Stringy approach to the Minimal Supersymmetric Standard Model
Superstring theory is applied to construct the Minimal Supersymmetric Standard Model. The mass spectrum, partial widths and production cross sections of superpartners are calculated. This approach gives concrete predictions for superpartner searches at the LHC.
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irk-123456789-1110672017-01-09T03:02:23Z Stringy approach to the Minimal Supersymmetric Standard Model Malyuta, Yu.M. Obikhod, T.V. Ядерная физика и элементарные частицы Superstring theory is applied to construct the Minimal Supersymmetric Standard Model. The mass spectrum, partial widths and production cross sections of superpartners are calculated. This approach gives concrete predictions for superpartner searches at the LHC. Теорію суперструн застосовано для побудови Мінімальної суперсиметричної стандартної моделі. Виконано обчислення спектра масс, парціальних ширин і перерізів народження суперпартнерів. Цей підхід дає конкретні передбачення для пошуку суперпартнерів на LHC. Теория суперструн применена для построения Минимальной суперсимметричной стандартной модели. Проведены вычисления спектра масс, парциальных ширин и сечений рождения суперпартнеров. Этот подход дает конкретные предсказания для поиска суперпартнеров на LHC. 2010 Article Stringy approach to the Minimal Supersymmetric Standard Model / Yu.M. Malyuta, T.V. Obikhod // Вопросы атомной науки и техники. — 2011. — № 3. — С. 10-13. — Бібліогр.: 11 назв. — англ. 1562-6016 PACS: 11.25.-w, 12.60.Jv, 02.10.Ws http://dspace.nbuv.gov.ua/handle/123456789/111067 en Вопросы атомной науки и техники Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
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Ядерная физика и элементарные частицы Ядерная физика и элементарные частицы Malyuta, Yu.M. Obikhod, T.V. Stringy approach to the Minimal Supersymmetric Standard Model Вопросы атомной науки и техники |
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Superstring theory is applied to construct the Minimal Supersymmetric Standard Model. The mass spectrum, partial widths and production cross sections of superpartners are calculated. This approach gives concrete predictions for superpartner searches at the LHC. |
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Stringy approach to the Minimal Supersymmetric Standard Model |
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Stringy approach to the Minimal Supersymmetric Standard Model |
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Stringy approach to the Minimal Supersymmetric Standard Model |
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Stringy approach to the Minimal Supersymmetric Standard Model |
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stringy approach to the minimal supersymmetric standard model |
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Stringy approach to the Minimal Supersymmetric Standard Model / Yu.M. Malyuta, T.V. Obikhod // Вопросы атомной науки и техники. — 2011. — № 3. — С. 10-13. — Бібліогр.: 11 назв. — англ. |
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Вопросы атомной науки и техники |
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STRINGY APPROACH TO THE MINIMAL
SUPERSYMMETRIC STANDARD MODEL
Yu.M. Malyuta, T.V. Obikhod ∗
Institute for Nuclear Research National Academy of Sciences of Ukraine, 03068, Kiev, Ukraine
(Received March 10, 2010)
Superstring theory is applied to construct the Minimal Supersymmetric Standard Model. The mass spectrum, partial
widths and production cross sections of superpartners are calculated. This approach gives concrete predictions for
superpartner searches at the LHC.
PACS: 11.25.-w, 12.60.Jv, 02.10.Ws
1. INTRODUCTION
The purpose of the present work is to construct the
Minimal Supersymmetric Standard Model [1] from
superstring theory [2]. This aim is achieved by using
the notion of derived category [3]. Such approach al-
lows to determine the mass spectrum, partial widths
and production cross sections of superpartners.
These predictions are important from experimen-
tal point of view as they are connected with searches
for new physics at the LHC.
