Les Houches

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Responsible: Jose Mi No

Members: Ken Mimasu, Werner Porod, Jérémy Bernon, Andrey Katz, Dipan Sengupta

In the context of 2HDM, there is no a priory reason to expect that the neutral states A0, H0 should be close in mass, only one of the two has to be relatively close in mass to H+ due to T-parameter constraints. When |m_A0 - m_H0| > m_Z and/or |m_H+ - m_{H0/A0}| > m_W, various possible decays open: (depending on the spectrum) A0 → H0 Z, H0 → A0 Z, H+ → H0 W+, H+ → A0 W+, A0 → H+ W-, H0 → H+ W- (other possible non-SM decays which appear for a sizable mass splitting are H0 → A0 A0 and H0 → H+ H-).

These decays typically dominate the Br of the mother particle when the splitting is large, on one side weakening searches of the mother particle via other Br, on the other providing a new discovery mode for both mother and daughter particles (usually very clean).

Possible projects/actions to be done:

1. Assume light A0 scenario for 2HDM (e.g. arXiv:1412.3385). Use of g g → H0 → Z A0 → ll bb to probe this region for low tan_beta (< 5) as a complementary search to bbA0

Literature: