[Clas_cascades] pentaquark search with pK0Km skim

[Zhiwen Zhao]

Hi,Igor

On 2/14/2010 12:45 PM, Igor Strakovsky wrote:
> Hi Zhiwen,
>
> Thank you for your prompt reaction. I would afraid to make a claim until
> to get strong arguments. It sounds that you do not have them yet
Exactly, I am not making any claim
>
> A little bit more below
>
> On Sat, 13 Feb 2010 22:28:40 -0500, Zhiwen Zhao <zwzhao at jlab.org> wrote:
>
>> Hi, Igor
>>
>> No, I am not sure at this point as the result is just a first look
>> into the data, not even qualified as preliminary.
>> However these cuts I showed are supposed either to enhance the theta+
>> signal or to match LEPS condition.
>
> As your slides shown that you did not do exact LEPS condition
For angle, LEPS has horizontal 20 degree and vertical 10 degree coverage. So far 
I require theta < 20 degree and it's only for Km, not for all charged particles 
like LEPS. I will test more cuts.
For photon energy, my cut matches their condition 2-2.4GeV
>
>> I have looked their Anti-cuts also, no sign of theta+ either.
>> Some cuts I didn't show such as photon selection,PID, fiducial,
>> vertex, sc dad counter etc, are mostly standard and similar to what
>> Hovanes used in his
>
> As far as you probably know, CLAS has so many standards. It is good to
> clarify them
Some cuts you can see from Hovanes's analysis note
http://clasweb.jlab.org/rungroups/eg3/wiki/index.php/Analysis_review_by_Hadron_Spectroscopy_Working_Group
I am in the process of writing Lambda1520 note also.
>
>> eg3 pentaquark Phi-- upper limit analysis which is currently under
>> review.
>> The same PK0Km channel is used for Lambda1520 study which is my thesis
>> topic, I have preliminary cross section now.
>
> Sorry, I know nothing about your theses and would love to see your
> Lambda(1520). Unfortunately, the size of your figures do not allow
> to see details
Here's a talk I gave for Lambda1520
http://clasweb.jlab.org/rungroups/eg3/wiki/images/5/52/ApsApril2010_zwzhao_Lambda1520.pdf
I apologize for the figures, I will update them with better ones.
>
>> I have MC for the Lambda1520 production, but not PK0Km yet.
>
> Can you show them, please? What did you use as the generator
will do.
I use fsgen which is a phase space generator with t-slope=2 as input for my 
Lambda1520 channel.
>
>> I will add more stuff on the wiki when the analysis proceeds.
>> Any comment from you is greatly appreciated.
>
> Thanks, I look forward to learn more details from you
> Igor
>
>> Zhiwen
>>
>>
>> On 2/12/2010 1:14 AM, Igor Strakovsky wrote:
>>> Hi Zhiwen,
>>>
>>> How are so sure? You made so many cuts... Can you explain all of them?
>>> Can you show any well known resonances? Do you have MC?
>>>
>>> Igor
>>>
>>> On Fri, 12 Feb 2010 01:04:37 -0500, Zhiwen Zhao <zwzhao at jlab.org> wrote:
>>>
>>>> hi, Eg3er
>>>>
>>>> Here is some updates of the pentaquark search with pK0Km skim
>>>> http://clasweb.jlab.org/rungroups/eg3/wiki/index.php/PrtK0Km_theta1530
>>>> So far, there's no sign of pentaquark.
>>>> Any commend is appreciated.
>>>>
>>>> Zhiwen
>>>> _______________________________________________
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>>>
>>> Igor Strakovsky, SAID CNS The George Washington University
>>> Tel: 703-726-8344(NV),202-994-4742(FB),Skype: igors1945_2
>>> Fax: 202-994-3001(FB),Emails: igor at va.gwu.edu, igor at jlab.org