SUSY at TeV33 - Snowmass Plans

We outline a preliminary plan of action for TeV33 SUSY studies at Snowmass. We invite participation in refining these plans and in preparing for the workshop during the intervening weeks before Snowmass. The primary goals of the TeV33 SUSY subgroup at Snowmass will be to:

The baseline scenario for TeV33 is defined to be 30 fb^-1 of data at 2 TeV by the end of 2006. The maximum instantaneous luminosity will reach 10^33 cm^-2 sec^-1. TeV33 is assumed to follow Run II at the Tevatron, which will have a maximum luminosity of 2x10^32 and fully upgraded Run II detectors.

Extensive work was done during the TeV2000 studies to explore the discovery reach of the Tevatron in supersymmetric parameter space. Much effort was also devoted to understand the degradation of discovery reach in a high luminosity environment. While this latter work needs to be continued for TeV33, the most important emphasis for Snowmass will be the exploration of SUSY signals. Chances are good that first signals of supersymmetry (or deviations with the Standard Model) are observed at LEP II or in Run II. At Snowmass, we plan to study a few possible supersymmetric scenarios with realistic detector simulations and see what information about supersymmetry, its internal structure, etc. we can extract with the TeV33 program. What is the SUSY potential of TeV33 following discovery?

In consultation with the theory interface group, we have chosen the following 4 points for detailed studies at Snowmass. These points do not exhaust all possible supersymmetric signatures at the Tevatron. Rather, they exemplify a few of the many signatures that may be accessible at the Tevatron - signatures which are crucial in order to show that supergravity inspired low energy supersymmetry is the underlying theory behind any observed deviation from the Standard Model.

SUGRA inspired points

(Assume m_t=175 GeV)

Point 1:

Point 2:

Note: This point has been taken to overlap with NLC point 3 and LHC parameter space point 4.

Point 3:

Point 4:

The strategy will be to perform detailed simulations, extract signal, and show what can be learned about the underlying SUSY parameters. The 3l cases may be especially good ( e.g. Norman's study ), since we can perhaps plot m(l+l-) and find mz2-mz1. This will give important information for unravelling the other SUSY signals.

Alternative SUSY scenarios

A Theory Support Page , is being set up which contains information about five alternate points:

Note - both points 4 and 5 have hard photon signatures, which were not studied by the TeV2000 SUSY group.

Particle generators

In order to accommodate all possible scenarios, we do not choose a specific particle generator for Snowmass simulations. ISAJET and SPYTHIA are the two most commonly used for tevatron simulations. A new version of ISAJET is available (see appendix ) to accommodate the alternate SUSY scenarios.

Detector simulation

For detector simulation of signal and physics background we propose to use a fast simulation program. While both collider experiments have their own but rather different simulation packages, we propose to use MCFAST with a CDF/D0 averaged geometry/acceptance/resolution. MCFAST is a generic detector simulation package, developed to study various geometry options for a b-physics oriented collider detector. It is maintained by the Fermilab Computing Division and available for all Fermilab supported platforms. With the use of MCFAST we hope to perform SUSY physics studies independant from detailed evaluation of specific detectors.

Organization of Work

In order to organize the simulation effort during Snowmass, we propose the following subdivisions, motivated by distinct physics signatures and distinct detector capabilities:

All of these signatures will be explored within the framework of the specific points in parameter space mentioned above. We urge every participant to sign up for one of these channels. Please let us know your interests, comments and suggestions.

Appendix

BROOKHAVEN NATIONAL LABORATORY

MEMORANDUM

Date: 20 May 1996

To: ISAJET Users

From: H. Baer, F.E. Paige, S.D. Protopopescu, X. Tata

Subject: ISAJET 7.19

Version 7.19 of ISAJET is now available. The new version includes the top mass in the cross sections for g b -> W t and g t -> Z t. When the $t$ mass is taken into account, the process g t -> W b can have a pole in the physical region, so it has been removed; see the documentation for more discussion.

The new version also allows the user to set arbitrary masses for the U(1) and SU(2) gaugino mases in the MSSM rather than deriving these from the gluino mass using grand unification. This could be useful in studying one of the SUSY interpretations of a CDF e+ e- gamma gamma plus missing energy event recently suggested by Ambrosanio, Kane, Kribs, Martin and Mrenna. Note, however, that radiative decay are not included, although the user can force them and multiply by the appropriate branching ratios calculated by Haber and Wyler, Nucl. Phys. B323, 267 (1989).

A number of bugs have also been corrected. As a result, users should upgrade even if they do not plan to use the new features.