We present new results for the theoretical prediction of doubly-polarized cross sections of $WZ$ events at the LHC using leptonic decays. Compared to the previous studies, two new kinematic cuts are considered. These cuts are designed to enhance the doubly-longitudinal (LL) polarization and, at the same time, study the Radiation Amplitude Zero effect. We found a new cut on the rapidity separation between the $Z$ boson and the electron from the $W$ decay which makes the LL fraction largest, namely $|Δy_{Z,e}| < 0.5$. This result is obtained at the next-to-leading order in the strong and electroweak couplings.
Invited "News & Views" for the journal, SCIENCE CHINA: Physics, Mechanics & Astronomy, on a recently new search for the doubly charmed baryon $Ξ_{cc}^+$ at the LHC, which is done by the LHCb Collaboration, arXiv:1909.12273.
The production of doubly charged Higgs bosons (H^{\pm\pm}) at the CERN LHC can give rise to distinctive multi-lepton signatures. The discovery potential of H^{\pm\pm} can be optimized by considering a search strategy which is sensitive to both of the dominant production mechanisms, q\bar q\to H^{++}H^{--} and q\bar {q'}\to H^{\pm\pm}H^{\mp}. We compare the discovery potential for the signatures of exactly four leptons and at least three leptons in the final state, using the same set of cuts. We have carried out fast detector simulations at the LHC for both signal and backgrounds for a wide ran…
In this Letter, we study the latest bound on the mass of doubly charged Higgs bosons, $H^{\pm\pm}$, assuming that they dominantly decay into a diboson. The new bound is obtained by comparing the inclusive searches for events with a same-sign dilepton by the ATLAS Collaboration using the latest 20.3 fb$^{-1}$ data at the LHC 8 TeV run with theoretical prediction based on the Higgs triplet model with next-to-leading order QCD corrections. We find that the lower mass bound on $H^{\pm\pm}$ is about 84 GeV.
Accessing the polarization of weak bosons provides an important probe for the mechanism of electroweak symmetry breaking. Relying on the double-pole approximation and on the separation of polarizations at the amplitude level, we study WZ production at the LHC, with both bosons in a definite polarization mode, including NLO QCD effects. We compare results obtained defining the polarization vectors in two different frames. Integrated and differential cross-sections in a realistic fiducial region are presented.
We analyse the signal sensitivity of multi-lepton final states at collider that can arise from doubly and singly charged Higgs decay in a type-II seesaw framework. We assume triplet vev to be very small and degenerate masses for both the charged Higgs states. The leptonic branching ratio of doubly and singly charged Higgs states have a large dependency on the neutrino oscillation parameters, lightest neutrino mass scale, as well as neutrino mass hierarchy. We explore this as well as the relation between the leptonic branching ratios of the singly and doubly charged Higgs states in detail. We e…
This paper studies the pair production of the doubly charged Higgs boson of the left-right symmetric models using multilepton final state in the vector boson fusion (VBF)-like processes. The study is performed in the framework consistent with the model's correction to the standard model $ρ_{EW}$ parameter. VBF topological cuts, number of leptons in the final state and $p_T$ cuts on the leptons are found to be effective in suppressing the background. Significant mass reach can be achieved for exclusion/discovery of the doubly charge Higgs boson for the upcoming LHC run with a luminosity of $\ma…
Production and decays of doubly charged Higgs bosons at the LHC and future hadron colliders triggered by vector boson fusion mechanism are discussed in the context of the Minimal Left-Right Symmetric Model. Our analysis is based on the Higgs boson mass spectrum compatible with available constraints which include FCNC effects and vacuum stability of the scalar potential. Though the parity breaking scale $v_R$ is large ($\sim$ few TeV) and scalar masses which contribute to FCNC effects are even larger, consistent Higgs boson mass spectrum still allows us to keep doubly charged scalar masses belo…
The theoretical analysis of production, lifetime, and decays of doubly heavy baryons is presented. The lifetime of $Ξ_{cc}^{++}$ baryon recently measured by the LHCb Collaboration is used to estimate the lifetimes of other doubly heavy baryons. The production and the possibility of observation of $Ξ_{bc}$ baryon at LHC are discussed.
