 |  | In these pages some useful information can be found on our study of the ATLAS discovery reach for several final states of the Left Right Twin Higgs model. |
Benchmark points
Three points in parameter space are being considered so far. The three points correspond to different values of the essential scale of the model that governs the masses of the heavy partners of gauge bosons and top quark. The three values of f are chosen in such a way to yield masses of the heavy partner of the W gauge boson of 1 (1.25), 2 and 3 TeV. All other parameters remain fixed. In particular, the three points have a quite large value for the top - heavy top mixing parameter of M=150 GeV. For the first point, one of the most important decays phi +/- tb is kinematically forbidden. Therefore, another point with WH = 1250 GeV is created, where this decay is just above threshold.
The masses of the particles in the model have been calculated using the formulae given in the article on Twin Higgs phenomenology by Shufang Su (hep/ph-0611015). Widths and branching ratios are determined using calcHep.
WH = 1 TeV
calcHep parameter file
Particle masses:
| particle | mass (GeV) | width (GeV) |
| Heavy W partner WH | 1000 | 23.4 |
| Heavy Z partner ZH | 1196.2 | 24.8 |
| Heavy top partner tH | 487.1 | 5.03 |
| Charged Higgs (&phi±) | 160.1 | 0 |
| lightest neutral Higgs (&phi0 / Ax) | 107.1 | - |
| H1/H2 | 302.5 | - |
Branching ratios involved in cascade decays:
| particle | Branching fraction (%) |
| WH &rarr uD, cS) | 64 |
| WH &rarr uS, cD) | 3.6 |
| WH &rarr tH b | 20.6 |
| WH &rarr t b | 4.2 |
| WH &rarr Ax &phi± | 2.7 |
| tH &rarr b &phi± | 72.7 |
| tH &rarr t H | 11.3 |
| tH &rarr W b | 9.6 |
| tH &rarr t Ax | 3.4 |
| tH &rarr Z t | 3.1 |
| &phi± &rarr c S | 100 |
| ZH &rarr ee,&mu &mu ,&tau &tau | 3 * 2.42 |
| ZH &rarr neutrinos | 3 * 0.88 |
| ZH &rarr tt | 2.5 |
| ZH &rarr bb, ss, dd | 3 * 18.9 |
| ZH &rarr cc, uu | s * 10.8 |
| ZH &rarr Z H | 0.44 |
| ZH &rarr h1 H1, h2, H2 | 2*0.28 |
| ZH &rarr &phi± &phi± | 0.7 |
| ZH &rarr H Ax | 0.6 |
| ZH &rarr tH tH, | 2.2 |
| ZH &rarr t tH, T, tH | 2* 2.2 |
The decay of the heavy Z to a Standard Model Z and a Higgs boson is particularly interesting. While the charged Higgs to tb branching ratio goes to 0 for all masses as the M parameter goes to 0 - thus closing the door on many of the cascade decays - the Z H channel in the LR twin Higgs model remains unaffected (BR (Z &rarr Z H) = 0.44 % for this case),
WH = 1.250 GeV
calcHep parameter file
Particle masses:
| particle | mass (GeV) | width (GeV) |
| Heavy W partner WH | 1250 | 29.6 |
| Heavy Z partner ZH | 1495.0 | 31.2 |
| Heavy top partner tH | 567.8 | 5.5 |
| Charged Higgs (&phi±) | 184.1 | 0 |
| lightest neutril Higgs (&phi0 / Ax) | 109.4 | - |
| H1/H2 | 350.2 | - |
Branching ratios involved in cascade decays:
| particle | Branching fraction (%) |
