A
bstract
We report on the status of supersymmetric seesaw models in the light of recent experimental results on
μ
→
e
+
γ
,
θ
13
and the light Higgs mass at the LHC. SO(10)-like relations are ...assumed for neutrino Dirac Yukawa couplings and two cases of mixing, one large, PMNS-like, and another small, CKM-like, are considered. It is shown that for the large mixing case, only a small range of parameter space with moderate tan
β
is still allowed. This remaining region can be ruled out by an order of magnitude improvement in the current limit on BR(
μ
→
e
+
γ
). We also explore a model with non-universal Higgs mass boundary conditions at the high scale. It is shown that the renormalization group induced flavor violating slepton mass terms are highly sensitive to the Higgs boundary conditions. Depending on the choice of the parameters, they can either lead to strong enhancements or cancellations within the flavor violating terms. Such cancellations might relax the severe constraints imposed by lepton flavor violation compared to mSUGRA. Nevertheless for a large region of parameter space the predicted rates lie within the reach of future experiments once the light Higgs mass constraint is imposed. We also update the potential of the ongoing and future experimental searches for lepton flavor violation in constraining the supersymmetric parameter space.
Supersymmetry: a decade after Higgs discovery Suryanarayana Mummidi, V.; Lamba, Priyanka; Vempati, Sudhir K.
Indian Journal of Physics/Indian journal of physics/Indian Journal of Physics and Proceedings of the Indian Association for the Cultivation of Science,
09/2023, Letnik:
97, Številka:
11
Journal Article
Recenzirano
Odprti dostop
Supersymmetric extensions of the Standard Model have been in vogue for over half a century. They have many interesting theoretical properties like calculability, absence of quadratic divergences, and ...phenomenologically impactful features like gauge coupling unification, dark matter candidates, signatures at present and future colliders, etc. A defining feature of these models is the calculability of Higgs mass in terms of a few parameters. The discovery of a Higgs particle with a mass of around 125 GeV thus has significant implications. The null results for the searches of superpartners at LHC have also put further constraints. Taken together with direct detection limits on weakly interacting massive particle dark matter, it appears that TeV scale supersymmetry is not realized in Nature, and the theoretical expectations have reached a turning point. The present onslaught from the experiments suggests that supersymmetric models need a more complex particle structure, Lagrangian and breaking patterns to be a natural solution to the hierarchy problem. We review existing models and discuss their feasibility in the current and future experimental programs.
In the context of supersymmetric grand unified theories with soft breaking terms arising at the Planck scale, it is generally possible to link flavor changing neutral current and CP violating ...processes occurring in the leptonic and hadronic sectors. We study the correlation between flavor changing squark and slepton mass insertions in models à la SU(5). We show that the constraints coming from lepton flavor violation exhibit a strong impact on CP-violating B decays.
We systematically analyze the correlations between the various leptonic and hadronic flavor violating processes arising in SUSY Grand Unified Theories. Using the GUT-symmetric relations between the ...soft SUSY breaking parameters, we assess the impact of hadronic and leptonic flavor observables on the SUSY sources of flavor violation.
Nowadays in India, diabetic patients are more increasing. The major issue with diabetic patients is Diabetic retinopathy which causes the loss of vision. For the ophthalmologist, it is very difficult ...to identify the diabetic retinopathy because of the low resolution of the eyes. For the specialists, it is easy to find the blood vessels in the retina to diagnose the many populations in a very short time. Various existing methods are used to find the abnormal retinal images of diabetic patients based on their image features. But the results are not that much accurate. In this paper, an enhanced image filter with local entropy thresholding for blood vessel extraction under different normal or abnormal conditions is proposed to improve the performance of the patient information.
That
μ→
e,
γ and
τ→
μ,
γ are sensitive probes of SUSY models with a see-saw mechanism is a well accepted fact. Here we propose a ‘top–down’ approach in a general SUSY
SO(10) scheme. In this ...framework, we show that at least one of the neutrino Yukawa couplings is as large as the top Yukawa coupling. This leads to a strong enhancement of these leptonic flavour changing decay rates. We examine two ‘extreme’ cases, where the lepton mixing angles in the neutrino Yukawa couplings are either small (CKM-like) or large (PMNS-like). In these two cases, we quantify the sensitivity of leptonic radiative decays to the SUSY mass spectrum. In the PMNS case, we find that the ongoing experiments at the B-factories can completely probe the spectrum up to gaugino masses of 500 GeV (any tan
β). Even in the case of CKM-like mixings, large regions of the parameter space will be probed in the near future, making these two processes leading candidates for indirect SUSY searches.
We derive general expressions for soft terms in supergravity where
D-terms contribute significantly to the supersymmetry breaking in addition to the standard
F-type breaking terms. Such
D-terms can ...strongly influence the scalar mass squared terms, while having limited impact on gaugino masses and the
B-terms. We present parameterisations for the soft terms when
D-terms dominate over
F-terms or become comparable with them. Novel patterns emerge which can be tested phenomenologically. In a mixed anomaly-
D mediated scenario, the scalars have masses from
D-mediation, whereas gaugino masses are generated by anomaly mediation. As an application of this analysis, we show that while the “split supersymmetry” like mass spectrum with one fine tuned Higgs is not an automatic outcome of these scenarios, explicit models can be constructed where it can be realised. Finally, we show that large
D-mediated supersymmetry breaking can be realised in string models based on intersecting D-branes. Examples are presented where the moduli are stabilised in the presence of large
D-terms using non-perturbative gaugino condensation like effects.
Flavoured co-annihilation CHOWDHURY, D; GARANI, R; VEMPATI, S K
Pramāṇa,
10/2012, Letnik:
79, Številka:
4
Journal Article
Recenzirano
Odprti dostop
In minimal supergravity (mSUGRA) or CMSSM, one of the main co-annihilating partners of the neutralino is the lightest stau,
. In the presence of flavour violation in the right-handed sector, the ...co-annihilating partner would be a flavour mixed state. The flavour effect is two-fold: (a) It changes the mass of
, thus modifying the parameter space of the co-annihilation and (b) flavour violating scatterings could now contribute to the cross-sections in the early Universe. In fact, it is shown that for large enough
δ
~0.2, these processes would constitute the dominant channels in co-annihilation regions. The amount of flavour mixing permissible is constrained by flavour violating
τ
→
μ
or
τ
→
e
processes. For Δ
RR
mass insertions, the constraints from flavour violation are not strong enough in some regions of the parameter space due to partial cancellations in the amplitudes. In mSUGRA, the regions with cancelations within LFV amplitudes do not overlap with the regions of co-annihilations. In non-universal Higgs model (NUHM), however, these regions do overlap leading to significant flavoured co-annihilations. At the LHC and other colliders, these regions can constitute for interesting signals.
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