We have investigated the possibility of direct tests of little Higgs models incorporating triplet Higgs neutrino mass mechanism at LHC experiments. We have performed Monte Carlo studies of Drell-Yan pair production of doubly charged Higgs boson Φ^{++} followed by its leptonic decays which branching ratios are fixed from the neutrino oscillation data. We propose appropriate selection rules for the four-lepton signal, including reconstructed taus, which are optimized for the discovery of Φ^{++} with the lowest LHC luminosity. As the Standard Model background can be effectively eliminated, an imp…
Search for a Doubly Charged Scalar at the LHC and FCC-hh
Universidade Federal do Rio Grande do Norte（北里奥格兰德联邦大学）；Millennium Institute for Subatomic Physics at High-Energy Frontier (SAPHIR)（高能前沿亚原子物理千年研究所）；Departamento de Física, Universidade Federal do Rio Grande do Norte（北里奥格兰德联邦大学物理系）；Departamento de Física, Facultad de Ciencias, Universidad de La Serena（拉塞雷纳大学理学院物理系）；Center for Theoretical and Experimental Particle Physics - CTEPP, Facultad de Ciencias Exactas, Universidad Andrés Bello（安德烈斯·贝略大学精确科学学院理论及实验粒子物理中心）；Laboratoire de Physique Théorique et Hautes Énergies (LPTHE), UMR 7589, Sorbonne Université et CNRS（索邦大学与法国国家科学研究中心理论及高能物理实验室）
We present search prospects and phenomenology of doubly resonant signals that come from the decay of a neutral weak-singlet color-octet vector state ω_8 into a lighter weak-triplet color-octet scalar π_8, which can arise in several theories beyond the Standard Model. Taking m_{ω_8}-m_{π_8}>m_W, we demonstrate an analysis of the signals pp \to ω_8 \to π^\pm_8 W^\mp (π^0_8 Z) \to g W^\pm W^\mp (g Z Z). The present 8 TeV LHC run is found to have the potential to exclude or discover the signal for a range of masses and parameters. The preferred search channel has a boosted W-tagged jet forming a r…
In the paper we discuss contribution of the doubly intrinsic heavy mechanism into the production of $B_c$ meson, the doubly heavy baryons and the all-charm tetraquark at a future fixed-target experiment at the LHC (AFTER@LHC). The production cross sections and the mean values of Feynman-x for the finale states are presented.
The cleanest of them all: NLO electroweak corrections to vector-boson scattering into doubly polarised ZZ pairs at the LHC
Institut für Theoretische Physik und Astrophysik, Universität Würzburg（维尔茨堡大学理论物理与天体物理研究所）；Dipartimento di Fisica, Università di Torino and INFN, Sezione di Torino（都灵大学物理系和意大利国家核物理研究院都灵分部）；Università degli Studi di Milano–Bicocca and INFN Sezione di Milano–Bicocca（米兰-比可卡大学和意大利国家核物理研究院米兰-比可卡分部）
Doubly charged Higgs bosons are very important in particle physics nowadays because they can give mass to neutrinos through seesaw mechanisms. In this work we present the results in the searching for doubly charged Higgs at the CERN LHC for a 3-3-1 model.
Doubly charged scalars are common figures in several beyond the Standard Model studies, especially those related to neutrino masses. In this work, we estimate the High-Luminosity (HL-LHC) and High-Energy LHC (HE-LHC) sensitivity to doubly charged scalars assuming they decay promptly and exclusively into charged leptons. Our study focuses on the fit to the same-sign dilepton mass spectra and it is based on proton-proton collisions at $13$ TeV, $14$ TeV and $27$ TeV with integrated luminosity of $\mathcal{L}=139 fb^{-1}, 3 $ab$^{-1}$ and $15$ab$^{-1}$. We find that HL-LHC may probe doubly charge…
We studied the signatures at the LHC of the electroweak SU(2) lepton doublet which embeds a doubly charged lepton. The doubly charged lepton pair and single production rates, which are different from the triplet case, are studied and all the detectable decay modes are considered. We also applied the same kinematic cuts as in triplet case to reduce the background at LHC and the needed integrated luminosities to find the doubly charged leptons with different masses are analyzed. We also suggested a method to distinguish the exotic lepton doublet and triplet.
