May, 2002



Charge for the American Linear Collider Physics Group

The American Linear Collider Physics Group has been created to
establish and manage a process that leads to a forefront
experimental program at a high-energy electron-positron linear
collider (LC). To be successful, this process must demonstrate
that such a physics program can, with a high level of confidence,
be carried out within a reasonable time frame and within a
reasonable budget. Given the strong international interest in this physics,
the ALCPG's role should be understood as the North American part of
a larger global effort. The ALCPG should maintain strong ties
to other groups with similar goals around the world.

The ALCPG has several main tasks, all of which will be performed
in the working groups (WGs). 

(1) The WGs should describe the essential elements of an LC physics
    program. From this broad program, the ALCPG should pick a
    representative set of critical physics measurements for detailed
    study and full simulation. This set of measurements should
    be reviewed from time to time to determine whether it
    should be enlarged or otherwise modified.

    A preliminary definition of this physics program should be an early
    milestone in the schedule.

(2) The ALCPG should coordinate the efforts of the WGs 
    to establish a comprehensive set of detector and 
    accelerator requirements to carry out the critical physics
    measurements. In practice, this work will require close collaboration
    between the working groups focusing on physics issues,
    the detector design, and the detector/accelerator interface.
    Issues related to machine parameters and how they
    affect the detector and the physics program need
    particular attention. The ALCPG should work closely with
    the accelerator community to investigate all significant issues.
    These requirements could be defined in the context of
    some particular initial detector concept, but they should be
    as generic as possible to allow for consideration of
    competing detector technologies. The requirements should be
    justified with specific reference to the critical physics
    measurements or to the experimental environment.

    The completion of a detector requirements document represents
    one milestone.

(3) The WGs should evaluate a reasonable range of
    detector options using a set of well documented,
    common simulation tools. Both alternative detector
    technologies and different configurations for a
    specific technology should be compared in detail,
    and the tradeoffs in performance and cost should be
    documented. Finally, the ALCPG should produce
    a design for at least one detector that can carry
    out the program of critical physics measurements.
    The detector design and the analysis of its ability
    to accomplish the critical physics program should
    be documented in detail.

    The production of this document represents another milestone.

(4) Given that these detector/physics studies are likely
    to lead to questions that can be answered only with
    R&D, the ALCPG should help to formulate a process by
    which R&D proposals can be evaluated. However, since funding
    for such proposals would be provided largely
    by government agencies with their own reviewing
    processes, the (limited) role of the ALCPG in this process
    needs to be worked out in conjunction with the funding agencies.

(5) Given the importance of documentation, the ALCPG
    should establish a documentation system as early
    as possible. It is anticipated that significant
    support will be required to establish and maintain
    this system.

(6) The ALCPG should establish a set of milestones
    and a schedule for accomplishing these tasks.
    A regular set of meetings should be planned to
    provide a structure for presenting results and
    for improving cooperation.

(7) The ALCPG should encourage and facilitate the participation
    of interested groups in the process of planning the
    experimental program.