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Naturalness in low-scale SUSY models and "non-linear" MSSM.

Antoniadis I, Babalic EM, Ghilencea DM - Eur Phys J C Part Fields (2014)

Bottom Line: This is done without introducing additional fields in the visible sector, unlike other models that attempt to reduce [Formula: see text].In the present case [Formula: see text] is reduced due to additional (effective) quartic Higgs couplings proportional to the ratio [Formula: see text] of the visible to the hidden sector SUSY breaking scales.By increasing the hidden sector scale [Formula: see text] one obtains a continuous transition for fine-tuning values, from this model to the usual (gravity mediated) MSSM-like models.

View Article: PubMed Central - PubMed

Affiliation: CERN Theory Division, 1211 Geneva 23, Switzerland.

ABSTRACT

In MSSM models with various boundary conditions for the soft breaking terms ([Formula: see text]) and for a Higgs mass of 126 GeV, there is a (minimal) electroweak fine-tuning [Formula: see text] to [Formula: see text] for the constrained MSSM and [Formula: see text] for non-universal gaugino masses. These values, often regarded as unacceptably large, may indicate a problem of supersymmetry (SUSY) breaking, rather than of SUSY itself. A minimal modification of these models is to lower the SUSY breaking scale in the hidden sector ([Formula: see text]) to few TeV, which we show to restore naturalness to more acceptable levels [Formula: see text] for the most conservative case of low [Formula: see text] and ultraviolet boundary conditions as in the constrained MSSM. This is done without introducing additional fields in the visible sector, unlike other models that attempt to reduce [Formula: see text]. In the present case [Formula: see text] is reduced due to additional (effective) quartic Higgs couplings proportional to the ratio [Formula: see text] of the visible to the hidden sector SUSY breaking scales. These couplings are generated by the auxiliary component of the goldstino superfield. The model is discussed in the limit its sgoldstino component is integrated out so this superfield is realized non-linearly (hence the name of the model) while the other MSSM superfields are in their linear realization. By increasing the hidden sector scale [Formula: see text] one obtains a continuous transition for fine-tuning values, from this model to the usual (gravity mediated) MSSM-like models.

No MeSH data available.


Related in: MedlinePlus

The EW fine-tuning  (left) and  (right) as functions of the SM-like Higgs mass  (in GeV), all evaluated at one loop, for . These plots have a fixed value  TeV of the SUSY breaking scale and  increases from left () to right () as shown by different colors: black/leftmost region: ; purple: ; blue: ; cyan: ; yellow: ; red/rightmost region:  (a larger  region is on top of that of smaller ). For  GeV, minimal  and , while in the corresponding constrained MSSM minimal values (for ), –, too large to be shown here; for details see figures 1–8 in [30]. The wide range of values for  was chosen only to display the  dependence and to allow for the 2–3 GeV theoretical error of  [42–44]
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Fig2: The EW fine-tuning (left) and (right) as functions of the SM-like Higgs mass (in GeV), all evaluated at one loop, for . These plots have a fixed value  TeV of the SUSY breaking scale and increases from left () to right () as shown by different colors: black/leftmost region: ; purple: ; blue: ; cyan: ; yellow: ; red/rightmost region: (a larger region is on top of that of smaller ). For  GeV, minimal and , while in the corresponding constrained MSSM minimal values (for ), –, too large to be shown here; for details see figures 1–8 in [30]. The wide range of values for was chosen only to display the dependence and to allow for the 2–3 GeV theoretical error of [42–44]

Mentions: Using the results in Eqs. (31) to (37) we evaluated and for fixed values of the SUSY breaking scale in the hidden sector for , subject to the EW constraints (for a discussion of these, see [30]). Note that imposing the Higgs mass range of  GeV (to allow for the theoretical error [42–44]) automatically respects these constraints [30]. For a rapid convergence of the perturbative expansion in of the Lagrangian we demanded that , where stands for SUSY breaking terms.11 The results are shown in Figs. 2, 3, and 4.