Doubly charged Higgs bosons are predicted in many new physics models with an extended Higgs sector that contains a Higgs triplet field. Current experimental searches have been focusing mainly on the scenario in which the same-sign dilepton decay modes are the dominant ones. We study the scenario where the vacuum expectation value of the triplet field is sufficiently large so that the associated charged Higgs bosons decay dominantly to a pair of weak gauge bosons instead. A detailed simulation of the signal and the backgrounds is performed for the CERN Large Hadron Collider at the collision ene…
The type II seesaw model predicts the existence of a doubly charged Higgs boson ($H ^{\pm\pm}$), which can be produced through the Drell - Yan process and photon -- induced interactions at hadronic colliders. In recent years, such reactions have been largely investigated in inclusive processes, where both incident protons breakup and a large number of particles is produced in addition to the doubly charged Higgs pair. In this paper, we investigate, for the first time, the possibility of searching for $H ^{\pm\pm}$ in exclusive processes, which are characterized by two rapidity gaps and two int…
Using a peculiar version of the SU(3)L x U(1)N electroweak model, we investigate the production of doubly charged Higgs boson at the Large Hadron Collider. Our results include branching ratio calculations for the doubly charged Higgs and for one of the neutral scalar bosons of the model.
In this paper we investigate the LHC potential for discovering doubly-charged vector bileptons considering the measurable process $p,p$ $\rightarrow$ $e^{\mp}e^{\mp}μ^{\pm}μ^{\pm} X$. We perform the study using four different bilepton masses and three different exotics quark masses. Minimal LHC integrated luminosities needed for discovering and for setting limits on bilepton masses are obtained for both 7 TeV and 14 TeV center-of-mass energies. We find that these spectacular signatures can be observed at the LHC in the next years up to a bilepton mass of order of 1 TeV.
We studied the signatures of an electroweak SU(2) lepton triplet which contains a doubly charged heavy lepton. The most interesting and easily detected final states are originating from the doubly charged lepton pair and single production, that we analyzed at a center of mass energy of 14 TeV. We propose useful kinematic cuts to reduce the backgrounds and computed the integrated luminosity needed to discover or exclude the doubly charged leptons for various masses.
We present new results for next-to-leading order (NLO) electroweak (EW) corrections to double polarization signals in the $WZ$ production channel at the LHC using the $e^+ν_e μ^+ μ^-$ final state. It is found that the EW corrections are most sizable in the transverse momentum distributions of the doubly longitudinal polarization, being around -10% compared to the NLO QCD prediction at $p_{T,e}\approx 200$ GeV, which is in the accessible energy range of the current LHC data.
