Explaining the CMSeejjandepTj

Abstract

We show that superstring inspired E6 models can explain both the recently detected excess eejj and e / p T jj signals at CMS, and also allow for leptogenesis. Working in a R-parity conserving low energy supersymmetric effective model, we show that the excess CMS events can be produced via the decay of exotic sleptons in Alternative Left-Right Symmetric Model of E6, which can also accommodate leptogenesis at a high scale. On the other hand, either the eejj excess or the e / p T jj excess can be produced via the decays of right handed gauge bosons, but some of these scenarios may not accommodate letptogenesis as there will be strong B − L violation at low energy, which, along with the anomalous fast electroweak B + L violation, will wash out all baryon asymmetry. Baryogenesis below the electroweak scale may then need to be implemented in these models.PACS numbers: 98.80. Cq,14.60.St,11.30.Fs I. INTRODUCTIONRecently the CMS Collaboration at the LHC at CERN announced their results for the right-handed gauge boson W R search at a center of mass energy of √ s = 8TeV and 19.7fb −1 of integrated luminosity. They have used the final state eejj to probe pp → W R → eN R → eejj, with the cuts p T > 60 GeV, |η| < 2.5 (p T > 40 GeV, |η| < 2.5) for leading (subleading) electron. The invariant mass m eejj is calculated for all events satisfying m ee > 200 GeV. In the bin 1.8 TeV < m eejj < 2.2 TeV roughly 14 events have been observed with 4 expected background events, amounting to a 2.8σ local excess, which, however, can not be explained by W R decay in Left-Right Symmetric Models (LRSM) with strict left-right symmetry (gauge couplings g L = g R ) [1]. The CMS search for di-leptoquark production, at a center of mass energy of √ s = 8TeV and 19.6fb −1 of integrated luminosity has reported a 2.4σ and a 2.6σ local excess in eejj and e / p T jj channels 1 respectively, and has excluded the first generation scalar leptoquarks with masses less than 1005 (845) GeV for β = 1(0.5), where β is the branching fraction of a leptoquark to a charged lepton and a quark [2]. In the eejj channel for a 650 GeV leptoquark signal using the optimization cuts S T > 850 GeV, m ee > 155 GeV and m min ej > 270 GeV (where S T is the scalar sum of the p T of two leptons and two jets), 36 events have been observed compared with 20.49 ± 2.4 ± 2.45(syst.) expected events from the Standard Model (SM) backgrounds implying a 2.4σ local excess. While in the e / p T jj chan- * Electronic address: mansi@prl.res.in † Electronic address: chandan@prl.res.in ‡ Electronic address: raghavan@prl.res.in § Electronic address: utpal@prl.res.in 1 The e / p T jj channel is often referred to as eνjj channel in the literature. Also note that the "ee" in eejj refers to two first generation charged leptons, not necessarily of the same sign. nel using the optimization cuts S T > 1040 GeV, m / E T > 145 GeV, m ej > 555 GeV and m T,e/ p T (where S T is now the scalar sum of the missing energy / E T and p T of the electron and two jets), 18 events have been observed compared with...

Reconciling the 2 TeV excesses at the LHC in a linear seesaw left-right model

“…Other analyses in the context of LRSMs were performed in [40,[42][43][44][45][46][47]. The excess has also been discussed in wider theoretical contexts [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][64][65].…”

B ¯ → D ∗ τ ν ¯ $$ \overline{B}\to {D}^{\left(\ast \right)}\tau \overline{\nu} $$ excesses in ALRSM constrained from B, D decays and D 0 − D ¯ 0 $$ {D}^0-{\overline{D}}^0 $$ mixing

“…Thus, ALRSM has the attractive feature that it can explain both the excess eejj and e / p T jj signals and also high-scale leptogenesis [46]. Having introduced ALRSM above now we are ready to analyze the semitauonic B decayB → D ( * ) τν based on the general framework introduced in section 2.…”

“…(3.4) gives the following assignments of R-parity, baryon number (B) and lepton number (L) for the exotic fermions ensuring proton stability. h is a leptoquark with R = −1, B = ALRSM can explain both eejj and e / p T jj signals from the decay of scalar superpartners of the exotic particles, for example, through (i) resonant production of the exotic sleptoñ E, subsequently decaying into a charged lepton and a neutrino, followed by R-parity conserving interactions of the neutrino producing an excess of events in both eejj and e / p T jj channels [46] (ii) pair production of scalar leptoquarksh. On the other hand, high scale leptogenesis can be obtained via the decay of the heavy Majorana neutrino N c in ALRSM.…”

“…In this paper we study the flavor structure of the E 6 motivated Alternative Left-Right Symmetric Model (ALRSM) [52], which can explain the CMS excesses and accommodate high scale leptogenesis 1 [46], to explore if this framework can address the experimental data for R(D ( * ) ) explaining the discrepancy with the SM expectations. This scenario is particularly interesting because unlike the R-parity violating MSSM in refs.…”

“…[38], while other NP scenarios have been proposed in refs. [39][40][41][42][43][44][45][46][47][48][49][50][51]. Interestingly, in some of these NP scenarios attempts were made to explain the discrepancies in decays of B meson in an unified framework [43] or separately [26].…”