Folks, I thought you had all gotten this message, but fisrt a mistyped the listserver name, and when forwarding the retruned mail - it was absorbed by a black hole since it did not like the subject- and I was not notifies thereof. Here again its rather important ----- Original Message ----- From: "Flemming Videbaek" <videbaek@sgs1.hirg.bnl.gov> To: <brahms-dev-l@bnl.gov> Sent: Tuesday, January 02, 2001 9:02 PM Subject: Fw: Returned mail - nameserver error report > > > > While attempting to extract DN/deta from TPM1 data from the most recent = > > datareduction pass I came ac known across a potential disturbing = > > problem.. As part of the analysis I looked at the VTX(BB)-VTX(tracks in = > > TPM1). This has in general be known to be centered a 0 (using official = > > offsets). The analysis selected central events using the new macro by = > > JH. > > I found that an additional offset of 3.7 cm was needed. This was just = > > introuduced and analysis progressed until I decided > > to look at the Dn/Deta for all centralities.(6,6-20,20-50,50-100 %). The = > > disturbing fact is that the vertex difference has a clear dependence on = > > centralitychanging by about 4 cm from central to peripheral. > > - The BrRdoModule is weas the standard from Brat > > - The BrCalibrBB.dat from BratSys/params (Dec-21). > > > > Integrated over all events the sigma is 3.2-3.4 cm, but for a small = > > centrality bin down to about 2.2->2.5 cm.=20 > > Is this a problem with the analysis done from the DataSelection or a = > > more general problem with the BB calibrations and > > vertex determination. If so there is ca clear room for improvement, and = > > possible also the timing can be better. > > Using the ZDC vertex no such correlation is seen , albeit wider. Look at = > > the file > > pii3: ~videbaek/bbZvsMult.ps > > > > Since this has implication (in a good direction) I am wondering if any = > > has comments/knowledge on this this (in particular Yuru, Bjoern ?). II = > > have discussed with JH if we can determined if such dependence also = > > shows up in the timing > > part of the BB module (by looking at MRS data where the time-to-Tofw has = > > a close to constant pathlengthy and thus can be used to check such = > > effect in the t0 part. > > > > Flemming > > > > > > ------------------------------------------------------ > > Flemming Videbaekma=20 > > Physics Department > > Brookhaven National Laboratory > > > > tlf: 631-344-4106 > > fax 631-344-1334 > > e-mail: videbaek@bnl.gov > > > > ------=_NextPart_000_0007_01C074FF.1112C860 > > Content-Type: text/html; > > charset="iso-8859-1" > > Content-Transfer-Encoding: quoted-printable > > > > <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> > > <HTML><HEAD> > > <META content=3D"text/html; charset=3Diso-8859-1" = > > http-equiv=3DContent-Type> > > <META content=3D"MSHTML 5.00.2920.0" name=3DGENERATOR> > > <STYLE></STYLE> > > </HEAD> > > <BODY bgColor=3D#ffffff> > > <DIV><FONT face=3DArial size=3D2>While attempting to extract DN/deta = > > from TPM1 data=20 > > from the most recent datareduction pass I came ac known across a = > > potential=20 > > disturbing problem.. As part of the analysis I looked at the = > > VTX(BB)-VTX(tracks=20 > > in TPM1). This has in general be known to be centered a 0 (using = > > official=20 > > offsets). The analysis selected central events using the new macro by=20 > > JH.</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>I found that an additional offset of = > > 3.7 cm was=20 > > needed. This was just introuduced and analysis progressed until I=20 > > decided</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>to look at the Dn/Deta for all=20 > > centralities.(6,6-20,20-50,50-100 %). The disturbing fact is that the = > > vertex=20 > > difference has a clear dependence on centralitychanging by about 4 cm = > > from=20 > > central to peripheral.</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>- The BrRdoModule is weas the standard = > > from=20 > > Brat</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>- The BrCalibrBB.dat from = > > BratSys/params=20 > > (Dec-21).</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2></FONT> </DIV> > > <DIV><FONT face=3DArial size=3D2>Integrated over all events the sigma is = > > 3.2-3.4 cm,=20 > > but for a small centrality bin down to about 2.2->2.5 cm. = > > </FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>Is this a problem with the analysis = > > done from the=20 > > DataSelection or a more general problem with the BB calibrations=20 > > and</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>vertex determination. If so there is ca = > > clear room=20 > > for improvement, and possible also the timing can be = > > better.</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>Using the ZDC vertex no such = > > correlation is seen ,=20 > > albeit wider. Look at the file</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>pii3: =20 > > ~videbaek/bbZvsMult.ps</FONT></DIV> > > <DIV> </DIV> > > <DIV><FONT face=3DArial size=3D2>Since this has implication (in a good = > > direction) I=20 > > am wondering if any has comments/knowledge on this this (in particular = > > Yuru,=20 > > Bjoern ?). II have discussed with JH if we can determined if such = > > dependence=20 > > also shows up in the timing</FONT></DIV> > > <DIV><FONT face=3DArial size=3D2>part of the BB module (by looking at = > > MRS data where=20 > > the time-to-Tofw has a close to constant pathlengthy and thus can be = > > used to=20 > > check such effect in th</FONT><FONT face=3DArial size=3D2>e t0 = > > part.</FONT></DIV> > > <DIV> </DIV> > > <DIV><FONT face=3DArial size=3D2>Flemming</FONT></DIV> > > <DIV> </DIV> > > <DIV> </DIV> > > <DIV><FONT face=3DArial=20 > > size=3D2>------------------------------------------------------<BR>Flemmi= > > ng=20 > > Videbaekma <BR>Physics Department<BR>Brookhaven National = > > Laboratory</FONT></DIV> > > <DIV> </DIV> > > <DIV><FONT face=3DArial size=3D2>tlf: 631-344-4106<BR>fax = > > 631-344-1334<BR>e-mail: <A=20 > > href=3D"mailto:videbaek@bnl.gov">videbaek@bnl.gov</A></FONT></DIV></BODY>= > > </HTML> > > > > ------=_NextPart_000_0007_01C074FF.1112C860-- > > > > > > --------End of Unsent Message > > >
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