We study the production of doubly charged excited leptons at the LHC. These exotic states are predicted in extended weak isospin composite models. A recent analysis of such exotic states was based on a pure gauge model with magnetic type interactions. We include here the mechanism of contact interactions and show that this turns out to dominate the production of the doubly charged leptons. We perform a feasibility analysis of the observation of the tri-lepton signature associated with the production of the exotic doubly charged lepton simulating the response of a generic detector. We give excl…
When the doubly-charged Higgs bosons $H^{\pm\pm}$ mainly decay into the same-sign dilepton, a lower bound on the mass is around 400 GeV by the current LHC data. On the other hand, no such bound has been reported by using the data at LEP and at the LHC for the case where the same-sign diboson decay $H^{\pm\pm}\to W^{\pm(*)} W^{\pm(*)}$ is dominant. We study limits on the mass for such a case by using the current experimental data. From the precise measurement of the total width of the Z boson at the LEP experiment, the mass below 43 GeV is excluded with the 95% C.L. It turns out that the result…
We investigate the production of vector-like quarks with charge $5/3$ at the LHC and their subsequent decays into new singly or doubly charged bosons plus a heavy quark (top or bottom). In particular, we explore final states with same-sign di-leptons (electron or muon pairs), with the leptons coming from the decay of the new bosons and, in the case of production of singly charged bosons, from top quarks as well. These processes are predicted by classes of models based on extensions of the gauge group of the Standard Model, such as the 331 Model, where the electroweak symmetry is described by $…
The Higgs-portal lepton flavor violation is studied in a vectorlike lepton model. For evading the constraints from rare $Z\to \ell^\pm_i \ell^\mp_j$ decays, we introduce two triplet vectorlike leptons, $(1,3)_{-1}$ and $(1,3)_{0}$. The resultant branching ratio for $h\to μτ$ can be up to $10^{-4}$ when the constraints from the invisible $Z$ decays are applied. As a result, the signal strength for $ττ$ channel has a $12\%$ deviation from the standard model prediction, while the muon $g-2$ is two-order of magnitude smaller than the data and $BR(τ\to μγ)$ is of order of $10^{-12}$. A predicted do…
We discuss a minimal and simple extension of the standard electroweak model and discuss its uniqueness properties. Its most readily testable prediction is the existence of $|Q|= |L|= 2$ gauge bosons, bileptons, which decay into like-sign lepton pairs. We discuss how a discovery could be made at the LHC.
We have investigated in detail a model that contains an additional SU(2) singlet and triplet scalar fields than the Standard Model (SM). This allows the radiative generation of Majorana neutrino masses at two-loop order with the help of doubly charged Higgs bosons that arise from the extended Higgs sector. We studied in detail the phenomenology of the Higgs and neutrino sectors of the model. We give the analytical form of the masses of scalar and pseudoscalar bosons and their mixings, and the structure of the active neutrino mass matrix. It is found that the model accommodates only normal neut…
We study how the elements of the leptonic right-handed mixing matrix can be determined at the LHC in the minimal Left-Right symmetric extension of the standard model. We do it by explicitly relating them with physical quantities of the Keung-Senjanović process and the lepton number violating decays of the right doubly charged scalar. We also point out that the left and right doubly charged scalars can be distinguished at the LHC, without measuring the polarization of the final state leptons coming from their decays.
We consider the collider phenomenology of a simple extension of the Standard Model (SM), which consists of an EW isospin $3/2$ scalar, $Δ$ and a pair of EW isospin $1$ vector like fermions, $Σ$ and $\barΣ$, responsible for generating tiny neutrino mass via the effective dimension seven operator. This scalar quadruplet with hypercharge Y = 3 has a plethora of implications at the collider experiments. Its signatures at TeV scale colliders are expected to be seen, if the quadruplet masses are not too far above the electroweak symmetry breaking scale. In this article, we study the phenomenology of…