2. DERIVED CATEGORY
Derived categories are the mathematical foundation
of superstring theory. We consider the derived cate-
gory of distinguished triangles over the abelian cate-
gory of McKay quivers [3]. Objects of this category
are distinguished triangles
(numbers a, b, c and a
′
, b
′
, c
′
denote orbifold charges
[4] characterizing McKay quivers); morphisms of this
category are morphisms of distinguished triangles. In
this approach D-branes are described by quivers Q :
and open superstrings are described by Exti(Q, Q
′
)
groups determined by the diagram [3] :
3. PARTICLE CONTENT
It was shown in [5] that the moduli space of the open
superstring has the form
Ext0(Q, Q
′
) = C aa
′
+bb
′
+cc
′
,
Ext1(Q, Q
′
) = C 3ab
′
+3bc
′
+3ca
′
.
(1)
Substituting in (1) orbifold charges
a = b = c = a′ = b′ = c′ = 4
∗Corresponding author E-mail address: obikhod@kinr.kiev.ua
10 PROBLEMS OF ATOMIC SCIENCE AND TECHNOLOGY, 2011, N3.
Series: Nuclear Physics Investigations (55), p.10-13.
and using the Langlands hypothesis [6], we obtain the
realization of (1) in terms of SU(5) multiplets
3× (24 + 5H + 5H + 5M + 5M + 10M + 10M ) .
This result determines the particle content of the
MSSM.
4. SUPERPOTENTIAL
The gauge invariant MSSM superpotential takes
the form
WSU(5) = λd
ij · 5H × 5(i)
M × 10(j)
M +
+λu
ij · 5H × 10(i)
M × 10(j)
M + µ · 5H × 5H ,
(2)
where 5H and 5H are Higgs multiplets, 5(i)
M and 10(j)
M
are multiplets of quark and lepton superpartners,
λd
ij , λu
ij are Yukawa coupling constants and µ is the
Higgs mixing parameter.
5. MASS SPECTRUM
The analysis of Yukawa coupling constants, based on
observational hints and theoretical considerations, al-
lows to restrict the parameter space in (2) to five free
parameters [7]:
M0 = 0.01 GeV , M1/2 = 600 GeV ,
A0 = 0 , tanβ = 35 , sgn(µ) = +1 .
(3)
Using this restricted parameter set it is possible to
calculate the mass spectrum of superpartners by ap-
plication of the computer program SOFTSUSY [8].
This MSSM spectrum is shown in Table 1.
Table 1. Mass spectrum of superpartners
GeV GeV GeV
ũR 1187 g̃ 1354
ũL 1232 ν̃e 391 χ̃0
1 249
d̃R 1182 ẽR 224 χ̃0
2 471
d̃L 1235 ẽL 398 χ̃0
3 727
c̃R 1187 χ̃0
4 738
c̃L 1232 ν̃µ 391 χ̃±1 470
s̃R 1182 µ̃R 224 χ̃±2 738
s̃L 1235 µ̃L 398
t̃1 958 h0 116
t̃2 1155 ν̃τ 379 A0 671
b̃1 1095 τ̃1 127 H0 671
b̃2 1148 τ̃2 408 H± 676
6. PARTIAL WIDTHS
Using the parameter set (3) it is possible to calcu-
late partial widths of superpartners by application of
the computer program SDECAY [9]. These partial
widths are shown in Tables 2, 3, 4, 5.
