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","193"],["dc.bibliographiccitation.issue","5"],["dc.bibliographiccitation.journal","Journal of High Energy Physics"],["dc.bibliographiccitation.volume","2019"],["dc.contributor.author","Biswas, Anirban"],["dc.contributor.author","Choubey, Sandhya"],["dc.contributor.author","Covi, Laura"],["dc.contributor.author","Khan, Sarif"],["dc.date.accessioned","2021-11-22T14:31:46Z"],["dc.date.available","2021-11-22T14:31:46Z"],["dc.date.issued","2019"],["dc.description.abstract","In this work, we explain three beyond standard model (BSM) phenomena, namely neutrino masses, the baryon asymmetry of the Universe and Dark Matter, within a single model and in each explanation the right handed (RH) neutrinos play the prime role. Indeed by just introducing two RH neutrinos we can generate the neutrino masses by the Type-I seesaw mechanism. The baryon asymmetry of the Universe can arise from thermal leptogenesis from the decay of lightest RH neutrino before the decoupling of the electroweak sphaleron transitions, which redistribute the B − L number into a baryon number. At the same time, the decay of the RH neutrino can produce the Dark Matter (DM) as an asymmetric Dark Matter component. The source of CP violation in the two sectors is exactly the same, related to the complex couplings of the neutrinos. By determining the comoving number density for different values of the CP violation in the DM sector, we obtain a particular value of the DM mass after satisfying the relic density bound. We also give prediction for the DM direct detection (DD) in the near future by different ongoing DD experiments."],["dc.identifier.doi","10.1007/JHEP05(2019)193"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16224"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/93401"],["dc.language.iso","en"],["dc.notes.intern","Migrated from goescholar"],["dc.relation","info:eu-repo/grantAgreement/EC/H2020/690575/EU//InvisiblesPlus"],["dc.relation","info:eu-repo/grantAgreement/EC/H2020/674896/EU//ELUSIVES"],["dc.relation.eissn","1029-8479"],["dc.rights","CC BY 4.0"],["dc.rights.access","openAccess"],["dc.rights.uri","https://creativecommons.org/licenses/by/4.0"],["dc.subject","Cosmology of Theories beyond the SM; Neutrino Physics"],["dc.subject.ddc","530"],["dc.title","Common origin of baryon asymmetry, Dark Matter and neutrino mass"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dc.type.peerReviewed","yes"],["dc.type.version","published_version"],["dspace.entity.type","Publication"]]

[["dc.bibliographiccitation.issue","6"],["dc.bibliographiccitation.journal","Journal of High Energy Physics"],["dc.bibliographiccitation.volume","2019"],["dc.contributor.author","Abdallah, Waleed"],["dc.contributor.author","Choubey, Sandhya"],["dc.contributor.author","Khan, Sarif"],["dc.date.accessioned","2020-12-10T14:07:34Z"],["dc.date.available","2020-12-10T14:07:34Z"],["dc.date.issued","2019"],["dc.description.abstract","The non-thermal dark matter (DM) production via the so-called freeze-in mechanism provides a simple alternative to the standard thermal WIMP scenario. In this work, we consider a popular (1)_{B-L}$ extension of the standard model (SM) in the context of inverse seesaw mechanism which has at least one (fermionic) FIMP DM candidate. Due to the added $\\mathbb{Z}_{2}$ symmetry, a SM gauge singlet fermion, with mass of order keV, is stable and can be a warm DM candidate. Also, the same $\\mathbb{Z}_{2}$ symmetry helps the lightest right-handed neutrino, with mass of order GeV, to be a stable or long-lived particle by making a corresponding Yukawa coupling very small. This provides a possibility of a two component DM scenario as well. Firstly, in the absence of a GeV DM component (i.e., without tuning its corresponding Yukawa coupling to be very small), we consider only a keV DM as a single component DM, which is produced by the freeze-in mechanism via the decay of the extra '$ gauge boson associated to (1)_{B-L}$ and can consistently explain the DM relic density measurements. In contrast with most of the existing literature, we have found a reasonable DM production from the annihilation processes. After numerically studying the DM production, we show the dependence of the DM relic density as a function of its relevant free parameters. We use these results to obtain the parameter space regions that are compatible with the DM relic density bound. Secondly, we study a two component DM scenario and emphasize that the current DM relic density bound can be satisfied for a wide range of parameter space."],["dc.identifier.arxiv","1904.10015v2"],["dc.identifier.doi","10.1007/JHEP06(2019)095"],["dc.identifier.eissn","1029-8479"],["dc.identifier.purl","https://resolver.sub.uni-goettingen.de/purl?gs-1/16261"],["dc.identifier.uri","https://resolver.sub.uni-goettingen.de/purl?gro-2/70241"],["dc.language.iso","en"],["dc.notes.intern","DOI Import GROB-354"],["dc.relation.issn","1029-8479"],["dc.rights","CC BY 3.0"],["dc.rights.uri","https://creativecommons.org/licenses/by/3.0/"],["dc.title","FIMP dark matter candidate(s) in a -L$ model with inverse seesaw mechanism"],["dc.type","journal_article"],["dc.type.internalPublication","yes"],["dspace.entity.type","Publication"]]