there is a new type of particle that interacts like this", not "what if the extra dimensions contain traversible time loops".
There is an interesting sideline to this story. The paper came out in 2011, and later that year, the OPERA neutrino experiment in Italy announced an alleged observation of neutrinos moving faster than light (later attributed to a measurement error); and one of the authors of this paper, had earlier coauthored a paper called "Neutrino time travel". The idea that there's indirect evidence of faster-than-light neutrinos occasionally comes up in neutrino literature and probably encouraged them to develop these theoretical possibilities.