Naturalness in low-scale SUSY models and "non-linear" MSSM.

Antoniadis I, Babalic EM, Ghilencea DM - Eur Phys J C Part Fields (2014)

The EW fine-tuning  (left) and  (right) as functions of the SM-like Higgs mass  (in GeV), all evaluated at one loop, for . These plots have a fixed value  TeV of the SUSY breaking scale and  increases from left () to right () as shown by different colors: black/leftmost region: ; purple: ; blue: ; cyan: ; yellow: ; red/rightmost region:  (a larger  region is on top of that of smaller ). For  GeV, minimal  and , while in the corresponding constrained MSSM minimal values (for ), –, too large to be shown here; for details see figures 1–8 in [30]. The wide range of values for  was chosen only to display the  dependence and to allow for the 2–3 GeV theoretical error of  [42–44]
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4383770&req=5

Fig2: The EW fine-tuning (left) and (right) as functions of the SM-like Higgs mass (in GeV), all evaluated at one loop, for . These plots have a fixed value  TeV of the SUSY breaking scale and increases from left () to right () as shown by different colors: black/leftmost region: ; purple: ; blue: ; cyan: ; yellow: ; red/rightmost region: (a larger region is on top of that of smaller ). For  GeV, minimal and , while in the corresponding constrained MSSM minimal values (for ), –, too large to be shown here; for details see figures 1–8 in [30]. The wide range of values for was chosen only to display the dependence and to allow for the 2–3 GeV theoretical error of [42–44]
Mentions: Using the results in Eqs. (31) to (37) we evaluated and for fixed values of the SUSY breaking scale in the hidden sector for , subject to the EW constraints (for a discussion of these, see [30]). Note that imposing the Higgs mass range of  GeV (to allow for the theoretical error [42–44]) automatically respects these constraints [30]. For a rapid convergence of the perturbative expansion in of the Lagrangian we demanded that , where stands for SUSY breaking terms.11 The results are shown in Figs. 2, 3, and 4.

Bottom Line: This is done without introducing additional fields in the visible sector, unlike other models that attempt to reduce [Formula: see text].In the present case [Formula: see text] is reduced due to additional (effective) quartic Higgs couplings proportional to the ratio [Formula: see text] of the visible to the hidden sector SUSY breaking scales.By increasing the hidden sector scale [Formula: see text] one obtains a continuous transition for fine-tuning values, from this model to the usual (gravity mediated) MSSM-like models.

View Article: PubMed Central - PubMed

Affiliation: CERN Theory Division, 1211 Geneva 23, Switzerland.

ABSTRACT

In MSSM models with various boundary conditions for the soft breaking terms ([Formula: see text]) and for a Higgs mass of 126 GeV, there is a (minimal) electroweak fine-tuning [Formula: see text] to [Formula: see text] for the constrained MSSM and [Formula: see text] for non-universal gaugino masses. These values, often regarded as unacceptably large, may indicate a problem of supersymmetry (SUSY) breaking, rather than of SUSY itself. A minimal modification of these models is to lower the SUSY breaking scale in the hidden sector ([Formula: see text]) to few TeV, which we show to restore naturalness to more acceptable levels [Formula: see text] for the most conservative case of low [Formula: see text] and ultraviolet boundary conditions as in the constrained MSSM. This is done without introducing additional fields in the visible sector, unlike other models that attempt to reduce [Formula: see text]. In the present case [Formula: see text] is reduced due to additional (effective) quartic Higgs couplings proportional to the ratio [Formula: see text] of the visible to the hidden sector SUSY breaking scales. These couplings are generated by the auxiliary component of the goldstino superfield. The model is discussed in the limit its sgoldstino component is integrated out so this superfield is realized non-linearly (hence the name of the model) while the other MSSM superfields are in their linear realization. By increasing the hidden sector scale [Formula: see text] one obtains a continuous transition for fine-tuning values, from this model to the usual (gravity mediated) MSSM-like models.

No MeSH data available.


Related in: MedlinePlus