Table 2. Partial widths of superpartners
channel BR channel BR
ν̃e χ̃0
1νe 1.000
ẽL χ̃0
1e 1.000
ν̃µ χ̃0
1νµ 1.000
µ̃L χ̃0
1µ 1.000
ν̃τ χ̃0
1ντ 0.072 τ̃1W
+ 0.928
τ̃2 χ̃0
1τ 0.107 τ̃1Z 0.527
τ̃1h
0 0.365
ũR χ̃0
1u 0.997 χ̃0
4u 0.002
ũL χ̃0
1u 0.013 χ̃+
1 d 0.646
χ̃0
2u 0.320 χ̃+
2 d 0.012
χ̃0
4u 0.008
d̃R χ̃0
1d 0.997 χ̃0
4d 0.002
d̃L χ̃0
1d 0.016 χ̃−1 u 0.628
χ̃0
2d 0.317 χ̃−2 u 0.027
χ̃0
4d 0.011
c̃R χ̃0
1c 0.997 χ̃0
4c 0.002
c̃L χ̃0
1c 0.013 χ̃+
1 s 0.646
χ̃0
2c 0.320 χ̃0
2s 0.012
χ̃0
4c 0.008
s̃R χ̃0
1s 0.997 χ̃0
4s 0.002
s̃L χ̃0
1s 0.016 χ̃−1 c 0.628
χ̃0
2s 0.317 χ̃−2 c 0.027
χ̃0
4s 0.011
t̃1 χ̃0
1t 0.216 χ̃0
4t 0.032
χ̃0
2t 0.105 χ̃+
1 b 0.249
χ̃0
3t 0.171 χ̃+
2 b 0.227
Table 3. Partial widths of superpartners
channel BR channel BR
t̃2 χ̃0
1t 0.025 χ̃+
1 b 0.247
χ̃0
2t 0.111 χ̃+
2 b 0.165
χ̃0
3t 0.114 t̃1h
0 0.045
χ̃0
4t 0.213 t̃1Z 0.080
b̃1 χ̃0
1b 0.055 χ̃−1 t 0.390
χ̃0
2b 0.220 χ̃−2 t 0.183
χ̃0
3b 0.063 t̃1W
− 0.047
χ̃0
4b 0.041
b̃2 χ̃0
1b 0.023 χ̃−1 t 0.161
χ̃0
2b 0.091 χ̃−2 t 0.425
χ̃0
3b 0.079 t̃1W
− 0.125
χ̃0
4b 0.095
g̃ d̃Ld∗ 0.019 c̃Lc∗ 0.020
d̃∗Ld 0.019 c̃∗Lc 0.020
d̃Rd∗ 0.038 c̃Rc∗ 0.036
d̃∗Rd 0.038 c̃∗Rc 0.036
ũLu∗ 0.020 b̃1b
∗ 0.078
ũ∗Lu 0.020 b̃∗1b 0.078
ũRu∗ 0.036 b̃2b
∗ 0.054
ũ∗Ru 0.036 b̃∗2b 0.054
s̃Ls∗ 0.019 t̃1t
∗ 0.097
s̃∗Ls 0.019 t̃∗1t 0.097
s̃Rs∗ 0.038 t̃2t
∗ 0.043
s̃∗Rs 0.038 t̃∗2t 0.043
11
Table 4. Partial widths of superpartners
channel BR channel BR
A0 bb∗ 0.858 τ̃−1 τ̃+
2 0.004
τ+τ− 0.130 τ̃+
1 τ̃−2 0.004
tt∗ 0.002
H0 bb∗ 0.859 τ̃−1 τ̃+
1 0.003
τ+τ− 0.130 τ̃−1 τ̃+
2 0.002
tt∗ 0.002 τ̃+
1 τ̃−2 0.002
H+ cb∗ 0.001 tb∗ 0.818
τ+ντ 0.169 τ̃+
1 ν̃τ 0.010
χ̃0
1 ẽ−Re+ 0.032 µ̃+
Rµ− 0.032
ẽ+
Re− 0.032 τ̃−1 τ+ 0.436
µ̃−Rµ+ 0.032 τ̃+
1 τ− 0.436
χ̃0
2 χ̃0
1Z 0.001 τ̃−2 τ+ 0.037
χ̃0
1h
0 0.010 τ̃+
2 τ− 0.037
ẽ−Le+ 0.056 ν̃eν
∗
e 0.064
ẽ+
Le− 0.056 ν̃∗e νe 0.064
µ̃−Lµ+ 0.056 ν̃µν∗µ 0.064
µ̃+
Lµ− 0.056 ν̃∗µνµ 0.064
τ̃−1 τ+ 0.135 ν̃τν∗τ 0.081
τ̃+
1 τ− 0.135 ν̃∗τ ντ 0.081
χ̃0
3 χ̃0
1Z 0.080 χ̃0
2h
0 0.007
χ̃0
2Z 0.193 τ̃−1 τ+ 0.088
χ̃+
1 W− 0.211 τ̃+
1 τ− 0.088
χ̃−1 W+ 0.211 τ̃−2 τ+ 0.051
χ̃0
1h
0 0.016 τ̃+
2 τ− 0.051
7. CROSS SECTIONS
Using the parameter set (3) it is possible to calculate
production cross sections of superpartners by appli-
cation of the computer program PYTHIA [10]. These
cross sections at center-of-mass energy
√
s = 14 TeV
are shown in Table 6.
