Twice-Charged Twins on the Hunt ⚡ экспресс
We study the pair production of doubly charged bileptons and assess their discovery potential at the HL-LHC, accounting for projected integrated luminosities. Production probabilities are determined by the bilepton mass (m_Y) and the mass of exotic heavy quarks (m_D). Two complementary mechanisms are considered: direct pair production of bileptons and production through heavy quark decays; the latter usually offers much larger cross sections and yields clean signatures, even when produced off-shell. The direct channel is mainly sensitive to m_Y, while the heavy-quark channel is sensitive to m_D. Thanks to a nearly background-free signature of four high-energy leptons, Run-2 data can only discover bileptons with m_D ≲ 1 TeV, whereas the HL-LHC will achieve a 5σ discovery up to m_D ≲ 2.5 TeV (almost independent of m_Y) and/or m_Y ≲ 2 TeV (even with a heavy D). These results demonstrate the complementarity of the channels and map out the parameter regions accessible for future new-physics searches.
By the rules of the Standard Model, electric charge is always a multiple of the electron charge—nature deals in whole units. But the equations allow particles with a double charge—bileptons. These 'charged twins' became the collider's quarry: they give themselves away by decaying into four light leptons, much like twins leaving paired footprints. This signal is clean—nothing else produces such a recognizable pattern. A direct hunt is tough: it's easier to ambush exotic quarks—massive relatives of the proton's 'building blocks.' They spit out a bilepton, which instantly breaks apart into a quartet of leptons. Today's collider notices the prey if the quarks are lighter than 1 TeV (a thousand proton masses). After the upgrade (High-Luminosity LHC), the detection range will grow: up to 2.5 TeV for the quarks and up to 2 TeV for the twins themselves. Success would be a scientific bombshell: the law of lepton number conservation—the inviolability of the total count of light particles—would be violated. Nature would allow them to change. And perhaps these particles will help unravel the nature of dark matter.
🎯 The name 'bilepton' comes from Latin bi- (two) and 'lepton': the particle seems to play for two at once in the quantum world. Its discovery would show for the first time that the number of light particles does not have to be conserved—a familiar law of the micro-world would be broken.