We show that the photon-photon fusion process contributes significantly to the pair production of doubly charged Higgs bosons at the LHC at a level comparable to the Drell-Yan production. We reinterpret the ATLAS lower limit of 570 GeV (420 GeV) on the mass of $Δ_{L}^{\pm\pm}$ ($Δ_{R}^{\pm\pm}$) arising from $SU(2)_L$ triplet (singlet) scalar by including the photon initiated process and derive a new lower limit of 748 GeV (570 GeV), assuming that $Δ^{\pm \pm}$ decays into $e^\pm e^\pm$ 100% of the time. We have also shown that the 5$σ$ discovery reach for ${Δ_{L}^{\pm\pm}}$ (${Δ_{R}^{\pm\pm}}…
Motivated by the recent LHCb observation of doubly-charmed baryon $Ξ_{cc}^{++}$ in the $Λ_c^+ K^-π^+π^+$ final state, we analyze the weak decays of doubly heavy baryons $Ξ_{cc}$, $Ω_{cc}$, $Ξ_{bc}$, $Ω_{bc}$, $Ξ_{bb}$ and $Ω_{bb}$ under the flavor SU(3) symmetry. Decay amplitudes for various semileptonic and nonleptonic decays are parametrized in terms of a few SU(3) irreducible amplitudes. We find a number of relations or sum rules between decay widths and CP asymmetries, which can be examined in future measurements at experimental facilities like LHC, Belle II and CEPC. Moreover once a few d…
Since the LHCb collaboration announced the observation of the doubly charmed baryon $Ξ_{cc}^{++}$, a series of studies of doubly heavy baryons have been presented. In this work, I analyse the non-leptonic weak decays of doubly heavy baryons $Ξ_{bc}$ and $Ω_{bc}$ under the flavor $SU(3)$ symmetry. I mainly focus on the $W$-exchange diagrams, which will contribute to the decay channels with final states are light meson and light baryon. These channels would be helpful for searching for $Ξ_{bc}$ and $Ω_{bc}$ at LHC. And these channels and relations of corresponding decay widths could be examined …
We study the pair production of doubly charged Higgs bosons at the Large Hadron Collider (LHC), assuming the doubly charged Higgs to be part of an SU(2)_L triplet which generates Majorana masses for left-handed neutrinos. Such pair-production has the advantage that it is not constrained by the triplet vacuum expectation value, which tends to make the single production rate rather small. We point out that, in addition to the Drell-Yan (DY) production mechanism, two-photon processes also contribute to H++H++ production at a level comparable to the QCD corrections to the DY channel. Decays of the…
We explore a realistic supersymmetric SU(2)_L \times SU(2)_R \times U(1)_B-L model spontaneously broken at around 10^12 GeV. The presence of D and F-flat directions gives rise to TeV mass doubly charged particles which can be found at the LHC. We implement TeV scale leptogenesis and employing both type I and II seesaw, the three light neutrinos are partially degenerate with masses in the 0.02-0.1 eV range. The effective mass parameter for neutrinoless double beta decay is 0.03-0.05 eV. We also find the interesting relation tan 2 θ_13 ~ [Δm^2_{\odot} / Δm^2_{atm}] [sin 2 θ_12 /tan 2 θ_23] <~ 0.…
We investigate the hadronic production of the doubly heavy baryon $Ξ_{bc}$ at the large hadron collider (LHC), where contributions from the four $(bc)$-diquark states $(bc)_{\bf\bar{3},6}[^1S_0]$ and $(bc)_{\bf\bar{3},6}[^3S_1]$ have been taken into consideration. Numerical results show that under the condition of $p_T>4$ GeV and $|y|<1.5$, sizable $Ξ_{bc}$ events about $ 1.7\times 10^7$ and $3.5\times10^9$ per year can be produced for the center-of-mass energy $\sqrt{S}=7$ TeV and $\sqrt{S}=14$ TeV respectively. For experimental usage, the total and the interested differential cross-sections …
We review the SM extensions with scalar multiplets including doubly-charged components eventually observable as di-leptonic resonances at the LHC. Special emphasis is payed to the limits on LNV implied by doubly-charged scalar searches at the LHC, and to the characterization of the multiplet doubly-charged scalars belong to if they are observed to decay into same-sign charged lepton pairs.
We explore an intriguing possibility to test the type-II seesaw mechanism of neutrino mass generation at the Large Hadron Collider (LHC). We show that the lepton-number-violating signatures of heavy Majorana neutrinos N_i (for i=1, 2, 3) and doubly-charged Higgs bosons H^++(H^--) can be closely correlated with each other in a class of TeV-scale type-II seesaw models. Taking the minimal version of such models for example, we calculate the cross sections of pp -> l^+_αl^+_βX (l^-_αl^-_βX) processes mediated separately by N_1 and H^++(H^--), and illustrate their nontrivial correlation at the LHC.
