Sigma baryonu: Revizyonlar arasındaki fark

[kontrol edilmiş revizyon]

← Önceki sürümle aradaki fark Sonraki sürümle aradaki fark →

İçerik silindi İçerik eklendi

Satır içi

Sayfanın 06.01, 25 Eylül 2018 tarihindeki hâli

Sigma baryonları, birinci çeşni nesillerinden (yukarı veya aşağı kuarklar) iki kuarka, daha yüksek çeşnili nesillerinden ise üçüncü bir kuarka sahip; herhangi iki kuark çeşnisinin işaret değiştirmesine rağmen dalga fonksiyonunun değiştirmediği hadron parçacığı ailesidir. Bu nedenlerden ötürü bu tip parçacıklar birer baryondur, toplam izospinleri 1'dir ve nötr olabildikleri gibi +2, +1 ya da -1 temel yüke sahip olabilirler. Yalnızca çeşni değişimi sırasında dalga fonksiyonunun farklılık göstermesi açısından Lambda baryonlarından ayrılırlar.

Üçüncü kuark; garip (sembolleri:
Σ+
,
Σ0
,
Σ-
), tılsım (sembolleri:
Σ++
c,
Σ+
c,
Σ0
c), alt (sembolleri:
Σ+
b,
Σ0
b,
Σ-
b) ya da üst (sembolleri:
Σ++
t,
Σ+
t,
Σ0
t) kuark olabilir. Buna karşın üst Sigma baryonların, Standart Model'de öngörüldüğü şekilde üst kuarkların ortalama yaşam sürelerinin yaklaşık 5×10^-25 s olması sebebiyle gözlemlenmesi mümkün değildir.^[1]

List

The symbols encountered in these lists are: I (isospin), J (total angular momentum), P (parity), u (up quark), d (down quark), s (strange quark), c (charm quark), t (top quark), b (bottom quark), Q (electric charge), S (strangeness), C (charmness), B′ (bottomness), 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 vice versa), 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 and are consistent with the measurements.^[2]^[3]

J^P = 1/2⁺ Sigma baryons

J^P = 1/2⁺ Sigma baryons
Particle name	Symbol	Quark content	Rest mass (MeV/c²)	I	J^P	Q (e)	S	C	B'	T	Mean lifetime (s)	Commonly decays to
Sigma^[4]	Σ+	u u s	1,189.37 ± 0.07	1	1/2⁺	+1	−1	0	0	0	8.018 ± 0.026 × 10⁻¹¹	p+ + π0 or n0 + π+
Sigma^[5]	Σ0	u d s	1,192.642 ± 0.024	1	1/2⁺	0	−1	0	0	0	7.4 ± 0.7 × 10⁻²⁰	Λ0 + γ
Sigma^[6]	Σ-	d d s	1,197.449 ± 0.030	1	1/2⁺	−1	−1	0	0	0	1.479 ± 0.011 × 10⁻¹⁰	n0 + π-
charmed Sigma^[7]	Σ++ c(2455)	u u c	2,454.02 ± 0.18	1	1/2 ⁺	+2	0	+1	0	0	3.0 ± 0.4 × 10⁻²²^{^[a]}	Λ+ c + π+
charmed Sigma^[7]	Σ+ c(2455)	u d c	2,452.9 ± 0.4	1	1/2 ⁺	+1	0	+1	0	0	>1.4 × 10⁻²²^{^[a]}	Λ+ c + π0
charmed Sigma^[7]	Σ0 c(2455)	d d c	2,453.76 ± 0.18	1	1/2 ⁺	0	0	+1	0	0	3.0 ± 0.5 × 10⁻²²^{^[a]}	Λ+ c + π-
bottom Sigma^[8]	Σ+ b	u u b	5,807.7 ± 3.8	1	1/2 ⁺	+1	0	0	−1	0	Unknown	Λ0 b + π+ (seen)
bottom Sigma^{^†}	Σ0 b	u d b	Unknown	1	1/2 ⁺	0	0	0	−1	0	Unknown	Unknown
bottom Sigma^[8]	Σ- b	d d b	5,815.2 ± 2.7	1	1/2 ⁺	−1	0	0	−1	0	Unknown	Λ0 b + π- (seen)
Top Sigma^{^†}	Σ++ t	u u t	—	1	1/2 ⁺	+2	0	0	0	+1	—	—
Top Sigma^{^†}	Σ+ t	u d t	—	1	1/2 ⁺	+1	0	0	0	+1	—	—
Top Sigma^{^†}	Σ0 t	d d t	—	1	1/2 ⁺	0	0	0	0	+1	—	—

^† ^ The standard model predicts that this particle cannot exist due to the short lifetime of the top quark.
^[a] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħ/Γ is given instead.
^[b] ^ The specific values of the name has not been decided yet, but will likely be close to
Σ
b(5810).