Table 5. Partial widths of superpartners
channel BR channel BR
χ̃0
4 χ̃0
1Z 0.016 µ̃−Rµ+ 0.001
χ̃0
2Z 0.009 µ̃+
Rµ− 0.001
χ̃+
1 W− 0.208 τ̃−1 τ+ 0.061
χ̃−1 W+ 0.208 τ̃+
1 τ− 0.061
χ̃0
1h
0 0.069 τ̃−2 τ+ 0.058
χ̃0
2h
0 0.171 τ̃+
2 τ− 0.058
ẽ−Le+ 0.005 ν̃eν
∗
e 0.009
ẽ+
Le− 0.005 ν̃∗e νe 0.009
ẽ−Re+ 0.001 ν̃µν∗µ 0.009
ẽ+
Re− 0.001 ν̃∗µνµ 0.009
µ̃−Lµ+ 0.005 ν̃τν∗τ 0.010
µ̃+
Lµ− 0.005 ν̃∗τ ντ 0.010
χ̃+
1 ν̃ee
+ 0.135 µ̃+
Lνµ 0.108
ν̃µµ+ 0.135 τ̃+
1 ντ 0.261
ν̃ττ+ 0.176 τ̃+
2 ντ 0.067
ẽ+
Lνe 0.108 χ̃0
1W
+ 0.010
χ̃+
2 ν̃ee
+ 0.009 τ̃+
2 ντ 0.051
ν̃µµ+ 0.009 χ̃+
1 Z 0.206
ν̃ττ+ 0.105 χ̃0
1W
+ 0.079
ẽ+
Lνe 0.020 χ̃0
2W
+ 0.214
µ̃+
Lνµ 0.020 χ̃+
1 h0 0.183
τ̃+
1 ντ 0.104
Table 6. Cross sections of superpartners
channel cross section
gg → g̃g̃ σg̃g̃ = 0.307 pb
gu → g̃ũ σg̃ũ = 0.891 pb
du → d̃ũ σd̃ũ = 0.466 pb
uu → χ̃+
1 χ̃−1 σ
χ̃+
1 χ̃−1
= 0.157 pb
du → χ̃+
1 χ̃0
2 σ
χ̃+
1 χ̃0
2
= 0.208 pb
Table 7. Lower limits on masses reached at colliders
particle Condition Lower limit (GeV) Source
χ̃±1 gaugino Mν̃ > 200 GeV 103 LEP 2
Mν̃ > Mχ̃± 85 LEP 2
any Mν̃ 45 Z width
Higgsino M2 < 1 TeV 99 LEP 2
GMSB 150 D0 isolated photons
RPV LLE worst case 87 LEP 2
LQD m0 > 500 GeV 88 LEP 2
χ̃0
1 indirect any tanβ, Mν̃ > 500 GeV 39 LEP 2
any tanβ, any m0 36 LEP 2
any tanβ, any m0, SUGRA Higgs 59 LEP 2 combined
GMSB 93 LEP 2 combined
RPV LLE worst case 23 LEP 2
ẽR eχ̃0
1 ∆M > 10 GeV 99 LEP 2 combined
µ̃R µχ̃0
1 ∆M > 10 GeV 95 LEP 2 combined
τ̃R τχ̃0
1 Mχ̃0
1
< 20 GeV 80 LEP 2 combined
ν̃ 43 Z width
µ̃R, τ̃R stable 86 LEP 2 combined
t̃1 cχ̃0
1 any θmix, ∆M > 10 GeV 95 LEP 2 combined
any θmix, Mχ̃0
1
∼ 1
2
Mt̃ 115 CDF
any θmix, and any ∆M 59 ALEPH
blν̃ any θmix, ∆M > 7 GeV 96 LEP 2 combined
g̃ any Mq̃ 195 CDF jets+ET
q̃ Mq̃ = Mg̃ 300 CDF jets+ET
12
8. COMPARISON WITH EXPERIMENTS
Comparison of the predicted MSSM spectrum with
experimental data obtained at the LEP and TEVA-
TRON [11] (see Table 7) shows, that the calculated
masses exceed the lower limits on masses reached
at colliders. New searches for superpartners will be
made at the LHC.