| WH &rarr uD, cS) | 68 |
| WH &rarr uS, cD) | 3.5 |
| WH &rarr tH b | 22.7 |
| WH &rarr t b | 2.9 |
| WH &rarr Ax &phi± | 2.7 |
| tH &rarr b &phi± | 79.0 |
| tH &rarr t H | 7.9 |
| tH &rarr W b | 7.5 |
| tH &rarr t Ax | 2.9 |
| tH &rarr Z t | 2.8 |
| &phi± &rarr t b | 88.2 |
| &phi± &rarr c s | 11.8 |
| ZH &rarr ee,&mu &mu ,&tau &tau | 3 * 2.40 |
| ZH &rarr neutrinos | 3 * 0.87 |
| ZH &rarr tt | 3.1 |
| ZH &rarr bb, ss, dd | 3 * 18.8 |
| ZH &rarr cc, uu | s * 10.7 |
| ZH &rarr Z H | 0.43 |
| ZH &rarr h1 H1, h2, H2 | 2*0.3 |
| ZH &rarr &phi± &phi± | 0.7 |
| ZH &rarr H Ax | 0.4 |
| ZH &rarr tH tH, | 3.5 |
| ZH &rarr t tH, T, tH | 2*1.7 |
| ZH &rarr W W | 0.45 |
WH = 2 TeV
calcHep parameter file
Particle masses:
| particle | mass (GeV) | width (GeV) |
| Heavy W partner WH | 2000 | 48.1 |
| Heavy Z partner ZH | 2407.4 | 51.1 |
| Heavy top partner tH | 812.2 | 7.12 |
| Charged Higgs (&phi±) | 260.2 | 0 |
| lightest neutral Higgs (&phi0 / Ax) | 115.9 | - |
| H1/H2 | 536.9 | - |
Branching ratios involved in cascade decays:
| particle | Branching fraction (%) |
| WH &rarr uD, cS) | 67 |
| WH &rarr uS, cD) | 3.5 |
| WH &rarr tH b | 25.5 |
| WH &rarr t b | 1.3 |
| WH &rarr Ax &phi± | 2.8 |
| tH &rarr b &phi± | 89.4 |
| tH &rarr t H | 3.2 |
| tH &rarr W b | 4.0 |
| tH &rarr t Ax | 1.7 |
| tH &rarr Z t | 1.7 |
| &phi± &rarr t b | 99.1 |
| &phi± &rarr c S | 0.9 |
| ZH &rarr ee,&mu &mu ,&tau &tau | 3 * 2.37 |
| ZH &rarr neutrinos | 3 * 0.86 |
| ZH &rarr tt | 4.0 |
| ZH &rarr bb, ss, dd | 3 * 18.5 |
| ZH &rarr cc, uu | 2 * 10.5 |
| ZH &rarr Z H | 0.43 |
| ZH &rarr h1 H1, h2, H2 | 2*0.3 |
| ZH &rarr &phi± &phi± | 0.7 |
| ZH &rarr H Ax | 0.2 |
| ZH &rarr tH tH, | 5.6 |
| ZH &rarr t tH, T, tH | 2*0.84 |
| ZH &rarr W W | 0.44 |
WH = 3 TeV
calcHep parameter file
Particle masses:
| particle | mass (GeV) | width (GeV) |
| Heavy W partner WH | 3000 | 72.8 |
| Heavy Z partner ZH | 3587.4 | 76.5 |
| Heavy top partner tH | 1143.5 | 9.5 |
| Charged Higgs (&phi±) | 362.5 | 0 |
| lightest neutral Higgs (&phi0 / Ax) | 119.4 | - |
| H1/H2 | 773.6 | - |
Branching ratios involved in cascade decays:
| particle | Branching fraction (%) |
| WH &rarr uD, cS) | 66 |
| WH &rarr uS, cD) | 3.4 |
| WH &rarr tH b | 26.8 |
| WH &rarr t b | 0.6 |
| WH &rarr Ax &phi± | 2.8 |
| tH &rarr b &phi± | 94.6 |
| tH &rarr t H | 1.4 |
| tH &rarr W b | 2.1 |
| tH &rarr t Ax | 1.0 |
| tH &rarr Z t | 1.0 |
| &phi± &rarr t b | 99.1 |
| &phi± &rarr c S | 0.9 |
| ZH &rarr ee,&mu &mu ,&tau &tau | 3 * 2.36 |
| ZH &rarr neutrinos | 3 * 0.85 |
| ZH &rarr tt | 4.4 |
| ZH &rarr bb, ss, dd | 3 * 18.4 |
| ZH &rarr cc, uu | 2 * 10.5 |
| ZH &rarr Z H | 0.43 |
| ZH &rarr h1 H1, h2, H2 | 2*0.3 |
| ZH &rarr &phi± &phi± | 0.7 |
| ZH &rarr H Ax | 0.1 |
| ZH &rarr tH tH, | 6.7 |
| ZH &rarr t tH, T, tH | 2*0.42 |
| ZH &rarr W W | 0.43 |
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