Sigma baryon - AbsoluteAstronomy.com

The Sigma baryons are a family of subatomic

Subatomic particle

In physics or chemistry, subatomic particles are the smaller particles composing nucleons and atoms. There are two types of subatomic particles: elementary particles, which are not made of other particles, and composite particles...

hadron

Hadron

In particle physics, a hadron is a composite particle made of quarks held together by the strong force...

particles which have a +2, +1 or -1 elementary charge

Elementary charge

The elementary charge, usually denoted as e, is the electric charge carried by a single proton, or equivalently, the absolute value of the electric charge carried by a single electron. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called...

or are neutral

Neutral particle

In physics, a neutral particle is a particle with no electric charge. This is not to be confused with a real neutral particle, a neutral particle that is also identical to its own antiparticle.-Stable or long-lived neutral particles:...

. They are baryon

Baryon

A baryon is a composite particle made up of three quarks . Baryons and mesons belong to the hadron family, which are the quark-based particles...

s containing three quarks: two up

Up quark

The up quark or u quark is the lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the down quark, forms the neutrons and protons of atomic nuclei...

and/or down

Down quark

The down quark or d quark is the second-lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the up quark, forms the neutrons and protons of atomic nuclei...

quarks, and one third quark, which can be either a strange

Strange quark

The strange quark or s quark is the third-lightest of all quarks, a type of elementary particle. Strange quarks are found in hadrons, which are subatomic particles. Example of hadrons containing strange quarks include kaons , strange D mesons , Sigma baryons , and other strange particles...

(symbols , ), a charm

Charm quark

The charm quark or c quark is the third most massive of all quarks, a type of elementary particle. Charm quarks are found in hadrons, which are subatomic particles made of quarks...

(symbols , ), a bottom

Bottom quark

The bottom quark, also known as the beauty quark, is a third-generation quark with a charge of − e. Although all quarks are described in a similar way by the quantum chromodynamics, the bottom quark's large bare mass , combined with low values of the CKM matrix elements Vub and Vcb, gives it a...

(symbols , ) or a top

Top quark

The top quark, also known as the t quark or truth quark, is an elementary particle and a fundamental constituent of matter. Like all quarks, the top quark is an elementary fermion with spin-, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and...

(symbols , ) quark. However, the top Sigmas are not expected to be observed as the Standard Model

Standard Model

The Standard Model of particle physics is a theory concerning the electromagnetic, weak, and strong nuclear interactions, which mediate the dynamics of the known subatomic particles. Developed throughout the mid to late 20th century, the current formulation was finalized in the mid 1970s upon...

predicts the mean lifetime of top quarks to be roughly . This is about 20 times shorter than the timescale for strong interactions, and therefore it does not form hadrons

Hadronization

In particle physics, hadronization is the process of the formation of hadrons out of quarks and gluons. This occurs after high-energy collisions in a particle collider in which free quarks or gluons are created. Due to postulated colour confinement, these cannot exist individually...

List

The symbols encountered in these lists are: I (isospin
Isospin
In physics, and specifically, particle physics, isospin is a quantum number related to the strong interaction. This term was derived from isotopic spin, but the term is confusing as two isotopes of a nucleus have different numbers of nucleons; in contrast, rotations of isospin maintain the number...

), J (total angular momentum), P (parity
Parity (physics)
In physics, a parity transformation is the flip in the sign of one spatial coordinate. In three dimensions, it is also commonly described by the simultaneous flip in the sign of all three spatial coordinates:...

), u (up quark
Up quark
The up quark or u quark is the lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the down quark, forms the neutrons and protons of atomic nuclei...

), d (down quark
Down quark
The down quark or d quark is the second-lightest of all quarks, a type of elementary particle, and a major constituent of matter. It, along with the up quark, forms the neutrons and protons of atomic nuclei...

), s (strange quark
Strange quark
The strange quark or s quark is the third-lightest of all quarks, a type of elementary particle. Strange quarks are found in hadrons, which are subatomic particles. Example of hadrons containing strange quarks include kaons , strange D mesons , Sigma baryons , and other strange particles...

