Date: Sat, 22 Jul 2006 13:10:04 +0200 (CEST)
From: Tommaso Lari <Tommaso.Lari@mi.infn.it>
To: Christopher Lester <lester@hep.phy.cam.ac.uk>
Cc: Davide.Costanzo@cern.ch
Subject: Re: 2 lepton + missing ET, etc
                                                                               
                                                                               
Dear Christofer,
 thanks for your e-mail.
                                                                               
    The activity of the SUSY WG in the next six months will be focused on the
analysis of CSC full simulation data and the preparation of the corresponding
notes (I guess you have the CSC notes spreadsheet, do you?). The analysis
you are interested in fits in the "exclusive studies" (SUSY-6). The editors
of the corresponding note are myself and Costanzo, which I have put in cc.
    Your plans are not overlapping that much with mine, we will study the
2-lepton+jet+missingEt search channel, dilepton edge reconstruction,
top background estimation and b-tagging in SUSY events.
                                                                               
    I have not yet a complete picture of the contributors to these studies,
and thus of the possible overlaps and uncovered items. However, your plans
seem quite good to me.
                                                                               
    You should start by preparing your analysis on the data samples
produced with 11.0.42. SU2, SU3, ttbar, and several other background
are already available on the grid.
                                                                               
    Most urgently, you should check that the signal and background samples
relevant for your analysis are indeed foreseen. I am thinking in particular
to the direct slepton production. Is it significant for any of
our points (SU1, SU3, SU8.x, - forget SU2)? I don't remember if this
signature was studied in full simulation before.
                                                                               
    We probably should aim to repeat the analysis done for DC1 and Rome,
with the inclusion of trigger efficiencies and SM backgrounds. I remember
there were problems with the jet+lepton threshold (events below the
threshold) which were never explained to my knowledge.
                                                                               
cheers,
                                                                               
Tommaso

On Tue, 18 Jul 2006, Christopher Lester wrote:
                                                                               
>
>
> Hi Tommaso,
>
> I don't think we've directly corresponded before, but I'm the
> Cambridge person behind MT2 (Stransverse mase) and many of the
> markov-chain susy parameter space / sparticle-chain reconstruction
> papers that the Cambridge group has been concentrating on over the
> past few years.
>
> My reason for writing is in connection with the Susy CSC effort, as
> I've now reached a point where I actually have some time *myself* to
> begin contributing effort in this area -- up to now I've been fairly
> busy with getting parts of the SCT DAQ up and running for SCT
> assembly, and so actual Cambridge effort has been restricted to the
> work that our students Martin White and Alan Phillips have been able
> to supply.
>
> I'm contacting you because your name is already down against most of
> the areas which I think I could most usefully help / be involved
> with, and I don't want to waste time doing things that you've already
> done etc.
>
> I think I am most interested in contibuting effort toward:
>
> (1) investigation of signals relating to MT2 -- eg dilepton (or dijet)
> signals where each lepton (or jet) comes from "one side" of the
> primary interaction -- eg dislepton production (or disquark)
> production with direct decay to neutralinos.
>
> (2) anything to do with lepton, jet, missing et signatures relevant
> for "standard susy chain" investigation (squark->chi2->slepton->chi1
> etc)
>
> (3) anything to do with categorising the chains in (2) according to
> whether the chain features:
>
>      (udsc) a light squark
>      (b) a sbottom
>      (t) a stop
>
> because there (one hopes) might be some ability to distinguish these
> chains (some of the time) by b-tagging and reconstructing Ws from top
> decays --- this would be needed to control for expected mass
> differences between 3rd and non-3rd generation squarks.
>
> What do you think would be a good thing to start doing now that I
> have some time?
>
> I will be attending this Thursday's SUSY phone meeting.
>
> [Unfortunatley, although Martin and Alan have been able to attend
> most of the recent meeting, I have been absent from all but a few
> minutes of the last few meetings so I am rather behind when it comes
> to gauging what the most important things are which people want to
> see investigated right now!]
>
> Yours interestedly,
>
> Christopher
>
> P.S.
> Would it be possible to see your transparencies for Thursday's talk
> ASAP (prior to the talk?) so that I can gauge what you have been
> doing so far?
>
> ----------------------------------------------------
> Dr Christopher Lester        Tel: +44 (0)1223 337231
> Room 959, Rutherford Building,  Cavendish Laboratory
> Madingley Road, Cambridge, CB3 0HE,   United Kingdom