Wrong graviton masses in jet jet to gamma graviton or jet graviton

[Jan Winter]

The mishandling of the graviton masses in these processes during the matrix-element calculation leads to huge discrepancies between the pT distributions of the final-state particles taken at status level 3 (hard process) or level 1 (outgoing stable). The shift-onshell routines that come with the QED radiation phase eventually correct for the wrong graviton mass which in turn leads to the strong differences in the pTs.

[Jan Winter]

run card

[Jan Winter]

status 3 pT of gamma

[Jan Winter]

status 1 pT of gamma

[Jan Winter]

The ME calculation for these processes turns out to be OK (x-checked with old version 113). In fact in the calculation of these processes we have to deal with a whole tower of graviton states of different masses. The shift-onshell routines that are necessary before QED radiation corrections can be determined have to preserve these masses, which result from the ME calculations.

Changes have been committed on trunk as r16550. @ Marek, can you please check if things look alright?

@ Sherpas, there is one warning that comes out of the Initialization_Handler.C. If the scale M_S is smaller than the CMS energy, the user is told that they apply the ADD model beyond its valid range. For hadronic collisions, this test doesn't mean much. Shall we remove it or specify?

[Jan Winter]

Patches to resolve this issue for versions 1.2.2 and 1.2.3 are now provided on the corresponding Sherpa download pages. Please apply them following the instructions given there.

[Stefan Hoeche]

Milestone rel-1.3.0 deleted