We examine the same-sign single dilepton productions of $\ell_i^{\pm}\ell_j^{\pm} (\ell_{i,j}=e,μ)$ in high-energy proton-proton collisions at the Large Hadron Collider (LHC) in models with doubly charged Higgs scalars as well as heavy Majorana neutrinos. We demonstrate that these spectacular productions can be detected at the LHC for a class model in which the doubly charged Higgs scalars couple only to the right-handed charged leptons. The ranges of the possible doubly charged Higgs masses and mixings to observe the processes at the LHC are discussed.
Institute of Physics, Bhubaneswar（布巴内斯瓦尔物理研究所）；Department of Physics, SGTB Khalsa College（SGTB卡尔萨学院物理系）；Department of Physics and Astrophysics, University of Delhi（德里大学物理与天体物理学系）；Homi Bhabha National Institute（霍米·巴巴国立研究所）
The doubly charged Higgs bosons $H^{\pm\pm}$ searches at the Large Hadron Collider (LHC) have been studied extensively and strong bound is available for $H^{\pm\pm}$ dominantly decaying into a pair of same-sign di-leptons. In this paper we point out that there is a large cavity in the light $H^{\pm\pm}$ mass region left unexcluded. In particular, $H^{\pm\pm}$ can dominantly decay into $WW$ or $WW^*$ (For instance, in the type-II seesaw mechanism the triplet acquires a vacuum expectation value around 1 GeV.), and then it is found that $H^{\pm\pm}$ with mass even below $2m_W$ remains untouched b…
We present a detailed discussion on the doubly charmed baryon $Ξ_{cc}$ production at the RHIC and LHC via the proton-nucleus ($p$-N) and nucleus-nucleus (N-N) collision modes. The extrinsic charm mechanism via the subprocesses $g+c\to (cc)[n]+\bar{c}$ and $c+c\to (cc)[n]+g$ together with the gluon-gluon fusion mechanism via the subprocess $g+g\to(cc)[n]+\bar{c}+\bar{c}$ have been taken into consideration, where the intermediate diquark is in $[n]=[^1S_0]_{\bf 6}$-state or $[^3S_1]_{\bar{\bf 3}}$-state, respectively. Total and differential cross sections have been discussed under various collis…
In this work productions of charged and doubly charged scalars and their lepton flavor violating collider signals in the framework of littlest Higgs model at LHC are studied. In the allowed parameter region of the littlest Higgs model, the production rates of the scalars of littlest Higgs model via $pp \to ϕ^{++}ϕ^{-}$, $pp \to ϕ^+ϕ^-$ and $pp \to ϕ^{++}ϕ^{--}$ processes are calculated. We obtained that charged and doubly charged scalar pairs can be produced at LHC . Considering the possible lepton flavor violating decays of charged scalars found in literature, final state analysis is done. Th…
Longitudinal vector boson scattering provides an important probe of electroweak symmetry breaking, bringing sensitivity to physics beyond the Standard Model as well as constraining properties of the Higgs boson. It is a difficult process to study due to the small production cross section and challenging separation of the different polarization states. We study the sensitivity to longitudinal $WV$ vector boson scattering at the high-luminosity Large Hadron Collider in semileptonic final states. While these are characterized by larger background contributions compared to fully leptonic final sta…
We have investigated production of doubly charged Higgs particles $Δ_{L,R}^{++}$ via WW fusion process in proton-proton collisions at LHC energies in the framework of the left-right symmetric model. The production cross section of the right-triplet Higgs is for representative values of model parameters at femtobarn level. The discovery reach depends on the mass of the right-handed gauge boson W_R. At best $Δ_R^{++}$ mass up to 2.4 TeV are achievable within one year run. For $Δ^{++}_L$ the corresponding limit is 1.75 TeV which depends on the value of the left-triplet vev v_L. Comparison with Dr…
