117174894
Probing Higgs bosons via the type III seesaw mechanism at the LHC
We show that the type III seesaw mechanism opens up a promising possibility of searching the Higgs boson in the $b \bar b$ channel through the Higgs production associated with a charged lepton coming from the decay of the triplet seesaw particle. In particular we look for the $2b$ signals with trileptons or same-sign dileptons to construct the Higgs and the triplet fermion mass and calculate the reach with the integrated luminosity of 10 fb$^{-1}$ at the 14 TeV LHC.
12790212
Signatures of gaugino mass non-universality in cascade Higgs production at the LHC
Supersymmetric cascades, involving charginos and neutralinos at various stages, contribute in a significant way to Higgs production at the LHC. We explore the nature of such cascades, completely relaxing the universality of the gaugino masses. It is found that the deviation from the scenario with universal gaugino masses would be reflected in the relative production rates for the lightest neutral Higgs and the charged Higgses.
118627555
Higgs signatures in inverse seesaw model at the LHC
A bstractIn the inverse seesaw mechanism where the spontaneously broken B-L symmetry induces tiny B-L violating Majorana masses for right-handed neutrinos, non-standard Higgs signatures can arise due to a possible Higgs doublet and singlet mixing and/or Higgs boson decays to a left- and right-handed neutrino. This leads to a remarkable feature of hadronically quiet di-lepton final states which can exhibit, in particular, lepton flavour violating signatures coming from flavour-dependent neutrino Yukawa couplings. In this process, one lepton coming from the right-handed decay could be soft enough can be missed by the trigger level cuts of CMS and ATLAS for the di-lepton plus missing energy signature. The prospects of such a signature are investigated for 8 TeV and 14 TeV center of mass energy of the LHC, taking the maximum value of the allowed neutrino Yukawa coupling and the right-handed neutrino mass of 100 GeV. A PYTHIA level simulation shows that the integrated luminosity of 10-20/fb and 1.6/fb for 8 TeV is required to observe the inclusive leptonic and lepton flavour violating signatures, respectively. For 14 TeV, the reach is more and a larger parameter space of the inverse seesaw model can be probed.
118524249
Unusual Higgs boson signal in R-parity violating nonminimal supersymmetric models at the LHC
We predict an unconventional background free signal of the Higgs boson in $R$-parity violating nonminimal supersymmetric models at the Large Hadron Collider (LHC). The signal comprises dilepton plus four hadronic jets and two large displaced vertices. The displaced leptons and jets are coming from the decay of the lightest supersymmetric particle (LSP), which is predominantly a gauge-singlet neutrino. A pair of such LSPs can couple to a Higgs boson, created via gluon fusion. We have analyzed two cases - one corresponding to the tree-level Higgs boson mass and another with the one-loop corrected mass of the Higgs boson. A reliable Higgs mass reconstruction using this signal can lead to discovery at the LHC with center-of-mass energy $\sqrt{s}=14~\rm{TeV}$ and 5 fb$^{-1}$ of integrated luminosity $(\mathcal{L})$. Even at $\sqrt{s}=7~\rm{TeV}$ and $\mathcal{L}$ = 5 fb$^{-1}$, a reasonable number of events are expected. Besides, mass reconstruction of a gauge-singlet LSP can provide an estimate of the seesaw scale.
118467851
Displaced Higgs production in type III seesaw
We point out that the type III seesaw mechanism introducing fermion triplets predicts peculiar Higgs boson signatures of displaced vertices with two b jets and one or two charged particles which can be cleanly identified. In a supersymmetric theory, the scalar partner of the fermion triplet contains a neutral dark matter candidate which is almost degenerate with its charged components. A Higgs boson can be produced together with such a dark matter triplet in the cascade decay chain of a strongly produced squark or gluino. When the next lightest supersymmetric particle (NLSP) is bino/wino-like, there appears a Higgs boson associated with two charged tracks of a charged lepton and a heavy charged scalar at a displacement larger than about 1 mm. The corresponding production cross-section is about 0.5 fb for the squark/gluino mass of 1 TeV. In the case of the stau NLSP, it decays mainly to a Higgs boson and a heavy charged scalar whose decay length is larger than 0.1 mm for the stau NLSP mixing with the left-handed stau smaller than 0.3. As this process can have a large cascade production ∼2 pb for the squark/gluino mass ∼1 TeV, one may be able to probe it at the early stage of the LHC experiment.
16388458
Probing non-universal gaugino masses via Higgs boson production under SUSY cascades at the LHC: a detailed study
Cascade decays of Supersymmetric (SUSY) particles are likely to be prolific sources of Higgs bosons at the Large Hadron Collider (LHC). In this work, we explore, with the help of detailed simulation, the role of non-universal gaugino masses in the production of the Higgs bosons under SUSY cascades. The analysis is carried out by choosing an appropriate set of benchmark points with non-universal gaugino masses in the relevant SUSY parameter space and then contrasting the resulting observations with the corresponding cases having universal relationship among the same. It is shown that even of data at an early phase of the LHC-run with 10 fb−1 one would be able to see, under favourable situations, the imprint of non-universal gaugino masses by reconstructing various Higgs boson resonances and comparing their rates. With increased accumulated luminosities, the indications would naturally become distinct over a larger region of the parameter space.
