A neutrino ( or ) (denoted by the Greek letter ν) is a fermion (an elementary particle with spin of 1/2) that interacts only via the weak interaction and gravity. The neutrino is so named because it is electrically neutral and because its rest mass is so small (-ino) that it was long thought to be zero. The rest mass of the neutrino is much smaller than that of the other known elementary particles excluding massless particles. The weak force has a very short range, the gravitational interaction is extremely weak, and neutrinos do not participate in the strong interaction. Thus, neutrinos typically pass through normal matter unimpeded and undetected.Weak interactions create neutrinos in one of three leptonic flavors: electron neutrinos (νe), muon neutrinos (νμ), or tau neutrinos (ντ), in association with the corresponding charged lepton. Although neutrinos were long believed to be massless, it is now known that there are three discrete neutrino masses with different tiny values, but they do not correspond uniquely to the three flavors. A neutrino created with a specific flavor has an associated specific quantum superposition of all three mass states. As a result, neutrinos oscillate between different flavors in flight. For example, an electron neutrino produced in a beta decay reaction may interact in a distant detector as a muon or tau neutrino. Although only differences between squares of the three mass values are known as of 2019, cosmological observations imply that the sum of the three masses (< 2.14 × 10−37 kg) must be less than one millionth that of the electron mass (9.11 × 10−31 kg).For each neutrino, there also exists a corresponding antiparticle, called an antineutrino, which also has spin of 1/2 and no electric charge. Antineutrinos are distinguished from the neutrinos by having opposite signs of lepton number and right-handed instead of left-handed chirality. To conserve total lepton number (in nuclear beta decay), electron neutrinos only appear together with positrons (anti-electrons) or electron-antineutrinos, whereas electron antineutrinos only appear with electrons or electron neutrinos.Neutrinos are created by various radioactive decays; the following list is not exhaustive, but includes some of those processes:
beta decay of atomic nuclei or hadrons,
natural nuclear reactions such as those that take place in the core of a star
artificial nuclear reactions in nuclear reactors, nuclear bombs, or particle accelerators
during a supernova
during the spin-down of a neutron star
when cosmic rays or accelerated particle beams strike atoms.The majority of neutrinos which are detected about the Earth are from nuclear reactions inside the Sun. At the surface of the Earth, the flux is about 65 billion (6.5×1010) solar neutrinos, per second per square centimeter. Neutrinos can be used for tomography of the interior of the earth.Research is intense in the hunt to elucidate the essential nature of neutrinos, with aspirations of finding:
the three neutrino mass values
the degree of CP violation in the leptonic sector (which may lead to leptogenesis)
evidence of physics which might break the Standard Model of particle physics, such as neutrinoless double beta decay, which would be evidence for violation of lepton number conservation.
Okay, I admit that I laughed out loud when I saw this title at the Cern Courier, but it wasn't laughter at the observation being wrong...
Are neutrinos seasonal?
http://www.cerncourier.com/main/article/39/1/6
Carl
Perhaps I'm simply missing something, but it seems to me that the "evidence" to support the belief that neutrinos change "flavor" is very weak at best. From my perspective, the current argument amounts to "we don't receive every item we sent, so one of them must have changed into a toad"...
Greetings,
I read that there are 3 types of neutrinos, muon, tau and electron. Current theory supported by experiments at SuperKamiokande Detector and 'SNO' suggest that neutrinos can change flavor in the order of electron--> muon--->tau. Also, most now believe that neutrinos are...
Abstract: Since 1982 the Koide mass relation has provided an amazingly
accurate relation between the masses of the charged leptons. In
this note we show how the Koide relation can be expanded to cover
the neutrinos, and we use the relation to predict neutrino masses.
Full paper attached...
I am trying to understand the PBS NOVA ‘The Ghost Particle’ shown Tuesday 28 February 2006.
http://www.pbs.org/wgbh/nova/neutrino/
Question 1 - When neutrinos pass through the Earth interacting in a statistically predictable manner, is this an example of quantum tunneling conforming to a...
i heard that neutrino isn't made of quarks, it almost has no mass but it has a anti matter. what is the difference between a neutrino and its anti particle? what parity is?:confused:
thanks in advance
Hey,
I am just asking a few questions about neutrinos...