J^P = 3/2⁺ Sigma baryons

J^P = 3/2⁺ Sigma baryons
Particle name	Symbol	Quark content	Rest mass (MeV/c²)	I	J^P	Q (e)	S	C	B'	T	Mean lifetime (s)	Commonly decays to
Sigma^[9]	Σ∗+ (1385)	u u s	1,382.8 ± 0.4	1	3/2⁺	+1	−1	0	0	0	1.84 ± 0.04 × 10⁻²³^{^[c]}	Λ0 + π+ or Σ+ + π0 or Σ0 + π+
Sigma^[9]	Σ∗0 (1385)	u d s	1,383.7 ± 1.0	1	3/2⁺	0	−1	0	0	0	1.8 ± 0.3 × 10⁻²³^{^[c]}	Λ0 + π0 or Σ+ + π- or Σ0 + π0
Sigma^[9]	Σ∗- (1385)	d d s	1,387.2 ± 0.5	1	3/2⁺	−1	−1	0	0	0	1.67 ± 0.09 × 10⁻²³^{^[c]}	Λ0 + π- or Σ0 + π- or Σ- + π0 or
charmed Sigma^[10]	Σ∗++ c(2520)	u u c	2,518.4 ± 0.6	1	3/2 ⁺	+2	0	+1	0	0	4.4 ± 0.6 × 10⁻²³^{^[c]}	Λ+ c + π+
charmed Sigma^[10]	Σ∗+ c(2520)	u d c	2,517.5 ± 2.3	1	3/2 ⁺	+1	0	+1	0	0	>3.9 × 10⁻²³^{^[c]}	Λ+ c + π0
charmed Sigma^[10]	Σ∗0 c(2520)	d d c	2,518.0 ± 0.5	1	3/2 ⁺	0	0	+1	0	0	4.1 ± 0.5 × 10⁻²³^{^[c]}	Λ+ c + π-
bottom Sigma^{^†}	Σ∗+ b	u u b	Unknown	1	3/2 ⁺	+1	0	0	−1	0	Unknown	Unknown
bottom Sigma^{^†}	Σ∗0 b	u d b	Unknown	1	3/2 ⁺	0	0	0	−1	0	Unknown	Unknown
bottom Sigma^{^†}	Σ∗- b	d d b	Unknown	1	3/2 ⁺	−1	0	0	−1	0	Unknown	Unknown
Top Sigma^{^†}	Σ∗++ t	u u t	—	1	3/2 ⁺	+2	0	0	0	+1	—	—
Top Sigma^{^†}	Σ∗+ t	u d t	—	1	3/2 ⁺	+1	0	0	0	+1	—	—
Top Sigma^{^†}	Σ∗0 t	d d t	—	1	3/2 ⁺	0	0	0	0	+1	—	—

^† ^ The standard model predicts that this particle cannot exist due to the short lifetime of the top quark.
^[c] ^ PDG reports the resonance width (Γ). Here the conversion τ = ħ/Γ is given instead.

Kaynakça

^ Quadt, A. (2006). "Top quark physics at hadron colliders". European Physical Journal C (İngilizce). 48 (3). ss. 835-1000. Bibcode:2006EPJC...48..835Q. doi:10.1140/epjc/s2006-02631-6.
^ C. Amsler et al. (2008): Particle summary tables – Baryons
^ J. G. Körner et al. (1994)
^ C. Amsler et al. (2008): Particle listings –
Σ+
^ C. Amsler et al. (2008): Particle listings –
Σ0
^ C. Amsler et al. (2008): Particle listings –
Σ-
^ ^a ^b ^c C. Amsler et al. (2008): Particle listings –
Σ
c(2455)
^ ^a ^b T. Aaltonen et al. (2007a)
^ ^a ^b ^c C. Amsler et al. (2008): Particle listings –
Σ
(1385)
^ ^a ^b ^c C. Amsler et al. (2008): Particle listings –
Σ
c(2520)

[Quadt-1] Quadt, A. (2006). "Top quark physics at hadron colliders". European Physical Journal C (İngilizce). 48 (3). ss. 835-1000. Bibcode:2006EPJC...48..835Q. doi:10.1140/epjc/s2006-02631-6.

[2] C. Amsler et al. (2008): Particle summary tables – Baryons

[3] J. G. Körner et al. (1994)

[PDGSigma+-4] C. Amsler et al. (2008): Particle listings –
Σ+

[PDGSigma0-5] C. Amsler et al. (2008): Particle listings –
Σ0

[PDGSigma--6] C. Amsler et al. (2008): Particle listings –
Σ-

[PDGCharmedSigma(2455)-7] C. Amsler et al. (2008): Particle listings –
Σ
c(2455)

[BottomSigma-8] T. Aaltonen et al. (2007a)

[PDGSigma*-9] C. Amsler et al. (2008): Particle listings –
Σ
(1385)

[PDGCharmedSigma*-10] C. Amsler et al. (2008): Particle listings –
Σ
c(2520)

[1]

[2]

[3]

[4]

[5]

[6]

[7]

[a]

[8]

†

[9]

[c]

[10]

†

Sayfanın 06.01, 25 Eylül 2018 tarihindeki hâli

List

JP = 1/2+ Sigma baryons

JP = 3/2+ Sigma baryons

Kaynakça

J^P = 1/2⁺ Sigma baryons

J^P = 3/2⁺ Sigma baryons