117982466
Lepton-hadron relation and the nucleon-nucleon potential
SummaryOn the basis of the structure of hadrons as envisaged in a lepton-hadron relation proposed in a recent paper, we here study the nuclear force in the intermediate region. It is found that the phase shifts can nicely be interpreted on the basis of the exchange of π, ω, ρ and f0 mesons as demanded by the constituent hadrons and no 2π or any other particle exchange on thead hoc basis is needed to fit the data. Our predictions are found to be in excellent agreement with the experimental results.RiassuntoSulla base della struttura degli adroni, come intuita in una relazione leptone-adrone proposta in un recente lavoro, si studia in questo contesto la forza nucleare nella regione intermedia. Si trova che gli spostamenti di fase possono essere interpretati bene sulla base degli scambi dei mesoni π, ω, ρ e f0 come richiesto dagli adroni costituenti, e nessun scambio di 2π o qualsiasi altra particella su una basead hoc è necessario per approssimare i dati. Si trova che le nostre predizioni sono in accordo eccellente con i risultati sperimentali.РезюмеНа основе структуры адронов, предложенной в предыдущей статье, мы исследуем ядерную силу в промежуточной области. Получается, что фазовые сдвиги могут быть интерпретированы на основе обмена π, ω, ρ и f0 мезонами. Наши предсказания очень хорошо согласуются с экспериментальными результатами.
118755865
Weak interaction of photons and neutrino-electron scattering
SummaryThe neutrino-electron scattering has been discussed according to the photon-neutrino weak-coupling theory. The results are then compared with those obtained in the current-current coupling theory. The rate for neutrino-electron scattering has also been discussed for nondegenerate and degenerate gases. Astrophysical applications are then made by evaluating the ratio of the neutrino mean free path to the stellar radius. It is shown that, according to the photon-neutrino weak coupling, the neutrino mean free path exceeds the stellar radius for massive stars, white dwarfs and neutron stars. This result is significant in the sense that according to the current-current coupling theory, the ratio of the neutrino mean free path to the stellar radius for neutron stars can be much less than unity, though for other types of stars the neutrino mean free path exceeds the stellar radius. Finally, some remarks are made about the experiment attempted by Reines and Kropp to detect solar neutrinos using knock-on electrons produced in the neutrino-electron scattering.RiassuntoSi è discusso lo scattering neutrino-elettrone secondo la teoria dell’accoppiamento debole fotone-neutrino. Si sono confrontati i risultati con quelli ottenuti nella teoria dell’accoppiamento corrente-corrente. Si è anche discusso il rapporto di scattering neutrino-elettrone per gas degeneri e non degeneri. Si sono applicati i risultati all’astrofisica calcolando il rapporto del cammino libero medio al raggio stellare. Si dimostra che, in accordo con l’accoppiamento debole fotone-neutrino, il cammino libero medio del neutrino è maggiore del raggio stellare per le stelle di grande massa, le nane bianche e le stelle di neutroni. Il risultato è significativo nel senso che, secondo la teoria dell’accoppiamento corrente-corrente, il rapporto del cammino libero medio del neutrino col raggio stellare per le stelle di neutroni può essere molto minore dell’unità, sebbene per altri tipi di stelle il cammino libero medio del neutrino sia maggiore del raggio stellare. Infine si commenta l’esperimento tentato da Reines e Kropp per rilevare neutrini solari tramite gli elettroni di knock-on prodotti nello scattering neutrino-elettrone.РезюмеБыло рассмотрено нейтрино-электронное рассеяние в соответствии с теорией слабой связи фотон-нейтрино. Затем полученные результаты сравниваются с резулятатами, полученными в теории ток-токовой связи. Также обсуждалась интенсивность нейтрино-электронного рассеяния для невырожденного и вырожденного газов. Затем проводятся астрофизические применения, посредством вычисления отношения средней длины свободного пробега нейтрино к радиусу звезды. Показывается, что в соответствии со слабой связью фотон-нейтрино средняя длина свободного пробега нейтрино превышает радиус звезды для массивных звезд, белых карликов и нейтронных звезд. Этот результат является важным в том смысле, что в соответствии с теорией ток-токовой связи отношение средней длины свободного пробега нейтрино к радиусу звезды для нейтронных звезд может быть много меньше единицы, хотя для других типов звезд длина свободного пробега неитрино превышает радиус звезды. В заключение приводятся некоторые замечания относительно эксперимента, предпринятого Рейнсом и Кроппом, по детектированию солнечных нейтрино, используя δ-электроны, рожденные при нетрино-электронном рассеянии.
123158600
Non-Hermitian operators, localization problem, and the conservation of fermion number
The localization problem of relativistic particles is studied, considering that an elementary spin-1/2 particle of nonvanishing mass actually corresponds to an extended body. The role of non-Hermitian operators in describing such a system is discussed and it is pointed out that the localization of such a system is linked to the global conservation of fermion number given by the “internal helicity” of such a system. The localization region is then determined by means of imprimitivity systems for particular representations of the de Sitter groupS0(4, 1).
120699236
TOPOLOGICAL ASPECTS OF CHIRAL ANOMALY, ORIGIN OF MASS AND ELECTROWEAK THEORY
It is here shown that the topological property of a fermion which gives rise to the fermion number and is related to chiral anomaly may be taken to lead to weak interaction gauge bosons when currents are written in chiral form. The gauge bosons attain mass topologically through the generation of internal helicities and thus no Higgs scalar is needed to have spontaneous symmetry breaking. Moreover the group structure SU(2)×U(1) is inbuilt here for electroweak unification. The Weinberg angle gets a physical meaning and strangeness changing neutral lepton current interaction is automatically forbidden. This formalism also suggests that at very high temperature, weak interaction will be of long range in nature.
121542781
Equivalence of three-dimensional Ising model and fermionic string
The equivalence of a three-dimensional Ising model and a fermionic string as pointed out by Polyakov has been established here from the point of view of the geometrical aspects of a Polyakov string.