References
1. H.E. Haber. Introductory low-energy supersym-
metry // arXiv: hep-ph/9306207.
2. C. Vafa, et al. Stringy reflections on LHC
// http://www.claymath.org/workshops/lhc/.
3. P.S. Aspinwall. D-branes on Calabi-Yau mani-
folds // arXiv: hep-th/0403166.
4. M.R. Douglas, B. Fiol and C. Römelsberger. The
spectrum of BPS branes on a noncompact Calabi-
Yau // JHEP. 2005, 09, p.1-57.
5. S. Katz, T. Pantev, and E. Sharpe. D-branes,
orbifolds, and Ext groups // Nucl. Phys. 2003,
B673, p.263-300.
6. W. Schmid. Homogeneous complex manifolds
and representations of semisimple Lie groups //
Proc. Natl. Acad. Sci. USA. 1968, 69, p.56-59.
7. J.J. Heckman, and C. Vafa. F-theory, GUTs, and
the weak scale // arXiv:0809.1098 [hep-th].
8. B.C. Allanach. SOFTSUSY2.0: a program for
calculating supersymmetric spectra // Comput.
Phys. Commun. 2002, 143, p.305-331.
9. M. Muhlleitner, A. Djouadi, and Y. Mambrini.
SDECAY: a fortran code for the decays of the
supersymmetric particles in the MSSM // Com-
put. Phys. Commun. 2005, 168, p.46-70.
10. T. Sjöstrand, S. Mrenna and P. Skands. PYTHIA
6.4 Physics and Manual // JHEP. 2006, 05, p.1-
26.
11. M. Schmitt. Supersymmetry, Part II (Experi-
ment) // Phys. Lett. 2004, B592, p.1014-1023.
СТРУННЫЙ ПОДХОД К МИНИМАЛЬНОЙ СУПЕРСИММЕТРИЧНОЙ
СТАНДАРТНОЙ МОДЕЛИ
Ю.М. Малюта, Т.В. Обиход
Теория суперструн применена для построения Минимальной суперсимметричной стандартной модели.
Проведены вычисления спектра масс, парциальных ширин и сечений рождения суперпартнеров. Этот
подход дает конкретные предсказания для поиска суперпартнеров на LHC.
СТРУННИЙ ПIДХIД ДО МIНIМАЛЬНОЇ СУПЕРСИМЕТРИЧНОЇ СТАНДАРТНОЇ
МОДЕЛI
Ю.М. Малюта, Т.В. Обiход
Теорiю суперструн застосовано для побудови Мiнiмальної суперсиметричної стандартної моделi. Вико-
нано обчислення спектра масс, парцiальних ширин i перерiзiв народження суперпартнерiв. Цей пiдхiд
дає конкретнi передбачення для пошуку суперпартнерiв на LHC.
13
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