Khan, Sarif

[["dc.bibliographiccitation.artnumber","133"],["dc.bibliographiccitation.issue","11"],["dc.bibliographiccitation.journal","Journal of High Energy Physics"],["dc.bibliographiccitation.volume","2022"],["dc.contributor.author","Bélanger, Geneviève"],["dc.contributor.author","Choubey, Sandhya"],["dc.contributor.author","Godbole, Rohini M."],["dc.contributor.author","Khan, Sarif"],["dc.contributor.author","Mitra, Manimala"],["dc.contributor.author","Roy, Abhishek"],["dc.date.accessioned","2022-11-28T11:27:37Z"],["dc.date.available","2022-11-28T11:27:37Z"],["dc.date.issued","2022-11-23"],["dc.date.updated","2022-11-28T08:12:54Z"],["dc.description.abstract","Abstract\n \n We present an extension of the SM involving three triplet fermions, one triplet scalar and one singlet fermion, which can explain both neutrino masses and dark matter. One triplet of fermions and the singlet are odd under a Z2 symmetry, thus the model features two possible dark matter candidates. The two remaining Z2-even triplet fermions can reproduce the neutrino masses and oscillation parameters consistent with observations. We consider the case where the singlet has feeble couplings while the triplet is weakly interacting and investigate the different possibilities for reproducing the observed dark matter relic density. This includes production of the triplet WIMP from freeze-out and from decay of the singlet as well as freeze-in production of the singlet from decay of particles that belong to the thermal bath or are thermally decoupled. While freeze-in production is usually dominated by decay processes, we also show cases where the annihilation of bath particles give substantial contribution to the final relic density. This occurs when the new scalars are below the TeV scale, thus in the reach of the LHC. The next-to-lightest odd particle can be long-lived and can alter the successful BBN predictions for the abundance of light elements, these constraints are relevant in both the scenarios where the singlet or the triplet are the long-lived particle. In the case where the triplet is the DM, the model is subject to constraints from ongoing direct, indirect and collider experiments. When the singlet is the DM, the triplet which is the next-to-lightest odd particle can be long-lived and can be probed at the proposed MATHUSLA detector. Finally we also address the detection prospects of triplet fermions and scalars at the LHC."],["dc.identifier.citation","Journal of High Energy Physics. 2022 Nov 23;2022(11):133"],["dc.identifier.doi","10.1007/JHEP11(2022)133"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/117765"],["dc.language.iso","en"],["dc.publisher","Springer Berlin Heidelberg"],["dc.rights.holder","The Author(s)"],["dc.subject","Models for Dark Matter"],["dc.subject","Particle Nature of Dark Matter"],["dc.title","WIMP and FIMP dark matter in singlet-triplet fermionic model"],["dc.type","journal_article"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","37"],["dc.bibliographiccitation.issue","7"],["dc.bibliographiccitation.journal","Journal of High Energy Physics"],["dc.bibliographiccitation.volume","2022"],["dc.contributor.author","Biswas, Anirban"],["dc.contributor.author","Khan, Sarif"],["dc.date.accessioned","2022-08-04T12:00:08Z"],["dc.date.available","2022-08-04T12:00:08Z"],["dc.date.issued","2022-07-06"],["dc.date.updated","2022-07-25T11:18:47Z"],["dc.description.abstract","The quest for new physics beyond the Standard Model is boosted by the recently observed deviation in the anomalous magnetic moments of muon and electron from their respective theoretical prediction. In the present work, we have proposed a suitable extension of the minimal Lμ − Lτ model to address these two experimental results as the minimal model is unable to provide any realistic solution. In our model, a new Yukawa interaction involving first generation of leptons, a singlet vector like fermion (χ±) and a scalar (either an SU(2)L doublet Φ 4 ′ $ {\\Phi}_4^{\\prime } $ or a complex singlet Φ 4 ′ $ {\\Phi}_4^{\\prime } $ ) provides the additional one loop contribution to ae only on top of the usual contribution coming from the Lμ − Lτ gauge boson (Zμτ) to both electron and muon. The judicious choice of Lμ − Lτ charges to these new fields results in a strongly interacting scalar dark matter in O $ \\mathcal{O} $ (MeV) range after taking into account the bounds from relic density, unitarity and self interaction. The freeze-out dynamics of dark matter is greatly influenced by 3 → 2 scatterings while the kinetic equilibrium with the SM bath is ensured by 2 → 2 scatterings with neutrinos where Zμτ plays a pivotal role. The detection of dark matter is possible directly through scatterings with nuclei mediated by the SM Z bosons. Moreover, our proposed model can also be tested in the upcoming e+e− colliders by searching opposite sign di-electron and missing energy signal i.e. at the final state."],["dc.identifier.citation","Journal of High Energy Physics. 2022 Jul 06;2022(7):37"],["dc.identifier.doi","10.1007/JHEP07(2022)037"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/112642"],["dc.language.iso","en"],["dc.rights","CC BY 4.0"],["dc.rights.holder","The Author(s)"],["dc.subject","Cosmology of Theories BSM"],["dc.subject","Early Universe Particle Physics"],["dc.subject","Particle Nature of Dark Matter"],["dc.subject","Specific BSM Phenomenology"],["dc.title","(g − 2)e, μ and strongly interacting dark matter with collider implications"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.artnumber","26"],["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Journal of High Energy Physics"],["dc.bibliographiccitation.volume","2022"],["dc.contributor.author","Costa, Francesco"],["dc.contributor.author","Khan, Sarif"],["dc.contributor.author","Kim, Jinsu"],["dc.date.accessioned","2022-06-17T12:40:57Z"],["dc.date.available","2022-06-17T12:40:57Z"],["dc.date.issued","2022-06-06"],["dc.date.updated","2022-06-17T08:03:23Z"],["dc.description.abstract","We consider an extension of the Standard Model that accounts for the muon g − 2 tension and neutrino masses and study in detail dark matter phenomenology. The model under consideration includes a WIMP and a FIMP scalar dark matter candidates and thus gives rise to two-component dark matter scenarios. We discuss different regimes and mechanisms of production, including the novel freeze-in semi-production, and show that the WIMP and FIMP together compose the observed relic density today. The presence of the extra scalar fields allows phase transitions of the first order. We examine the evolution of the vacuum state and discuss stochastic gravitational wave signals associated with the first-order phase transition. We show that the gravitational wave signals may be probed by future gravitational wave experiments which may serve as a complementary detection signal."],["dc.identifier.citation","Journal of High Energy Physics. 2022 Jun 06;2022(6):26"],["dc.identifier.doi","10.1007/JHEP06(2022)026"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/111435"],["dc.language.iso","en"],["dc.rights.holder","The Author(s)"],["dc.subject","Cosmology of Theories BSM"],["dc.subject","Models for Dark Matter"],["dc.subject","Particle Nature of Dark Matter"],["dc.subject","Phase Transitions in the Early Universe"],["dc.title","A two-component dark matter model and its associated gravitational waves"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.subtype","original_ja"],["dspace.entity.type","Publication"]]