[Clas_cascades] pentaquark search with pK0Km skim

[Igor Strakovsky]

Hi Zhiwen,

On Wed, 17 Feb 2010 16:56:21 -0500, Zhiwen Zhao <zwzhao at jlab.org> wrote:

> 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

Well, as I said your condition does not fit LEPS configuration well;)

>>> 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.

Thank you for your figures, I missed them.  It seems to me that our coming
paper addressed to the analysis of the Hall A Lambda(1520) electroproduction
data at small Q2 may be interesting for you.  I hope we will submit it in
2-3 weeks.

To be honest, your analysis of the neutron data is a big problem for me
because you did not take into account FSI

>>> 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.

OK, thanks.  Igor

>>> 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