Dear Jens Jorgen,
Thanks for the clarification on the calculation! I was missing the
second term in the k-/k+ ratio. Is there a good reference for
this? Just based on the papers that we cite, I would have taken
the particle production to scale as
1/exp[{E - mu_b B - mu_s S}/T],
with B and S being the baryon and
strangeness numbers for the resulting hadrons.
Regards,
Steve
on 7/7/02 5:36 AM, Jens Jørgen Gaardhøje at gardhoje@nbi.dk wrote:
> Dear Steve,
> Thanks for your precise and relevant comments. They are now in version 3.05,
> which I will however not circulate until monday evening - to minimize
> confusion among the crowd.
>
> The Becattini curve has yet to find its way into figure 4. (CLAUS !?)
>
> I have gone through the calc. again and find no mistake in the relationship
> mu_s=1/4 . mu_q.
>
> pbar/p = exp( -2mu_b/T) = exp(-6mu_q/T)
>
> k-/k+ = exp( 2 mu_s/T) . exp( -2 mu_q/T) ; since K- has an anti-u and a s,
> and antiparticles contribute with opposite sign chem. pot. etc.
>
> This leads to the relation k-/k+= exp(2mu_s/T) . (pbar/p)**1/3 (1)
>
> We observe k-/k+ = (pbar/p)**1/4.
>
> equating k-/k+ above with the RH side leds to the quoted identity.
>
> Another approach would have been to fit the data to an expression like (1)
> and let mu_s and T vary. => CLAUS CAN YOU DO THAT??
>
> Please let me know if we agree on the formalism.
> cheers
> JJ
>
>
> ____________________________________________________________
> Jens Jørgen Gaardhøje, Assoc. Prof., Dr. Sc.
> Niels Bohr Institute, Blegdamsvej 17, 2100 Copenhagen, Denmark.
> Tlf: (+45) 35 32 53 09, secr. (+45) 35 32 52 09, Fax: (+45) 35 32 50 16.
> UNESCO Natl. Comm., secr. (+45) 33 92 52 16.
> Email: gardhoje@nbi.dk.
> ____________________________________________________________
>
>
> ----- Original Message -----
> From: "Stephen J. Sanders" <ssanders@ku.edu>
> To: <brahms-l@bnl.gov>
> Sent: Saturday, July 06, 2002 11:34 PM
> Subject: Comments on version 3.04
>
>
>> Dear Jens Jorgen and Claus,
>> Overall the paper seems to tell an interesting story. Nice job.
>> Some comments:
>>
>> PRL required full postal addresses. For the US institutions, this means
> you
>> will need to
>> supply the states and postal zip codes.
>>
>> Abstract:
>> "ratios at midrapidity" (typo in draft)
>> "from mu_b=120 MeV at forward rapidity to mu_b ~25MeV at mid-rapidity"
>> (otherwise the reader will
>> assume a parallel structure to the previous sentence where one
>> goes FROM midrapidity TO
>> forward rapidity)
>>
>> Paragraph 1.
>> "...considerable transparency is expected for Au+Au collisions, even
> for
>> central events."
>> (current sentence is poorly formed and confusing)
>> "...near midrapidity and pbar/p and K-/K+ particle number ratios with
>> values near unity."
>> (current sentence poorly formed...)
>> "...described above, reminiscent..." (remove "a" before reminiscent)
>>
>> Paragraph 3.
>> "...ratios are approaching unity, with values of 0.75+-0.04(pbar/p),
>> 0.95+-0.05(K-/K+), and
>> 1.01+-0.04(pi-/pi+), respectively."
>> (What does "over 0.95+-0.05" mean?!!!! Is this a claim that we don't
>> believe the quoted uncertainty?
>>
>> Paragraph 5.
>> "p=5.5 and 8GeV/c, respectively." (add comma)
>>
>> Paragraph 6.
>> "The primary event trigger was based on two Zero Degree Calorimeters
>> (ZDCs) located +/-18m
>> from the nominal IP [12]. The reaction centrality was determined
> using
>> a plastic
>> scintillator tile array surrounding the intersection region[7,8,12].
>> Beam-Beam Counters (BBCs),
>> consisting of two arrays of Cherenkov radiators positions +-2.15 m
> from
>> the IP, measured charged
>> hadrons in the pseudorapidity range 3.0<|eta|<3.8. For the 25% most
>> central collisions, the BBCs
>> allow collision vertex determination with a resolution of sig_z~0.65
> cm
>> and supply the start time
>> for the time-of-flight measurement with sig_t<~30 ps."
>> (Otherwise ZDC is used in Paragraphs 8, but never defined.)
>>
>> Paragraph 8.
>> "...expected \beta^{-1} vs. momentum behavior for..." (add behavior)
>> "...BBC-ZDC..." (We used BBC in the multiplicity papers and it
> would
>> be nice to be consistent...)
>>
>> Paragraph 9.
>> "In the MRS the background contribution to the proton yields,
> arising
>> mainly..." (Otherwise,
>> I'm not sure what is meant by "from protons"...)
>>
>> Paragraph 11.
>> "{\it etc.}" (add period to indicate abbreviation of "et cetera")
>>
>> Paragraph 12.
>> "Systematic uncertainties are estimated as 2% in the case of pions
> and
>> kaons and as 4% in the case
>> of protons." (Both instances of "to" should be changed to "as".)
>>
>> "...invariant plateau around midrapidity as proposed by Bjorken."
> (add
>> "as")
>>
>> Paragraph 14.
>> (Here I am suggesting a rewording that would have made this
> discussion
>> clearer to me after reading
>> the EARLIER Braun-Munzinger papers, which we don't cite. However, I
>> am also not
>> getting your expression of mu_s=1/4 mu_q, so I may be missing
>> something else....(I find
>> mu_s = mu_b/4 rather than mu_q/4))
>>
>> " ...expressed by a power low K-/K+=(pbar/p)^{1/4}. The exponent
> gives
>> the scaling factor between
>> the strange and baryon chemical potentials. For a vanishing
>> strange-quark chemical
>> potential \mu_{qs}, this
>> exponent is expected to have a value of 1/3 (where mu_{qs}=\mu_B/3 -
>> \mu_S). The present
>> result sugests \mu_S = \mu_B / 4."
>>
>> Figure Caption 4.
>> Becattini results stated in caption is not shown (on my figure...)
>>
>> Regards,
>> Steve
>>
>>
>>
>
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