), c (charm quark
Charm quark
The charm quark or c quark is the third most massive of all quarks, a type of elementary particle. Charm quarks are found in hadrons, which are subatomic particles made of quarks...

), t (top quark
Top quark
The top quark, also known as the t quark or truth quark, is an elementary particle and a fundamental constituent of matter. Like all quarks, the top quark is an elementary fermion with spin-, and experiences all four fundamental interactions: gravitation, electromagnetism, weak interactions, and...

), b (bottom quark
Bottom quark
The bottom quark, also known as the beauty quark, is a third-generation quark with a charge of − e. Although all quarks are described in a similar way by the quantum chromodynamics, the bottom quark's large bare mass , combined with low values of the CKM matrix elements Vub and Vcb, gives it a...

), Q (charge
Charge (physics)
In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers.-Formal definition:...

), B (baryon number), S (strangeness
Strangeness
In particle physics, strangeness S is a property of particles, expressed as a quantum number, for describing decay of particles in strong and electromagnetic reactions, which occur in a short period of time...

), C (charmness), B′ (bottomness
Bottomness
In physics, bottomness also called beauty, is a flavour quantum number reflecting the difference between the number of bottom antiquarks and the number of bottom quarks that are present in a particle: B^\prime = -Bottom quarks have a bottomness of −1 while bottom antiquarks have a...

), T (topness), as well as other subatomic particles (hover for name).

Antiparticles are not listed in the table; however, they simply would have all quarks changed to antiquarks, and Q, B, S, C, B′, T, would be of opposite signs. I, J, and P values in red have not been firmly established by experiments, but are predicted by the quark model

Quark model

In physics, the quark model is a classification scheme for hadrons in terms of their valence quarks—the quarks and antiquarks which give rise to the quantum numbers of the hadrons....

and are consistent with the measurements.

J^P = ⁺ Sigma baryons

J^P = ⁺ Sigma baryons
Particle name	Symbol	Rest mass (MeV/c Speed of light The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time... ²)	I Isospin In physics, and specifically, particle physics, isospin is a quantum number related to the strong interaction. This term was derived from isotopic spin, but the term is confusing as two isotopes of a nucleus have different numbers of nucleons; in contrast, rotations of isospin maintain the number...	J^{PParity (physics) In physics, a parity transformation is the flip in the sign of one spatial coordinate. In three dimensions, it is also commonly described by the simultaneous flip in the sign of all three spatial coordinates:...}	Q Charge (physics) In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers.-Formal definition:... (e Elementary charge The elementary charge, usually denoted as e, is the electric charge carried by a single proton, or equivalently, the absolute value of the electric charge carried by a single electron. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called... )	S Strangeness In particle physics, strangeness S is a property of particles, expressed as a quantum number, for describing decay of particles in strong and electromagnetic reactions, which occur in a short period of time...	C	B' Bottomness In physics, bottomness also called beauty, is a flavour quantum number reflecting the difference between the number of bottom antiquarks and the number of bottom quarks that are present in a particle: B^\prime = -Bottom quarks have a bottomness of −1 while bottom antiquarks have a...	T	Mean lifetime (s Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock.... )	Commonly decays to
Sigma		1,189.37 ± 0.07	1	⁺	+1	−1	0	0	0
Sigma		1,192.642 ± 0.024	1	⁺	0	−1	0	0	0
Sigma		1,197.449 ± 0.030	1	⁺	−1	−1	0	0	0
charmed Sigma	(2455)	2,454.02 ± 0.18	1	⁺	+2	0	+1	0	0
charmed Sigma	(2455)	2,452.9 ± 0.4	1	⁺	+1	0	+1	0	0
charmed Sigma	(2455)	2,453.76 ± 0.18	1	⁺	0	0	+1	0	0
bottom Sigma	(?)		1	⁺	+1	0	0	−1	0	Unknown
bottom Sigma	(?)	Unknown	1	⁺	0	0	0	−1	0	Unknown	Unknown
bottom Sigma	(?)	5,815.2 ± 2.7	1	⁺	−1	0	0	−1	0	Unknown
Top Sigma		—	1	⁺	+2	0	0	0	+1	—	—
Top Sigma		—	1	⁺	+1	0	0	0	+1	—	—
Top Sigma		—	1	⁺	0	0	0	0	+1	—	—

^† Particle currently unobserved, but predicted by the standard model.