Are they affected by gravitational, electromagnetic, or nuclear forces?
In other words is there any means of containment for neutrino particles?
Also how would one generate neutrinos... if its possible?
Neutrinos are emitted during the beta-decay process.
Neutrinos definitely have spin. Do neutrinos have mass? Most texts say neutrinos have zero or negligible rest mass. But Neutrinos travel with the speed of light. So how can any particle with finite mass travel with the speed of light? If so...
If i remember correctly from astrophysics. Neutrinos are said to be relatively uninteractive. Now is that statement an theory or a fact?
whereby "fact" i mean that we see it pass through without interacting
and "theory" we observe the effects of 1 neutrino going into a system
and coming...
Compute the flux of neutrinos arriving at Earth, i.e. the number of neutrions that land on each square meter of Earth's surface each second.
The question is referring to neutrinos created in the photon-photon chain in the Sun.
I already computed that the Sun releases 1.78*10^{38} neutrinos...
some theorist predicts proton can decay, since the decay of proton does not violate any fundemantal conservation law. My question is, could neutrino decay? How come I have never heard of anyone say neutrino could decay?
I have two questions about neutrinos that I haven't been able to figure out:
1. The evidence seems to indicate that neutrinos have rest mass. Since it is invisible to charge and electromagnetic fields and, apparently, gluon fields, how does it interact with matter at all? I think it may have...
How are the electron neutrino, the muon neutrino and the tau neutrino different from each other (except for the leptonic number they carry)?
I heard they BEHAVE like their associated Lepton (el., muon, tau). If so, in what way?
Thanks.
What do people think of the idea that the type of matter a neutrino passes through can affect it's probability of being a certain flavour/colour.
eg, through rock it is more likley to be one colour,
through air it is more likley to be another colour.
I bumbed in such event in on book written in middle 80's.
Does anyone know anything of such phenomena? Has that theory been killed or is there any info available of it anywhere??
Oh joy... I'm writing an essay of neutrinos, and I am really lost.. :|
Oh, and another question... Any other...
Hey, guys! I have exciting news about neutrinos.
Neutrinos are fundamental particles that are neutral in charge and approximately the size of an electron. They come in three favors, and these flavors are: electron neutrion, muon neutrino, and tau neutrino. There symbols are...
i wanted to find out what percent of C neutrinos travel at.
so i got on the web and found pages quoting 'light speed' and 'almost light speed'.
my understanding was that they travel slower than light becuase they change flavour as they travel, (they couldn't change if going at light...
Now that it is becoming apparent that neutrinos are massive (albeit rather small), I have a question that bears upon the accepted symmetry framework as applied to weak interacton.
We know from weak decay (say Beta) that there is parity asymmetry, that the resultant neutrinos are polarized...
I'm a newb so forgive me if this question is ridiculous. In theory(cuz we have no idea of really knowing) how many neutrinos are traveling through the Earth at any given time. Or better yet, how many are traveling through let's say a 1 m x 1m square in any arbitrary position on earth. I'm not...
Hi guys just had a question. I know about neutrinos and how they act - their being able to pass through matter leaving it as it was but my question was how are what are the basics of neutrinos are they antimatter particles of some particle? Someone please enlighten me, thanks.
hi,
Before i begin i am not sure where to put this post wether here or in the general section.
Is Newtons 3rd law broken?
Neutrinos don't follow this rule. the neutrinos can just pass through particles. so don't they break the 3rd rule? :confused:
the cosmic photon background (CMB) evidently contains a lot of information about gravity and the structure of the universe
and it is expected that when instruments get good enough we will
see a cosmic neutrino background (CNB) consisting of even older particles
what do you know about this...
What are the characteristic differences between the two?
I was under the impressions that antimatter and matter had the same characteristics except for an opposite charge. But a neutrino has no charge.
Thanks,
Glenn