Very recently, the LHCb collaboration has observed in the final state $Λ_c^+ K^-π^+π^+$ a resonant structure that is identified as the doubly-charmed baryon $Ξ_{cc}^{++}$. Inspired by this observation, we investigate the weak decays of doubly heavy baryons $Ξ_{cc}^{++}$, $Ξ_{cc}^{+}$, $Ω_{cc}^{+}$, $Ξ_{bc}^{(\prime)+}$, $Ξ_{bc}^{(\prime)0}$, $Ω_{bc}^{(\prime)0}$, $Ξ_{bb}^{0}$, $Ξ_{bb}^{-}$ and $Ω_{bb}^{-}$ and focus on the decays into spin $1/2$ baryons in this paper. At the quark level these decay processes are induced by the $c\to d/s$ or $b\to u/c$ transitions, and the two spectator quarks …
The only possible doubly-charged scalar decays into two Standard Model particles are into pairs of same-sign charged leptons, H$^{\pm\pm}\rightarrow {l}^\pm {l}^\pm, {l} = e, μ, τ$, or gauge bosons, H$^{\pm\pm}\rightarrow W^\pm W^\pm$; being necessary the observation of both to assert the violation of lepton number. However, present ATLAS and CMS limits on doubly-charged scalar production are obtained under specific assumptions on its branching fractions into dileptons only. Although they can be extended to include decays into dibosons and lepton number violating processes. Moreover, the produ…
We analyze the next-to-leading order QCD corrections to the production of doubly-charged Higgs particles at hadron colliders in extensions of the SM with Higgs isospin triplets. At both the Tevatron and the LHC, these corrections are found to be moderate in size increasing the cross sections by about 20--30%. The residual theoretical uncertainties are of the order of 10--15% which is sufficient for experimental searches for these particles at the Tevatron and LHC.
In type II seesaw model of neutrino mass generation, we study a remarkable signal of same-sign tetra-lepton (SS4L) signal at the Large hadron collider. When doubly charged Higgs is lightest, the heavier singly charged or neutral Higgs boson produces a doubly charged Higgs boson through its fast gauge decay. This leads to a novel signature of same-sign tetra-leptons resulting from a pair production of same-sign doubly charged Higgs bosons. We study production cross section for the SS4L signal in parameter space of the mass splitting among triplet components and the triplet vacuum expectation va…
We consider the production at the LHC of exotic composite leptons of charge Q=+2e. Such states are allowed in composite models which contain extended isospin multiplets (Iw=1 and Iw=3/2). These doubly charged leptons couple with Standard Model [SM] fermions via gauge interactions, thereby delineating and restricting their possible decay channels. We discuss the production cross section at the LHC of L++ (p p --> L++, l-) and concentrate on the leptonic signature deriving from the cascade decays L++ --> W+, l+ --> l+, l+, ν_l i.e. p p --> l-, l+, l+, ν_l showing that the invariant mass distribu…
We study the LHC discovery potential of the double-bottom tetraquarks $bb \bar u \bar d$, $bb \bar u \bar s$ and $bb \bar d \bar s$, the lightest of which having $J^P=1^+$, called $T^{\{bb\}}_{[\bar u \bar d]}$, $T^{\{bb\}}_{[\bar u \bar s]}$ and $T^{\{bb\}}_{[\bar d \bar s]}$, are expected to be stable against strong decays. Employing the Monte Carlo generators MadGraph5$\_$aMC@NLO and Pythia6, we simulate the process $pp\to \bar b b\bar b b$ and calculate the $b b$-diquark jet configurations, specified by the invariant mass interval $m_{bb} < M_{T^{\{bb\}}_{[\bar q \bar q']}} + ΔM$. Estimate…
In the framework of diquark model for production we discuss the yields and observation prospects for excited states of doubly heavy baryons at LHC kinematic conditions.
Testing lepton-flavor-violating decay of doubly charged Higgs bosons in type-II seesaw via photon fusion at the high-energy LHC
School of Microelectronics and Control Engineering, Changzhou University（常州大学微电子与控制工程学院）；Physics Department and Institute of Theoretical Physics, Nanjing Normal University（南京师范大学物理系和理论物理研究所）；Nanjing Key Laboratory of Particle Physics and Astrophysics（南京粒子物理与天体物理重点实验室）