^[a] PDG reports the resonance width (Γ). Here the conversion τ = is given instead.

^[b] The specific values of the name has not been decided yet, but will likely be close to (5810).

J^P = ⁺ Sigma baryons

J^P = ⁺ Sigma baryons
Particle name	Symbol	Rest mass (MeV/c Speed of light The speed of light in vacuum, usually denoted by c, is a physical constant important in many areas of physics. Its value is 299,792,458 metres per second, a figure that is exact since the length of the metre is defined from this constant and the international standard for time... ²)	I Isospin In physics, and specifically, particle physics, isospin is a quantum number related to the strong interaction. This term was derived from isotopic spin, but the term is confusing as two isotopes of a nucleus have different numbers of nucleons; in contrast, rotations of isospin maintain the number...	J^{PParity (physics) In physics, a parity transformation is the flip in the sign of one spatial coordinate. In three dimensions, it is also commonly described by the simultaneous flip in the sign of all three spatial coordinates:...}	Q Charge (physics) In physics, a charge may refer to one of many different quantities, such as the electric charge in electromagnetism or the color charge in quantum chromodynamics. Charges are associated with conserved quantum numbers.-Formal definition:... (e Elementary charge The elementary charge, usually denoted as e, is the electric charge carried by a single proton, or equivalently, the absolute value of the electric charge carried by a single electron. This elementary charge is a fundamental physical constant. To avoid confusion over its sign, e is sometimes called... )	S Strangeness In particle physics, strangeness S is a property of particles, expressed as a quantum number, for describing decay of particles in strong and electromagnetic reactions, which occur in a short period of time...	C	B' Bottomness In physics, bottomness also called beauty, is a flavour quantum number reflecting the difference between the number of bottom antiquarks and the number of bottom quarks that are present in a particle: B^\prime = -Bottom quarks have a bottomness of −1 while bottom antiquarks have a...	T	Mean lifetime (s Second The second is a unit of measurement of time, and is the International System of Units base unit of time. It may be measured using a clock.... )	Commonly decays to
Sigma	(1385)	1,382.8 ± 0.4	1	⁺	+1	−1	0	0	0
Sigma	(1385)	1,383.7 ± 1.0	1	⁺	0	−1	0	0	0
Sigma	(1385)	1,387.2 ± 0.5	1	⁺	−1	−1	0	0	0
charmed Sigma	(2520)	2,518.4 ± 0.6	1	⁺	+2	0	+1	0	0
charmed Sigma	(2520)	2,517.5 ± 2.3	1	⁺	+1	0	+1	0	0
charmed Sigma	(2520)	2,518.0 ± 0.5	1	⁺	0	0	+1	0	0
bottom Sigma		Unknown	1	⁺	+1	0	0	−1	0	Unknown	Unknown
bottom Sigma		Unknown	1	⁺	0	0	0	−1	0	Unknown	Unknown
bottom Sigma		Unknown	1	⁺	−1	0	0	−1	0	Unknown	Unknown
Top Sigma		—	1	⁺	+2	0	0	0	+1	—	—
Top Sigma		—	1	⁺	+1	0	0	0	+1	—	—
Top Sigma		—	1	⁺	0	0	0	0	+1	—	—

^† Particle currently unobserved, but predicted by the standard model.

^[c] PDG reports the resonance width (Γ). Here the conversion τ = is given instead.

List

JP = + Sigma baryons

JP = + Sigma baryons

See also

J^P = ⁺ Sigma baryons

J^P = ⁺ Sigma baryons